e14743d1 |
1 | /* |
2 | SDL - Simple DirectMedia Layer |
3 | Copyright (C) 1997-2009 Sam Lantinga |
4 | |
5 | This library is free software; you can redistribute it and/or |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either |
8 | version 2.1 of the License, or (at your option) any later version. |
9 | |
10 | This library is distributed in the hope that it will be useful, |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
13 | Lesser General Public License for more details. |
14 | |
15 | You should have received a copy of the GNU Lesser General Public |
16 | License along with this library; if not, write to the Free Software |
17 | Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
18 | |
19 | Sam Lantinga |
20 | slouken@libsdl.org |
21 | */ |
22 | #include "SDL_config.h" |
23 | |
24 | /* This file contains portable memory management functions for SDL */ |
25 | |
26 | #include "SDL_stdinc.h" |
27 | |
28 | #ifndef HAVE_MALLOC |
29 | |
30 | #define LACKS_SYS_TYPES_H |
31 | #define LACKS_STDIO_H |
32 | #define LACKS_STRINGS_H |
33 | #define LACKS_STRING_H |
34 | #define LACKS_STDLIB_H |
35 | #define ABORT |
36 | |
37 | /* |
38 | This is a version (aka dlmalloc) of malloc/free/realloc written by |
39 | Doug Lea and released to the public domain, as explained at |
40 | http://creativecommons.org/licenses/publicdomain. Send questions, |
41 | comments, complaints, performance data, etc to dl@cs.oswego.edu |
42 | |
43 | * Version 2.8.3 Thu Sep 22 11:16:15 2005 Doug Lea (dl at gee) |
44 | |
45 | Note: There may be an updated version of this malloc obtainable at |
46 | ftp://gee.cs.oswego.edu/pub/misc/malloc.c |
47 | Check before installing! |
48 | |
49 | * Quickstart |
50 | |
51 | This library is all in one file to simplify the most common usage: |
52 | ftp it, compile it (-O3), and link it into another program. All of |
53 | the compile-time options default to reasonable values for use on |
54 | most platforms. You might later want to step through various |
55 | compile-time and dynamic tuning options. |
56 | |
57 | For convenience, an include file for code using this malloc is at: |
58 | ftp://gee.cs.oswego.edu/pub/misc/malloc-2.8.3.h |
59 | You don't really need this .h file unless you call functions not |
60 | defined in your system include files. The .h file contains only the |
61 | excerpts from this file needed for using this malloc on ANSI C/C++ |
62 | systems, so long as you haven't changed compile-time options about |
63 | naming and tuning parameters. If you do, then you can create your |
64 | own malloc.h that does include all settings by cutting at the point |
65 | indicated below. Note that you may already by default be using a C |
66 | library containing a malloc that is based on some version of this |
67 | malloc (for example in linux). You might still want to use the one |
68 | in this file to customize settings or to avoid overheads associated |
69 | with library versions. |
70 | |
71 | * Vital statistics: |
72 | |
73 | Supported pointer/size_t representation: 4 or 8 bytes |
74 | size_t MUST be an unsigned type of the same width as |
75 | pointers. (If you are using an ancient system that declares |
76 | size_t as a signed type, or need it to be a different width |
77 | than pointers, you can use a previous release of this malloc |
78 | (e.g. 2.7.2) supporting these.) |
79 | |
80 | Alignment: 8 bytes (default) |
81 | This suffices for nearly all current machines and C compilers. |
82 | However, you can define MALLOC_ALIGNMENT to be wider than this |
83 | if necessary (up to 128bytes), at the expense of using more space. |
84 | |
85 | Minimum overhead per allocated chunk: 4 or 8 bytes (if 4byte sizes) |
86 | 8 or 16 bytes (if 8byte sizes) |
87 | Each malloced chunk has a hidden word of overhead holding size |
88 | and status information, and additional cross-check word |
89 | if FOOTERS is defined. |
90 | |
91 | Minimum allocated size: 4-byte ptrs: 16 bytes (including overhead) |
92 | 8-byte ptrs: 32 bytes (including overhead) |
93 | |
94 | Even a request for zero bytes (i.e., malloc(0)) returns a |
95 | pointer to something of the minimum allocatable size. |
96 | The maximum overhead wastage (i.e., number of extra bytes |
97 | allocated than were requested in malloc) is less than or equal |
98 | to the minimum size, except for requests >= mmap_threshold that |
99 | are serviced via mmap(), where the worst case wastage is about |
100 | 32 bytes plus the remainder from a system page (the minimal |
101 | mmap unit); typically 4096 or 8192 bytes. |
102 | |
103 | Security: static-safe; optionally more or less |
104 | The "security" of malloc refers to the ability of malicious |
105 | code to accentuate the effects of errors (for example, freeing |
106 | space that is not currently malloc'ed or overwriting past the |
107 | ends of chunks) in code that calls malloc. This malloc |
108 | guarantees not to modify any memory locations below the base of |
109 | heap, i.e., static variables, even in the presence of usage |
110 | errors. The routines additionally detect most improper frees |
111 | and reallocs. All this holds as long as the static bookkeeping |
112 | for malloc itself is not corrupted by some other means. This |
113 | is only one aspect of security -- these checks do not, and |
114 | cannot, detect all possible programming errors. |
115 | |
116 | If FOOTERS is defined nonzero, then each allocated chunk |
117 | carries an additional check word to verify that it was malloced |
118 | from its space. These check words are the same within each |
119 | execution of a program using malloc, but differ across |
120 | executions, so externally crafted fake chunks cannot be |
121 | freed. This improves security by rejecting frees/reallocs that |
122 | could corrupt heap memory, in addition to the checks preventing |
123 | writes to statics that are always on. This may further improve |
124 | security at the expense of time and space overhead. (Note that |
125 | FOOTERS may also be worth using with MSPACES.) |
126 | |
127 | By default detected errors cause the program to abort (calling |
128 | "abort()"). You can override this to instead proceed past |
129 | errors by defining PROCEED_ON_ERROR. In this case, a bad free |
130 | has no effect, and a malloc that encounters a bad address |
131 | caused by user overwrites will ignore the bad address by |
132 | dropping pointers and indices to all known memory. This may |
133 | be appropriate for programs that should continue if at all |
134 | possible in the face of programming errors, although they may |
135 | run out of memory because dropped memory is never reclaimed. |
136 | |
137 | If you don't like either of these options, you can define |
138 | CORRUPTION_ERROR_ACTION and USAGE_ERROR_ACTION to do anything |
139 | else. And if if you are sure that your program using malloc has |
140 | no errors or vulnerabilities, you can define INSECURE to 1, |
141 | which might (or might not) provide a small performance improvement. |
142 | |
143 | Thread-safety: NOT thread-safe unless USE_LOCKS defined |
144 | When USE_LOCKS is defined, each public call to malloc, free, |
145 | etc is surrounded with either a pthread mutex or a win32 |
146 | spinlock (depending on WIN32). This is not especially fast, and |
147 | can be a major bottleneck. It is designed only to provide |
148 | minimal protection in concurrent environments, and to provide a |
149 | basis for extensions. If you are using malloc in a concurrent |
150 | program, consider instead using ptmalloc, which is derived from |
151 | a version of this malloc. (See http://www.malloc.de). |
152 | |
153 | System requirements: Any combination of MORECORE and/or MMAP/MUNMAP |
154 | This malloc can use unix sbrk or any emulation (invoked using |
155 | the CALL_MORECORE macro) and/or mmap/munmap or any emulation |
156 | (invoked using CALL_MMAP/CALL_MUNMAP) to get and release system |
157 | memory. On most unix systems, it tends to work best if both |
158 | MORECORE and MMAP are enabled. On Win32, it uses emulations |
159 | based on VirtualAlloc. It also uses common C library functions |
160 | like memset. |
161 | |
162 | Compliance: I believe it is compliant with the Single Unix Specification |
163 | (See http://www.unix.org). Also SVID/XPG, ANSI C, and probably |
164 | others as well. |
165 | |
166 | * Overview of algorithms |
167 | |
168 | This is not the fastest, most space-conserving, most portable, or |
169 | most tunable malloc ever written. However it is among the fastest |
170 | while also being among the most space-conserving, portable and |
171 | tunable. Consistent balance across these factors results in a good |
172 | general-purpose allocator for malloc-intensive programs. |
173 | |
174 | In most ways, this malloc is a best-fit allocator. Generally, it |
175 | chooses the best-fitting existing chunk for a request, with ties |
176 | broken in approximately least-recently-used order. (This strategy |
177 | normally maintains low fragmentation.) However, for requests less |
178 | than 256bytes, it deviates from best-fit when there is not an |
179 | exactly fitting available chunk by preferring to use space adjacent |
180 | to that used for the previous small request, as well as by breaking |
181 | ties in approximately most-recently-used order. (These enhance |
182 | locality of series of small allocations.) And for very large requests |
183 | (>= 256Kb by default), it relies on system memory mapping |
184 | facilities, if supported. (This helps avoid carrying around and |
185 | possibly fragmenting memory used only for large chunks.) |
186 | |
187 | All operations (except malloc_stats and mallinfo) have execution |
188 | times that are bounded by a constant factor of the number of bits in |
189 | a size_t, not counting any clearing in calloc or copying in realloc, |
190 | or actions surrounding MORECORE and MMAP that have times |
191 | proportional to the number of non-contiguous regions returned by |
192 | system allocation routines, which is often just 1. |
193 | |
194 | The implementation is not very modular and seriously overuses |
195 | macros. Perhaps someday all C compilers will do as good a job |
196 | inlining modular code as can now be done by brute-force expansion, |
197 | but now, enough of them seem not to. |
198 | |
199 | Some compilers issue a lot of warnings about code that is |
200 | dead/unreachable only on some platforms, and also about intentional |
201 | uses of negation on unsigned types. All known cases of each can be |
202 | ignored. |
203 | |
204 | For a longer but out of date high-level description, see |
205 | http://gee.cs.oswego.edu/dl/html/malloc.html |
206 | |
207 | * MSPACES |
208 | If MSPACES is defined, then in addition to malloc, free, etc., |
209 | this file also defines mspace_malloc, mspace_free, etc. These |
210 | are versions of malloc routines that take an "mspace" argument |
211 | obtained using create_mspace, to control all internal bookkeeping. |
212 | If ONLY_MSPACES is defined, only these versions are compiled. |
213 | So if you would like to use this allocator for only some allocations, |
214 | and your system malloc for others, you can compile with |
215 | ONLY_MSPACES and then do something like... |
216 | static mspace mymspace = create_mspace(0,0); // for example |
217 | #define mymalloc(bytes) mspace_malloc(mymspace, bytes) |
218 | |
219 | (Note: If you only need one instance of an mspace, you can instead |
220 | use "USE_DL_PREFIX" to relabel the global malloc.) |
221 | |
222 | You can similarly create thread-local allocators by storing |
223 | mspaces as thread-locals. For example: |
224 | static __thread mspace tlms = 0; |
225 | void* tlmalloc(size_t bytes) { |
226 | if (tlms == 0) tlms = create_mspace(0, 0); |
227 | return mspace_malloc(tlms, bytes); |
228 | } |
229 | void tlfree(void* mem) { mspace_free(tlms, mem); } |
230 | |
231 | Unless FOOTERS is defined, each mspace is completely independent. |
232 | You cannot allocate from one and free to another (although |
233 | conformance is only weakly checked, so usage errors are not always |
234 | caught). If FOOTERS is defined, then each chunk carries around a tag |
235 | indicating its originating mspace, and frees are directed to their |
236 | originating spaces. |
237 | |
238 | ------------------------- Compile-time options --------------------------- |
239 | |
240 | Be careful in setting #define values for numerical constants of type |
241 | size_t. On some systems, literal values are not automatically extended |
242 | to size_t precision unless they are explicitly casted. |
243 | |
244 | WIN32 default: defined if _WIN32 defined |
245 | Defining WIN32 sets up defaults for MS environment and compilers. |
246 | Otherwise defaults are for unix. |
247 | |
248 | MALLOC_ALIGNMENT default: (size_t)8 |
249 | Controls the minimum alignment for malloc'ed chunks. It must be a |
250 | power of two and at least 8, even on machines for which smaller |
251 | alignments would suffice. It may be defined as larger than this |
252 | though. Note however that code and data structures are optimized for |
253 | the case of 8-byte alignment. |
254 | |
255 | MSPACES default: 0 (false) |
256 | If true, compile in support for independent allocation spaces. |
257 | This is only supported if HAVE_MMAP is true. |
258 | |
259 | ONLY_MSPACES default: 0 (false) |
260 | If true, only compile in mspace versions, not regular versions. |
261 | |
262 | USE_LOCKS default: 0 (false) |
263 | Causes each call to each public routine to be surrounded with |
264 | pthread or WIN32 mutex lock/unlock. (If set true, this can be |
265 | overridden on a per-mspace basis for mspace versions.) |
266 | |
267 | FOOTERS default: 0 |
268 | If true, provide extra checking and dispatching by placing |
269 | information in the footers of allocated chunks. This adds |
270 | space and time overhead. |
271 | |
272 | INSECURE default: 0 |
273 | If true, omit checks for usage errors and heap space overwrites. |
274 | |
275 | USE_DL_PREFIX default: NOT defined |
276 | Causes compiler to prefix all public routines with the string 'dl'. |
277 | This can be useful when you only want to use this malloc in one part |
278 | of a program, using your regular system malloc elsewhere. |
279 | |
280 | ABORT default: defined as abort() |
281 | Defines how to abort on failed checks. On most systems, a failed |
282 | check cannot die with an "assert" or even print an informative |
283 | message, because the underlying print routines in turn call malloc, |
284 | which will fail again. Generally, the best policy is to simply call |
285 | abort(). It's not very useful to do more than this because many |
286 | errors due to overwriting will show up as address faults (null, odd |
287 | addresses etc) rather than malloc-triggered checks, so will also |
288 | abort. Also, most compilers know that abort() does not return, so |
289 | can better optimize code conditionally calling it. |
290 | |
291 | PROCEED_ON_ERROR default: defined as 0 (false) |
292 | Controls whether detected bad addresses cause them to bypassed |
293 | rather than aborting. If set, detected bad arguments to free and |
294 | realloc are ignored. And all bookkeeping information is zeroed out |
295 | upon a detected overwrite of freed heap space, thus losing the |
296 | ability to ever return it from malloc again, but enabling the |
297 | application to proceed. If PROCEED_ON_ERROR is defined, the |
298 | static variable malloc_corruption_error_count is compiled in |
299 | and can be examined to see if errors have occurred. This option |
300 | generates slower code than the default abort policy. |
301 | |
302 | DEBUG default: NOT defined |
303 | The DEBUG setting is mainly intended for people trying to modify |
304 | this code or diagnose problems when porting to new platforms. |
305 | However, it may also be able to better isolate user errors than just |
306 | using runtime checks. The assertions in the check routines spell |
307 | out in more detail the assumptions and invariants underlying the |
308 | algorithms. The checking is fairly extensive, and will slow down |
309 | execution noticeably. Calling malloc_stats or mallinfo with DEBUG |
310 | set will attempt to check every non-mmapped allocated and free chunk |
311 | in the course of computing the summaries. |
312 | |
313 | ABORT_ON_ASSERT_FAILURE default: defined as 1 (true) |
314 | Debugging assertion failures can be nearly impossible if your |
315 | version of the assert macro causes malloc to be called, which will |
316 | lead to a cascade of further failures, blowing the runtime stack. |
317 | ABORT_ON_ASSERT_FAILURE cause assertions failures to call abort(), |
318 | which will usually make debugging easier. |
319 | |
320 | MALLOC_FAILURE_ACTION default: sets errno to ENOMEM, or no-op on win32 |
321 | The action to take before "return 0" when malloc fails to be able to |
322 | return memory because there is none available. |
323 | |
324 | HAVE_MORECORE default: 1 (true) unless win32 or ONLY_MSPACES |
325 | True if this system supports sbrk or an emulation of it. |
326 | |
327 | MORECORE default: sbrk |
328 | The name of the sbrk-style system routine to call to obtain more |
329 | memory. See below for guidance on writing custom MORECORE |
330 | functions. The type of the argument to sbrk/MORECORE varies across |
331 | systems. It cannot be size_t, because it supports negative |
332 | arguments, so it is normally the signed type of the same width as |
333 | size_t (sometimes declared as "intptr_t"). It doesn't much matter |
334 | though. Internally, we only call it with arguments less than half |
335 | the max value of a size_t, which should work across all reasonable |
336 | possibilities, although sometimes generating compiler warnings. See |
337 | near the end of this file for guidelines for creating a custom |
338 | version of MORECORE. |
339 | |
340 | MORECORE_CONTIGUOUS default: 1 (true) |
341 | If true, take advantage of fact that consecutive calls to MORECORE |
342 | with positive arguments always return contiguous increasing |
343 | addresses. This is true of unix sbrk. It does not hurt too much to |
344 | set it true anyway, since malloc copes with non-contiguities. |
345 | Setting it false when definitely non-contiguous saves time |
346 | and possibly wasted space it would take to discover this though. |
347 | |
348 | MORECORE_CANNOT_TRIM default: NOT defined |
349 | True if MORECORE cannot release space back to the system when given |
350 | negative arguments. This is generally necessary only if you are |
351 | using a hand-crafted MORECORE function that cannot handle negative |
352 | arguments. |
353 | |
354 | HAVE_MMAP default: 1 (true) |
355 | True if this system supports mmap or an emulation of it. If so, and |
356 | HAVE_MORECORE is not true, MMAP is used for all system |
357 | allocation. If set and HAVE_MORECORE is true as well, MMAP is |
358 | primarily used to directly allocate very large blocks. It is also |
359 | used as a backup strategy in cases where MORECORE fails to provide |
360 | space from system. Note: A single call to MUNMAP is assumed to be |
361 | able to unmap memory that may have be allocated using multiple calls |
362 | to MMAP, so long as they are adjacent. |
363 | |
364 | HAVE_MREMAP default: 1 on linux, else 0 |
365 | If true realloc() uses mremap() to re-allocate large blocks and |
366 | extend or shrink allocation spaces. |
367 | |
368 | MMAP_CLEARS default: 1 on unix |
369 | True if mmap clears memory so calloc doesn't need to. This is true |
370 | for standard unix mmap using /dev/zero. |
371 | |
372 | USE_BUILTIN_FFS default: 0 (i.e., not used) |
373 | Causes malloc to use the builtin ffs() function to compute indices. |
374 | Some compilers may recognize and intrinsify ffs to be faster than the |
375 | supplied C version. Also, the case of x86 using gcc is special-cased |
376 | to an asm instruction, so is already as fast as it can be, and so |
377 | this setting has no effect. (On most x86s, the asm version is only |
378 | slightly faster than the C version.) |
379 | |
380 | malloc_getpagesize default: derive from system includes, or 4096. |
381 | The system page size. To the extent possible, this malloc manages |
382 | memory from the system in page-size units. This may be (and |
383 | usually is) a function rather than a constant. This is ignored |
384 | if WIN32, where page size is determined using getSystemInfo during |
385 | initialization. |
386 | |
387 | USE_DEV_RANDOM default: 0 (i.e., not used) |
388 | Causes malloc to use /dev/random to initialize secure magic seed for |
389 | stamping footers. Otherwise, the current time is used. |
390 | |
391 | NO_MALLINFO default: 0 |
392 | If defined, don't compile "mallinfo". This can be a simple way |
393 | of dealing with mismatches between system declarations and |
394 | those in this file. |
395 | |
396 | MALLINFO_FIELD_TYPE default: size_t |
397 | The type of the fields in the mallinfo struct. This was originally |
398 | defined as "int" in SVID etc, but is more usefully defined as |
399 | size_t. The value is used only if HAVE_USR_INCLUDE_MALLOC_H is not set |
400 | |
401 | REALLOC_ZERO_BYTES_FREES default: not defined |
402 | This should be set if a call to realloc with zero bytes should |
403 | be the same as a call to free. Some people think it should. Otherwise, |
404 | since this malloc returns a unique pointer for malloc(0), so does |
405 | realloc(p, 0). |
406 | |
407 | LACKS_UNISTD_H, LACKS_FCNTL_H, LACKS_SYS_PARAM_H, LACKS_SYS_MMAN_H |
408 | LACKS_STRINGS_H, LACKS_STRING_H, LACKS_SYS_TYPES_H, LACKS_ERRNO_H |
409 | LACKS_STDLIB_H default: NOT defined unless on WIN32 |
410 | Define these if your system does not have these header files. |
411 | You might need to manually insert some of the declarations they provide. |
412 | |
413 | DEFAULT_GRANULARITY default: page size if MORECORE_CONTIGUOUS, |
414 | system_info.dwAllocationGranularity in WIN32, |
415 | otherwise 64K. |
416 | Also settable using mallopt(M_GRANULARITY, x) |
417 | The unit for allocating and deallocating memory from the system. On |
418 | most systems with contiguous MORECORE, there is no reason to |
419 | make this more than a page. However, systems with MMAP tend to |
420 | either require or encourage larger granularities. You can increase |
421 | this value to prevent system allocation functions to be called so |
422 | often, especially if they are slow. The value must be at least one |
423 | page and must be a power of two. Setting to 0 causes initialization |
424 | to either page size or win32 region size. (Note: In previous |
425 | versions of malloc, the equivalent of this option was called |
426 | "TOP_PAD") |
427 | |
428 | DEFAULT_TRIM_THRESHOLD default: 2MB |
429 | Also settable using mallopt(M_TRIM_THRESHOLD, x) |
430 | The maximum amount of unused top-most memory to keep before |
431 | releasing via malloc_trim in free(). Automatic trimming is mainly |
432 | useful in long-lived programs using contiguous MORECORE. Because |
433 | trimming via sbrk can be slow on some systems, and can sometimes be |
434 | wasteful (in cases where programs immediately afterward allocate |
435 | more large chunks) the value should be high enough so that your |
436 | overall system performance would improve by releasing this much |
437 | memory. As a rough guide, you might set to a value close to the |
438 | average size of a process (program) running on your system. |
439 | Releasing this much memory would allow such a process to run in |
440 | memory. Generally, it is worth tuning trim thresholds when a |
441 | program undergoes phases where several large chunks are allocated |
442 | and released in ways that can reuse each other's storage, perhaps |
443 | mixed with phases where there are no such chunks at all. The trim |
444 | value must be greater than page size to have any useful effect. To |
445 | disable trimming completely, you can set to MAX_SIZE_T. Note that the trick |
446 | some people use of mallocing a huge space and then freeing it at |
447 | program startup, in an attempt to reserve system memory, doesn't |
448 | have the intended effect under automatic trimming, since that memory |
449 | will immediately be returned to the system. |
450 | |
451 | DEFAULT_MMAP_THRESHOLD default: 256K |
452 | Also settable using mallopt(M_MMAP_THRESHOLD, x) |
453 | The request size threshold for using MMAP to directly service a |
454 | request. Requests of at least this size that cannot be allocated |
455 | using already-existing space will be serviced via mmap. (If enough |
456 | normal freed space already exists it is used instead.) Using mmap |
457 | segregates relatively large chunks of memory so that they can be |
458 | individually obtained and released from the host system. A request |
459 | serviced through mmap is never reused by any other request (at least |
460 | not directly; the system may just so happen to remap successive |
461 | requests to the same locations). Segregating space in this way has |
462 | the benefits that: Mmapped space can always be individually released |
463 | back to the system, which helps keep the system level memory demands |
464 | of a long-lived program low. Also, mapped memory doesn't become |
465 | `locked' between other chunks, as can happen with normally allocated |
466 | chunks, which means that even trimming via malloc_trim would not |
467 | release them. However, it has the disadvantage that the space |
468 | cannot be reclaimed, consolidated, and then used to service later |
469 | requests, as happens with normal chunks. The advantages of mmap |
470 | nearly always outweigh disadvantages for "large" chunks, but the |
471 | value of "large" may vary across systems. The default is an |
472 | empirically derived value that works well in most systems. You can |
473 | disable mmap by setting to MAX_SIZE_T. |
474 | |
475 | */ |
476 | |
477 | #ifndef WIN32 |
478 | #ifdef _WIN32 |
479 | #define WIN32 1 |
480 | #endif /* _WIN32 */ |
481 | #endif /* WIN32 */ |
482 | #ifdef WIN32 |
483 | #define WIN32_LEAN_AND_MEAN |
484 | #include <windows.h> |
485 | #define HAVE_MMAP 1 |
486 | #define HAVE_MORECORE 0 |
487 | #define LACKS_UNISTD_H |
488 | #define LACKS_SYS_PARAM_H |
489 | #define LACKS_SYS_MMAN_H |
490 | #define LACKS_STRING_H |
491 | #define LACKS_STRINGS_H |
492 | #define LACKS_SYS_TYPES_H |
493 | #define LACKS_ERRNO_H |
494 | #define LACKS_FCNTL_H |
495 | #define MALLOC_FAILURE_ACTION |
496 | #define MMAP_CLEARS 0 /* WINCE and some others apparently don't clear */ |
497 | #endif /* WIN32 */ |
498 | |
499 | #if defined(DARWIN) || defined(_DARWIN) |
500 | /* Mac OSX docs advise not to use sbrk; it seems better to use mmap */ |
501 | #ifndef HAVE_MORECORE |
502 | #define HAVE_MORECORE 0 |
503 | #define HAVE_MMAP 1 |
504 | #endif /* HAVE_MORECORE */ |
505 | #endif /* DARWIN */ |
506 | |
507 | #ifndef LACKS_SYS_TYPES_H |
508 | #include <sys/types.h> /* For size_t */ |
509 | #endif /* LACKS_SYS_TYPES_H */ |
510 | |
511 | /* The maximum possible size_t value has all bits set */ |
512 | #define MAX_SIZE_T (~(size_t)0) |
513 | |
514 | #ifndef ONLY_MSPACES |
515 | #define ONLY_MSPACES 0 |
516 | #endif /* ONLY_MSPACES */ |
517 | #ifndef MSPACES |
518 | #if ONLY_MSPACES |
519 | #define MSPACES 1 |
520 | #else /* ONLY_MSPACES */ |
521 | #define MSPACES 0 |
522 | #endif /* ONLY_MSPACES */ |
523 | #endif /* MSPACES */ |
524 | #ifndef MALLOC_ALIGNMENT |
525 | #define MALLOC_ALIGNMENT ((size_t)8U) |
526 | #endif /* MALLOC_ALIGNMENT */ |
527 | #ifndef FOOTERS |
528 | #define FOOTERS 0 |
529 | #endif /* FOOTERS */ |
530 | #ifndef ABORT |
531 | #define ABORT abort() |
532 | #endif /* ABORT */ |
533 | #ifndef ABORT_ON_ASSERT_FAILURE |
534 | #define ABORT_ON_ASSERT_FAILURE 1 |
535 | #endif /* ABORT_ON_ASSERT_FAILURE */ |
536 | #ifndef PROCEED_ON_ERROR |
537 | #define PROCEED_ON_ERROR 0 |
538 | #endif /* PROCEED_ON_ERROR */ |
539 | #ifndef USE_LOCKS |
540 | #define USE_LOCKS 0 |
541 | #endif /* USE_LOCKS */ |
542 | #ifndef INSECURE |
543 | #define INSECURE 0 |
544 | #endif /* INSECURE */ |
545 | #ifndef HAVE_MMAP |
546 | #define HAVE_MMAP 1 |
547 | #endif /* HAVE_MMAP */ |
548 | #ifndef MMAP_CLEARS |
549 | #define MMAP_CLEARS 1 |
550 | #endif /* MMAP_CLEARS */ |
551 | #ifndef HAVE_MREMAP |
552 | #ifdef linux |
553 | #define HAVE_MREMAP 1 |
554 | #else /* linux */ |
555 | #define HAVE_MREMAP 0 |
556 | #endif /* linux */ |
557 | #endif /* HAVE_MREMAP */ |
558 | #ifndef MALLOC_FAILURE_ACTION |
559 | #define MALLOC_FAILURE_ACTION errno = ENOMEM; |
560 | #endif /* MALLOC_FAILURE_ACTION */ |
561 | #ifndef HAVE_MORECORE |
562 | #if ONLY_MSPACES |
563 | #define HAVE_MORECORE 0 |
564 | #else /* ONLY_MSPACES */ |
565 | #define HAVE_MORECORE 1 |
566 | #endif /* ONLY_MSPACES */ |
567 | #endif /* HAVE_MORECORE */ |
568 | #if !HAVE_MORECORE |
569 | #define MORECORE_CONTIGUOUS 0 |
570 | #else /* !HAVE_MORECORE */ |
571 | #ifndef MORECORE |
572 | #define MORECORE sbrk |
573 | #endif /* MORECORE */ |
574 | #ifndef MORECORE_CONTIGUOUS |
575 | #define MORECORE_CONTIGUOUS 1 |
576 | #endif /* MORECORE_CONTIGUOUS */ |
577 | #endif /* HAVE_MORECORE */ |
578 | #ifndef DEFAULT_GRANULARITY |
579 | #if MORECORE_CONTIGUOUS |
580 | #define DEFAULT_GRANULARITY (0) /* 0 means to compute in init_mparams */ |
581 | #else /* MORECORE_CONTIGUOUS */ |
582 | #define DEFAULT_GRANULARITY ((size_t)64U * (size_t)1024U) |
583 | #endif /* MORECORE_CONTIGUOUS */ |
584 | #endif /* DEFAULT_GRANULARITY */ |
585 | #ifndef DEFAULT_TRIM_THRESHOLD |
586 | #ifndef MORECORE_CANNOT_TRIM |
587 | #define DEFAULT_TRIM_THRESHOLD ((size_t)2U * (size_t)1024U * (size_t)1024U) |
588 | #else /* MORECORE_CANNOT_TRIM */ |
589 | #define DEFAULT_TRIM_THRESHOLD MAX_SIZE_T |
590 | #endif /* MORECORE_CANNOT_TRIM */ |
591 | #endif /* DEFAULT_TRIM_THRESHOLD */ |
592 | #ifndef DEFAULT_MMAP_THRESHOLD |
593 | #if HAVE_MMAP |
594 | #define DEFAULT_MMAP_THRESHOLD ((size_t)256U * (size_t)1024U) |
595 | #else /* HAVE_MMAP */ |
596 | #define DEFAULT_MMAP_THRESHOLD MAX_SIZE_T |
597 | #endif /* HAVE_MMAP */ |
598 | #endif /* DEFAULT_MMAP_THRESHOLD */ |
599 | #ifndef USE_BUILTIN_FFS |
600 | #define USE_BUILTIN_FFS 0 |
601 | #endif /* USE_BUILTIN_FFS */ |
602 | #ifndef USE_DEV_RANDOM |
603 | #define USE_DEV_RANDOM 0 |
604 | #endif /* USE_DEV_RANDOM */ |
605 | #ifndef NO_MALLINFO |
606 | #define NO_MALLINFO 0 |
607 | #endif /* NO_MALLINFO */ |
608 | #ifndef MALLINFO_FIELD_TYPE |
609 | #define MALLINFO_FIELD_TYPE size_t |
610 | #endif /* MALLINFO_FIELD_TYPE */ |
611 | |
612 | #define memset SDL_memset |
613 | #define memcpy SDL_memcpy |
614 | #define malloc SDL_malloc |
615 | #define calloc SDL_calloc |
616 | #define realloc SDL_realloc |
617 | #define free SDL_free |
618 | |
619 | /* |
620 | mallopt tuning options. SVID/XPG defines four standard parameter |
621 | numbers for mallopt, normally defined in malloc.h. None of these |
622 | are used in this malloc, so setting them has no effect. But this |
623 | malloc does support the following options. |
624 | */ |
625 | |
626 | #define M_TRIM_THRESHOLD (-1) |
627 | #define M_GRANULARITY (-2) |
628 | #define M_MMAP_THRESHOLD (-3) |
629 | |
630 | /* ------------------------ Mallinfo declarations ------------------------ */ |
631 | |
632 | #if !NO_MALLINFO |
633 | /* |
634 | This version of malloc supports the standard SVID/XPG mallinfo |
635 | routine that returns a struct containing usage properties and |
636 | statistics. It should work on any system that has a |
637 | /usr/include/malloc.h defining struct mallinfo. The main |
638 | declaration needed is the mallinfo struct that is returned (by-copy) |
639 | by mallinfo(). The malloinfo struct contains a bunch of fields that |
640 | are not even meaningful in this version of malloc. These fields are |
641 | are instead filled by mallinfo() with other numbers that might be of |
642 | interest. |
643 | |
644 | HAVE_USR_INCLUDE_MALLOC_H should be set if you have a |
645 | /usr/include/malloc.h file that includes a declaration of struct |
646 | mallinfo. If so, it is included; else a compliant version is |
647 | declared below. These must be precisely the same for mallinfo() to |
648 | work. The original SVID version of this struct, defined on most |
649 | systems with mallinfo, declares all fields as ints. But some others |
650 | define as unsigned long. If your system defines the fields using a |
651 | type of different width than listed here, you MUST #include your |
652 | system version and #define HAVE_USR_INCLUDE_MALLOC_H. |
653 | */ |
654 | |
655 | /* #define HAVE_USR_INCLUDE_MALLOC_H */ |
656 | |
657 | #ifdef HAVE_USR_INCLUDE_MALLOC_H |
658 | #include "/usr/include/malloc.h" |
659 | #else /* HAVE_USR_INCLUDE_MALLOC_H */ |
660 | |
661 | struct mallinfo { |
662 | MALLINFO_FIELD_TYPE arena; /* non-mmapped space allocated from system */ |
663 | MALLINFO_FIELD_TYPE ordblks; /* number of free chunks */ |
664 | MALLINFO_FIELD_TYPE smblks; /* always 0 */ |
665 | MALLINFO_FIELD_TYPE hblks; /* always 0 */ |
666 | MALLINFO_FIELD_TYPE hblkhd; /* space in mmapped regions */ |
667 | MALLINFO_FIELD_TYPE usmblks; /* maximum total allocated space */ |
668 | MALLINFO_FIELD_TYPE fsmblks; /* always 0 */ |
669 | MALLINFO_FIELD_TYPE uordblks; /* total allocated space */ |
670 | MALLINFO_FIELD_TYPE fordblks; /* total free space */ |
671 | MALLINFO_FIELD_TYPE keepcost; /* releasable (via malloc_trim) space */ |
672 | }; |
673 | |
674 | #endif /* HAVE_USR_INCLUDE_MALLOC_H */ |
675 | #endif /* NO_MALLINFO */ |
676 | |
677 | #ifdef __cplusplus |
678 | extern "C" { |
679 | #endif /* __cplusplus */ |
680 | |
681 | #if !ONLY_MSPACES |
682 | |
683 | /* ------------------- Declarations of public routines ------------------- */ |
684 | |
685 | #ifndef USE_DL_PREFIX |
686 | #define dlcalloc calloc |
687 | #define dlfree free |
688 | #define dlmalloc malloc |
689 | #define dlmemalign memalign |
690 | #define dlrealloc realloc |
691 | #define dlvalloc valloc |
692 | #define dlpvalloc pvalloc |
693 | #define dlmallinfo mallinfo |
694 | #define dlmallopt mallopt |
695 | #define dlmalloc_trim malloc_trim |
696 | #define dlmalloc_stats malloc_stats |
697 | #define dlmalloc_usable_size malloc_usable_size |
698 | #define dlmalloc_footprint malloc_footprint |
699 | #define dlmalloc_max_footprint malloc_max_footprint |
700 | #define dlindependent_calloc independent_calloc |
701 | #define dlindependent_comalloc independent_comalloc |
702 | #endif /* USE_DL_PREFIX */ |
703 | |
704 | |
705 | /* |
706 | malloc(size_t n) |
707 | Returns a pointer to a newly allocated chunk of at least n bytes, or |
708 | null if no space is available, in which case errno is set to ENOMEM |
709 | on ANSI C systems. |
710 | |
711 | If n is zero, malloc returns a minimum-sized chunk. (The minimum |
712 | size is 16 bytes on most 32bit systems, and 32 bytes on 64bit |
713 | systems.) Note that size_t is an unsigned type, so calls with |
714 | arguments that would be negative if signed are interpreted as |
715 | requests for huge amounts of space, which will often fail. The |
716 | maximum supported value of n differs across systems, but is in all |
717 | cases less than the maximum representable value of a size_t. |
718 | */ |
719 | void* dlmalloc(size_t); |
720 | |
721 | /* |
722 | free(void* p) |
723 | Releases the chunk of memory pointed to by p, that had been previously |
724 | allocated using malloc or a related routine such as realloc. |
725 | It has no effect if p is null. If p was not malloced or already |
726 | freed, free(p) will by default cause the current program to abort. |
727 | */ |
728 | void dlfree(void*); |
729 | |
730 | /* |
731 | calloc(size_t n_elements, size_t element_size); |
732 | Returns a pointer to n_elements * element_size bytes, with all locations |
733 | set to zero. |
734 | */ |
735 | void* dlcalloc(size_t, size_t); |
736 | |
737 | /* |
738 | realloc(void* p, size_t n) |
739 | Returns a pointer to a chunk of size n that contains the same data |
740 | as does chunk p up to the minimum of (n, p's size) bytes, or null |
741 | if no space is available. |
742 | |
743 | The returned pointer may or may not be the same as p. The algorithm |
744 | prefers extending p in most cases when possible, otherwise it |
745 | employs the equivalent of a malloc-copy-free sequence. |
746 | |
747 | If p is null, realloc is equivalent to malloc. |
748 | |
749 | If space is not available, realloc returns null, errno is set (if on |
750 | ANSI) and p is NOT freed. |
751 | |
752 | if n is for fewer bytes than already held by p, the newly unused |
753 | space is lopped off and freed if possible. realloc with a size |
754 | argument of zero (re)allocates a minimum-sized chunk. |
755 | |
756 | The old unix realloc convention of allowing the last-free'd chunk |
757 | to be used as an argument to realloc is not supported. |
758 | */ |
759 | |
760 | void* dlrealloc(void*, size_t); |
761 | |
762 | /* |
763 | memalign(size_t alignment, size_t n); |
764 | Returns a pointer to a newly allocated chunk of n bytes, aligned |
765 | in accord with the alignment argument. |
766 | |
767 | The alignment argument should be a power of two. If the argument is |
768 | not a power of two, the nearest greater power is used. |
769 | 8-byte alignment is guaranteed by normal malloc calls, so don't |
770 | bother calling memalign with an argument of 8 or less. |
771 | |
772 | Overreliance on memalign is a sure way to fragment space. |
773 | */ |
774 | void* dlmemalign(size_t, size_t); |
775 | |
776 | /* |
777 | valloc(size_t n); |
778 | Equivalent to memalign(pagesize, n), where pagesize is the page |
779 | size of the system. If the pagesize is unknown, 4096 is used. |
780 | */ |
781 | void* dlvalloc(size_t); |
782 | |
783 | /* |
784 | mallopt(int parameter_number, int parameter_value) |
785 | Sets tunable parameters The format is to provide a |
786 | (parameter-number, parameter-value) pair. mallopt then sets the |
787 | corresponding parameter to the argument value if it can (i.e., so |
788 | long as the value is meaningful), and returns 1 if successful else |
789 | 0. SVID/XPG/ANSI defines four standard param numbers for mallopt, |
790 | normally defined in malloc.h. None of these are use in this malloc, |
791 | so setting them has no effect. But this malloc also supports other |
792 | options in mallopt. See below for details. Briefly, supported |
793 | parameters are as follows (listed defaults are for "typical" |
794 | configurations). |
795 | |
796 | Symbol param # default allowed param values |
797 | M_TRIM_THRESHOLD -1 2*1024*1024 any (MAX_SIZE_T disables) |
798 | M_GRANULARITY -2 page size any power of 2 >= page size |
799 | M_MMAP_THRESHOLD -3 256*1024 any (or 0 if no MMAP support) |
800 | */ |
801 | int dlmallopt(int, int); |
802 | |
803 | /* |
804 | malloc_footprint(); |
805 | Returns the number of bytes obtained from the system. The total |
806 | number of bytes allocated by malloc, realloc etc., is less than this |
807 | value. Unlike mallinfo, this function returns only a precomputed |
808 | result, so can be called frequently to monitor memory consumption. |
809 | Even if locks are otherwise defined, this function does not use them, |
810 | so results might not be up to date. |
811 | */ |
812 | size_t dlmalloc_footprint(void); |
813 | |
814 | /* |
815 | malloc_max_footprint(); |
816 | Returns the maximum number of bytes obtained from the system. This |
817 | value will be greater than current footprint if deallocated space |
818 | has been reclaimed by the system. The peak number of bytes allocated |
819 | by malloc, realloc etc., is less than this value. Unlike mallinfo, |
820 | this function returns only a precomputed result, so can be called |
821 | frequently to monitor memory consumption. Even if locks are |
822 | otherwise defined, this function does not use them, so results might |
823 | not be up to date. |
824 | */ |
825 | size_t dlmalloc_max_footprint(void); |
826 | |
827 | #if !NO_MALLINFO |
828 | /* |
829 | mallinfo() |
830 | Returns (by copy) a struct containing various summary statistics: |
831 | |
832 | arena: current total non-mmapped bytes allocated from system |
833 | ordblks: the number of free chunks |
834 | smblks: always zero. |
835 | hblks: current number of mmapped regions |
836 | hblkhd: total bytes held in mmapped regions |
837 | usmblks: the maximum total allocated space. This will be greater |
838 | than current total if trimming has occurred. |
839 | fsmblks: always zero |
840 | uordblks: current total allocated space (normal or mmapped) |
841 | fordblks: total free space |
842 | keepcost: the maximum number of bytes that could ideally be released |
843 | back to system via malloc_trim. ("ideally" means that |
844 | it ignores page restrictions etc.) |
845 | |
846 | Because these fields are ints, but internal bookkeeping may |
847 | be kept as longs, the reported values may wrap around zero and |
848 | thus be inaccurate. |
849 | */ |
850 | struct mallinfo dlmallinfo(void); |
851 | #endif /* NO_MALLINFO */ |
852 | |
853 | /* |
854 | independent_calloc(size_t n_elements, size_t element_size, void* chunks[]); |
855 | |
856 | independent_calloc is similar to calloc, but instead of returning a |
857 | single cleared space, it returns an array of pointers to n_elements |
858 | independent elements that can hold contents of size elem_size, each |
859 | of which starts out cleared, and can be independently freed, |
860 | realloc'ed etc. The elements are guaranteed to be adjacently |
861 | allocated (this is not guaranteed to occur with multiple callocs or |
862 | mallocs), which may also improve cache locality in some |
863 | applications. |
864 | |
865 | The "chunks" argument is optional (i.e., may be null, which is |
866 | probably the most typical usage). If it is null, the returned array |
867 | is itself dynamically allocated and should also be freed when it is |
868 | no longer needed. Otherwise, the chunks array must be of at least |
869 | n_elements in length. It is filled in with the pointers to the |
870 | chunks. |
871 | |
872 | In either case, independent_calloc returns this pointer array, or |
873 | null if the allocation failed. If n_elements is zero and "chunks" |
874 | is null, it returns a chunk representing an array with zero elements |
875 | (which should be freed if not wanted). |
876 | |
877 | Each element must be individually freed when it is no longer |
878 | needed. If you'd like to instead be able to free all at once, you |
879 | should instead use regular calloc and assign pointers into this |
880 | space to represent elements. (In this case though, you cannot |
881 | independently free elements.) |
882 | |
883 | independent_calloc simplifies and speeds up implementations of many |
884 | kinds of pools. It may also be useful when constructing large data |
885 | structures that initially have a fixed number of fixed-sized nodes, |
886 | but the number is not known at compile time, and some of the nodes |
887 | may later need to be freed. For example: |
888 | |
889 | struct Node { int item; struct Node* next; }; |
890 | |
891 | struct Node* build_list() { |
892 | struct Node** pool; |
893 | int n = read_number_of_nodes_needed(); |
894 | if (n <= 0) return 0; |
895 | pool = (struct Node**)(independent_calloc(n, sizeof(struct Node), 0); |
896 | if (pool == 0) die(); |
897 | // organize into a linked list... |
898 | struct Node* first = pool[0]; |
899 | for (i = 0; i < n-1; ++i) |
900 | pool[i]->next = pool[i+1]; |
901 | free(pool); // Can now free the array (or not, if it is needed later) |
902 | return first; |
903 | } |
904 | */ |
905 | void** dlindependent_calloc(size_t, size_t, void**); |
906 | |
907 | /* |
908 | independent_comalloc(size_t n_elements, size_t sizes[], void* chunks[]); |
909 | |
910 | independent_comalloc allocates, all at once, a set of n_elements |
911 | chunks with sizes indicated in the "sizes" array. It returns |
912 | an array of pointers to these elements, each of which can be |
913 | independently freed, realloc'ed etc. The elements are guaranteed to |
914 | be adjacently allocated (this is not guaranteed to occur with |
915 | multiple callocs or mallocs), which may also improve cache locality |
916 | in some applications. |
917 | |
918 | The "chunks" argument is optional (i.e., may be null). If it is null |
919 | the returned array is itself dynamically allocated and should also |
920 | be freed when it is no longer needed. Otherwise, the chunks array |
921 | must be of at least n_elements in length. It is filled in with the |
922 | pointers to the chunks. |
923 | |
924 | In either case, independent_comalloc returns this pointer array, or |
925 | null if the allocation failed. If n_elements is zero and chunks is |
926 | null, it returns a chunk representing an array with zero elements |
927 | (which should be freed if not wanted). |
928 | |
929 | Each element must be individually freed when it is no longer |
930 | needed. If you'd like to instead be able to free all at once, you |
931 | should instead use a single regular malloc, and assign pointers at |
932 | particular offsets in the aggregate space. (In this case though, you |
933 | cannot independently free elements.) |
934 | |
935 | independent_comallac differs from independent_calloc in that each |
936 | element may have a different size, and also that it does not |
937 | automatically clear elements. |
938 | |
939 | independent_comalloc can be used to speed up allocation in cases |
940 | where several structs or objects must always be allocated at the |
941 | same time. For example: |
942 | |
943 | struct Head { ... } |
944 | struct Foot { ... } |
945 | |
946 | void send_message(char* msg) { |
947 | int msglen = strlen(msg); |
948 | size_t sizes[3] = { sizeof(struct Head), msglen, sizeof(struct Foot) }; |
949 | void* chunks[3]; |
950 | if (independent_comalloc(3, sizes, chunks) == 0) |
951 | die(); |
952 | struct Head* head = (struct Head*)(chunks[0]); |
953 | char* body = (char*)(chunks[1]); |
954 | struct Foot* foot = (struct Foot*)(chunks[2]); |
955 | // ... |
956 | } |
957 | |
958 | In general though, independent_comalloc is worth using only for |
959 | larger values of n_elements. For small values, you probably won't |
960 | detect enough difference from series of malloc calls to bother. |
961 | |
962 | Overuse of independent_comalloc can increase overall memory usage, |
963 | since it cannot reuse existing noncontiguous small chunks that |
964 | might be available for some of the elements. |
965 | */ |
966 | void** dlindependent_comalloc(size_t, size_t*, void**); |
967 | |
968 | |
969 | /* |
970 | pvalloc(size_t n); |
971 | Equivalent to valloc(minimum-page-that-holds(n)), that is, |
972 | round up n to nearest pagesize. |
973 | */ |
974 | void* dlpvalloc(size_t); |
975 | |
976 | /* |
977 | malloc_trim(size_t pad); |
978 | |
979 | If possible, gives memory back to the system (via negative arguments |
980 | to sbrk) if there is unused memory at the `high' end of the malloc |
981 | pool or in unused MMAP segments. You can call this after freeing |
982 | large blocks of memory to potentially reduce the system-level memory |
983 | requirements of a program. However, it cannot guarantee to reduce |
984 | memory. Under some allocation patterns, some large free blocks of |
985 | memory will be locked between two used chunks, so they cannot be |
986 | given back to the system. |
987 | |
988 | The `pad' argument to malloc_trim represents the amount of free |
989 | trailing space to leave untrimmed. If this argument is zero, only |
990 | the minimum amount of memory to maintain internal data structures |
991 | will be left. Non-zero arguments can be supplied to maintain enough |
992 | trailing space to service future expected allocations without having |
993 | to re-obtain memory from the system. |
994 | |
995 | Malloc_trim returns 1 if it actually released any memory, else 0. |
996 | */ |
997 | int dlmalloc_trim(size_t); |
998 | |
999 | /* |
1000 | malloc_usable_size(void* p); |
1001 | |
1002 | Returns the number of bytes you can actually use in |
1003 | an allocated chunk, which may be more than you requested (although |
1004 | often not) due to alignment and minimum size constraints. |
1005 | You can use this many bytes without worrying about |
1006 | overwriting other allocated objects. This is not a particularly great |
1007 | programming practice. malloc_usable_size can be more useful in |
1008 | debugging and assertions, for example: |
1009 | |
1010 | p = malloc(n); |
1011 | assert(malloc_usable_size(p) >= 256); |
1012 | */ |
1013 | size_t dlmalloc_usable_size(void*); |
1014 | |
1015 | /* |
1016 | malloc_stats(); |
1017 | Prints on stderr the amount of space obtained from the system (both |
1018 | via sbrk and mmap), the maximum amount (which may be more than |
1019 | current if malloc_trim and/or munmap got called), and the current |
1020 | number of bytes allocated via malloc (or realloc, etc) but not yet |
1021 | freed. Note that this is the number of bytes allocated, not the |
1022 | number requested. It will be larger than the number requested |
1023 | because of alignment and bookkeeping overhead. Because it includes |
1024 | alignment wastage as being in use, this figure may be greater than |
1025 | zero even when no user-level chunks are allocated. |
1026 | |
1027 | The reported current and maximum system memory can be inaccurate if |
1028 | a program makes other calls to system memory allocation functions |
1029 | (normally sbrk) outside of malloc. |
1030 | |
1031 | malloc_stats prints only the most commonly interesting statistics. |
1032 | More information can be obtained by calling mallinfo. |
1033 | */ |
1034 | void dlmalloc_stats(void); |
1035 | |
1036 | #endif /* ONLY_MSPACES */ |
1037 | |
1038 | #if MSPACES |
1039 | |
1040 | /* |
1041 | mspace is an opaque type representing an independent |
1042 | region of space that supports mspace_malloc, etc. |
1043 | */ |
1044 | typedef void* mspace; |
1045 | |
1046 | /* |
1047 | create_mspace creates and returns a new independent space with the |
1048 | given initial capacity, or, if 0, the default granularity size. It |
1049 | returns null if there is no system memory available to create the |
1050 | space. If argument locked is non-zero, the space uses a separate |
1051 | lock to control access. The capacity of the space will grow |
1052 | dynamically as needed to service mspace_malloc requests. You can |
1053 | control the sizes of incremental increases of this space by |
1054 | compiling with a different DEFAULT_GRANULARITY or dynamically |
1055 | setting with mallopt(M_GRANULARITY, value). |
1056 | */ |
1057 | mspace create_mspace(size_t capacity, int locked); |
1058 | |
1059 | /* |
1060 | destroy_mspace destroys the given space, and attempts to return all |
1061 | of its memory back to the system, returning the total number of |
1062 | bytes freed. After destruction, the results of access to all memory |
1063 | used by the space become undefined. |
1064 | */ |
1065 | size_t destroy_mspace(mspace msp); |
1066 | |
1067 | /* |
1068 | create_mspace_with_base uses the memory supplied as the initial base |
1069 | of a new mspace. Part (less than 128*sizeof(size_t) bytes) of this |
1070 | space is used for bookkeeping, so the capacity must be at least this |
1071 | large. (Otherwise 0 is returned.) When this initial space is |
1072 | exhausted, additional memory will be obtained from the system. |
1073 | Destroying this space will deallocate all additionally allocated |
1074 | space (if possible) but not the initial base. |
1075 | */ |
1076 | mspace create_mspace_with_base(void* base, size_t capacity, int locked); |
1077 | |
1078 | /* |
1079 | mspace_malloc behaves as malloc, but operates within |
1080 | the given space. |
1081 | */ |
1082 | void* mspace_malloc(mspace msp, size_t bytes); |
1083 | |
1084 | /* |
1085 | mspace_free behaves as free, but operates within |
1086 | the given space. |
1087 | |
1088 | If compiled with FOOTERS==1, mspace_free is not actually needed. |
1089 | free may be called instead of mspace_free because freed chunks from |
1090 | any space are handled by their originating spaces. |
1091 | */ |
1092 | void mspace_free(mspace msp, void* mem); |
1093 | |
1094 | /* |
1095 | mspace_realloc behaves as realloc, but operates within |
1096 | the given space. |
1097 | |
1098 | If compiled with FOOTERS==1, mspace_realloc is not actually |
1099 | needed. realloc may be called instead of mspace_realloc because |
1100 | realloced chunks from any space are handled by their originating |
1101 | spaces. |
1102 | */ |
1103 | void* mspace_realloc(mspace msp, void* mem, size_t newsize); |
1104 | |
1105 | /* |
1106 | mspace_calloc behaves as calloc, but operates within |
1107 | the given space. |
1108 | */ |
1109 | void* mspace_calloc(mspace msp, size_t n_elements, size_t elem_size); |
1110 | |
1111 | /* |
1112 | mspace_memalign behaves as memalign, but operates within |
1113 | the given space. |
1114 | */ |
1115 | void* mspace_memalign(mspace msp, size_t alignment, size_t bytes); |
1116 | |
1117 | /* |
1118 | mspace_independent_calloc behaves as independent_calloc, but |
1119 | operates within the given space. |
1120 | */ |
1121 | void** mspace_independent_calloc(mspace msp, size_t n_elements, |
1122 | size_t elem_size, void* chunks[]); |
1123 | |
1124 | /* |
1125 | mspace_independent_comalloc behaves as independent_comalloc, but |
1126 | operates within the given space. |
1127 | */ |
1128 | void** mspace_independent_comalloc(mspace msp, size_t n_elements, |
1129 | size_t sizes[], void* chunks[]); |
1130 | |
1131 | /* |
1132 | mspace_footprint() returns the number of bytes obtained from the |
1133 | system for this space. |
1134 | */ |
1135 | size_t mspace_footprint(mspace msp); |
1136 | |
1137 | /* |
1138 | mspace_max_footprint() returns the peak number of bytes obtained from the |
1139 | system for this space. |
1140 | */ |
1141 | size_t mspace_max_footprint(mspace msp); |
1142 | |
1143 | |
1144 | #if !NO_MALLINFO |
1145 | /* |
1146 | mspace_mallinfo behaves as mallinfo, but reports properties of |
1147 | the given space. |
1148 | */ |
1149 | struct mallinfo mspace_mallinfo(mspace msp); |
1150 | #endif /* NO_MALLINFO */ |
1151 | |
1152 | /* |
1153 | mspace_malloc_stats behaves as malloc_stats, but reports |
1154 | properties of the given space. |
1155 | */ |
1156 | void mspace_malloc_stats(mspace msp); |
1157 | |
1158 | /* |
1159 | mspace_trim behaves as malloc_trim, but |
1160 | operates within the given space. |
1161 | */ |
1162 | int mspace_trim(mspace msp, size_t pad); |
1163 | |
1164 | /* |
1165 | An alias for mallopt. |
1166 | */ |
1167 | int mspace_mallopt(int, int); |
1168 | |
1169 | #endif /* MSPACES */ |
1170 | |
1171 | #ifdef __cplusplus |
1172 | }; /* end of extern "C" */ |
1173 | #endif /* __cplusplus */ |
1174 | |
1175 | /* |
1176 | ======================================================================== |
1177 | To make a fully customizable malloc.h header file, cut everything |
1178 | above this line, put into file malloc.h, edit to suit, and #include it |
1179 | on the next line, as well as in programs that use this malloc. |
1180 | ======================================================================== |
1181 | */ |
1182 | |
1183 | /* #include "malloc.h" */ |
1184 | |
1185 | /*------------------------------ internal #includes ---------------------- */ |
1186 | |
1187 | #ifdef _MSC_VER |
1188 | #pragma warning( disable : 4146 ) /* no "unsigned" warnings */ |
1189 | #endif /* _MSC_VER */ |
1190 | |
1191 | #ifndef LACKS_STDIO_H |
1192 | #include <stdio.h> /* for printing in malloc_stats */ |
1193 | #endif |
1194 | |
1195 | #ifndef LACKS_ERRNO_H |
1196 | #include <errno.h> /* for MALLOC_FAILURE_ACTION */ |
1197 | #endif /* LACKS_ERRNO_H */ |
1198 | #if FOOTERS |
1199 | #include <time.h> /* for magic initialization */ |
1200 | #endif /* FOOTERS */ |
1201 | #ifndef LACKS_STDLIB_H |
1202 | #include <stdlib.h> /* for abort() */ |
1203 | #endif /* LACKS_STDLIB_H */ |
1204 | #ifdef DEBUG |
1205 | #if ABORT_ON_ASSERT_FAILURE |
1206 | #define assert(x) if(!(x)) ABORT |
1207 | #else /* ABORT_ON_ASSERT_FAILURE */ |
1208 | #include <assert.h> |
1209 | #endif /* ABORT_ON_ASSERT_FAILURE */ |
1210 | #else /* DEBUG */ |
1211 | #define assert(x) |
1212 | #endif /* DEBUG */ |
1213 | #ifndef LACKS_STRING_H |
1214 | #include <string.h> /* for memset etc */ |
1215 | #endif /* LACKS_STRING_H */ |
1216 | #if USE_BUILTIN_FFS |
1217 | #ifndef LACKS_STRINGS_H |
1218 | #include <strings.h> /* for ffs */ |
1219 | #endif /* LACKS_STRINGS_H */ |
1220 | #endif /* USE_BUILTIN_FFS */ |
1221 | #if HAVE_MMAP |
1222 | #ifndef LACKS_SYS_MMAN_H |
1223 | #include <sys/mman.h> /* for mmap */ |
1224 | #endif /* LACKS_SYS_MMAN_H */ |
1225 | #ifndef LACKS_FCNTL_H |
1226 | #include <fcntl.h> |
1227 | #endif /* LACKS_FCNTL_H */ |
1228 | #endif /* HAVE_MMAP */ |
1229 | #if HAVE_MORECORE |
1230 | #ifndef LACKS_UNISTD_H |
1231 | #include <unistd.h> /* for sbrk */ |
1232 | #else /* LACKS_UNISTD_H */ |
1233 | #if !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__NetBSD__) |
1234 | extern void* sbrk(ptrdiff_t); |
1235 | #endif /* FreeBSD etc */ |
1236 | #endif /* LACKS_UNISTD_H */ |
1237 | #endif /* HAVE_MMAP */ |
1238 | |
1239 | #ifndef WIN32 |
1240 | #ifndef malloc_getpagesize |
1241 | # ifdef _SC_PAGESIZE /* some SVR4 systems omit an underscore */ |
1242 | # ifndef _SC_PAGE_SIZE |
1243 | # define _SC_PAGE_SIZE _SC_PAGESIZE |
1244 | # endif |
1245 | # endif |
1246 | # ifdef _SC_PAGE_SIZE |
1247 | # define malloc_getpagesize sysconf(_SC_PAGE_SIZE) |
1248 | # else |
1249 | # if defined(BSD) || defined(DGUX) || defined(HAVE_GETPAGESIZE) |
1250 | extern size_t getpagesize(); |
1251 | # define malloc_getpagesize getpagesize() |
1252 | # else |
1253 | # ifdef WIN32 /* use supplied emulation of getpagesize */ |
1254 | # define malloc_getpagesize getpagesize() |
1255 | # else |
1256 | # ifndef LACKS_SYS_PARAM_H |
1257 | # include <sys/param.h> |
1258 | # endif |
1259 | # ifdef EXEC_PAGESIZE |
1260 | # define malloc_getpagesize EXEC_PAGESIZE |
1261 | # else |
1262 | # ifdef NBPG |
1263 | # ifndef CLSIZE |
1264 | # define malloc_getpagesize NBPG |
1265 | # else |
1266 | # define malloc_getpagesize (NBPG * CLSIZE) |
1267 | # endif |
1268 | # else |
1269 | # ifdef NBPC |
1270 | # define malloc_getpagesize NBPC |
1271 | # else |
1272 | # ifdef PAGESIZE |
1273 | # define malloc_getpagesize PAGESIZE |
1274 | # else /* just guess */ |
1275 | # define malloc_getpagesize ((size_t)4096U) |
1276 | # endif |
1277 | # endif |
1278 | # endif |
1279 | # endif |
1280 | # endif |
1281 | # endif |
1282 | # endif |
1283 | #endif |
1284 | #endif |
1285 | |
1286 | /* ------------------- size_t and alignment properties -------------------- */ |
1287 | |
1288 | /* The byte and bit size of a size_t */ |
1289 | #define SIZE_T_SIZE (sizeof(size_t)) |
1290 | #define SIZE_T_BITSIZE (sizeof(size_t) << 3) |
1291 | |
1292 | /* Some constants coerced to size_t */ |
1293 | /* Annoying but necessary to avoid errors on some plaftorms */ |
1294 | #define SIZE_T_ZERO ((size_t)0) |
1295 | #define SIZE_T_ONE ((size_t)1) |
1296 | #define SIZE_T_TWO ((size_t)2) |
1297 | #define TWO_SIZE_T_SIZES (SIZE_T_SIZE<<1) |
1298 | #define FOUR_SIZE_T_SIZES (SIZE_T_SIZE<<2) |
1299 | #define SIX_SIZE_T_SIZES (FOUR_SIZE_T_SIZES+TWO_SIZE_T_SIZES) |
1300 | #define HALF_MAX_SIZE_T (MAX_SIZE_T / 2U) |
1301 | |
1302 | /* The bit mask value corresponding to MALLOC_ALIGNMENT */ |
1303 | #define CHUNK_ALIGN_MASK (MALLOC_ALIGNMENT - SIZE_T_ONE) |
1304 | |
1305 | /* True if address a has acceptable alignment */ |
1306 | #define is_aligned(A) (((size_t)((A)) & (CHUNK_ALIGN_MASK)) == 0) |
1307 | |
1308 | /* the number of bytes to offset an address to align it */ |
1309 | #define align_offset(A)\ |
1310 | ((((size_t)(A) & CHUNK_ALIGN_MASK) == 0)? 0 :\ |
1311 | ((MALLOC_ALIGNMENT - ((size_t)(A) & CHUNK_ALIGN_MASK)) & CHUNK_ALIGN_MASK)) |
1312 | |
1313 | /* -------------------------- MMAP preliminaries ------------------------- */ |
1314 | |
1315 | /* |
1316 | If HAVE_MORECORE or HAVE_MMAP are false, we just define calls and |
1317 | checks to fail so compiler optimizer can delete code rather than |
1318 | using so many "#if"s. |
1319 | */ |
1320 | |
1321 | |
1322 | /* MORECORE and MMAP must return MFAIL on failure */ |
1323 | #define MFAIL ((void*)(MAX_SIZE_T)) |
1324 | #define CMFAIL ((char*)(MFAIL)) /* defined for convenience */ |
1325 | |
1326 | #if !HAVE_MMAP |
1327 | #define IS_MMAPPED_BIT (SIZE_T_ZERO) |
1328 | #define USE_MMAP_BIT (SIZE_T_ZERO) |
1329 | #define CALL_MMAP(s) MFAIL |
1330 | #define CALL_MUNMAP(a, s) (-1) |
1331 | #define DIRECT_MMAP(s) MFAIL |
1332 | |
1333 | #else /* HAVE_MMAP */ |
1334 | #define IS_MMAPPED_BIT (SIZE_T_ONE) |
1335 | #define USE_MMAP_BIT (SIZE_T_ONE) |
1336 | |
1337 | #ifndef WIN32 |
1338 | #define CALL_MUNMAP(a, s) munmap((a), (s)) |
1339 | #define MMAP_PROT (PROT_READ|PROT_WRITE) |
1340 | #if !defined(MAP_ANONYMOUS) && defined(MAP_ANON) |
1341 | #define MAP_ANONYMOUS MAP_ANON |
1342 | #endif /* MAP_ANON */ |
1343 | #ifdef MAP_ANONYMOUS |
1344 | #define MMAP_FLAGS (MAP_PRIVATE|MAP_ANONYMOUS) |
1345 | #define CALL_MMAP(s) mmap(0, (s), MMAP_PROT, MMAP_FLAGS, -1, 0) |
1346 | #else /* MAP_ANONYMOUS */ |
1347 | /* |
1348 | Nearly all versions of mmap support MAP_ANONYMOUS, so the following |
1349 | is unlikely to be needed, but is supplied just in case. |
1350 | */ |
1351 | #define MMAP_FLAGS (MAP_PRIVATE) |
1352 | static int dev_zero_fd = -1; /* Cached file descriptor for /dev/zero. */ |
1353 | #define CALL_MMAP(s) ((dev_zero_fd < 0) ? \ |
1354 | (dev_zero_fd = open("/dev/zero", O_RDWR), \ |
1355 | mmap(0, (s), MMAP_PROT, MMAP_FLAGS, dev_zero_fd, 0)) : \ |
1356 | mmap(0, (s), MMAP_PROT, MMAP_FLAGS, dev_zero_fd, 0)) |
1357 | #endif /* MAP_ANONYMOUS */ |
1358 | |
1359 | #define DIRECT_MMAP(s) CALL_MMAP(s) |
1360 | #else /* WIN32 */ |
1361 | |
1362 | /* Win32 MMAP via VirtualAlloc */ |
1363 | static void* win32mmap(size_t size) { |
1364 | void* ptr = VirtualAlloc(0, size, MEM_RESERVE|MEM_COMMIT, PAGE_READWRITE); |
1365 | return (ptr != 0)? ptr: MFAIL; |
1366 | } |
1367 | |
1368 | /* For direct MMAP, use MEM_TOP_DOWN to minimize interference */ |
1369 | static void* win32direct_mmap(size_t size) { |
1370 | void* ptr = VirtualAlloc(0, size, MEM_RESERVE|MEM_COMMIT|MEM_TOP_DOWN, |
1371 | PAGE_READWRITE); |
1372 | return (ptr != 0)? ptr: MFAIL; |
1373 | } |
1374 | |
1375 | /* This function supports releasing coalesed segments */ |
1376 | static int win32munmap(void* ptr, size_t size) { |
1377 | MEMORY_BASIC_INFORMATION minfo; |
1378 | char* cptr = ptr; |
1379 | while (size) { |
1380 | if (VirtualQuery(cptr, &minfo, sizeof(minfo)) == 0) |
1381 | return -1; |
1382 | if (minfo.BaseAddress != cptr || minfo.AllocationBase != cptr || |
1383 | minfo.State != MEM_COMMIT || minfo.RegionSize > size) |
1384 | return -1; |
1385 | if (VirtualFree(cptr, 0, MEM_RELEASE) == 0) |
1386 | return -1; |
1387 | cptr += minfo.RegionSize; |
1388 | size -= minfo.RegionSize; |
1389 | } |
1390 | return 0; |
1391 | } |
1392 | |
1393 | #define CALL_MMAP(s) win32mmap(s) |
1394 | #define CALL_MUNMAP(a, s) win32munmap((a), (s)) |
1395 | #define DIRECT_MMAP(s) win32direct_mmap(s) |
1396 | #endif /* WIN32 */ |
1397 | #endif /* HAVE_MMAP */ |
1398 | |
1399 | #if HAVE_MMAP && HAVE_MREMAP |
1400 | #define CALL_MREMAP(addr, osz, nsz, mv) mremap((addr), (osz), (nsz), (mv)) |
1401 | #else /* HAVE_MMAP && HAVE_MREMAP */ |
1402 | #define CALL_MREMAP(addr, osz, nsz, mv) MFAIL |
1403 | #endif /* HAVE_MMAP && HAVE_MREMAP */ |
1404 | |
1405 | #if HAVE_MORECORE |
1406 | #define CALL_MORECORE(S) MORECORE(S) |
1407 | #else /* HAVE_MORECORE */ |
1408 | #define CALL_MORECORE(S) MFAIL |
1409 | #endif /* HAVE_MORECORE */ |
1410 | |
1411 | /* mstate bit set if continguous morecore disabled or failed */ |
1412 | #define USE_NONCONTIGUOUS_BIT (4U) |
1413 | |
1414 | /* segment bit set in create_mspace_with_base */ |
1415 | #define EXTERN_BIT (8U) |
1416 | |
1417 | |
1418 | /* --------------------------- Lock preliminaries ------------------------ */ |
1419 | |
1420 | #if USE_LOCKS |
1421 | |
1422 | /* |
1423 | When locks are defined, there are up to two global locks: |
1424 | |
1425 | * If HAVE_MORECORE, morecore_mutex protects sequences of calls to |
1426 | MORECORE. In many cases sys_alloc requires two calls, that should |
1427 | not be interleaved with calls by other threads. This does not |
1428 | protect against direct calls to MORECORE by other threads not |
1429 | using this lock, so there is still code to cope the best we can on |
1430 | interference. |
1431 | |
1432 | * magic_init_mutex ensures that mparams.magic and other |
1433 | unique mparams values are initialized only once. |
1434 | */ |
1435 | |
1436 | #ifndef WIN32 |
1437 | /* By default use posix locks */ |
1438 | #include <pthread.h> |
1439 | #define MLOCK_T pthread_mutex_t |
1440 | #define INITIAL_LOCK(l) pthread_mutex_init(l, NULL) |
1441 | #define ACQUIRE_LOCK(l) pthread_mutex_lock(l) |
1442 | #define RELEASE_LOCK(l) pthread_mutex_unlock(l) |
1443 | |
1444 | #if HAVE_MORECORE |
1445 | static MLOCK_T morecore_mutex = PTHREAD_MUTEX_INITIALIZER; |
1446 | #endif /* HAVE_MORECORE */ |
1447 | |
1448 | static MLOCK_T magic_init_mutex = PTHREAD_MUTEX_INITIALIZER; |
1449 | |
1450 | #else /* WIN32 */ |
1451 | /* |
1452 | Because lock-protected regions have bounded times, and there |
1453 | are no recursive lock calls, we can use simple spinlocks. |
1454 | */ |
1455 | |
1456 | #define MLOCK_T long |
1457 | static int win32_acquire_lock (MLOCK_T *sl) { |
1458 | for (;;) { |
1459 | #ifdef InterlockedCompareExchangePointer |
1460 | if (!InterlockedCompareExchange(sl, 1, 0)) |
1461 | return 0; |
1462 | #else /* Use older void* version */ |
1463 | if (!InterlockedCompareExchange((void**)sl, (void*)1, (void*)0)) |
1464 | return 0; |
1465 | #endif /* InterlockedCompareExchangePointer */ |
1466 | Sleep (0); |
1467 | } |
1468 | } |
1469 | |
1470 | static void win32_release_lock (MLOCK_T *sl) { |
1471 | InterlockedExchange (sl, 0); |
1472 | } |
1473 | |
1474 | #define INITIAL_LOCK(l) *(l)=0 |
1475 | #define ACQUIRE_LOCK(l) win32_acquire_lock(l) |
1476 | #define RELEASE_LOCK(l) win32_release_lock(l) |
1477 | #if HAVE_MORECORE |
1478 | static MLOCK_T morecore_mutex; |
1479 | #endif /* HAVE_MORECORE */ |
1480 | static MLOCK_T magic_init_mutex; |
1481 | #endif /* WIN32 */ |
1482 | |
1483 | #define USE_LOCK_BIT (2U) |
1484 | #else /* USE_LOCKS */ |
1485 | #define USE_LOCK_BIT (0U) |
1486 | #define INITIAL_LOCK(l) |
1487 | #endif /* USE_LOCKS */ |
1488 | |
1489 | #if USE_LOCKS && HAVE_MORECORE |
1490 | #define ACQUIRE_MORECORE_LOCK() ACQUIRE_LOCK(&morecore_mutex); |
1491 | #define RELEASE_MORECORE_LOCK() RELEASE_LOCK(&morecore_mutex); |
1492 | #else /* USE_LOCKS && HAVE_MORECORE */ |
1493 | #define ACQUIRE_MORECORE_LOCK() |
1494 | #define RELEASE_MORECORE_LOCK() |
1495 | #endif /* USE_LOCKS && HAVE_MORECORE */ |
1496 | |
1497 | #if USE_LOCKS |
1498 | #define ACQUIRE_MAGIC_INIT_LOCK() ACQUIRE_LOCK(&magic_init_mutex); |
1499 | #define RELEASE_MAGIC_INIT_LOCK() RELEASE_LOCK(&magic_init_mutex); |
1500 | #else /* USE_LOCKS */ |
1501 | #define ACQUIRE_MAGIC_INIT_LOCK() |
1502 | #define RELEASE_MAGIC_INIT_LOCK() |
1503 | #endif /* USE_LOCKS */ |
1504 | |
1505 | |
1506 | /* ----------------------- Chunk representations ------------------------ */ |
1507 | |
1508 | /* |
1509 | (The following includes lightly edited explanations by Colin Plumb.) |
1510 | |
1511 | The malloc_chunk declaration below is misleading (but accurate and |
1512 | necessary). It declares a "view" into memory allowing access to |
1513 | necessary fields at known offsets from a given base. |
1514 | |
1515 | Chunks of memory are maintained using a `boundary tag' method as |
1516 | originally described by Knuth. (See the paper by Paul Wilson |
1517 | ftp://ftp.cs.utexas.edu/pub/garbage/allocsrv.ps for a survey of such |
1518 | techniques.) Sizes of free chunks are stored both in the front of |
1519 | each chunk and at the end. This makes consolidating fragmented |
1520 | chunks into bigger chunks fast. The head fields also hold bits |
1521 | representing whether chunks are free or in use. |
1522 | |
1523 | Here are some pictures to make it clearer. They are "exploded" to |
1524 | show that the state of a chunk can be thought of as extending from |
1525 | the high 31 bits of the head field of its header through the |
1526 | prev_foot and PINUSE_BIT bit of the following chunk header. |
1527 | |
1528 | A chunk that's in use looks like: |
1529 | |
1530 | chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1531 | | Size of previous chunk (if P = 1) | |
1532 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1533 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |P| |
1534 | | Size of this chunk 1| +-+ |
1535 | mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1536 | | | |
1537 | +- -+ |
1538 | | | |
1539 | +- -+ |
1540 | | : |
1541 | +- size - sizeof(size_t) available payload bytes -+ |
1542 | : | |
1543 | chunk-> +- -+ |
1544 | | | |
1545 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1546 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |1| |
1547 | | Size of next chunk (may or may not be in use) | +-+ |
1548 | mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1549 | |
1550 | And if it's free, it looks like this: |
1551 | |
1552 | chunk-> +- -+ |
1553 | | User payload (must be in use, or we would have merged!) | |
1554 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1555 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |P| |
1556 | | Size of this chunk 0| +-+ |
1557 | mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1558 | | Next pointer | |
1559 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1560 | | Prev pointer | |
1561 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1562 | | : |
1563 | +- size - sizeof(struct chunk) unused bytes -+ |
1564 | : | |
1565 | chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1566 | | Size of this chunk | |
1567 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1568 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| |
1569 | | Size of next chunk (must be in use, or we would have merged)| +-+ |
1570 | mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1571 | | : |
1572 | +- User payload -+ |
1573 | : | |
1574 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1575 | |0| |
1576 | +-+ |
1577 | Note that since we always merge adjacent free chunks, the chunks |
1578 | adjacent to a free chunk must be in use. |
1579 | |
1580 | Given a pointer to a chunk (which can be derived trivially from the |
1581 | payload pointer) we can, in O(1) time, find out whether the adjacent |
1582 | chunks are free, and if so, unlink them from the lists that they |
1583 | are on and merge them with the current chunk. |
1584 | |
1585 | Chunks always begin on even word boundaries, so the mem portion |
1586 | (which is returned to the user) is also on an even word boundary, and |
1587 | thus at least double-word aligned. |
1588 | |
1589 | The P (PINUSE_BIT) bit, stored in the unused low-order bit of the |
1590 | chunk size (which is always a multiple of two words), is an in-use |
1591 | bit for the *previous* chunk. If that bit is *clear*, then the |
1592 | word before the current chunk size contains the previous chunk |
1593 | size, and can be used to find the front of the previous chunk. |
1594 | The very first chunk allocated always has this bit set, preventing |
1595 | access to non-existent (or non-owned) memory. If pinuse is set for |
1596 | any given chunk, then you CANNOT determine the size of the |
1597 | previous chunk, and might even get a memory addressing fault when |
1598 | trying to do so. |
1599 | |
1600 | The C (CINUSE_BIT) bit, stored in the unused second-lowest bit of |
1601 | the chunk size redundantly records whether the current chunk is |
1602 | inuse. This redundancy enables usage checks within free and realloc, |
1603 | and reduces indirection when freeing and consolidating chunks. |
1604 | |
1605 | Each freshly allocated chunk must have both cinuse and pinuse set. |
1606 | That is, each allocated chunk borders either a previously allocated |
1607 | and still in-use chunk, or the base of its memory arena. This is |
1608 | ensured by making all allocations from the the `lowest' part of any |
1609 | found chunk. Further, no free chunk physically borders another one, |
1610 | so each free chunk is known to be preceded and followed by either |
1611 | inuse chunks or the ends of memory. |
1612 | |
1613 | Note that the `foot' of the current chunk is actually represented |
1614 | as the prev_foot of the NEXT chunk. This makes it easier to |
1615 | deal with alignments etc but can be very confusing when trying |
1616 | to extend or adapt this code. |
1617 | |
1618 | The exceptions to all this are |
1619 | |
1620 | 1. The special chunk `top' is the top-most available chunk (i.e., |
1621 | the one bordering the end of available memory). It is treated |
1622 | specially. Top is never included in any bin, is used only if |
1623 | no other chunk is available, and is released back to the |
1624 | system if it is very large (see M_TRIM_THRESHOLD). In effect, |
1625 | the top chunk is treated as larger (and thus less well |
1626 | fitting) than any other available chunk. The top chunk |
1627 | doesn't update its trailing size field since there is no next |
1628 | contiguous chunk that would have to index off it. However, |
1629 | space is still allocated for it (TOP_FOOT_SIZE) to enable |
1630 | separation or merging when space is extended. |
1631 | |
1632 | 3. Chunks allocated via mmap, which have the lowest-order bit |
1633 | (IS_MMAPPED_BIT) set in their prev_foot fields, and do not set |
1634 | PINUSE_BIT in their head fields. Because they are allocated |
1635 | one-by-one, each must carry its own prev_foot field, which is |
1636 | also used to hold the offset this chunk has within its mmapped |
1637 | region, which is needed to preserve alignment. Each mmapped |
1638 | chunk is trailed by the first two fields of a fake next-chunk |
1639 | for sake of usage checks. |
1640 | |
1641 | */ |
1642 | |
1643 | struct malloc_chunk { |
1644 | size_t prev_foot; /* Size of previous chunk (if free). */ |
1645 | size_t head; /* Size and inuse bits. */ |
1646 | struct malloc_chunk* fd; /* double links -- used only if free. */ |
1647 | struct malloc_chunk* bk; |
1648 | }; |
1649 | |
1650 | typedef struct malloc_chunk mchunk; |
1651 | typedef struct malloc_chunk* mchunkptr; |
1652 | typedef struct malloc_chunk* sbinptr; /* The type of bins of chunks */ |
1653 | typedef size_t bindex_t; /* Described below */ |
1654 | typedef unsigned int binmap_t; /* Described below */ |
1655 | typedef unsigned int flag_t; /* The type of various bit flag sets */ |
1656 | |
1657 | /* ------------------- Chunks sizes and alignments ----------------------- */ |
1658 | |
1659 | #define MCHUNK_SIZE (sizeof(mchunk)) |
1660 | |
1661 | #if FOOTERS |
1662 | #define CHUNK_OVERHEAD (TWO_SIZE_T_SIZES) |
1663 | #else /* FOOTERS */ |
1664 | #define CHUNK_OVERHEAD (SIZE_T_SIZE) |
1665 | #endif /* FOOTERS */ |
1666 | |
1667 | /* MMapped chunks need a second word of overhead ... */ |
1668 | #define MMAP_CHUNK_OVERHEAD (TWO_SIZE_T_SIZES) |
1669 | /* ... and additional padding for fake next-chunk at foot */ |
1670 | #define MMAP_FOOT_PAD (FOUR_SIZE_T_SIZES) |
1671 | |
1672 | /* The smallest size we can malloc is an aligned minimal chunk */ |
1673 | #define MIN_CHUNK_SIZE\ |
1674 | ((MCHUNK_SIZE + CHUNK_ALIGN_MASK) & ~CHUNK_ALIGN_MASK) |
1675 | |
1676 | /* conversion from malloc headers to user pointers, and back */ |
1677 | #define chunk2mem(p) ((void*)((char*)(p) + TWO_SIZE_T_SIZES)) |
1678 | #define mem2chunk(mem) ((mchunkptr)((char*)(mem) - TWO_SIZE_T_SIZES)) |
1679 | /* chunk associated with aligned address A */ |
1680 | #define align_as_chunk(A) (mchunkptr)((A) + align_offset(chunk2mem(A))) |
1681 | |
1682 | /* Bounds on request (not chunk) sizes. */ |
1683 | #define MAX_REQUEST ((-MIN_CHUNK_SIZE) << 2) |
1684 | #define MIN_REQUEST (MIN_CHUNK_SIZE - CHUNK_OVERHEAD - SIZE_T_ONE) |
1685 | |
1686 | /* pad request bytes into a usable size */ |
1687 | #define pad_request(req) \ |
1688 | (((req) + CHUNK_OVERHEAD + CHUNK_ALIGN_MASK) & ~CHUNK_ALIGN_MASK) |
1689 | |
1690 | /* pad request, checking for minimum (but not maximum) */ |
1691 | #define request2size(req) \ |
1692 | (((req) < MIN_REQUEST)? MIN_CHUNK_SIZE : pad_request(req)) |
1693 | |
1694 | |
1695 | /* ------------------ Operations on head and foot fields ----------------- */ |
1696 | |
1697 | /* |
1698 | The head field of a chunk is or'ed with PINUSE_BIT when previous |
1699 | adjacent chunk in use, and or'ed with CINUSE_BIT if this chunk is in |
1700 | use. If the chunk was obtained with mmap, the prev_foot field has |
1701 | IS_MMAPPED_BIT set, otherwise holding the offset of the base of the |
1702 | mmapped region to the base of the chunk. |
1703 | */ |
1704 | |
1705 | #define PINUSE_BIT (SIZE_T_ONE) |
1706 | #define CINUSE_BIT (SIZE_T_TWO) |
1707 | #define INUSE_BITS (PINUSE_BIT|CINUSE_BIT) |
1708 | |
1709 | /* Head value for fenceposts */ |
1710 | #define FENCEPOST_HEAD (INUSE_BITS|SIZE_T_SIZE) |
1711 | |
1712 | /* extraction of fields from head words */ |
1713 | #define cinuse(p) ((p)->head & CINUSE_BIT) |
1714 | #define pinuse(p) ((p)->head & PINUSE_BIT) |
1715 | #define chunksize(p) ((p)->head & ~(INUSE_BITS)) |
1716 | |
1717 | #define clear_pinuse(p) ((p)->head &= ~PINUSE_BIT) |
1718 | #define clear_cinuse(p) ((p)->head &= ~CINUSE_BIT) |
1719 | |
1720 | /* Treat space at ptr +/- offset as a chunk */ |
1721 | #define chunk_plus_offset(p, s) ((mchunkptr)(((char*)(p)) + (s))) |
1722 | #define chunk_minus_offset(p, s) ((mchunkptr)(((char*)(p)) - (s))) |
1723 | |
1724 | /* Ptr to next or previous physical malloc_chunk. */ |
1725 | #define next_chunk(p) ((mchunkptr)( ((char*)(p)) + ((p)->head & ~INUSE_BITS))) |
1726 | #define prev_chunk(p) ((mchunkptr)( ((char*)(p)) - ((p)->prev_foot) )) |
1727 | |
1728 | /* extract next chunk's pinuse bit */ |
1729 | #define next_pinuse(p) ((next_chunk(p)->head) & PINUSE_BIT) |
1730 | |
1731 | /* Get/set size at footer */ |
1732 | #define get_foot(p, s) (((mchunkptr)((char*)(p) + (s)))->prev_foot) |
1733 | #define set_foot(p, s) (((mchunkptr)((char*)(p) + (s)))->prev_foot = (s)) |
1734 | |
1735 | /* Set size, pinuse bit, and foot */ |
1736 | #define set_size_and_pinuse_of_free_chunk(p, s)\ |
1737 | ((p)->head = (s|PINUSE_BIT), set_foot(p, s)) |
1738 | |
1739 | /* Set size, pinuse bit, foot, and clear next pinuse */ |
1740 | #define set_free_with_pinuse(p, s, n)\ |
1741 | (clear_pinuse(n), set_size_and_pinuse_of_free_chunk(p, s)) |
1742 | |
1743 | #define is_mmapped(p)\ |
1744 | (!((p)->head & PINUSE_BIT) && ((p)->prev_foot & IS_MMAPPED_BIT)) |
1745 | |
1746 | /* Get the internal overhead associated with chunk p */ |
1747 | #define overhead_for(p)\ |
1748 | (is_mmapped(p)? MMAP_CHUNK_OVERHEAD : CHUNK_OVERHEAD) |
1749 | |
1750 | /* Return true if malloced space is not necessarily cleared */ |
1751 | #if MMAP_CLEARS |
1752 | #define calloc_must_clear(p) (!is_mmapped(p)) |
1753 | #else /* MMAP_CLEARS */ |
1754 | #define calloc_must_clear(p) (1) |
1755 | #endif /* MMAP_CLEARS */ |
1756 | |
1757 | /* ---------------------- Overlaid data structures ----------------------- */ |
1758 | |
1759 | /* |
1760 | When chunks are not in use, they are treated as nodes of either |
1761 | lists or trees. |
1762 | |
1763 | "Small" chunks are stored in circular doubly-linked lists, and look |
1764 | like this: |
1765 | |
1766 | chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1767 | | Size of previous chunk | |
1768 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1769 | `head:' | Size of chunk, in bytes |P| |
1770 | mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1771 | | Forward pointer to next chunk in list | |
1772 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1773 | | Back pointer to previous chunk in list | |
1774 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1775 | | Unused space (may be 0 bytes long) . |
1776 | . . |
1777 | . | |
1778 | nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1779 | `foot:' | Size of chunk, in bytes | |
1780 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1781 | |
1782 | Larger chunks are kept in a form of bitwise digital trees (aka |
1783 | tries) keyed on chunksizes. Because malloc_tree_chunks are only for |
1784 | free chunks greater than 256 bytes, their size doesn't impose any |
1785 | constraints on user chunk sizes. Each node looks like: |
1786 | |
1787 | chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1788 | | Size of previous chunk | |
1789 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1790 | `head:' | Size of chunk, in bytes |P| |
1791 | mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1792 | | Forward pointer to next chunk of same size | |
1793 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1794 | | Back pointer to previous chunk of same size | |
1795 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1796 | | Pointer to left child (child[0]) | |
1797 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1798 | | Pointer to right child (child[1]) | |
1799 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1800 | | Pointer to parent | |
1801 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1802 | | bin index of this chunk | |
1803 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1804 | | Unused space . |
1805 | . | |
1806 | nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1807 | `foot:' | Size of chunk, in bytes | |
1808 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1809 | |
1810 | Each tree holding treenodes is a tree of unique chunk sizes. Chunks |
1811 | of the same size are arranged in a circularly-linked list, with only |
1812 | the oldest chunk (the next to be used, in our FIFO ordering) |
1813 | actually in the tree. (Tree members are distinguished by a non-null |
1814 | parent pointer.) If a chunk with the same size an an existing node |
1815 | is inserted, it is linked off the existing node using pointers that |
1816 | work in the same way as fd/bk pointers of small chunks. |
1817 | |
1818 | Each tree contains a power of 2 sized range of chunk sizes (the |
1819 | smallest is 0x100 <= x < 0x180), which is is divided in half at each |
1820 | tree level, with the chunks in the smaller half of the range (0x100 |
1821 | <= x < 0x140 for the top nose) in the left subtree and the larger |
1822 | half (0x140 <= x < 0x180) in the right subtree. This is, of course, |
1823 | done by inspecting individual bits. |
1824 | |
1825 | Using these rules, each node's left subtree contains all smaller |
1826 | sizes than its right subtree. However, the node at the root of each |
1827 | subtree has no particular ordering relationship to either. (The |
1828 | dividing line between the subtree sizes is based on trie relation.) |
1829 | If we remove the last chunk of a given size from the interior of the |
1830 | tree, we need to replace it with a leaf node. The tree ordering |
1831 | rules permit a node to be replaced by any leaf below it. |
1832 | |
1833 | The smallest chunk in a tree (a common operation in a best-fit |
1834 | allocator) can be found by walking a path to the leftmost leaf in |
1835 | the tree. Unlike a usual binary tree, where we follow left child |
1836 | pointers until we reach a null, here we follow the right child |
1837 | pointer any time the left one is null, until we reach a leaf with |
1838 | both child pointers null. The smallest chunk in the tree will be |
1839 | somewhere along that path. |
1840 | |
1841 | The worst case number of steps to add, find, or remove a node is |
1842 | bounded by the number of bits differentiating chunks within |
1843 | bins. Under current bin calculations, this ranges from 6 up to 21 |
1844 | (for 32 bit sizes) or up to 53 (for 64 bit sizes). The typical case |
1845 | is of course much better. |
1846 | */ |
1847 | |
1848 | struct malloc_tree_chunk { |
1849 | /* The first four fields must be compatible with malloc_chunk */ |
1850 | size_t prev_foot; |
1851 | size_t head; |
1852 | struct malloc_tree_chunk* fd; |
1853 | struct malloc_tree_chunk* bk; |
1854 | |
1855 | struct malloc_tree_chunk* child[2]; |
1856 | struct malloc_tree_chunk* parent; |
1857 | bindex_t index; |
1858 | }; |
1859 | |
1860 | typedef struct malloc_tree_chunk tchunk; |
1861 | typedef struct malloc_tree_chunk* tchunkptr; |
1862 | typedef struct malloc_tree_chunk* tbinptr; /* The type of bins of trees */ |
1863 | |
1864 | /* A little helper macro for trees */ |
1865 | #define leftmost_child(t) ((t)->child[0] != 0? (t)->child[0] : (t)->child[1]) |
1866 | |
1867 | /* ----------------------------- Segments -------------------------------- */ |
1868 | |
1869 | /* |
1870 | Each malloc space may include non-contiguous segments, held in a |
1871 | list headed by an embedded malloc_segment record representing the |
1872 | top-most space. Segments also include flags holding properties of |
1873 | the space. Large chunks that are directly allocated by mmap are not |
1874 | included in this list. They are instead independently created and |
1875 | destroyed without otherwise keeping track of them. |
1876 | |
1877 | Segment management mainly comes into play for spaces allocated by |
1878 | MMAP. Any call to MMAP might or might not return memory that is |
1879 | adjacent to an existing segment. MORECORE normally contiguously |
1880 | extends the current space, so this space is almost always adjacent, |
1881 | which is simpler and faster to deal with. (This is why MORECORE is |
1882 | used preferentially to MMAP when both are available -- see |
1883 | sys_alloc.) When allocating using MMAP, we don't use any of the |
1884 | hinting mechanisms (inconsistently) supported in various |
1885 | implementations of unix mmap, or distinguish reserving from |
1886 | committing memory. Instead, we just ask for space, and exploit |
1887 | contiguity when we get it. It is probably possible to do |
1888 | better than this on some systems, but no general scheme seems |
1889 | to be significantly better. |
1890 | |
1891 | Management entails a simpler variant of the consolidation scheme |
1892 | used for chunks to reduce fragmentation -- new adjacent memory is |
1893 | normally prepended or appended to an existing segment. However, |
1894 | there are limitations compared to chunk consolidation that mostly |
1895 | reflect the fact that segment processing is relatively infrequent |
1896 | (occurring only when getting memory from system) and that we |
1897 | don't expect to have huge numbers of segments: |
1898 | |
1899 | * Segments are not indexed, so traversal requires linear scans. (It |
1900 | would be possible to index these, but is not worth the extra |
1901 | overhead and complexity for most programs on most platforms.) |
1902 | * New segments are only appended to old ones when holding top-most |
1903 | memory; if they cannot be prepended to others, they are held in |
1904 | different segments. |
1905 | |
1906 | Except for the top-most segment of an mstate, each segment record |
1907 | is kept at the tail of its segment. Segments are added by pushing |
1908 | segment records onto the list headed by &mstate.seg for the |
1909 | containing mstate. |
1910 | |
1911 | Segment flags control allocation/merge/deallocation policies: |
1912 | * If EXTERN_BIT set, then we did not allocate this segment, |
1913 | and so should not try to deallocate or merge with others. |
1914 | (This currently holds only for the initial segment passed |
1915 | into create_mspace_with_base.) |
1916 | * If IS_MMAPPED_BIT set, the segment may be merged with |
1917 | other surrounding mmapped segments and trimmed/de-allocated |
1918 | using munmap. |
1919 | * If neither bit is set, then the segment was obtained using |
1920 | MORECORE so can be merged with surrounding MORECORE'd segments |
1921 | and deallocated/trimmed using MORECORE with negative arguments. |
1922 | */ |
1923 | |
1924 | struct malloc_segment { |
1925 | char* base; /* base address */ |
1926 | size_t size; /* allocated size */ |
1927 | struct malloc_segment* next; /* ptr to next segment */ |
1928 | flag_t sflags; /* mmap and extern flag */ |
1929 | }; |
1930 | |
1931 | #define is_mmapped_segment(S) ((S)->sflags & IS_MMAPPED_BIT) |
1932 | #define is_extern_segment(S) ((S)->sflags & EXTERN_BIT) |
1933 | |
1934 | typedef struct malloc_segment msegment; |
1935 | typedef struct malloc_segment* msegmentptr; |
1936 | |
1937 | /* ---------------------------- malloc_state ----------------------------- */ |
1938 | |
1939 | /* |
1940 | A malloc_state holds all of the bookkeeping for a space. |
1941 | The main fields are: |
1942 | |
1943 | Top |
1944 | The topmost chunk of the currently active segment. Its size is |
1945 | cached in topsize. The actual size of topmost space is |
1946 | topsize+TOP_FOOT_SIZE, which includes space reserved for adding |
1947 | fenceposts and segment records if necessary when getting more |
1948 | space from the system. The size at which to autotrim top is |
1949 | cached from mparams in trim_check, except that it is disabled if |
1950 | an autotrim fails. |
1951 | |
1952 | Designated victim (dv) |
1953 | This is the preferred chunk for servicing small requests that |
1954 | don't have exact fits. It is normally the chunk split off most |
1955 | recently to service another small request. Its size is cached in |
1956 | dvsize. The link fields of this chunk are not maintained since it |
1957 | is not kept in a bin. |
1958 | |
1959 | SmallBins |
1960 | An array of bin headers for free chunks. These bins hold chunks |
1961 | with sizes less than MIN_LARGE_SIZE bytes. Each bin contains |
1962 | chunks of all the same size, spaced 8 bytes apart. To simplify |
1963 | use in double-linked lists, each bin header acts as a malloc_chunk |
1964 | pointing to the real first node, if it exists (else pointing to |
1965 | itself). This avoids special-casing for headers. But to avoid |
1966 | waste, we allocate only the fd/bk pointers of bins, and then use |
1967 | repositioning tricks to treat these as the fields of a chunk. |
1968 | |
1969 | TreeBins |
1970 | Treebins are pointers to the roots of trees holding a range of |
1971 | sizes. There are 2 equally spaced treebins for each power of two |
1972 | from TREE_SHIFT to TREE_SHIFT+16. The last bin holds anything |
1973 | larger. |
1974 | |
1975 | Bin maps |
1976 | There is one bit map for small bins ("smallmap") and one for |
1977 | treebins ("treemap). Each bin sets its bit when non-empty, and |
1978 | clears the bit when empty. Bit operations are then used to avoid |
1979 | bin-by-bin searching -- nearly all "search" is done without ever |
1980 | looking at bins that won't be selected. The bit maps |
1981 | conservatively use 32 bits per map word, even if on 64bit system. |
1982 | For a good description of some of the bit-based techniques used |
1983 | here, see Henry S. Warren Jr's book "Hacker's Delight" (and |
1984 | supplement at http://hackersdelight.org/). Many of these are |
1985 | intended to reduce the branchiness of paths through malloc etc, as |
1986 | well as to reduce the number of memory locations read or written. |
1987 | |
1988 | Segments |
1989 | A list of segments headed by an embedded malloc_segment record |
1990 | representing the initial space. |
1991 | |
1992 | Address check support |
1993 | The least_addr field is the least address ever obtained from |
1994 | MORECORE or MMAP. Attempted frees and reallocs of any address less |
1995 | than this are trapped (unless INSECURE is defined). |
1996 | |
1997 | Magic tag |
1998 | A cross-check field that should always hold same value as mparams.magic. |
1999 | |
2000 | Flags |
2001 | Bits recording whether to use MMAP, locks, or contiguous MORECORE |
2002 | |
2003 | Statistics |
2004 | Each space keeps track of current and maximum system memory |
2005 | obtained via MORECORE or MMAP. |
2006 | |
2007 | Locking |
2008 | If USE_LOCKS is defined, the "mutex" lock is acquired and released |
2009 | around every public call using this mspace. |
2010 | */ |
2011 | |
2012 | /* Bin types, widths and sizes */ |
2013 | #define NSMALLBINS (32U) |
2014 | #define NTREEBINS (32U) |
2015 | #define SMALLBIN_SHIFT (3U) |
2016 | #define SMALLBIN_WIDTH (SIZE_T_ONE << SMALLBIN_SHIFT) |
2017 | #define TREEBIN_SHIFT (8U) |
2018 | #define MIN_LARGE_SIZE (SIZE_T_ONE << TREEBIN_SHIFT) |
2019 | #define MAX_SMALL_SIZE (MIN_LARGE_SIZE - SIZE_T_ONE) |
2020 | #define MAX_SMALL_REQUEST (MAX_SMALL_SIZE - CHUNK_ALIGN_MASK - CHUNK_OVERHEAD) |
2021 | |
2022 | struct malloc_state { |
2023 | binmap_t smallmap; |
2024 | binmap_t treemap; |
2025 | size_t dvsize; |
2026 | size_t topsize; |
2027 | char* least_addr; |
2028 | mchunkptr dv; |
2029 | mchunkptr top; |
2030 | size_t trim_check; |
2031 | size_t magic; |
2032 | mchunkptr smallbins[(NSMALLBINS+1)*2]; |
2033 | tbinptr treebins[NTREEBINS]; |
2034 | size_t footprint; |
2035 | size_t max_footprint; |
2036 | flag_t mflags; |
2037 | #if USE_LOCKS |
2038 | MLOCK_T mutex; /* locate lock among fields that rarely change */ |
2039 | #endif /* USE_LOCKS */ |
2040 | msegment seg; |
2041 | }; |
2042 | |
2043 | typedef struct malloc_state* mstate; |
2044 | |
2045 | /* ------------- Global malloc_state and malloc_params ------------------- */ |
2046 | |
2047 | /* |
2048 | malloc_params holds global properties, including those that can be |
2049 | dynamically set using mallopt. There is a single instance, mparams, |
2050 | initialized in init_mparams. |
2051 | */ |
2052 | |
2053 | struct malloc_params { |
2054 | size_t magic; |
2055 | size_t page_size; |
2056 | size_t granularity; |
2057 | size_t mmap_threshold; |
2058 | size_t trim_threshold; |
2059 | flag_t default_mflags; |
2060 | }; |
2061 | |
2062 | static struct malloc_params mparams; |
2063 | |
2064 | /* The global malloc_state used for all non-"mspace" calls */ |
2065 | static struct malloc_state _gm_; |
2066 | #define gm (&_gm_) |
2067 | #define is_global(M) ((M) == &_gm_) |
2068 | #define is_initialized(M) ((M)->top != 0) |
2069 | |
2070 | /* -------------------------- system alloc setup ------------------------- */ |
2071 | |
2072 | /* Operations on mflags */ |
2073 | |
2074 | #define use_lock(M) ((M)->mflags & USE_LOCK_BIT) |
2075 | #define enable_lock(M) ((M)->mflags |= USE_LOCK_BIT) |
2076 | #define disable_lock(M) ((M)->mflags &= ~USE_LOCK_BIT) |
2077 | |
2078 | #define use_mmap(M) ((M)->mflags & USE_MMAP_BIT) |
2079 | #define enable_mmap(M) ((M)->mflags |= USE_MMAP_BIT) |
2080 | #define disable_mmap(M) ((M)->mflags &= ~USE_MMAP_BIT) |
2081 | |
2082 | #define use_noncontiguous(M) ((M)->mflags & USE_NONCONTIGUOUS_BIT) |
2083 | #define disable_contiguous(M) ((M)->mflags |= USE_NONCONTIGUOUS_BIT) |
2084 | |
2085 | #define set_lock(M,L)\ |
2086 | ((M)->mflags = (L)?\ |
2087 | ((M)->mflags | USE_LOCK_BIT) :\ |
2088 | ((M)->mflags & ~USE_LOCK_BIT)) |
2089 | |
2090 | /* page-align a size */ |
2091 | #define page_align(S)\ |
2092 | (((S) + (mparams.page_size)) & ~(mparams.page_size - SIZE_T_ONE)) |
2093 | |
2094 | /* granularity-align a size */ |
2095 | #define granularity_align(S)\ |
2096 | (((S) + (mparams.granularity)) & ~(mparams.granularity - SIZE_T_ONE)) |
2097 | |
2098 | #define is_page_aligned(S)\ |
2099 | (((size_t)(S) & (mparams.page_size - SIZE_T_ONE)) == 0) |
2100 | #define is_granularity_aligned(S)\ |
2101 | (((size_t)(S) & (mparams.granularity - SIZE_T_ONE)) == 0) |
2102 | |
2103 | /* True if segment S holds address A */ |
2104 | #define segment_holds(S, A)\ |
2105 | ((char*)(A) >= S->base && (char*)(A) < S->base + S->size) |
2106 | |
2107 | /* Return segment holding given address */ |
2108 | static msegmentptr segment_holding(mstate m, char* addr) { |
2109 | msegmentptr sp = &m->seg; |
2110 | for (;;) { |
2111 | if (addr >= sp->base && addr < sp->base + sp->size) |
2112 | return sp; |
2113 | if ((sp = sp->next) == 0) |
2114 | return 0; |
2115 | } |
2116 | } |
2117 | |
2118 | /* Return true if segment contains a segment link */ |
2119 | static int has_segment_link(mstate m, msegmentptr ss) { |
2120 | msegmentptr sp = &m->seg; |
2121 | for (;;) { |
2122 | if ((char*)sp >= ss->base && (char*)sp < ss->base + ss->size) |
2123 | return 1; |
2124 | if ((sp = sp->next) == 0) |
2125 | return 0; |
2126 | } |
2127 | } |
2128 | |
2129 | #ifndef MORECORE_CANNOT_TRIM |
2130 | #define should_trim(M,s) ((s) > (M)->trim_check) |
2131 | #else /* MORECORE_CANNOT_TRIM */ |
2132 | #define should_trim(M,s) (0) |
2133 | #endif /* MORECORE_CANNOT_TRIM */ |
2134 | |
2135 | /* |
2136 | TOP_FOOT_SIZE is padding at the end of a segment, including space |
2137 | that may be needed to place segment records and fenceposts when new |
2138 | noncontiguous segments are added. |
2139 | */ |
2140 | #define TOP_FOOT_SIZE\ |
2141 | (align_offset(chunk2mem(0))+pad_request(sizeof(struct malloc_segment))+MIN_CHUNK_SIZE) |
2142 | |
2143 | |
2144 | /* ------------------------------- Hooks -------------------------------- */ |
2145 | |
2146 | /* |
2147 | PREACTION should be defined to return 0 on success, and nonzero on |
2148 | failure. If you are not using locking, you can redefine these to do |
2149 | anything you like. |
2150 | */ |
2151 | |
2152 | #if USE_LOCKS |
2153 | |
2154 | /* Ensure locks are initialized */ |
2155 | #define GLOBALLY_INITIALIZE() (mparams.page_size == 0 && init_mparams()) |
2156 | |
2157 | #define PREACTION(M) ((GLOBALLY_INITIALIZE() || use_lock(M))? ACQUIRE_LOCK(&(M)->mutex) : 0) |
2158 | #define POSTACTION(M) { if (use_lock(M)) RELEASE_LOCK(&(M)->mutex); } |
2159 | #else /* USE_LOCKS */ |
2160 | |
2161 | #ifndef PREACTION |
2162 | #define PREACTION(M) (0) |
2163 | #endif /* PREACTION */ |
2164 | |
2165 | #ifndef POSTACTION |
2166 | #define POSTACTION(M) |
2167 | #endif /* POSTACTION */ |
2168 | |
2169 | #endif /* USE_LOCKS */ |
2170 | |
2171 | /* |
2172 | CORRUPTION_ERROR_ACTION is triggered upon detected bad addresses. |
2173 | USAGE_ERROR_ACTION is triggered on detected bad frees and |
2174 | reallocs. The argument p is an address that might have triggered the |
2175 | fault. It is ignored by the two predefined actions, but might be |
2176 | useful in custom actions that try to help diagnose errors. |
2177 | */ |
2178 | |
2179 | #if PROCEED_ON_ERROR |
2180 | |
2181 | /* A count of the number of corruption errors causing resets */ |
2182 | int malloc_corruption_error_count; |
2183 | |
2184 | /* default corruption action */ |
2185 | static void reset_on_error(mstate m); |
2186 | |
2187 | #define CORRUPTION_ERROR_ACTION(m) reset_on_error(m) |
2188 | #define USAGE_ERROR_ACTION(m, p) |
2189 | |
2190 | #else /* PROCEED_ON_ERROR */ |
2191 | |
2192 | #ifndef CORRUPTION_ERROR_ACTION |
2193 | #define CORRUPTION_ERROR_ACTION(m) ABORT |
2194 | #endif /* CORRUPTION_ERROR_ACTION */ |
2195 | |
2196 | #ifndef USAGE_ERROR_ACTION |
2197 | #define USAGE_ERROR_ACTION(m,p) ABORT |
2198 | #endif /* USAGE_ERROR_ACTION */ |
2199 | |
2200 | #endif /* PROCEED_ON_ERROR */ |
2201 | |
2202 | /* -------------------------- Debugging setup ---------------------------- */ |
2203 | |
2204 | #if ! DEBUG |
2205 | |
2206 | #define check_free_chunk(M,P) |
2207 | #define check_inuse_chunk(M,P) |
2208 | #define check_malloced_chunk(M,P,N) |
2209 | #define check_mmapped_chunk(M,P) |
2210 | #define check_malloc_state(M) |
2211 | #define check_top_chunk(M,P) |
2212 | |
2213 | #else /* DEBUG */ |
2214 | #define check_free_chunk(M,P) do_check_free_chunk(M,P) |
2215 | #define check_inuse_chunk(M,P) do_check_inuse_chunk(M,P) |
2216 | #define check_top_chunk(M,P) do_check_top_chunk(M,P) |
2217 | #define check_malloced_chunk(M,P,N) do_check_malloced_chunk(M,P,N) |
2218 | #define check_mmapped_chunk(M,P) do_check_mmapped_chunk(M,P) |
2219 | #define check_malloc_state(M) do_check_malloc_state(M) |
2220 | |
2221 | static void do_check_any_chunk(mstate m, mchunkptr p); |
2222 | static void do_check_top_chunk(mstate m, mchunkptr p); |
2223 | static void do_check_mmapped_chunk(mstate m, mchunkptr p); |
2224 | static void do_check_inuse_chunk(mstate m, mchunkptr p); |
2225 | static void do_check_free_chunk(mstate m, mchunkptr p); |
2226 | static void do_check_malloced_chunk(mstate m, void* mem, size_t s); |
2227 | static void do_check_tree(mstate m, tchunkptr t); |
2228 | static void do_check_treebin(mstate m, bindex_t i); |
2229 | static void do_check_smallbin(mstate m, bindex_t i); |
2230 | static void do_check_malloc_state(mstate m); |
2231 | static int bin_find(mstate m, mchunkptr x); |
2232 | static size_t traverse_and_check(mstate m); |
2233 | #endif /* DEBUG */ |
2234 | |
2235 | /* ---------------------------- Indexing Bins ---------------------------- */ |
2236 | |
2237 | #define is_small(s) (((s) >> SMALLBIN_SHIFT) < NSMALLBINS) |
2238 | #define small_index(s) ((s) >> SMALLBIN_SHIFT) |
2239 | #define small_index2size(i) ((i) << SMALLBIN_SHIFT) |
2240 | #define MIN_SMALL_INDEX (small_index(MIN_CHUNK_SIZE)) |
2241 | |
2242 | /* addressing by index. See above about smallbin repositioning */ |
2243 | #define smallbin_at(M, i) ((sbinptr)((char*)&((M)->smallbins[(i)<<1]))) |
2244 | #define treebin_at(M,i) (&((M)->treebins[i])) |
2245 | |
2246 | /* assign tree index for size S to variable I */ |
2247 | #if defined(__GNUC__) && defined(i386) |
2248 | #define compute_tree_index(S, I)\ |
2249 | {\ |
2250 | size_t X = S >> TREEBIN_SHIFT;\ |
2251 | if (X == 0)\ |
2252 | I = 0;\ |
2253 | else if (X > 0xFFFF)\ |
2254 | I = NTREEBINS-1;\ |
2255 | else {\ |
2256 | unsigned int K;\ |
2257 | __asm__("bsrl %1,%0\n\t" : "=r" (K) : "rm" (X));\ |
2258 | I = (bindex_t)((K << 1) + ((S >> (K + (TREEBIN_SHIFT-1)) & 1)));\ |
2259 | }\ |
2260 | } |
2261 | #else /* GNUC */ |
2262 | #define compute_tree_index(S, I)\ |
2263 | {\ |
2264 | size_t X = S >> TREEBIN_SHIFT;\ |
2265 | if (X == 0)\ |
2266 | I = 0;\ |
2267 | else if (X > 0xFFFF)\ |
2268 | I = NTREEBINS-1;\ |
2269 | else {\ |
2270 | unsigned int Y = (unsigned int)X;\ |
2271 | unsigned int N = ((Y - 0x100) >> 16) & 8;\ |
2272 | unsigned int K = (((Y <<= N) - 0x1000) >> 16) & 4;\ |
2273 | N += K;\ |
2274 | N += K = (((Y <<= K) - 0x4000) >> 16) & 2;\ |
2275 | K = 14 - N + ((Y <<= K) >> 15);\ |
2276 | I = (K << 1) + ((S >> (K + (TREEBIN_SHIFT-1)) & 1));\ |
2277 | }\ |
2278 | } |
2279 | #endif /* GNUC */ |
2280 | |
2281 | /* Bit representing maximum resolved size in a treebin at i */ |
2282 | #define bit_for_tree_index(i) \ |
2283 | (i == NTREEBINS-1)? (SIZE_T_BITSIZE-1) : (((i) >> 1) + TREEBIN_SHIFT - 2) |
2284 | |
2285 | /* Shift placing maximum resolved bit in a treebin at i as sign bit */ |
2286 | #define leftshift_for_tree_index(i) \ |
2287 | ((i == NTREEBINS-1)? 0 : \ |
2288 | ((SIZE_T_BITSIZE-SIZE_T_ONE) - (((i) >> 1) + TREEBIN_SHIFT - 2))) |
2289 | |
2290 | /* The size of the smallest chunk held in bin with index i */ |
2291 | #define minsize_for_tree_index(i) \ |
2292 | ((SIZE_T_ONE << (((i) >> 1) + TREEBIN_SHIFT)) | \ |
2293 | (((size_t)((i) & SIZE_T_ONE)) << (((i) >> 1) + TREEBIN_SHIFT - 1))) |
2294 | |
2295 | |
2296 | /* ------------------------ Operations on bin maps ----------------------- */ |
2297 | |
2298 | /* bit corresponding to given index */ |
2299 | #define idx2bit(i) ((binmap_t)(1) << (i)) |
2300 | |
2301 | /* Mark/Clear bits with given index */ |
2302 | #define mark_smallmap(M,i) ((M)->smallmap |= idx2bit(i)) |
2303 | #define clear_smallmap(M,i) ((M)->smallmap &= ~idx2bit(i)) |
2304 | #define smallmap_is_marked(M,i) ((M)->smallmap & idx2bit(i)) |
2305 | |
2306 | #define mark_treemap(M,i) ((M)->treemap |= idx2bit(i)) |
2307 | #define clear_treemap(M,i) ((M)->treemap &= ~idx2bit(i)) |
2308 | #define treemap_is_marked(M,i) ((M)->treemap & idx2bit(i)) |
2309 | |
2310 | /* index corresponding to given bit */ |
2311 | |
2312 | #if defined(__GNUC__) && defined(i386) |
2313 | #define compute_bit2idx(X, I)\ |
2314 | {\ |
2315 | unsigned int J;\ |
2316 | __asm__("bsfl %1,%0\n\t" : "=r" (J) : "rm" (X));\ |
2317 | I = (bindex_t)J;\ |
2318 | } |
2319 | |
2320 | #else /* GNUC */ |
2321 | #if USE_BUILTIN_FFS |
2322 | #define compute_bit2idx(X, I) I = ffs(X)-1 |
2323 | |
2324 | #else /* USE_BUILTIN_FFS */ |
2325 | #define compute_bit2idx(X, I)\ |
2326 | {\ |
2327 | unsigned int Y = X - 1;\ |
2328 | unsigned int K = Y >> (16-4) & 16;\ |
2329 | unsigned int N = K; Y >>= K;\ |
2330 | N += K = Y >> (8-3) & 8; Y >>= K;\ |
2331 | N += K = Y >> (4-2) & 4; Y >>= K;\ |
2332 | N += K = Y >> (2-1) & 2; Y >>= K;\ |
2333 | N += K = Y >> (1-0) & 1; Y >>= K;\ |
2334 | I = (bindex_t)(N + Y);\ |
2335 | } |
2336 | #endif /* USE_BUILTIN_FFS */ |
2337 | #endif /* GNUC */ |
2338 | |
2339 | /* isolate the least set bit of a bitmap */ |
2340 | #define least_bit(x) ((x) & -(x)) |
2341 | |
2342 | /* mask with all bits to left of least bit of x on */ |
2343 | #define left_bits(x) ((x<<1) | -(x<<1)) |
2344 | |
2345 | /* mask with all bits to left of or equal to least bit of x on */ |
2346 | #define same_or_left_bits(x) ((x) | -(x)) |
2347 | |
2348 | |
2349 | /* ----------------------- Runtime Check Support ------------------------- */ |
2350 | |
2351 | /* |
2352 | For security, the main invariant is that malloc/free/etc never |
2353 | writes to a static address other than malloc_state, unless static |
2354 | malloc_state itself has been corrupted, which cannot occur via |
2355 | malloc (because of these checks). In essence this means that we |
2356 | believe all pointers, sizes, maps etc held in malloc_state, but |
2357 | check all of those linked or offsetted from other embedded data |
2358 | structures. These checks are interspersed with main code in a way |
2359 | that tends to minimize their run-time cost. |
2360 | |
2361 | When FOOTERS is defined, in addition to range checking, we also |
2362 | verify footer fields of inuse chunks, which can be used guarantee |
2363 | that the mstate controlling malloc/free is intact. This is a |
2364 | streamlined version of the approach described by William Robertson |
2365 | et al in "Run-time Detection of Heap-based Overflows" LISA'03 |
2366 | http://www.usenix.org/events/lisa03/tech/robertson.html The footer |
2367 | of an inuse chunk holds the xor of its mstate and a random seed, |
2368 | that is checked upon calls to free() and realloc(). This is |
2369 | (probablistically) unguessable from outside the program, but can be |
2370 | computed by any code successfully malloc'ing any chunk, so does not |
2371 | itself provide protection against code that has already broken |
2372 | security through some other means. Unlike Robertson et al, we |
2373 | always dynamically check addresses of all offset chunks (previous, |
2374 | next, etc). This turns out to be cheaper than relying on hashes. |
2375 | */ |
2376 | |
2377 | #if !INSECURE |
2378 | /* Check if address a is at least as high as any from MORECORE or MMAP */ |
2379 | #define ok_address(M, a) ((char*)(a) >= (M)->least_addr) |
2380 | /* Check if address of next chunk n is higher than base chunk p */ |
2381 | #define ok_next(p, n) ((char*)(p) < (char*)(n)) |
2382 | /* Check if p has its cinuse bit on */ |
2383 | #define ok_cinuse(p) cinuse(p) |
2384 | /* Check if p has its pinuse bit on */ |
2385 | #define ok_pinuse(p) pinuse(p) |
2386 | |
2387 | #else /* !INSECURE */ |
2388 | #define ok_address(M, a) (1) |
2389 | #define ok_next(b, n) (1) |
2390 | #define ok_cinuse(p) (1) |
2391 | #define ok_pinuse(p) (1) |
2392 | #endif /* !INSECURE */ |
2393 | |
2394 | #if (FOOTERS && !INSECURE) |
2395 | /* Check if (alleged) mstate m has expected magic field */ |
2396 | #define ok_magic(M) ((M)->magic == mparams.magic) |
2397 | #else /* (FOOTERS && !INSECURE) */ |
2398 | #define ok_magic(M) (1) |
2399 | #endif /* (FOOTERS && !INSECURE) */ |
2400 | |
2401 | |
2402 | /* In gcc, use __builtin_expect to minimize impact of checks */ |
2403 | #if !INSECURE |
2404 | #if defined(__GNUC__) && __GNUC__ >= 3 |
2405 | #define RTCHECK(e) __builtin_expect(e, 1) |
2406 | #else /* GNUC */ |
2407 | #define RTCHECK(e) (e) |
2408 | #endif /* GNUC */ |
2409 | #else /* !INSECURE */ |
2410 | #define RTCHECK(e) (1) |
2411 | #endif /* !INSECURE */ |
2412 | |
2413 | /* macros to set up inuse chunks with or without footers */ |
2414 | |
2415 | #if !FOOTERS |
2416 | |
2417 | #define mark_inuse_foot(M,p,s) |
2418 | |
2419 | /* Set cinuse bit and pinuse bit of next chunk */ |
2420 | #define set_inuse(M,p,s)\ |
2421 | ((p)->head = (((p)->head & PINUSE_BIT)|s|CINUSE_BIT),\ |
2422 | ((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT) |
2423 | |
2424 | /* Set cinuse and pinuse of this chunk and pinuse of next chunk */ |
2425 | #define set_inuse_and_pinuse(M,p,s)\ |
2426 | ((p)->head = (s|PINUSE_BIT|CINUSE_BIT),\ |
2427 | ((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT) |
2428 | |
2429 | /* Set size, cinuse and pinuse bit of this chunk */ |
2430 | #define set_size_and_pinuse_of_inuse_chunk(M, p, s)\ |
2431 | ((p)->head = (s|PINUSE_BIT|CINUSE_BIT)) |
2432 | |
2433 | #else /* FOOTERS */ |
2434 | |
2435 | /* Set foot of inuse chunk to be xor of mstate and seed */ |
2436 | #define mark_inuse_foot(M,p,s)\ |
2437 | (((mchunkptr)((char*)(p) + (s)))->prev_foot = ((size_t)(M) ^ mparams.magic)) |
2438 | |
2439 | #define get_mstate_for(p)\ |
2440 | ((mstate)(((mchunkptr)((char*)(p) +\ |
2441 | (chunksize(p))))->prev_foot ^ mparams.magic)) |
2442 | |
2443 | #define set_inuse(M,p,s)\ |
2444 | ((p)->head = (((p)->head & PINUSE_BIT)|s|CINUSE_BIT),\ |
2445 | (((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT), \ |
2446 | mark_inuse_foot(M,p,s)) |
2447 | |
2448 | #define set_inuse_and_pinuse(M,p,s)\ |
2449 | ((p)->head = (s|PINUSE_BIT|CINUSE_BIT),\ |
2450 | (((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT),\ |
2451 | mark_inuse_foot(M,p,s)) |
2452 | |
2453 | #define set_size_and_pinuse_of_inuse_chunk(M, p, s)\ |
2454 | ((p)->head = (s|PINUSE_BIT|CINUSE_BIT),\ |
2455 | mark_inuse_foot(M, p, s)) |
2456 | |
2457 | #endif /* !FOOTERS */ |
2458 | |
2459 | /* ---------------------------- setting mparams -------------------------- */ |
2460 | |
2461 | /* Initialize mparams */ |
2462 | static int init_mparams(void) { |
2463 | if (mparams.page_size == 0) { |
2464 | size_t s; |
2465 | |
2466 | mparams.mmap_threshold = DEFAULT_MMAP_THRESHOLD; |
2467 | mparams.trim_threshold = DEFAULT_TRIM_THRESHOLD; |
2468 | #if MORECORE_CONTIGUOUS |
2469 | mparams.default_mflags = USE_LOCK_BIT|USE_MMAP_BIT; |
2470 | #else /* MORECORE_CONTIGUOUS */ |
2471 | mparams.default_mflags = USE_LOCK_BIT|USE_MMAP_BIT|USE_NONCONTIGUOUS_BIT; |
2472 | #endif /* MORECORE_CONTIGUOUS */ |
2473 | |
2474 | #if (FOOTERS && !INSECURE) |
2475 | { |
2476 | #if USE_DEV_RANDOM |
2477 | int fd; |
2478 | unsigned char buf[sizeof(size_t)]; |
2479 | /* Try to use /dev/urandom, else fall back on using time */ |
2480 | if ((fd = open("/dev/urandom", O_RDONLY)) >= 0 && |
2481 | read(fd, buf, sizeof(buf)) == sizeof(buf)) { |
2482 | s = *((size_t *) buf); |
2483 | close(fd); |
2484 | } |
2485 | else |
2486 | #endif /* USE_DEV_RANDOM */ |
2487 | s = (size_t)(time(0) ^ (size_t)0x55555555U); |
2488 | |
2489 | s |= (size_t)8U; /* ensure nonzero */ |
2490 | s &= ~(size_t)7U; /* improve chances of fault for bad values */ |
2491 | |
2492 | } |
2493 | #else /* (FOOTERS && !INSECURE) */ |
2494 | s = (size_t)0x58585858U; |
2495 | #endif /* (FOOTERS && !INSECURE) */ |
2496 | ACQUIRE_MAGIC_INIT_LOCK(); |
2497 | if (mparams.magic == 0) { |
2498 | mparams.magic = s; |
2499 | /* Set up lock for main malloc area */ |
2500 | INITIAL_LOCK(&gm->mutex); |
2501 | gm->mflags = mparams.default_mflags; |
2502 | } |
2503 | RELEASE_MAGIC_INIT_LOCK(); |
2504 | |
2505 | #ifndef WIN32 |
2506 | mparams.page_size = malloc_getpagesize; |
2507 | mparams.granularity = ((DEFAULT_GRANULARITY != 0)? |
2508 | DEFAULT_GRANULARITY : mparams.page_size); |
2509 | #else /* WIN32 */ |
2510 | { |
2511 | SYSTEM_INFO system_info; |
2512 | GetSystemInfo(&system_info); |
2513 | mparams.page_size = system_info.dwPageSize; |
2514 | mparams.granularity = system_info.dwAllocationGranularity; |
2515 | } |
2516 | #endif /* WIN32 */ |
2517 | |
2518 | /* Sanity-check configuration: |
2519 | size_t must be unsigned and as wide as pointer type. |
2520 | ints must be at least 4 bytes. |
2521 | alignment must be at least 8. |
2522 | Alignment, min chunk size, and page size must all be powers of 2. |
2523 | */ |
2524 | if ((sizeof(size_t) != sizeof(char*)) || |
2525 | (MAX_SIZE_T < MIN_CHUNK_SIZE) || |
2526 | (sizeof(int) < 4) || |
2527 | (MALLOC_ALIGNMENT < (size_t)8U) || |
2528 | ((MALLOC_ALIGNMENT & (MALLOC_ALIGNMENT-SIZE_T_ONE)) != 0) || |
2529 | ((MCHUNK_SIZE & (MCHUNK_SIZE-SIZE_T_ONE)) != 0) || |
2530 | ((mparams.granularity & (mparams.granularity-SIZE_T_ONE)) != 0) || |
2531 | ((mparams.page_size & (mparams.page_size-SIZE_T_ONE)) != 0)) |
2532 | ABORT; |
2533 | } |
2534 | return 0; |
2535 | } |
2536 | |
2537 | /* support for mallopt */ |
2538 | static int change_mparam(int param_number, int value) { |
2539 | size_t val = (size_t)value; |
2540 | init_mparams(); |
2541 | switch(param_number) { |
2542 | case M_TRIM_THRESHOLD: |
2543 | mparams.trim_threshold = val; |
2544 | return 1; |
2545 | case M_GRANULARITY: |
2546 | if (val >= mparams.page_size && ((val & (val-1)) == 0)) { |
2547 | mparams.granularity = val; |
2548 | return 1; |
2549 | } |
2550 | else |
2551 | return 0; |
2552 | case M_MMAP_THRESHOLD: |
2553 | mparams.mmap_threshold = val; |
2554 | return 1; |
2555 | default: |
2556 | return 0; |
2557 | } |
2558 | } |
2559 | |
2560 | #if DEBUG |
2561 | /* ------------------------- Debugging Support --------------------------- */ |
2562 | |
2563 | /* Check properties of any chunk, whether free, inuse, mmapped etc */ |
2564 | static void do_check_any_chunk(mstate m, mchunkptr p) { |
2565 | assert((is_aligned(chunk2mem(p))) || (p->head == FENCEPOST_HEAD)); |
2566 | assert(ok_address(m, p)); |
2567 | } |
2568 | |
2569 | /* Check properties of top chunk */ |
2570 | static void do_check_top_chunk(mstate m, mchunkptr p) { |
2571 | msegmentptr sp = segment_holding(m, (char*)p); |
2572 | size_t sz = chunksize(p); |
2573 | assert(sp != 0); |
2574 | assert((is_aligned(chunk2mem(p))) || (p->head == FENCEPOST_HEAD)); |
2575 | assert(ok_address(m, p)); |
2576 | assert(sz == m->topsize); |
2577 | assert(sz > 0); |
2578 | assert(sz == ((sp->base + sp->size) - (char*)p) - TOP_FOOT_SIZE); |
2579 | assert(pinuse(p)); |
2580 | assert(!next_pinuse(p)); |
2581 | } |
2582 | |
2583 | /* Check properties of (inuse) mmapped chunks */ |
2584 | static void do_check_mmapped_chunk(mstate m, mchunkptr p) { |
2585 | size_t sz = chunksize(p); |
2586 | size_t len = (sz + (p->prev_foot & ~IS_MMAPPED_BIT) + MMAP_FOOT_PAD); |
2587 | assert(is_mmapped(p)); |
2588 | assert(use_mmap(m)); |
2589 | assert((is_aligned(chunk2mem(p))) || (p->head == FENCEPOST_HEAD)); |
2590 | assert(ok_address(m, p)); |
2591 | assert(!is_small(sz)); |
2592 | assert((len & (mparams.page_size-SIZE_T_ONE)) == 0); |
2593 | assert(chunk_plus_offset(p, sz)->head == FENCEPOST_HEAD); |
2594 | assert(chunk_plus_offset(p, sz+SIZE_T_SIZE)->head == 0); |
2595 | } |
2596 | |
2597 | /* Check properties of inuse chunks */ |
2598 | static void do_check_inuse_chunk(mstate m, mchunkptr p) { |
2599 | do_check_any_chunk(m, p); |
2600 | assert(cinuse(p)); |
2601 | assert(next_pinuse(p)); |
2602 | /* If not pinuse and not mmapped, previous chunk has OK offset */ |
2603 | assert(is_mmapped(p) || pinuse(p) || next_chunk(prev_chunk(p)) == p); |
2604 | if (is_mmapped(p)) |
2605 | do_check_mmapped_chunk(m, p); |
2606 | } |
2607 | |
2608 | /* Check properties of free chunks */ |
2609 | static void do_check_free_chunk(mstate m, mchunkptr p) { |
2610 | size_t sz = p->head & ~(PINUSE_BIT|CINUSE_BIT); |
2611 | mchunkptr next = chunk_plus_offset(p, sz); |
2612 | do_check_any_chunk(m, p); |
2613 | assert(!cinuse(p)); |
2614 | assert(!next_pinuse(p)); |
2615 | assert (!is_mmapped(p)); |
2616 | if (p != m->dv && p != m->top) { |
2617 | if (sz >= MIN_CHUNK_SIZE) { |
2618 | assert((sz & CHUNK_ALIGN_MASK) == 0); |
2619 | assert(is_aligned(chunk2mem(p))); |
2620 | assert(next->prev_foot == sz); |
2621 | assert(pinuse(p)); |
2622 | assert (next == m->top || cinuse(next)); |
2623 | assert(p->fd->bk == p); |
2624 | assert(p->bk->fd == p); |
2625 | } |
2626 | else /* markers are always of size SIZE_T_SIZE */ |
2627 | assert(sz == SIZE_T_SIZE); |
2628 | } |
2629 | } |
2630 | |
2631 | /* Check properties of malloced chunks at the point they are malloced */ |
2632 | static void do_check_malloced_chunk(mstate m, void* mem, size_t s) { |
2633 | if (mem != 0) { |
2634 | mchunkptr p = mem2chunk(mem); |
2635 | size_t sz = p->head & ~(PINUSE_BIT|CINUSE_BIT); |
2636 | do_check_inuse_chunk(m, p); |
2637 | assert((sz & CHUNK_ALIGN_MASK) == 0); |
2638 | assert(sz >= MIN_CHUNK_SIZE); |
2639 | assert(sz >= s); |
2640 | /* unless mmapped, size is less than MIN_CHUNK_SIZE more than request */ |
2641 | assert(is_mmapped(p) || sz < (s + MIN_CHUNK_SIZE)); |
2642 | } |
2643 | } |
2644 | |
2645 | /* Check a tree and its subtrees. */ |
2646 | static void do_check_tree(mstate m, tchunkptr t) { |
2647 | tchunkptr head = 0; |
2648 | tchunkptr u = t; |
2649 | bindex_t tindex = t->index; |
2650 | size_t tsize = chunksize(t); |
2651 | bindex_t idx; |
2652 | compute_tree_index(tsize, idx); |
2653 | assert(tindex == idx); |
2654 | assert(tsize >= MIN_LARGE_SIZE); |
2655 | assert(tsize >= minsize_for_tree_index(idx)); |
2656 | assert((idx == NTREEBINS-1) || (tsize < minsize_for_tree_index((idx+1)))); |
2657 | |
2658 | do { /* traverse through chain of same-sized nodes */ |
2659 | do_check_any_chunk(m, ((mchunkptr)u)); |
2660 | assert(u->index == tindex); |
2661 | assert(chunksize(u) == tsize); |
2662 | assert(!cinuse(u)); |
2663 | assert(!next_pinuse(u)); |
2664 | assert(u->fd->bk == u); |
2665 | assert(u->bk->fd == u); |
2666 | if (u->parent == 0) { |
2667 | assert(u->child[0] == 0); |
2668 | assert(u->child[1] == 0); |
2669 | } |
2670 | else { |
2671 | assert(head == 0); /* only one node on chain has parent */ |
2672 | head = u; |
2673 | assert(u->parent != u); |
2674 | assert (u->parent->child[0] == u || |
2675 | u->parent->child[1] == u || |
2676 | *((tbinptr*)(u->parent)) == u); |
2677 | if (u->child[0] != 0) { |
2678 | assert(u->child[0]->parent == u); |
2679 | assert(u->child[0] != u); |
2680 | do_check_tree(m, u->child[0]); |
2681 | } |
2682 | if (u->child[1] != 0) { |
2683 | assert(u->child[1]->parent == u); |
2684 | assert(u->child[1] != u); |
2685 | do_check_tree(m, u->child[1]); |
2686 | } |
2687 | if (u->child[0] != 0 && u->child[1] != 0) { |
2688 | assert(chunksize(u->child[0]) < chunksize(u->child[1])); |
2689 | } |
2690 | } |
2691 | u = u->fd; |
2692 | } while (u != t); |
2693 | assert(head != 0); |
2694 | } |
2695 | |
2696 | /* Check all the chunks in a treebin. */ |
2697 | static void do_check_treebin(mstate m, bindex_t i) { |
2698 | tbinptr* tb = treebin_at(m, i); |
2699 | tchunkptr t = *tb; |
2700 | int empty = (m->treemap & (1U << i)) == 0; |
2701 | if (t == 0) |
2702 | assert(empty); |
2703 | if (!empty) |
2704 | do_check_tree(m, t); |
2705 | } |
2706 | |
2707 | /* Check all the chunks in a smallbin. */ |
2708 | static void do_check_smallbin(mstate m, bindex_t i) { |
2709 | sbinptr b = smallbin_at(m, i); |
2710 | mchunkptr p = b->bk; |
2711 | unsigned int empty = (m->smallmap & (1U << i)) == 0; |
2712 | if (p == b) |
2713 | assert(empty); |
2714 | if (!empty) { |
2715 | for (; p != b; p = p->bk) { |
2716 | size_t size = chunksize(p); |
2717 | mchunkptr q; |
2718 | /* each chunk claims to be free */ |
2719 | do_check_free_chunk(m, p); |
2720 | /* chunk belongs in bin */ |
2721 | assert(small_index(size) == i); |
2722 | assert(p->bk == b || chunksize(p->bk) == chunksize(p)); |
2723 | /* chunk is followed by an inuse chunk */ |
2724 | q = next_chunk(p); |
2725 | if (q->head != FENCEPOST_HEAD) |
2726 | do_check_inuse_chunk(m, q); |
2727 | } |
2728 | } |
2729 | } |
2730 | |
2731 | /* Find x in a bin. Used in other check functions. */ |
2732 | static int bin_find(mstate m, mchunkptr x) { |
2733 | size_t size = chunksize(x); |
2734 | if (is_small(size)) { |
2735 | bindex_t sidx = small_index(size); |
2736 | sbinptr b = smallbin_at(m, sidx); |
2737 | if (smallmap_is_marked(m, sidx)) { |
2738 | mchunkptr p = b; |
2739 | do { |
2740 | if (p == x) |
2741 | return 1; |
2742 | } while ((p = p->fd) != b); |
2743 | } |
2744 | } |
2745 | else { |
2746 | bindex_t tidx; |
2747 | compute_tree_index(size, tidx); |
2748 | if (treemap_is_marked(m, tidx)) { |
2749 | tchunkptr t = *treebin_at(m, tidx); |
2750 | size_t sizebits = size << leftshift_for_tree_index(tidx); |
2751 | while (t != 0 && chunksize(t) != size) { |
2752 | t = t->child[(sizebits >> (SIZE_T_BITSIZE-SIZE_T_ONE)) & 1]; |
2753 | sizebits <<= 1; |
2754 | } |
2755 | if (t != 0) { |
2756 | tchunkptr u = t; |
2757 | do { |
2758 | if (u == (tchunkptr)x) |
2759 | return 1; |
2760 | } while ((u = u->fd) != t); |
2761 | } |
2762 | } |
2763 | } |
2764 | return 0; |
2765 | } |
2766 | |
2767 | /* Traverse each chunk and check it; return total */ |
2768 | static size_t traverse_and_check(mstate m) { |
2769 | size_t sum = 0; |
2770 | if (is_initialized(m)) { |
2771 | msegmentptr s = &m->seg; |
2772 | sum += m->topsize + TOP_FOOT_SIZE; |
2773 | while (s != 0) { |
2774 | mchunkptr q = align_as_chunk(s->base); |
2775 | mchunkptr lastq = 0; |
2776 | assert(pinuse(q)); |
2777 | while (segment_holds(s, q) && |
2778 | q != m->top && q->head != FENCEPOST_HEAD) { |
2779 | sum += chunksize(q); |
2780 | if (cinuse(q)) { |
2781 | assert(!bin_find(m, q)); |
2782 | do_check_inuse_chunk(m, q); |
2783 | } |
2784 | else { |
2785 | assert(q == m->dv || bin_find(m, q)); |
2786 | assert(lastq == 0 || cinuse(lastq)); /* Not 2 consecutive free */ |
2787 | do_check_free_chunk(m, q); |
2788 | } |
2789 | lastq = q; |
2790 | q = next_chunk(q); |
2791 | } |
2792 | s = s->next; |
2793 | } |
2794 | } |
2795 | return sum; |
2796 | } |
2797 | |
2798 | /* Check all properties of malloc_state. */ |
2799 | static void do_check_malloc_state(mstate m) { |
2800 | bindex_t i; |
2801 | size_t total; |
2802 | /* check bins */ |
2803 | for (i = 0; i < NSMALLBINS; ++i) |
2804 | do_check_smallbin(m, i); |
2805 | for (i = 0; i < NTREEBINS; ++i) |
2806 | do_check_treebin(m, i); |
2807 | |
2808 | if (m->dvsize != 0) { /* check dv chunk */ |
2809 | do_check_any_chunk(m, m->dv); |
2810 | assert(m->dvsize == chunksize(m->dv)); |
2811 | assert(m->dvsize >= MIN_CHUNK_SIZE); |
2812 | assert(bin_find(m, m->dv) == 0); |
2813 | } |
2814 | |
2815 | if (m->top != 0) { /* check top chunk */ |
2816 | do_check_top_chunk(m, m->top); |
2817 | assert(m->topsize == chunksize(m->top)); |
2818 | assert(m->topsize > 0); |
2819 | assert(bin_find(m, m->top) == 0); |
2820 | } |
2821 | |
2822 | total = traverse_and_check(m); |
2823 | assert(total <= m->footprint); |
2824 | assert(m->footprint <= m->max_footprint); |
2825 | } |
2826 | #endif /* DEBUG */ |
2827 | |
2828 | /* ----------------------------- statistics ------------------------------ */ |
2829 | |
2830 | #if !NO_MALLINFO |
2831 | static struct mallinfo internal_mallinfo(mstate m) { |
2832 | struct mallinfo nm = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; |
2833 | if (!PREACTION(m)) { |
2834 | check_malloc_state(m); |
2835 | if (is_initialized(m)) { |
2836 | size_t nfree = SIZE_T_ONE; /* top always free */ |
2837 | size_t mfree = m->topsize + TOP_FOOT_SIZE; |
2838 | size_t sum = mfree; |
2839 | msegmentptr s = &m->seg; |
2840 | while (s != 0) { |
2841 | mchunkptr q = align_as_chunk(s->base); |
2842 | while (segment_holds(s, q) && |
2843 | q != m->top && q->head != FENCEPOST_HEAD) { |
2844 | size_t sz = chunksize(q); |
2845 | sum += sz; |
2846 | if (!cinuse(q)) { |
2847 | mfree += sz; |
2848 | ++nfree; |
2849 | } |
2850 | q = next_chunk(q); |
2851 | } |
2852 | s = s->next; |
2853 | } |
2854 | |
2855 | nm.arena = sum; |
2856 | nm.ordblks = nfree; |
2857 | nm.hblkhd = m->footprint - sum; |
2858 | nm.usmblks = m->max_footprint; |
2859 | nm.uordblks = m->footprint - mfree; |
2860 | nm.fordblks = mfree; |
2861 | nm.keepcost = m->topsize; |
2862 | } |
2863 | |
2864 | POSTACTION(m); |
2865 | } |
2866 | return nm; |
2867 | } |
2868 | #endif /* !NO_MALLINFO */ |
2869 | |
2870 | static void internal_malloc_stats(mstate m) { |
2871 | if (!PREACTION(m)) { |
2872 | size_t maxfp = 0; |
2873 | size_t fp = 0; |
2874 | size_t used = 0; |
2875 | check_malloc_state(m); |
2876 | if (is_initialized(m)) { |
2877 | msegmentptr s = &m->seg; |
2878 | maxfp = m->max_footprint; |
2879 | fp = m->footprint; |
2880 | used = fp - (m->topsize + TOP_FOOT_SIZE); |
2881 | |
2882 | while (s != 0) { |
2883 | mchunkptr q = align_as_chunk(s->base); |
2884 | while (segment_holds(s, q) && |
2885 | q != m->top && q->head != FENCEPOST_HEAD) { |
2886 | if (!cinuse(q)) |
2887 | used -= chunksize(q); |
2888 | q = next_chunk(q); |
2889 | } |
2890 | s = s->next; |
2891 | } |
2892 | } |
2893 | |
2894 | #ifndef LACKS_STDIO_H |
2895 | fprintf(stderr, "max system bytes = %10lu\n", (unsigned long)(maxfp)); |
2896 | fprintf(stderr, "system bytes = %10lu\n", (unsigned long)(fp)); |
2897 | fprintf(stderr, "in use bytes = %10lu\n", (unsigned long)(used)); |
2898 | #endif |
2899 | |
2900 | POSTACTION(m); |
2901 | } |
2902 | } |
2903 | |
2904 | /* ----------------------- Operations on smallbins ----------------------- */ |
2905 | |
2906 | /* |
2907 | Various forms of linking and unlinking are defined as macros. Even |
2908 | the ones for trees, which are very long but have very short typical |
2909 | paths. This is ugly but reduces reliance on inlining support of |
2910 | compilers. |
2911 | */ |
2912 | |
2913 | /* Link a free chunk into a smallbin */ |
2914 | #define insert_small_chunk(M, P, S) {\ |
2915 | bindex_t I = small_index(S);\ |
2916 | mchunkptr B = smallbin_at(M, I);\ |
2917 | mchunkptr F = B;\ |
2918 | assert(S >= MIN_CHUNK_SIZE);\ |
2919 | if (!smallmap_is_marked(M, I))\ |
2920 | mark_smallmap(M, I);\ |
2921 | else if (RTCHECK(ok_address(M, B->fd)))\ |
2922 | F = B->fd;\ |
2923 | else {\ |
2924 | CORRUPTION_ERROR_ACTION(M);\ |
2925 | }\ |
2926 | B->fd = P;\ |
2927 | F->bk = P;\ |
2928 | P->fd = F;\ |
2929 | P->bk = B;\ |
2930 | } |
2931 | |
2932 | /* Unlink a chunk from a smallbin */ |
2933 | #define unlink_small_chunk(M, P, S) {\ |
2934 | mchunkptr F = P->fd;\ |
2935 | mchunkptr B = P->bk;\ |
2936 | bindex_t I = small_index(S);\ |
2937 | assert(P != B);\ |
2938 | assert(P != F);\ |
2939 | assert(chunksize(P) == small_index2size(I));\ |
2940 | if (F == B)\ |
2941 | clear_smallmap(M, I);\ |
2942 | else if (RTCHECK((F == smallbin_at(M,I) || ok_address(M, F)) &&\ |
2943 | (B == smallbin_at(M,I) || ok_address(M, B)))) {\ |
2944 | F->bk = B;\ |
2945 | B->fd = F;\ |
2946 | }\ |
2947 | else {\ |
2948 | CORRUPTION_ERROR_ACTION(M);\ |
2949 | }\ |
2950 | } |
2951 | |
2952 | /* Unlink the first chunk from a smallbin */ |
2953 | #define unlink_first_small_chunk(M, B, P, I) {\ |
2954 | mchunkptr F = P->fd;\ |
2955 | assert(P != B);\ |
2956 | assert(P != F);\ |
2957 | assert(chunksize(P) == small_index2size(I));\ |
2958 | if (B == F)\ |
2959 | clear_smallmap(M, I);\ |
2960 | else if (RTCHECK(ok_address(M, F))) {\ |
2961 | B->fd = F;\ |
2962 | F->bk = B;\ |
2963 | }\ |
2964 | else {\ |
2965 | CORRUPTION_ERROR_ACTION(M);\ |
2966 | }\ |
2967 | } |
2968 | |
2969 | /* Replace dv node, binning the old one */ |
2970 | /* Used only when dvsize known to be small */ |
2971 | #define replace_dv(M, P, S) {\ |
2972 | size_t DVS = M->dvsize;\ |
2973 | if (DVS != 0) {\ |
2974 | mchunkptr DV = M->dv;\ |
2975 | assert(is_small(DVS));\ |
2976 | insert_small_chunk(M, DV, DVS);\ |
2977 | }\ |
2978 | M->dvsize = S;\ |
2979 | M->dv = P;\ |
2980 | } |
2981 | |
2982 | /* ------------------------- Operations on trees ------------------------- */ |
2983 | |
2984 | /* Insert chunk into tree */ |
2985 | #define insert_large_chunk(M, X, S) {\ |
2986 | tbinptr* H;\ |
2987 | bindex_t I;\ |
2988 | compute_tree_index(S, I);\ |
2989 | H = treebin_at(M, I);\ |
2990 | X->index = I;\ |
2991 | X->child[0] = X->child[1] = 0;\ |
2992 | if (!treemap_is_marked(M, I)) {\ |
2993 | mark_treemap(M, I);\ |
2994 | *H = X;\ |
2995 | X->parent = (tchunkptr)H;\ |
2996 | X->fd = X->bk = X;\ |
2997 | }\ |
2998 | else {\ |
2999 | tchunkptr T = *H;\ |
3000 | size_t K = S << leftshift_for_tree_index(I);\ |
3001 | for (;;) {\ |
3002 | if (chunksize(T) != S) {\ |
3003 | tchunkptr* C = &(T->child[(K >> (SIZE_T_BITSIZE-SIZE_T_ONE)) & 1]);\ |
3004 | K <<= 1;\ |
3005 | if (*C != 0)\ |
3006 | T = *C;\ |
3007 | else if (RTCHECK(ok_address(M, C))) {\ |
3008 | *C = X;\ |
3009 | X->parent = T;\ |
3010 | X->fd = X->bk = X;\ |
3011 | break;\ |
3012 | }\ |
3013 | else {\ |
3014 | CORRUPTION_ERROR_ACTION(M);\ |
3015 | break;\ |
3016 | }\ |
3017 | }\ |
3018 | else {\ |
3019 | tchunkptr F = T->fd;\ |
3020 | if (RTCHECK(ok_address(M, T) && ok_address(M, F))) {\ |
3021 | T->fd = F->bk = X;\ |
3022 | X->fd = F;\ |
3023 | X->bk = T;\ |
3024 | X->parent = 0;\ |
3025 | break;\ |
3026 | }\ |
3027 | else {\ |
3028 | CORRUPTION_ERROR_ACTION(M);\ |
3029 | break;\ |
3030 | }\ |
3031 | }\ |
3032 | }\ |
3033 | }\ |
3034 | } |
3035 | |
3036 | /* |
3037 | Unlink steps: |
3038 | |
3039 | 1. If x is a chained node, unlink it from its same-sized fd/bk links |
3040 | and choose its bk node as its replacement. |
3041 | 2. If x was the last node of its size, but not a leaf node, it must |
3042 | be replaced with a leaf node (not merely one with an open left or |
3043 | right), to make sure that lefts and rights of descendents |
3044 | correspond properly to bit masks. We use the rightmost descendent |
3045 | of x. We could use any other leaf, but this is easy to locate and |
3046 | tends to counteract removal of leftmosts elsewhere, and so keeps |
3047 | paths shorter than minimally guaranteed. This doesn't loop much |
3048 | because on average a node in a tree is near the bottom. |
3049 | 3. If x is the base of a chain (i.e., has parent links) relink |
3050 | x's parent and children to x's replacement (or null if none). |
3051 | */ |
3052 | |
3053 | #define unlink_large_chunk(M, X) {\ |
3054 | tchunkptr XP = X->parent;\ |
3055 | tchunkptr R;\ |
3056 | if (X->bk != X) {\ |
3057 | tchunkptr F = X->fd;\ |
3058 | R = X->bk;\ |
3059 | if (RTCHECK(ok_address(M, F))) {\ |
3060 | F->bk = R;\ |
3061 | R->fd = F;\ |
3062 | }\ |
3063 | else {\ |
3064 | CORRUPTION_ERROR_ACTION(M);\ |
3065 | }\ |
3066 | }\ |
3067 | else {\ |
3068 | tchunkptr* RP;\ |
3069 | if (((R = *(RP = &(X->child[1]))) != 0) ||\ |
3070 | ((R = *(RP = &(X->child[0]))) != 0)) {\ |
3071 | tchunkptr* CP;\ |
3072 | while ((*(CP = &(R->child[1])) != 0) ||\ |
3073 | (*(CP = &(R->child[0])) != 0)) {\ |
3074 | R = *(RP = CP);\ |
3075 | }\ |
3076 | if (RTCHECK(ok_address(M, RP)))\ |
3077 | *RP = 0;\ |
3078 | else {\ |
3079 | CORRUPTION_ERROR_ACTION(M);\ |
3080 | }\ |
3081 | }\ |
3082 | }\ |
3083 | if (XP != 0) {\ |
3084 | tbinptr* H = treebin_at(M, X->index);\ |
3085 | if (X == *H) {\ |
3086 | if ((*H = R) == 0) \ |
3087 | clear_treemap(M, X->index);\ |
3088 | }\ |
3089 | else if (RTCHECK(ok_address(M, XP))) {\ |
3090 | if (XP->child[0] == X) \ |
3091 | XP->child[0] = R;\ |
3092 | else \ |
3093 | XP->child[1] = R;\ |
3094 | }\ |
3095 | else\ |
3096 | CORRUPTION_ERROR_ACTION(M);\ |
3097 | if (R != 0) {\ |
3098 | if (RTCHECK(ok_address(M, R))) {\ |
3099 | tchunkptr C0, C1;\ |
3100 | R->parent = XP;\ |
3101 | if ((C0 = X->child[0]) != 0) {\ |
3102 | if (RTCHECK(ok_address(M, C0))) {\ |
3103 | R->child[0] = C0;\ |
3104 | C0->parent = R;\ |
3105 | }\ |
3106 | else\ |
3107 | CORRUPTION_ERROR_ACTION(M);\ |
3108 | }\ |
3109 | if ((C1 = X->child[1]) != 0) {\ |
3110 | if (RTCHECK(ok_address(M, C1))) {\ |
3111 | R->child[1] = C1;\ |
3112 | C1->parent = R;\ |
3113 | }\ |
3114 | else\ |
3115 | CORRUPTION_ERROR_ACTION(M);\ |
3116 | }\ |
3117 | }\ |
3118 | else\ |
3119 | CORRUPTION_ERROR_ACTION(M);\ |
3120 | }\ |
3121 | }\ |
3122 | } |
3123 | |
3124 | /* Relays to large vs small bin operations */ |
3125 | |
3126 | #define insert_chunk(M, P, S)\ |
3127 | if (is_small(S)) insert_small_chunk(M, P, S)\ |
3128 | else { tchunkptr TP = (tchunkptr)(P); insert_large_chunk(M, TP, S); } |
3129 | |
3130 | #define unlink_chunk(M, P, S)\ |
3131 | if (is_small(S)) unlink_small_chunk(M, P, S)\ |
3132 | else { tchunkptr TP = (tchunkptr)(P); unlink_large_chunk(M, TP); } |
3133 | |
3134 | |
3135 | /* Relays to internal calls to malloc/free from realloc, memalign etc */ |
3136 | |
3137 | #if ONLY_MSPACES |
3138 | #define internal_malloc(m, b) mspace_malloc(m, b) |
3139 | #define internal_free(m, mem) mspace_free(m,mem); |
3140 | #else /* ONLY_MSPACES */ |
3141 | #if MSPACES |
3142 | #define internal_malloc(m, b)\ |
3143 | (m == gm)? dlmalloc(b) : mspace_malloc(m, b) |
3144 | #define internal_free(m, mem)\ |
3145 | if (m == gm) dlfree(mem); else mspace_free(m,mem); |
3146 | #else /* MSPACES */ |
3147 | #define internal_malloc(m, b) dlmalloc(b) |
3148 | #define internal_free(m, mem) dlfree(mem) |
3149 | #endif /* MSPACES */ |
3150 | #endif /* ONLY_MSPACES */ |
3151 | |
3152 | /* ----------------------- Direct-mmapping chunks ----------------------- */ |
3153 | |
3154 | /* |
3155 | Directly mmapped chunks are set up with an offset to the start of |
3156 | the mmapped region stored in the prev_foot field of the chunk. This |
3157 | allows reconstruction of the required argument to MUNMAP when freed, |
3158 | and also allows adjustment of the returned chunk to meet alignment |
3159 | requirements (especially in memalign). There is also enough space |
3160 | allocated to hold a fake next chunk of size SIZE_T_SIZE to maintain |
3161 | the PINUSE bit so frees can be checked. |
3162 | */ |
3163 | |
3164 | /* Malloc using mmap */ |
3165 | static void* mmap_alloc(mstate m, size_t nb) { |
3166 | size_t mmsize = granularity_align(nb + SIX_SIZE_T_SIZES + CHUNK_ALIGN_MASK); |
3167 | if (mmsize > nb) { /* Check for wrap around 0 */ |
3168 | char* mm = (char*)(DIRECT_MMAP(mmsize)); |
3169 | if (mm != CMFAIL) { |
3170 | size_t offset = align_offset(chunk2mem(mm)); |
3171 | size_t psize = mmsize - offset - MMAP_FOOT_PAD; |
3172 | mchunkptr p = (mchunkptr)(mm + offset); |
3173 | p->prev_foot = offset | IS_MMAPPED_BIT; |
3174 | (p)->head = (psize|CINUSE_BIT); |
3175 | mark_inuse_foot(m, p, psize); |
3176 | chunk_plus_offset(p, psize)->head = FENCEPOST_HEAD; |
3177 | chunk_plus_offset(p, psize+SIZE_T_SIZE)->head = 0; |
3178 | |
3179 | if (mm < m->least_addr) |
3180 | m->least_addr = mm; |
3181 | if ((m->footprint += mmsize) > m->max_footprint) |
3182 | m->max_footprint = m->footprint; |
3183 | assert(is_aligned(chunk2mem(p))); |
3184 | check_mmapped_chunk(m, p); |
3185 | return chunk2mem(p); |
3186 | } |
3187 | } |
3188 | return 0; |
3189 | } |
3190 | |
3191 | /* Realloc using mmap */ |
3192 | static mchunkptr mmap_resize(mstate m, mchunkptr oldp, size_t nb) { |
3193 | size_t oldsize = chunksize(oldp); |
3194 | if (is_small(nb)) /* Can't shrink mmap regions below small size */ |
3195 | return 0; |
3196 | /* Keep old chunk if big enough but not too big */ |
3197 | if (oldsize >= nb + SIZE_T_SIZE && |
3198 | (oldsize - nb) <= (mparams.granularity << 1)) |
3199 | return oldp; |
3200 | else { |
3201 | size_t offset = oldp->prev_foot & ~IS_MMAPPED_BIT; |
3202 | size_t oldmmsize = oldsize + offset + MMAP_FOOT_PAD; |
3203 | size_t newmmsize = granularity_align(nb + SIX_SIZE_T_SIZES + |
3204 | CHUNK_ALIGN_MASK); |
3205 | char* cp = (char*)CALL_MREMAP((char*)oldp - offset, |
3206 | oldmmsize, newmmsize, 1); |
3207 | if (cp != CMFAIL) { |
3208 | mchunkptr newp = (mchunkptr)(cp + offset); |
3209 | size_t psize = newmmsize - offset - MMAP_FOOT_PAD; |
3210 | newp->head = (psize|CINUSE_BIT); |
3211 | mark_inuse_foot(m, newp, psize); |
3212 | chunk_plus_offset(newp, psize)->head = FENCEPOST_HEAD; |
3213 | chunk_plus_offset(newp, psize+SIZE_T_SIZE)->head = 0; |
3214 | |
3215 | if (cp < m->least_addr) |
3216 | m->least_addr = cp; |
3217 | if ((m->footprint += newmmsize - oldmmsize) > m->max_footprint) |
3218 | m->max_footprint = m->footprint; |
3219 | check_mmapped_chunk(m, newp); |
3220 | return newp; |
3221 | } |
3222 | } |
3223 | return 0; |
3224 | } |
3225 | |
3226 | /* -------------------------- mspace management -------------------------- */ |
3227 | |
3228 | /* Initialize top chunk and its size */ |
3229 | static void init_top(mstate m, mchunkptr p, size_t psize) { |
3230 | /* Ensure alignment */ |
3231 | size_t offset = align_offset(chunk2mem(p)); |
3232 | p = (mchunkptr)((char*)p + offset); |
3233 | psize -= offset; |
3234 | |
3235 | m->top = p; |
3236 | m->topsize = psize; |
3237 | p->head = psize | PINUSE_BIT; |
3238 | /* set size of fake trailing chunk holding overhead space only once */ |
3239 | chunk_plus_offset(p, psize)->head = TOP_FOOT_SIZE; |
3240 | m->trim_check = mparams.trim_threshold; /* reset on each update */ |
3241 | } |
3242 | |
3243 | /* Initialize bins for a new mstate that is otherwise zeroed out */ |
3244 | static void init_bins(mstate m) { |
3245 | /* Establish circular links for smallbins */ |
3246 | bindex_t i; |
3247 | for (i = 0; i < NSMALLBINS; ++i) { |
3248 | sbinptr bin = smallbin_at(m,i); |
3249 | bin->fd = bin->bk = bin; |
3250 | } |
3251 | } |
3252 | |
3253 | #if PROCEED_ON_ERROR |
3254 | |
3255 | /* default corruption action */ |
3256 | static void reset_on_error(mstate m) { |
3257 | int i; |
3258 | ++malloc_corruption_error_count; |
3259 | /* Reinitialize fields to forget about all memory */ |
3260 | m->smallbins = m->treebins = 0; |
3261 | m->dvsize = m->topsize = 0; |
3262 | m->seg.base = 0; |
3263 | m->seg.size = 0; |
3264 | m->seg.next = 0; |
3265 | m->top = m->dv = 0; |
3266 | for (i = 0; i < NTREEBINS; ++i) |
3267 | *treebin_at(m, i) = 0; |
3268 | init_bins(m); |
3269 | } |
3270 | #endif /* PROCEED_ON_ERROR */ |
3271 | |
3272 | /* Allocate chunk and prepend remainder with chunk in successor base. */ |
3273 | static void* prepend_alloc(mstate m, char* newbase, char* oldbase, |
3274 | size_t nb) { |
3275 | mchunkptr p = align_as_chunk(newbase); |
3276 | mchunkptr oldfirst = align_as_chunk(oldbase); |
3277 | size_t psize = (char*)oldfirst - (char*)p; |
3278 | mchunkptr q = chunk_plus_offset(p, nb); |
3279 | size_t qsize = psize - nb; |
3280 | set_size_and_pinuse_of_inuse_chunk(m, p, nb); |
3281 | |
3282 | assert((char*)oldfirst > (char*)q); |
3283 | assert(pinuse(oldfirst)); |
3284 | assert(qsize >= MIN_CHUNK_SIZE); |
3285 | |
3286 | /* consolidate remainder with first chunk of old base */ |
3287 | if (oldfirst == m->top) { |
3288 | size_t tsize = m->topsize += qsize; |
3289 | m->top = q; |
3290 | q->head = tsize | PINUSE_BIT; |
3291 | check_top_chunk(m, q); |
3292 | } |
3293 | else if (oldfirst == m->dv) { |
3294 | size_t dsize = m->dvsize += qsize; |
3295 | m->dv = q; |
3296 | set_size_and_pinuse_of_free_chunk(q, dsize); |
3297 | } |
3298 | else { |
3299 | if (!cinuse(oldfirst)) { |
3300 | size_t nsize = chunksize(oldfirst); |
3301 | unlink_chunk(m, oldfirst, nsize); |
3302 | oldfirst = chunk_plus_offset(oldfirst, nsize); |
3303 | qsize += nsize; |
3304 | } |
3305 | set_free_with_pinuse(q, qsize, oldfirst); |
3306 | insert_chunk(m, q, qsize); |
3307 | check_free_chunk(m, q); |
3308 | } |
3309 | |
3310 | check_malloced_chunk(m, chunk2mem(p), nb); |
3311 | return chunk2mem(p); |
3312 | } |
3313 | |
3314 | |
3315 | /* Add a segment to hold a new noncontiguous region */ |
3316 | static void add_segment(mstate m, char* tbase, size_t tsize, flag_t mmapped) { |
3317 | /* Determine locations and sizes of segment, fenceposts, old top */ |
3318 | char* old_top = (char*)m->top; |
3319 | msegmentptr oldsp = segment_holding(m, old_top); |
3320 | char* old_end = oldsp->base + oldsp->size; |
3321 | size_t ssize = pad_request(sizeof(struct malloc_segment)); |
3322 | char* rawsp = old_end - (ssize + FOUR_SIZE_T_SIZES + CHUNK_ALIGN_MASK); |
3323 | size_t offset = align_offset(chunk2mem(rawsp)); |
3324 | char* asp = rawsp + offset; |
3325 | char* csp = (asp < (old_top + MIN_CHUNK_SIZE))? old_top : asp; |
3326 | mchunkptr sp = (mchunkptr)csp; |
3327 | msegmentptr ss = (msegmentptr)(chunk2mem(sp)); |
3328 | mchunkptr tnext = chunk_plus_offset(sp, ssize); |
3329 | mchunkptr p = tnext; |
3330 | int nfences = 0; |
3331 | |
3332 | /* reset top to new space */ |
3333 | init_top(m, (mchunkptr)tbase, tsize - TOP_FOOT_SIZE); |
3334 | |
3335 | /* Set up segment record */ |
3336 | assert(is_aligned(ss)); |
3337 | set_size_and_pinuse_of_inuse_chunk(m, sp, ssize); |
3338 | *ss = m->seg; /* Push current record */ |
3339 | m->seg.base = tbase; |
3340 | m->seg.size = tsize; |
3341 | m->seg.sflags = mmapped; |
3342 | m->seg.next = ss; |
3343 | |
3344 | /* Insert trailing fenceposts */ |
3345 | for (;;) { |
3346 | mchunkptr nextp = chunk_plus_offset(p, SIZE_T_SIZE); |
3347 | p->head = FENCEPOST_HEAD; |
3348 | ++nfences; |
3349 | if ((char*)(&(nextp->head)) < old_end) |
3350 | p = nextp; |
3351 | else |
3352 | break; |
3353 | } |
3354 | assert(nfences >= 2); |
3355 | |
3356 | /* Insert the rest of old top into a bin as an ordinary free chunk */ |
3357 | if (csp != old_top) { |
3358 | mchunkptr q = (mchunkptr)old_top; |
3359 | size_t psize = csp - old_top; |
3360 | mchunkptr tn = chunk_plus_offset(q, psize); |
3361 | set_free_with_pinuse(q, psize, tn); |
3362 | insert_chunk(m, q, psize); |
3363 | } |
3364 | |
3365 | check_top_chunk(m, m->top); |
3366 | } |
3367 | |
3368 | /* -------------------------- System allocation -------------------------- */ |
3369 | |
3370 | /* Get memory from system using MORECORE or MMAP */ |
3371 | static void* sys_alloc(mstate m, size_t nb) { |
3372 | char* tbase = CMFAIL; |
3373 | size_t tsize = 0; |
3374 | flag_t mmap_flag = 0; |
3375 | |
3376 | init_mparams(); |
3377 | |
3378 | /* Directly map large chunks */ |
3379 | if (use_mmap(m) && nb >= mparams.mmap_threshold) { |
3380 | void* mem = mmap_alloc(m, nb); |
3381 | if (mem != 0) |
3382 | return mem; |
3383 | } |
3384 | |
3385 | /* |
3386 | Try getting memory in any of three ways (in most-preferred to |
3387 | least-preferred order): |
3388 | 1. A call to MORECORE that can normally contiguously extend memory. |
3389 | (disabled if not MORECORE_CONTIGUOUS or not HAVE_MORECORE or |
3390 | or main space is mmapped or a previous contiguous call failed) |
3391 | 2. A call to MMAP new space (disabled if not HAVE_MMAP). |
3392 | Note that under the default settings, if MORECORE is unable to |
3393 | fulfill a request, and HAVE_MMAP is true, then mmap is |
3394 | used as a noncontiguous system allocator. This is a useful backup |
3395 | strategy for systems with holes in address spaces -- in this case |
3396 | sbrk cannot contiguously expand the heap, but mmap may be able to |
3397 | find space. |
3398 | 3. A call to MORECORE that cannot usually contiguously extend memory. |
3399 | (disabled if not HAVE_MORECORE) |
3400 | */ |
3401 | |
3402 | if (MORECORE_CONTIGUOUS && !use_noncontiguous(m)) { |
3403 | char* br = CMFAIL; |
3404 | msegmentptr ss = (m->top == 0)? 0 : segment_holding(m, (char*)m->top); |
3405 | size_t asize = 0; |
3406 | ACQUIRE_MORECORE_LOCK(); |
3407 | |
3408 | if (ss == 0) { /* First time through or recovery */ |
3409 | char* base = (char*)CALL_MORECORE(0); |
3410 | if (base != CMFAIL) { |
3411 | asize = granularity_align(nb + TOP_FOOT_SIZE + MALLOC_ALIGNMENT + SIZE_T_ONE); |
3412 | /* Adjust to end on a page boundary */ |
3413 | if (!is_page_aligned(base)) |
3414 | asize += (page_align((size_t)base) - (size_t)base); |
3415 | /* Can't call MORECORE if size is negative when treated as signed */ |
3416 | if (asize < HALF_MAX_SIZE_T && |
3417 | (br = (char*)(CALL_MORECORE(asize))) == base) { |
3418 | tbase = base; |
3419 | tsize = asize; |
3420 | } |
3421 | } |
3422 | } |
3423 | else { |
3424 | /* Subtract out existing available top space from MORECORE request. */ |
3425 | asize = granularity_align(nb - m->topsize + TOP_FOOT_SIZE + MALLOC_ALIGNMENT + SIZE_T_ONE); |
3426 | /* Use mem here only if it did continuously extend old space */ |
3427 | if (asize < HALF_MAX_SIZE_T && |
3428 | (br = (char*)(CALL_MORECORE(asize))) == ss->base+ss->size) { |
3429 | tbase = br; |
3430 | tsize = asize; |
3431 | } |
3432 | } |
3433 | |
3434 | if (tbase == CMFAIL) { /* Cope with partial failure */ |
3435 | if (br != CMFAIL) { /* Try to use/extend the space we did get */ |
3436 | if (asize < HALF_MAX_SIZE_T && |
3437 | asize < nb + TOP_FOOT_SIZE + SIZE_T_ONE) { |
3438 | size_t esize = granularity_align(nb + TOP_FOOT_SIZE + MALLOC_ALIGNMENT + SIZE_T_ONE - asize); |
3439 | if (esize < HALF_MAX_SIZE_T) { |
3440 | char* end = (char*)CALL_MORECORE(esize); |
3441 | if (end != CMFAIL) |
3442 | asize += esize; |
3443 | else { /* Can't use; try to release */ |
3444 | end = (char*)CALL_MORECORE(-asize); |
3445 | br = CMFAIL; |
3446 | } |
3447 | } |
3448 | } |
3449 | } |
3450 | if (br != CMFAIL) { /* Use the space we did get */ |
3451 | tbase = br; |
3452 | tsize = asize; |
3453 | } |
3454 | else |
3455 | disable_contiguous(m); /* Don't try contiguous path in the future */ |
3456 | } |
3457 | |
3458 | RELEASE_MORECORE_LOCK(); |
3459 | } |
3460 | |
3461 | if (HAVE_MMAP && tbase == CMFAIL) { /* Try MMAP */ |
3462 | size_t req = nb + TOP_FOOT_SIZE + MALLOC_ALIGNMENT + SIZE_T_ONE; |
3463 | size_t rsize = granularity_align(req); |
3464 | if (rsize > nb) { /* Fail if wraps around zero */ |
3465 | char* mp = (char*)(CALL_MMAP(rsize)); |
3466 | if (mp != CMFAIL) { |
3467 | tbase = mp; |
3468 | tsize = rsize; |
3469 | mmap_flag = IS_MMAPPED_BIT; |
3470 | } |
3471 | } |
3472 | } |
3473 | |
3474 | if (HAVE_MORECORE && tbase == CMFAIL) { /* Try noncontiguous MORECORE */ |
3475 | size_t asize = granularity_align(nb + TOP_FOOT_SIZE + MALLOC_ALIGNMENT + SIZE_T_ONE); |
3476 | if (asize < HALF_MAX_SIZE_T) { |
3477 | char* br = CMFAIL; |
3478 | char* end = CMFAIL; |
3479 | ACQUIRE_MORECORE_LOCK(); |
3480 | br = (char*)(CALL_MORECORE(asize)); |
3481 | end = (char*)(CALL_MORECORE(0)); |
3482 | RELEASE_MORECORE_LOCK(); |
3483 | if (br != CMFAIL && end != CMFAIL && br < end) { |
3484 | size_t ssize = end - br; |
3485 | if (ssize > nb + TOP_FOOT_SIZE) { |
3486 | tbase = br; |
3487 | tsize = ssize; |
3488 | } |
3489 | } |
3490 | } |
3491 | } |
3492 | |
3493 | if (tbase != CMFAIL) { |
3494 | |
3495 | if ((m->footprint += tsize) > m->max_footprint) |
3496 | m->max_footprint = m->footprint; |
3497 | |
3498 | if (!is_initialized(m)) { /* first-time initialization */ |
3499 | m->seg.base = m->least_addr = tbase; |
3500 | m->seg.size = tsize; |
3501 | m->seg.sflags = mmap_flag; |
3502 | m->magic = mparams.magic; |
3503 | init_bins(m); |
3504 | if (is_global(m)) |
3505 | init_top(m, (mchunkptr)tbase, tsize - TOP_FOOT_SIZE); |
3506 | else { |
3507 | /* Offset top by embedded malloc_state */ |
3508 | mchunkptr mn = next_chunk(mem2chunk(m)); |
3509 | init_top(m, mn, (size_t)((tbase + tsize) - (char*)mn) -TOP_FOOT_SIZE); |
3510 | } |
3511 | } |
3512 | |
3513 | else { |
3514 | /* Try to merge with an existing segment */ |
3515 | msegmentptr sp = &m->seg; |
3516 | while (sp != 0 && tbase != sp->base + sp->size) |
3517 | sp = sp->next; |
3518 | if (sp != 0 && |
3519 | !is_extern_segment(sp) && |
3520 | (sp->sflags & IS_MMAPPED_BIT) == mmap_flag && |
3521 | segment_holds(sp, m->top)) { /* append */ |
3522 | sp->size += tsize; |
3523 | init_top(m, m->top, m->topsize + tsize); |
3524 | } |
3525 | else { |
3526 | if (tbase < m->least_addr) |
3527 | m->least_addr = tbase; |
3528 | sp = &m->seg; |
3529 | while (sp != 0 && sp->base != tbase + tsize) |
3530 | sp = sp->next; |
3531 | if (sp != 0 && |
3532 | !is_extern_segment(sp) && |
3533 | (sp->sflags & IS_MMAPPED_BIT) == mmap_flag) { |
3534 | char* oldbase = sp->base; |
3535 | sp->base = tbase; |
3536 | sp->size += tsize; |
3537 | return prepend_alloc(m, tbase, oldbase, nb); |
3538 | } |
3539 | else |
3540 | add_segment(m, tbase, tsize, mmap_flag); |
3541 | } |
3542 | } |
3543 | |
3544 | if (nb < m->topsize) { /* Allocate from new or extended top space */ |
3545 | size_t rsize = m->topsize -= nb; |
3546 | mchunkptr p = m->top; |
3547 | mchunkptr r = m->top = chunk_plus_offset(p, nb); |
3548 | r->head = rsize | PINUSE_BIT; |
3549 | set_size_and_pinuse_of_inuse_chunk(m, p, nb); |
3550 | check_top_chunk(m, m->top); |
3551 | check_malloced_chunk(m, chunk2mem(p), nb); |
3552 | return chunk2mem(p); |
3553 | } |
3554 | } |
3555 | |
3556 | MALLOC_FAILURE_ACTION; |
3557 | return 0; |
3558 | } |
3559 | |
3560 | /* ----------------------- system deallocation -------------------------- */ |
3561 | |
3562 | /* Unmap and unlink any mmapped segments that don't contain used chunks */ |
3563 | static size_t release_unused_segments(mstate m) { |
3564 | size_t released = 0; |
3565 | msegmentptr pred = &m->seg; |
3566 | msegmentptr sp = pred->next; |
3567 | while (sp != 0) { |
3568 | char* base = sp->base; |
3569 | size_t size = sp->size; |
3570 | msegmentptr next = sp->next; |
3571 | if (is_mmapped_segment(sp) && !is_extern_segment(sp)) { |
3572 | mchunkptr p = align_as_chunk(base); |
3573 | size_t psize = chunksize(p); |
3574 | /* Can unmap if first chunk holds entire segment and not pinned */ |
3575 | if (!cinuse(p) && (char*)p + psize >= base + size - TOP_FOOT_SIZE) { |
3576 | tchunkptr tp = (tchunkptr)p; |
3577 | assert(segment_holds(sp, (char*)sp)); |
3578 | if (p == m->dv) { |
3579 | m->dv = 0; |
3580 | m->dvsize = 0; |
3581 | } |
3582 | else { |
3583 | unlink_large_chunk(m, tp); |
3584 | } |
3585 | if (CALL_MUNMAP(base, size) == 0) { |
3586 | released += size; |
3587 | m->footprint -= size; |
3588 | /* unlink obsoleted record */ |
3589 | sp = pred; |
3590 | sp->next = next; |
3591 | } |
3592 | else { /* back out if cannot unmap */ |
3593 | insert_large_chunk(m, tp, psize); |
3594 | } |
3595 | } |
3596 | } |
3597 | pred = sp; |
3598 | sp = next; |
3599 | } |
3600 | return released; |
3601 | } |
3602 | |
3603 | static int sys_trim(mstate m, size_t pad) { |
3604 | size_t released = 0; |
3605 | if (pad < MAX_REQUEST && is_initialized(m)) { |
3606 | pad += TOP_FOOT_SIZE; /* ensure enough room for segment overhead */ |
3607 | |
3608 | if (m->topsize > pad) { |
3609 | /* Shrink top space in granularity-size units, keeping at least one */ |
3610 | size_t unit = mparams.granularity; |
3611 | size_t extra = ((m->topsize - pad + (unit - SIZE_T_ONE)) / unit - |
3612 | SIZE_T_ONE) * unit; |
3613 | msegmentptr sp = segment_holding(m, (char*)m->top); |
3614 | |
3615 | if (!is_extern_segment(sp)) { |
3616 | if (is_mmapped_segment(sp)) { |
3617 | if (HAVE_MMAP && |
3618 | sp->size >= extra && |
3619 | !has_segment_link(m, sp)) { /* can't shrink if pinned */ |
3620 | size_t newsize = sp->size - extra; |
3621 | /* Prefer mremap, fall back to munmap */ |
3622 | if ((CALL_MREMAP(sp->base, sp->size, newsize, 0) != MFAIL) || |
3623 | (CALL_MUNMAP(sp->base + newsize, extra) == 0)) { |
3624 | released = extra; |
3625 | } |
3626 | } |
3627 | } |
3628 | else if (HAVE_MORECORE) { |
3629 | if (extra >= HALF_MAX_SIZE_T) /* Avoid wrapping negative */ |
3630 | extra = (HALF_MAX_SIZE_T) + SIZE_T_ONE - unit; |
3631 | ACQUIRE_MORECORE_LOCK(); |
3632 | { |
3633 | /* Make sure end of memory is where we last set it. */ |
3634 | char* old_br = (char*)(CALL_MORECORE(0)); |
3635 | if (old_br == sp->base + sp->size) { |
3636 | char* rel_br = (char*)(CALL_MORECORE(-extra)); |
3637 | char* new_br = (char*)(CALL_MORECORE(0)); |
3638 | if (rel_br != CMFAIL && new_br < old_br) |
3639 | released = old_br - new_br; |
3640 | } |
3641 | } |
3642 | RELEASE_MORECORE_LOCK(); |
3643 | } |
3644 | } |
3645 | |
3646 | if (released != 0) { |
3647 | sp->size -= released; |
3648 | m->footprint -= released; |
3649 | init_top(m, m->top, m->topsize - released); |
3650 | check_top_chunk(m, m->top); |
3651 | } |
3652 | } |
3653 | |
3654 | /* Unmap any unused mmapped segments */ |
3655 | if (HAVE_MMAP) |
3656 | released += release_unused_segments(m); |
3657 | |
3658 | /* On failure, disable autotrim to avoid repeated failed future calls */ |
3659 | if (released == 0) |
3660 | m->trim_check = MAX_SIZE_T; |
3661 | } |
3662 | |
3663 | return (released != 0)? 1 : 0; |
3664 | } |
3665 | |
3666 | /* ---------------------------- malloc support --------------------------- */ |
3667 | |
3668 | /* allocate a large request from the best fitting chunk in a treebin */ |
3669 | static void* tmalloc_large(mstate m, size_t nb) { |
3670 | tchunkptr v = 0; |
3671 | size_t rsize = -nb; /* Unsigned negation */ |
3672 | tchunkptr t; |
3673 | bindex_t idx; |
3674 | compute_tree_index(nb, idx); |
3675 | |
3676 | if ((t = *treebin_at(m, idx)) != 0) { |
3677 | /* Traverse tree for this bin looking for node with size == nb */ |
3678 | size_t sizebits = nb << leftshift_for_tree_index(idx); |
3679 | tchunkptr rst = 0; /* The deepest untaken right subtree */ |
3680 | for (;;) { |
3681 | tchunkptr rt; |
3682 | size_t trem = chunksize(t) - nb; |
3683 | if (trem < rsize) { |
3684 | v = t; |
3685 | if ((rsize = trem) == 0) |
3686 | break; |
3687 | } |
3688 | rt = t->child[1]; |
3689 | t = t->child[(sizebits >> (SIZE_T_BITSIZE-SIZE_T_ONE)) & 1]; |
3690 | if (rt != 0 && rt != t) |
3691 | rst = rt; |
3692 | if (t == 0) { |
3693 | t = rst; /* set t to least subtree holding sizes > nb */ |
3694 | break; |
3695 | } |
3696 | sizebits <<= 1; |
3697 | } |
3698 | } |
3699 | |
3700 | if (t == 0 && v == 0) { /* set t to root of next non-empty treebin */ |
3701 | binmap_t leftbits = left_bits(idx2bit(idx)) & m->treemap; |
3702 | if (leftbits != 0) { |
3703 | bindex_t i; |
3704 | binmap_t leastbit = least_bit(leftbits); |
3705 | compute_bit2idx(leastbit, i); |
3706 | t = *treebin_at(m, i); |
3707 | } |
3708 | } |
3709 | |
3710 | while (t != 0) { /* find smallest of tree or subtree */ |
3711 | size_t trem = chunksize(t) - nb; |
3712 | if (trem < rsize) { |
3713 | rsize = trem; |
3714 | v = t; |
3715 | } |
3716 | t = leftmost_child(t); |
3717 | } |
3718 | |
3719 | /* If dv is a better fit, return 0 so malloc will use it */ |
3720 | if (v != 0 && rsize < (size_t)(m->dvsize - nb)) { |
3721 | if (RTCHECK(ok_address(m, v))) { /* split */ |
3722 | mchunkptr r = chunk_plus_offset(v, nb); |
3723 | assert(chunksize(v) == rsize + nb); |
3724 | if (RTCHECK(ok_next(v, r))) { |
3725 | unlink_large_chunk(m, v); |
3726 | if (rsize < MIN_CHUNK_SIZE) |
3727 | set_inuse_and_pinuse(m, v, (rsize + nb)); |
3728 | else { |
3729 | set_size_and_pinuse_of_inuse_chunk(m, v, nb); |
3730 | set_size_and_pinuse_of_free_chunk(r, rsize); |
3731 | insert_chunk(m, r, rsize); |
3732 | } |
3733 | return chunk2mem(v); |
3734 | } |
3735 | } |
3736 | CORRUPTION_ERROR_ACTION(m); |
3737 | } |
3738 | return 0; |
3739 | } |
3740 | |
3741 | /* allocate a small request from the best fitting chunk in a treebin */ |
3742 | static void* tmalloc_small(mstate m, size_t nb) { |
3743 | tchunkptr t, v; |
3744 | size_t rsize; |
3745 | bindex_t i; |
3746 | binmap_t leastbit = least_bit(m->treemap); |
3747 | compute_bit2idx(leastbit, i); |
3748 | |
3749 | v = t = *treebin_at(m, i); |
3750 | rsize = chunksize(t) - nb; |
3751 | |
3752 | while ((t = leftmost_child(t)) != 0) { |
3753 | size_t trem = chunksize(t) - nb; |
3754 | if (trem < rsize) { |
3755 | rsize = trem; |
3756 | v = t; |
3757 | } |
3758 | } |
3759 | |
3760 | if (RTCHECK(ok_address(m, v))) { |
3761 | mchunkptr r = chunk_plus_offset(v, nb); |
3762 | assert(chunksize(v) == rsize + nb); |
3763 | if (RTCHECK(ok_next(v, r))) { |
3764 | unlink_large_chunk(m, v); |
3765 | if (rsize < MIN_CHUNK_SIZE) |
3766 | set_inuse_and_pinuse(m, v, (rsize + nb)); |
3767 | else { |
3768 | set_size_and_pinuse_of_inuse_chunk(m, v, nb); |
3769 | set_size_and_pinuse_of_free_chunk(r, rsize); |
3770 | replace_dv(m, r, rsize); |
3771 | } |
3772 | return chunk2mem(v); |
3773 | } |
3774 | } |
3775 | |
3776 | CORRUPTION_ERROR_ACTION(m); |
3777 | return 0; |
3778 | } |
3779 | |
3780 | /* --------------------------- realloc support --------------------------- */ |
3781 | |
3782 | static void* internal_realloc(mstate m, void* oldmem, size_t bytes) { |
3783 | if (bytes >= MAX_REQUEST) { |
3784 | MALLOC_FAILURE_ACTION; |
3785 | return 0; |
3786 | } |
3787 | if (!PREACTION(m)) { |
3788 | mchunkptr oldp = mem2chunk(oldmem); |
3789 | size_t oldsize = chunksize(oldp); |
3790 | mchunkptr next = chunk_plus_offset(oldp, oldsize); |
3791 | mchunkptr newp = 0; |
3792 | void* extra = 0; |
3793 | |
3794 | /* Try to either shrink or extend into top. Else malloc-copy-free */ |
3795 | |
3796 | if (RTCHECK(ok_address(m, oldp) && ok_cinuse(oldp) && |
3797 | ok_next(oldp, next) && ok_pinuse(next))) { |
3798 | size_t nb = request2size(bytes); |
3799 | if (is_mmapped(oldp)) |
3800 | newp = mmap_resize(m, oldp, nb); |
3801 | else if (oldsize >= nb) { /* already big enough */ |
3802 | size_t rsize = oldsize - nb; |
3803 | newp = oldp; |
3804 | if (rsize >= MIN_CHUNK_SIZE) { |
3805 | mchunkptr remainder = chunk_plus_offset(newp, nb); |
3806 | set_inuse(m, newp, nb); |
3807 | set_inuse(m, remainder, rsize); |
3808 | extra = chunk2mem(remainder); |
3809 | } |
3810 | } |
3811 | else if (next == m->top && oldsize + m->topsize > nb) { |
3812 | /* Expand into top */ |
3813 | size_t newsize = oldsize + m->topsize; |
3814 | size_t newtopsize = newsize - nb; |
3815 | mchunkptr newtop = chunk_plus_offset(oldp, nb); |
3816 | set_inuse(m, oldp, nb); |
3817 | newtop->head = newtopsize |PINUSE_BIT; |
3818 | m->top = newtop; |
3819 | m->topsize = newtopsize; |
3820 | newp = oldp; |
3821 | } |
3822 | } |
3823 | else { |
3824 | USAGE_ERROR_ACTION(m, oldmem); |
3825 | POSTACTION(m); |
3826 | return 0; |
3827 | } |
3828 | |
3829 | POSTACTION(m); |
3830 | |
3831 | if (newp != 0) { |
3832 | if (extra != 0) { |
3833 | internal_free(m, extra); |
3834 | } |
3835 | check_inuse_chunk(m, newp); |
3836 | return chunk2mem(newp); |
3837 | } |
3838 | else { |
3839 | void* newmem = internal_malloc(m, bytes); |
3840 | if (newmem != 0) { |
3841 | size_t oc = oldsize - overhead_for(oldp); |
3842 | memcpy(newmem, oldmem, (oc < bytes)? oc : bytes); |
3843 | internal_free(m, oldmem); |
3844 | } |
3845 | return newmem; |
3846 | } |
3847 | } |
3848 | return 0; |
3849 | } |
3850 | |
3851 | /* --------------------------- memalign support -------------------------- */ |
3852 | |
3853 | static void* internal_memalign(mstate m, size_t alignment, size_t bytes) { |
3854 | if (alignment <= MALLOC_ALIGNMENT) /* Can just use malloc */ |
3855 | return internal_malloc(m, bytes); |
3856 | if (alignment < MIN_CHUNK_SIZE) /* must be at least a minimum chunk size */ |
3857 | alignment = MIN_CHUNK_SIZE; |
3858 | if ((alignment & (alignment-SIZE_T_ONE)) != 0) {/* Ensure a power of 2 */ |
3859 | size_t a = MALLOC_ALIGNMENT << 1; |
3860 | while (a < alignment) a <<= 1; |
3861 | alignment = a; |
3862 | } |
3863 | |
3864 | if (bytes >= MAX_REQUEST - alignment) { |
3865 | if (m != 0) { /* Test isn't needed but avoids compiler warning */ |
3866 | MALLOC_FAILURE_ACTION; |
3867 | } |
3868 | } |
3869 | else { |
3870 | size_t nb = request2size(bytes); |
3871 | size_t req = nb + alignment + MIN_CHUNK_SIZE - CHUNK_OVERHEAD; |
3872 | char* mem = (char*)internal_malloc(m, req); |
3873 | if (mem != 0) { |
3874 | void* leader = 0; |
3875 | void* trailer = 0; |
3876 | mchunkptr p = mem2chunk(mem); |
3877 | |
3878 | if (PREACTION(m)) return 0; |
3879 | if ((((size_t)(mem)) % alignment) != 0) { /* misaligned */ |
3880 | /* |
3881 | Find an aligned spot inside chunk. Since we need to give |
3882 | back leading space in a chunk of at least MIN_CHUNK_SIZE, if |
3883 | the first calculation places us at a spot with less than |
3884 | MIN_CHUNK_SIZE leader, we can move to the next aligned spot. |
3885 | We've allocated enough total room so that this is always |
3886 | possible. |
3887 | */ |
3888 | char* br = (char*)mem2chunk((size_t)(((size_t)(mem + |
3889 | alignment - |
3890 | SIZE_T_ONE)) & |
3891 | -alignment)); |
3892 | char* pos = ((size_t)(br - (char*)(p)) >= MIN_CHUNK_SIZE)? |
3893 | br : br+alignment; |
3894 | mchunkptr newp = (mchunkptr)pos; |
3895 | size_t leadsize = pos - (char*)(p); |
3896 | size_t newsize = chunksize(p) - leadsize; |
3897 | |
3898 | if (is_mmapped(p)) { /* For mmapped chunks, just adjust offset */ |
3899 | newp->prev_foot = p->prev_foot + leadsize; |
3900 | newp->head = (newsize|CINUSE_BIT); |
3901 | } |
3902 | else { /* Otherwise, give back leader, use the rest */ |
3903 | set_inuse(m, newp, newsize); |
3904 | set_inuse(m, p, leadsize); |
3905 | leader = chunk2mem(p); |
3906 | } |
3907 | p = newp; |
3908 | } |
3909 | |
3910 | /* Give back spare room at the end */ |
3911 | if (!is_mmapped(p)) { |
3912 | size_t size = chunksize(p); |
3913 | if (size > nb + MIN_CHUNK_SIZE) { |
3914 | size_t remainder_size = size - nb; |
3915 | mchunkptr remainder = chunk_plus_offset(p, nb); |
3916 | set_inuse(m, p, nb); |
3917 | set_inuse(m, remainder, remainder_size); |
3918 | trailer = chunk2mem(remainder); |
3919 | } |
3920 | } |
3921 | |
3922 | assert (chunksize(p) >= nb); |
3923 | assert((((size_t)(chunk2mem(p))) % alignment) == 0); |
3924 | check_inuse_chunk(m, p); |
3925 | POSTACTION(m); |
3926 | if (leader != 0) { |
3927 | internal_free(m, leader); |
3928 | } |
3929 | if (trailer != 0) { |
3930 | internal_free(m, trailer); |
3931 | } |
3932 | return chunk2mem(p); |
3933 | } |
3934 | } |
3935 | return 0; |
3936 | } |
3937 | |
3938 | /* ------------------------ comalloc/coalloc support --------------------- */ |
3939 | |
3940 | static void** ialloc(mstate m, |
3941 | size_t n_elements, |
3942 | size_t* sizes, |
3943 | int opts, |
3944 | void* chunks[]) { |
3945 | /* |
3946 | This provides common support for independent_X routines, handling |
3947 | all of the combinations that can result. |
3948 | |
3949 | The opts arg has: |
3950 | bit 0 set if all elements are same size (using sizes[0]) |
3951 | bit 1 set if elements should be zeroed |
3952 | */ |
3953 | |
3954 | size_t element_size; /* chunksize of each element, if all same */ |
3955 | size_t contents_size; /* total size of elements */ |
3956 | size_t array_size; /* request size of pointer array */ |
3957 | void* mem; /* malloced aggregate space */ |
3958 | mchunkptr p; /* corresponding chunk */ |
3959 | size_t remainder_size; /* remaining bytes while splitting */ |
3960 | void** marray; /* either "chunks" or malloced ptr array */ |
3961 | mchunkptr array_chunk; /* chunk for malloced ptr array */ |
3962 | flag_t was_enabled; /* to disable mmap */ |
3963 | size_t size; |
3964 | size_t i; |
3965 | |
3966 | /* compute array length, if needed */ |
3967 | if (chunks != 0) { |
3968 | if (n_elements == 0) |
3969 | return chunks; /* nothing to do */ |
3970 | marray = chunks; |
3971 | array_size = 0; |
3972 | } |
3973 | else { |
3974 | /* if empty req, must still return chunk representing empty array */ |
3975 | if (n_elements == 0) |
3976 | return (void**)internal_malloc(m, 0); |
3977 | marray = 0; |
3978 | array_size = request2size(n_elements * (sizeof(void*))); |
3979 | } |
3980 | |
3981 | /* compute total element size */ |
3982 | if (opts & 0x1) { /* all-same-size */ |
3983 | element_size = request2size(*sizes); |
3984 | contents_size = n_elements * element_size; |
3985 | } |
3986 | else { /* add up all the sizes */ |
3987 | element_size = 0; |
3988 | contents_size = 0; |
3989 | for (i = 0; i != n_elements; ++i) |
3990 | contents_size += request2size(sizes[i]); |
3991 | } |
3992 | |
3993 | size = contents_size + array_size; |
3994 | |
3995 | /* |
3996 | Allocate the aggregate chunk. First disable direct-mmapping so |
3997 | malloc won't use it, since we would not be able to later |
3998 | free/realloc space internal to a segregated mmap region. |
3999 | */ |
4000 | was_enabled = use_mmap(m); |
4001 | disable_mmap(m); |
4002 | mem = internal_malloc(m, size - CHUNK_OVERHEAD); |
4003 | if (was_enabled) |
4004 | enable_mmap(m); |
4005 | if (mem == 0) |
4006 | return 0; |
4007 | |
4008 | if (PREACTION(m)) return 0; |
4009 | p = mem2chunk(mem); |
4010 | remainder_size = chunksize(p); |
4011 | |
4012 | assert(!is_mmapped(p)); |
4013 | |
4014 | if (opts & 0x2) { /* optionally clear the elements */ |
4015 | memset((size_t*)mem, 0, remainder_size - SIZE_T_SIZE - array_size); |
4016 | } |
4017 | |
4018 | /* If not provided, allocate the pointer array as final part of chunk */ |
4019 | if (marray == 0) { |
4020 | size_t array_chunk_size; |
4021 | array_chunk = chunk_plus_offset(p, contents_size); |
4022 | array_chunk_size = remainder_size - contents_size; |
4023 | marray = (void**) (chunk2mem(array_chunk)); |
4024 | set_size_and_pinuse_of_inuse_chunk(m, array_chunk, array_chunk_size); |
4025 | remainder_size = contents_size; |
4026 | } |
4027 | |
4028 | /* split out elements */ |
4029 | for (i = 0; ; ++i) { |
4030 | marray[i] = chunk2mem(p); |
4031 | if (i != n_elements-1) { |
4032 | if (element_size != 0) |
4033 | size = element_size; |
4034 | else |
4035 | size = request2size(sizes[i]); |
4036 | remainder_size -= size; |
4037 | set_size_and_pinuse_of_inuse_chunk(m, p, size); |
4038 | p = chunk_plus_offset(p, size); |
4039 | } |
4040 | else { /* the final element absorbs any overallocation slop */ |
4041 | set_size_and_pinuse_of_inuse_chunk(m, p, remainder_size); |
4042 | break; |
4043 | } |
4044 | } |
4045 | |
4046 | #if DEBUG |
4047 | if (marray != chunks) { |
4048 | /* final element must have exactly exhausted chunk */ |
4049 | if (element_size != 0) { |
4050 | assert(remainder_size == element_size); |
4051 | } |
4052 | else { |
4053 | assert(remainder_size == request2size(sizes[i])); |
4054 | } |
4055 | check_inuse_chunk(m, mem2chunk(marray)); |
4056 | } |
4057 | for (i = 0; i != n_elements; ++i) |
4058 | check_inuse_chunk(m, mem2chunk(marray[i])); |
4059 | |
4060 | #endif /* DEBUG */ |
4061 | |
4062 | POSTACTION(m); |
4063 | return marray; |
4064 | } |
4065 | |
4066 | |
4067 | /* -------------------------- public routines ---------------------------- */ |
4068 | |
4069 | #if !ONLY_MSPACES |
4070 | |
4071 | void* dlmalloc(size_t bytes) { |
4072 | /* |
4073 | Basic algorithm: |
4074 | If a small request (< 256 bytes minus per-chunk overhead): |
4075 | 1. If one exists, use a remainderless chunk in associated smallbin. |
4076 | (Remainderless means that there are too few excess bytes to |
4077 | represent as a chunk.) |
4078 | 2. If it is big enough, use the dv chunk, which is normally the |
4079 | chunk adjacent to the one used for the most recent small request. |
4080 | 3. If one exists, split the smallest available chunk in a bin, |
4081 | saving remainder in dv. |
4082 | 4. If it is big enough, use the top chunk. |
4083 | 5. If available, get memory from system and use it |
4084 | Otherwise, for a large request: |
4085 | 1. Find the smallest available binned chunk that fits, and use it |
4086 | if it is better fitting than dv chunk, splitting if necessary. |
4087 | 2. If better fitting than any binned chunk, use the dv chunk. |
4088 | 3. If it is big enough, use the top chunk. |
4089 | 4. If request size >= mmap threshold, try to directly mmap this chunk. |
4090 | 5. If available, get memory from system and use it |
4091 | |
4092 | The ugly goto's here ensure that postaction occurs along all paths. |
4093 | */ |
4094 | |
4095 | if (!PREACTION(gm)) { |
4096 | void* mem; |
4097 | size_t nb; |
4098 | if (bytes <= MAX_SMALL_REQUEST) { |
4099 | bindex_t idx; |
4100 | binmap_t smallbits; |
4101 | nb = (bytes < MIN_REQUEST)? MIN_CHUNK_SIZE : pad_request(bytes); |
4102 | idx = small_index(nb); |
4103 | smallbits = gm->smallmap >> idx; |
4104 | |
4105 | if ((smallbits & 0x3U) != 0) { /* Remainderless fit to a smallbin. */ |
4106 | mchunkptr b, p; |
4107 | idx += ~smallbits & 1; /* Uses next bin if idx empty */ |
4108 | b = smallbin_at(gm, idx); |
4109 | p = b->fd; |
4110 | assert(chunksize(p) == small_index2size(idx)); |
4111 | unlink_first_small_chunk(gm, b, p, idx); |
4112 | set_inuse_and_pinuse(gm, p, small_index2size(idx)); |
4113 | mem = chunk2mem(p); |
4114 | check_malloced_chunk(gm, mem, nb); |
4115 | goto postaction; |
4116 | } |
4117 | |
4118 | else if (nb > gm->dvsize) { |
4119 | if (smallbits != 0) { /* Use chunk in next nonempty smallbin */ |
4120 | mchunkptr b, p, r; |
4121 | size_t rsize; |
4122 | bindex_t i; |
4123 | binmap_t leftbits = (smallbits << idx) & left_bits(idx2bit(idx)); |
4124 | binmap_t leastbit = least_bit(leftbits); |
4125 | compute_bit2idx(leastbit, i); |
4126 | b = smallbin_at(gm, i); |
4127 | p = b->fd; |
4128 | assert(chunksize(p) == small_index2size(i)); |
4129 | unlink_first_small_chunk(gm, b, p, i); |
4130 | rsize = small_index2size(i) - nb; |
4131 | /* Fit here cannot be remainderless if 4byte sizes */ |
4132 | if (SIZE_T_SIZE != 4 && rsize < MIN_CHUNK_SIZE) |
4133 | set_inuse_and_pinuse(gm, p, small_index2size(i)); |
4134 | else { |
4135 | set_size_and_pinuse_of_inuse_chunk(gm, p, nb); |
4136 | r = chunk_plus_offset(p, nb); |
4137 | set_size_and_pinuse_of_free_chunk(r, rsize); |
4138 | replace_dv(gm, r, rsize); |
4139 | } |
4140 | mem = chunk2mem(p); |
4141 | check_malloced_chunk(gm, mem, nb); |
4142 | goto postaction; |
4143 | } |
4144 | |
4145 | else if (gm->treemap != 0 && (mem = tmalloc_small(gm, nb)) != 0) { |
4146 | check_malloced_chunk(gm, mem, nb); |
4147 | goto postaction; |
4148 | } |
4149 | } |
4150 | } |
4151 | else if (bytes >= MAX_REQUEST) |
4152 | nb = MAX_SIZE_T; /* Too big to allocate. Force failure (in sys alloc) */ |
4153 | else { |
4154 | nb = pad_request(bytes); |
4155 | if (gm->treemap != 0 && (mem = tmalloc_large(gm, nb)) != 0) { |
4156 | check_malloced_chunk(gm, mem, nb); |
4157 | goto postaction; |
4158 | } |
4159 | } |
4160 | |
4161 | if (nb <= gm->dvsize) { |
4162 | size_t rsize = gm->dvsize - nb; |
4163 | mchunkptr p = gm->dv; |
4164 | if (rsize >= MIN_CHUNK_SIZE) { /* split dv */ |
4165 | mchunkptr r = gm->dv = chunk_plus_offset(p, nb); |
4166 | gm->dvsize = rsize; |
4167 | set_size_and_pinuse_of_free_chunk(r, rsize); |
4168 | set_size_and_pinuse_of_inuse_chunk(gm, p, nb); |
4169 | } |
4170 | else { /* exhaust dv */ |
4171 | size_t dvs = gm->dvsize; |
4172 | gm->dvsize = 0; |
4173 | gm->dv = 0; |
4174 | set_inuse_and_pinuse(gm, p, dvs); |
4175 | } |
4176 | mem = chunk2mem(p); |
4177 | check_malloced_chunk(gm, mem, nb); |
4178 | goto postaction; |
4179 | } |
4180 | |
4181 | else if (nb < gm->topsize) { /* Split top */ |
4182 | size_t rsize = gm->topsize -= nb; |
4183 | mchunkptr p = gm->top; |
4184 | mchunkptr r = gm->top = chunk_plus_offset(p, nb); |
4185 | r->head = rsize | PINUSE_BIT; |
4186 | set_size_and_pinuse_of_inuse_chunk(gm, p, nb); |
4187 | mem = chunk2mem(p); |
4188 | check_top_chunk(gm, gm->top); |
4189 | check_malloced_chunk(gm, mem, nb); |
4190 | goto postaction; |
4191 | } |
4192 | |
4193 | mem = sys_alloc(gm, nb); |
4194 | |
4195 | postaction: |
4196 | POSTACTION(gm); |
4197 | return mem; |
4198 | } |
4199 | |
4200 | return 0; |
4201 | } |
4202 | |
4203 | void dlfree(void* mem) { |
4204 | /* |
4205 | Consolidate freed chunks with preceeding or succeeding bordering |
4206 | free chunks, if they exist, and then place in a bin. Intermixed |
4207 | with special cases for top, dv, mmapped chunks, and usage errors. |
4208 | */ |
4209 | |
4210 | if (mem != 0) { |
4211 | mchunkptr p = mem2chunk(mem); |
4212 | #if FOOTERS |
4213 | mstate fm = get_mstate_for(p); |
4214 | if (!ok_magic(fm)) { |
4215 | USAGE_ERROR_ACTION(fm, p); |
4216 | return; |
4217 | } |
4218 | #else /* FOOTERS */ |
4219 | #define fm gm |
4220 | #endif /* FOOTERS */ |
4221 | if (!PREACTION(fm)) { |
4222 | check_inuse_chunk(fm, p); |
4223 | if (RTCHECK(ok_address(fm, p) && ok_cinuse(p))) { |
4224 | size_t psize = chunksize(p); |
4225 | mchunkptr next = chunk_plus_offset(p, psize); |
4226 | if (!pinuse(p)) { |
4227 | size_t prevsize = p->prev_foot; |
4228 | if ((prevsize & IS_MMAPPED_BIT) != 0) { |
4229 | prevsize &= ~IS_MMAPPED_BIT; |
4230 | psize += prevsize + MMAP_FOOT_PAD; |
4231 | if (CALL_MUNMAP((char*)p - prevsize, psize) == 0) |
4232 | fm->footprint -= psize; |
4233 | goto postaction; |
4234 | } |
4235 | else { |
4236 | mchunkptr prev = chunk_minus_offset(p, prevsize); |
4237 | psize += prevsize; |
4238 | p = prev; |
4239 | if (RTCHECK(ok_address(fm, prev))) { /* consolidate backward */ |
4240 | if (p != fm->dv) { |
4241 | unlink_chunk(fm, p, prevsize); |
4242 | } |
4243 | else if ((next->head & INUSE_BITS) == INUSE_BITS) { |
4244 | fm->dvsize = psize; |
4245 | set_free_with_pinuse(p, psize, next); |
4246 | goto postaction; |
4247 | } |
4248 | } |
4249 | else |
4250 | goto erroraction; |
4251 | } |
4252 | } |
4253 | |
4254 | if (RTCHECK(ok_next(p, next) && ok_pinuse(next))) { |
4255 | if (!cinuse(next)) { /* consolidate forward */ |
4256 | if (next == fm->top) { |
4257 | size_t tsize = fm->topsize += psize; |
4258 | fm->top = p; |
4259 | p->head = tsize | PINUSE_BIT; |
4260 | if (p == fm->dv) { |
4261 | fm->dv = 0; |
4262 | fm->dvsize = 0; |
4263 | } |
4264 | if (should_trim(fm, tsize)) |
4265 | sys_trim(fm, 0); |
4266 | goto postaction; |
4267 | } |
4268 | else if (next == fm->dv) { |
4269 | size_t dsize = fm->dvsize += psize; |
4270 | fm->dv = p; |
4271 | set_size_and_pinuse_of_free_chunk(p, dsize); |
4272 | goto postaction; |
4273 | } |
4274 | else { |
4275 | size_t nsize = chunksize(next); |
4276 | psize += nsize; |
4277 | unlink_chunk(fm, next, nsize); |
4278 | set_size_and_pinuse_of_free_chunk(p, psize); |
4279 | if (p == fm->dv) { |
4280 | fm->dvsize = psize; |
4281 | goto postaction; |
4282 | } |
4283 | } |
4284 | } |
4285 | else |
4286 | set_free_with_pinuse(p, psize, next); |
4287 | insert_chunk(fm, p, psize); |
4288 | check_free_chunk(fm, p); |
4289 | goto postaction; |
4290 | } |
4291 | } |
4292 | erroraction: |
4293 | USAGE_ERROR_ACTION(fm, p); |
4294 | postaction: |
4295 | POSTACTION(fm); |
4296 | } |
4297 | } |
4298 | #if !FOOTERS |
4299 | #undef fm |
4300 | #endif /* FOOTERS */ |
4301 | } |
4302 | |
4303 | void* dlcalloc(size_t n_elements, size_t elem_size) { |
4304 | void* mem; |
4305 | size_t req = 0; |
4306 | if (n_elements != 0) { |
4307 | req = n_elements * elem_size; |
4308 | if (((n_elements | elem_size) & ~(size_t)0xffff) && |
4309 | (req / n_elements != elem_size)) |
4310 | req = MAX_SIZE_T; /* force downstream failure on overflow */ |
4311 | } |
4312 | mem = dlmalloc(req); |
4313 | if (mem != 0 && calloc_must_clear(mem2chunk(mem))) |
4314 | memset(mem, 0, req); |
4315 | return mem; |
4316 | } |
4317 | |
4318 | void* dlrealloc(void* oldmem, size_t bytes) { |
4319 | if (oldmem == 0) |
4320 | return dlmalloc(bytes); |
4321 | #ifdef REALLOC_ZERO_BYTES_FREES |
4322 | if (bytes == 0) { |
4323 | dlfree(oldmem); |
4324 | return 0; |
4325 | } |
4326 | #endif /* REALLOC_ZERO_BYTES_FREES */ |
4327 | else { |
4328 | #if ! FOOTERS |
4329 | mstate m = gm; |
4330 | #else /* FOOTERS */ |
4331 | mstate m = get_mstate_for(mem2chunk(oldmem)); |
4332 | if (!ok_magic(m)) { |
4333 | USAGE_ERROR_ACTION(m, oldmem); |
4334 | return 0; |
4335 | } |
4336 | #endif /* FOOTERS */ |
4337 | return internal_realloc(m, oldmem, bytes); |
4338 | } |
4339 | } |
4340 | |
4341 | void* dlmemalign(size_t alignment, size_t bytes) { |
4342 | return internal_memalign(gm, alignment, bytes); |
4343 | } |
4344 | |
4345 | void** dlindependent_calloc(size_t n_elements, size_t elem_size, |
4346 | void* chunks[]) { |
4347 | size_t sz = elem_size; /* serves as 1-element array */ |
4348 | return ialloc(gm, n_elements, &sz, 3, chunks); |
4349 | } |
4350 | |
4351 | void** dlindependent_comalloc(size_t n_elements, size_t sizes[], |
4352 | void* chunks[]) { |
4353 | return ialloc(gm, n_elements, sizes, 0, chunks); |
4354 | } |
4355 | |
4356 | void* dlvalloc(size_t bytes) { |
4357 | size_t pagesz; |
4358 | init_mparams(); |
4359 | pagesz = mparams.page_size; |
4360 | return dlmemalign(pagesz, bytes); |
4361 | } |
4362 | |
4363 | void* dlpvalloc(size_t bytes) { |
4364 | size_t pagesz; |
4365 | init_mparams(); |
4366 | pagesz = mparams.page_size; |
4367 | return dlmemalign(pagesz, (bytes + pagesz - SIZE_T_ONE) & ~(pagesz - SIZE_T_ONE)); |
4368 | } |
4369 | |
4370 | int dlmalloc_trim(size_t pad) { |
4371 | int result = 0; |
4372 | if (!PREACTION(gm)) { |
4373 | result = sys_trim(gm, pad); |
4374 | POSTACTION(gm); |
4375 | } |
4376 | return result; |
4377 | } |
4378 | |
4379 | size_t dlmalloc_footprint(void) { |
4380 | return gm->footprint; |
4381 | } |
4382 | |
4383 | size_t dlmalloc_max_footprint(void) { |
4384 | return gm->max_footprint; |
4385 | } |
4386 | |
4387 | #if !NO_MALLINFO |
4388 | struct mallinfo dlmallinfo(void) { |
4389 | return internal_mallinfo(gm); |
4390 | } |
4391 | #endif /* NO_MALLINFO */ |
4392 | |
4393 | void dlmalloc_stats() { |
4394 | internal_malloc_stats(gm); |
4395 | } |
4396 | |
4397 | size_t dlmalloc_usable_size(void* mem) { |
4398 | if (mem != 0) { |
4399 | mchunkptr p = mem2chunk(mem); |
4400 | if (cinuse(p)) |
4401 | return chunksize(p) - overhead_for(p); |
4402 | } |
4403 | return 0; |
4404 | } |
4405 | |
4406 | int dlmallopt(int param_number, int value) { |
4407 | return change_mparam(param_number, value); |
4408 | } |
4409 | |
4410 | #endif /* !ONLY_MSPACES */ |
4411 | |
4412 | /* ----------------------------- user mspaces ---------------------------- */ |
4413 | |
4414 | #if MSPACES |
4415 | |
4416 | static mstate init_user_mstate(char* tbase, size_t tsize) { |
4417 | size_t msize = pad_request(sizeof(struct malloc_state)); |
4418 | mchunkptr mn; |
4419 | mchunkptr msp = align_as_chunk(tbase); |
4420 | mstate m = (mstate)(chunk2mem(msp)); |
4421 | memset(m, 0, msize); |
4422 | INITIAL_LOCK(&m->mutex); |
4423 | msp->head = (msize|PINUSE_BIT|CINUSE_BIT); |
4424 | m->seg.base = m->least_addr = tbase; |
4425 | m->seg.size = m->footprint = m->max_footprint = tsize; |
4426 | m->magic = mparams.magic; |
4427 | m->mflags = mparams.default_mflags; |
4428 | disable_contiguous(m); |
4429 | init_bins(m); |
4430 | mn = next_chunk(mem2chunk(m)); |
4431 | init_top(m, mn, (size_t)((tbase + tsize) - (char*)mn) - TOP_FOOT_SIZE); |
4432 | check_top_chunk(m, m->top); |
4433 | return m; |
4434 | } |
4435 | |
4436 | mspace create_mspace(size_t capacity, int locked) { |
4437 | mstate m = 0; |
4438 | size_t msize = pad_request(sizeof(struct malloc_state)); |
4439 | init_mparams(); /* Ensure pagesize etc initialized */ |
4440 | |
4441 | if (capacity < (size_t) -(msize + TOP_FOOT_SIZE + mparams.page_size)) { |
4442 | size_t rs = ((capacity == 0)? mparams.granularity : |
4443 | (capacity + TOP_FOOT_SIZE + msize)); |
4444 | size_t tsize = granularity_align(rs); |
4445 | char* tbase = (char*)(CALL_MMAP(tsize)); |
4446 | if (tbase != CMFAIL) { |
4447 | m = init_user_mstate(tbase, tsize); |
4448 | m->seg.sflags = IS_MMAPPED_BIT; |
4449 | set_lock(m, locked); |
4450 | } |
4451 | } |
4452 | return (mspace)m; |
4453 | } |
4454 | |
4455 | mspace create_mspace_with_base(void* base, size_t capacity, int locked) { |
4456 | mstate m = 0; |
4457 | size_t msize = pad_request(sizeof(struct malloc_state)); |
4458 | init_mparams(); /* Ensure pagesize etc initialized */ |
4459 | |
4460 | if (capacity > msize + TOP_FOOT_SIZE && |
4461 | capacity < (size_t) -(msize + TOP_FOOT_SIZE + mparams.page_size)) { |
4462 | m = init_user_mstate((char*)base, capacity); |
4463 | m->seg.sflags = EXTERN_BIT; |
4464 | set_lock(m, locked); |
4465 | } |
4466 | return (mspace)m; |
4467 | } |
4468 | |
4469 | size_t destroy_mspace(mspace msp) { |
4470 | size_t freed = 0; |
4471 | mstate ms = (mstate)msp; |
4472 | if (ok_magic(ms)) { |
4473 | msegmentptr sp = &ms->seg; |
4474 | while (sp != 0) { |
4475 | char* base = sp->base; |
4476 | size_t size = sp->size; |
4477 | flag_t flag = sp->sflags; |
4478 | sp = sp->next; |
4479 | if ((flag & IS_MMAPPED_BIT) && !(flag & EXTERN_BIT) && |
4480 | CALL_MUNMAP(base, size) == 0) |
4481 | freed += size; |
4482 | } |
4483 | } |
4484 | else { |
4485 | USAGE_ERROR_ACTION(ms,ms); |
4486 | } |
4487 | return freed; |
4488 | } |
4489 | |
4490 | /* |
4491 | mspace versions of routines are near-clones of the global |
4492 | versions. This is not so nice but better than the alternatives. |
4493 | */ |
4494 | |
4495 | |
4496 | void* mspace_malloc(mspace msp, size_t bytes) { |
4497 | mstate ms = (mstate)msp; |
4498 | if (!ok_magic(ms)) { |
4499 | USAGE_ERROR_ACTION(ms,ms); |
4500 | return 0; |
4501 | } |
4502 | if (!PREACTION(ms)) { |
4503 | void* mem; |
4504 | size_t nb; |
4505 | if (bytes <= MAX_SMALL_REQUEST) { |
4506 | bindex_t idx; |
4507 | binmap_t smallbits; |
4508 | nb = (bytes < MIN_REQUEST)? MIN_CHUNK_SIZE : pad_request(bytes); |
4509 | idx = small_index(nb); |
4510 | smallbits = ms->smallmap >> idx; |
4511 | |
4512 | if ((smallbits & 0x3U) != 0) { /* Remainderless fit to a smallbin. */ |
4513 | mchunkptr b, p; |
4514 | idx += ~smallbits & 1; /* Uses next bin if idx empty */ |
4515 | b = smallbin_at(ms, idx); |
4516 | p = b->fd; |
4517 | assert(chunksize(p) == small_index2size(idx)); |
4518 | unlink_first_small_chunk(ms, b, p, idx); |
4519 | set_inuse_and_pinuse(ms, p, small_index2size(idx)); |
4520 | mem = chunk2mem(p); |
4521 | check_malloced_chunk(ms, mem, nb); |
4522 | goto postaction; |
4523 | } |
4524 | |
4525 | else if (nb > ms->dvsize) { |
4526 | if (smallbits != 0) { /* Use chunk in next nonempty smallbin */ |
4527 | mchunkptr b, p, r; |
4528 | size_t rsize; |
4529 | bindex_t i; |
4530 | binmap_t leftbits = (smallbits << idx) & left_bits(idx2bit(idx)); |
4531 | binmap_t leastbit = least_bit(leftbits); |
4532 | compute_bit2idx(leastbit, i); |
4533 | b = smallbin_at(ms, i); |
4534 | p = b->fd; |
4535 | assert(chunksize(p) == small_index2size(i)); |
4536 | unlink_first_small_chunk(ms, b, p, i); |
4537 | rsize = small_index2size(i) - nb; |
4538 | /* Fit here cannot be remainderless if 4byte sizes */ |
4539 | if (SIZE_T_SIZE != 4 && rsize < MIN_CHUNK_SIZE) |
4540 | set_inuse_and_pinuse(ms, p, small_index2size(i)); |
4541 | else { |
4542 | set_size_and_pinuse_of_inuse_chunk(ms, p, nb); |
4543 | r = chunk_plus_offset(p, nb); |
4544 | set_size_and_pinuse_of_free_chunk(r, rsize); |
4545 | replace_dv(ms, r, rsize); |
4546 | } |
4547 | mem = chunk2mem(p); |
4548 | check_malloced_chunk(ms, mem, nb); |
4549 | goto postaction; |
4550 | } |
4551 | |
4552 | else if (ms->treemap != 0 && (mem = tmalloc_small(ms, nb)) != 0) { |
4553 | check_malloced_chunk(ms, mem, nb); |
4554 | goto postaction; |
4555 | } |
4556 | } |
4557 | } |
4558 | else if (bytes >= MAX_REQUEST) |
4559 | nb = MAX_SIZE_T; /* Too big to allocate. Force failure (in sys alloc) */ |
4560 | else { |
4561 | nb = pad_request(bytes); |
4562 | if (ms->treemap != 0 && (mem = tmalloc_large(ms, nb)) != 0) { |
4563 | check_malloced_chunk(ms, mem, nb); |
4564 | goto postaction; |
4565 | } |
4566 | } |
4567 | |
4568 | if (nb <= ms->dvsize) { |
4569 | size_t rsize = ms->dvsize - nb; |
4570 | mchunkptr p = ms->dv; |
4571 | if (rsize >= MIN_CHUNK_SIZE) { /* split dv */ |
4572 | mchunkptr r = ms->dv = chunk_plus_offset(p, nb); |
4573 | ms->dvsize = rsize; |
4574 | set_size_and_pinuse_of_free_chunk(r, rsize); |
4575 | set_size_and_pinuse_of_inuse_chunk(ms, p, nb); |
4576 | } |
4577 | else { /* exhaust dv */ |
4578 | size_t dvs = ms->dvsize; |
4579 | ms->dvsize = 0; |
4580 | ms->dv = 0; |
4581 | set_inuse_and_pinuse(ms, p, dvs); |
4582 | } |
4583 | mem = chunk2mem(p); |
4584 | check_malloced_chunk(ms, mem, nb); |
4585 | goto postaction; |
4586 | } |
4587 | |
4588 | else if (nb < ms->topsize) { /* Split top */ |
4589 | size_t rsize = ms->topsize -= nb; |
4590 | mchunkptr p = ms->top; |
4591 | mchunkptr r = ms->top = chunk_plus_offset(p, nb); |
4592 | r->head = rsize | PINUSE_BIT; |
4593 | set_size_and_pinuse_of_inuse_chunk(ms, p, nb); |
4594 | mem = chunk2mem(p); |
4595 | check_top_chunk(ms, ms->top); |
4596 | check_malloced_chunk(ms, mem, nb); |
4597 | goto postaction; |
4598 | } |
4599 | |
4600 | mem = sys_alloc(ms, nb); |
4601 | |
4602 | postaction: |
4603 | POSTACTION(ms); |
4604 | return mem; |
4605 | } |
4606 | |
4607 | return 0; |
4608 | } |
4609 | |
4610 | void mspace_free(mspace msp, void* mem) { |
4611 | if (mem != 0) { |
4612 | mchunkptr p = mem2chunk(mem); |
4613 | #if FOOTERS |
4614 | mstate fm = get_mstate_for(p); |
4615 | #else /* FOOTERS */ |
4616 | mstate fm = (mstate)msp; |
4617 | #endif /* FOOTERS */ |
4618 | if (!ok_magic(fm)) { |
4619 | USAGE_ERROR_ACTION(fm, p); |
4620 | return; |
4621 | } |
4622 | if (!PREACTION(fm)) { |
4623 | check_inuse_chunk(fm, p); |
4624 | if (RTCHECK(ok_address(fm, p) && ok_cinuse(p))) { |
4625 | size_t psize = chunksize(p); |
4626 | mchunkptr next = chunk_plus_offset(p, psize); |
4627 | if (!pinuse(p)) { |
4628 | size_t prevsize = p->prev_foot; |
4629 | if ((prevsize & IS_MMAPPED_BIT) != 0) { |
4630 | prevsize &= ~IS_MMAPPED_BIT; |
4631 | psize += prevsize + MMAP_FOOT_PAD; |
4632 | if (CALL_MUNMAP((char*)p - prevsize, psize) == 0) |
4633 | fm->footprint -= psize; |
4634 | goto postaction; |
4635 | } |
4636 | else { |
4637 | mchunkptr prev = chunk_minus_offset(p, prevsize); |
4638 | psize += prevsize; |
4639 | p = prev; |
4640 | if (RTCHECK(ok_address(fm, prev))) { /* consolidate backward */ |
4641 | if (p != fm->dv) { |
4642 | unlink_chunk(fm, p, prevsize); |
4643 | } |
4644 | else if ((next->head & INUSE_BITS) == INUSE_BITS) { |
4645 | fm->dvsize = psize; |
4646 | set_free_with_pinuse(p, psize, next); |
4647 | goto postaction; |
4648 | } |
4649 | } |
4650 | else |
4651 | goto erroraction; |
4652 | } |
4653 | } |
4654 | |
4655 | if (RTCHECK(ok_next(p, next) && ok_pinuse(next))) { |
4656 | if (!cinuse(next)) { /* consolidate forward */ |
4657 | if (next == fm->top) { |
4658 | size_t tsize = fm->topsize += psize; |
4659 | fm->top = p; |
4660 | p->head = tsize | PINUSE_BIT; |
4661 | if (p == fm->dv) { |
4662 | fm->dv = 0; |
4663 | fm->dvsize = 0; |
4664 | } |
4665 | if (should_trim(fm, tsize)) |
4666 | sys_trim(fm, 0); |
4667 | goto postaction; |
4668 | } |
4669 | else if (next == fm->dv) { |
4670 | size_t dsize = fm->dvsize += psize; |
4671 | fm->dv = p; |
4672 | set_size_and_pinuse_of_free_chunk(p, dsize); |
4673 | goto postaction; |
4674 | } |
4675 | else { |
4676 | size_t nsize = chunksize(next); |
4677 | psize += nsize; |
4678 | unlink_chunk(fm, next, nsize); |
4679 | set_size_and_pinuse_of_free_chunk(p, psize); |
4680 | if (p == fm->dv) { |
4681 | fm->dvsize = psize; |
4682 | goto postaction; |
4683 | } |
4684 | } |
4685 | } |
4686 | else |
4687 | set_free_with_pinuse(p, psize, next); |
4688 | insert_chunk(fm, p, psize); |
4689 | check_free_chunk(fm, p); |
4690 | goto postaction; |
4691 | } |
4692 | } |
4693 | erroraction: |
4694 | USAGE_ERROR_ACTION(fm, p); |
4695 | postaction: |
4696 | POSTACTION(fm); |
4697 | } |
4698 | } |
4699 | } |
4700 | |
4701 | void* mspace_calloc(mspace msp, size_t n_elements, size_t elem_size) { |
4702 | void* mem; |
4703 | size_t req = 0; |
4704 | mstate ms = (mstate)msp; |
4705 | if (!ok_magic(ms)) { |
4706 | USAGE_ERROR_ACTION(ms,ms); |
4707 | return 0; |
4708 | } |
4709 | if (n_elements != 0) { |
4710 | req = n_elements * elem_size; |
4711 | if (((n_elements | elem_size) & ~(size_t)0xffff) && |
4712 | (req / n_elements != elem_size)) |
4713 | req = MAX_SIZE_T; /* force downstream failure on overflow */ |
4714 | } |
4715 | mem = internal_malloc(ms, req); |
4716 | if (mem != 0 && calloc_must_clear(mem2chunk(mem))) |
4717 | memset(mem, 0, req); |
4718 | return mem; |
4719 | } |
4720 | |
4721 | void* mspace_realloc(mspace msp, void* oldmem, size_t bytes) { |
4722 | if (oldmem == 0) |
4723 | return mspace_malloc(msp, bytes); |
4724 | #ifdef REALLOC_ZERO_BYTES_FREES |
4725 | if (bytes == 0) { |
4726 | mspace_free(msp, oldmem); |
4727 | return 0; |
4728 | } |
4729 | #endif /* REALLOC_ZERO_BYTES_FREES */ |
4730 | else { |
4731 | #if FOOTERS |
4732 | mchunkptr p = mem2chunk(oldmem); |
4733 | mstate ms = get_mstate_for(p); |
4734 | #else /* FOOTERS */ |
4735 | mstate ms = (mstate)msp; |
4736 | #endif /* FOOTERS */ |
4737 | if (!ok_magic(ms)) { |
4738 | USAGE_ERROR_ACTION(ms,ms); |
4739 | return 0; |
4740 | } |
4741 | return internal_realloc(ms, oldmem, bytes); |
4742 | } |
4743 | } |
4744 | |
4745 | void* mspace_memalign(mspace msp, size_t alignment, size_t bytes) { |
4746 | mstate ms = (mstate)msp; |
4747 | if (!ok_magic(ms)) { |
4748 | USAGE_ERROR_ACTION(ms,ms); |
4749 | return 0; |
4750 | } |
4751 | return internal_memalign(ms, alignment, bytes); |
4752 | } |
4753 | |
4754 | void** mspace_independent_calloc(mspace msp, size_t n_elements, |
4755 | size_t elem_size, void* chunks[]) { |
4756 | size_t sz = elem_size; /* serves as 1-element array */ |
4757 | mstate ms = (mstate)msp; |
4758 | if (!ok_magic(ms)) { |
4759 | USAGE_ERROR_ACTION(ms,ms); |
4760 | return 0; |
4761 | } |
4762 | return ialloc(ms, n_elements, &sz, 3, chunks); |
4763 | } |
4764 | |
4765 | void** mspace_independent_comalloc(mspace msp, size_t n_elements, |
4766 | size_t sizes[], void* chunks[]) { |
4767 | mstate ms = (mstate)msp; |
4768 | if (!ok_magic(ms)) { |
4769 | USAGE_ERROR_ACTION(ms,ms); |
4770 | return 0; |
4771 | } |
4772 | return ialloc(ms, n_elements, sizes, 0, chunks); |
4773 | } |
4774 | |
4775 | int mspace_trim(mspace msp, size_t pad) { |
4776 | int result = 0; |
4777 | mstate ms = (mstate)msp; |
4778 | if (ok_magic(ms)) { |
4779 | if (!PREACTION(ms)) { |
4780 | result = sys_trim(ms, pad); |
4781 | POSTACTION(ms); |
4782 | } |
4783 | } |
4784 | else { |
4785 | USAGE_ERROR_ACTION(ms,ms); |
4786 | } |
4787 | return result; |
4788 | } |
4789 | |
4790 | void mspace_malloc_stats(mspace msp) { |
4791 | mstate ms = (mstate)msp; |
4792 | if (ok_magic(ms)) { |
4793 | internal_malloc_stats(ms); |
4794 | } |
4795 | else { |
4796 | USAGE_ERROR_ACTION(ms,ms); |
4797 | } |
4798 | } |
4799 | |
4800 | size_t mspace_footprint(mspace msp) { |
4801 | size_t result; |
4802 | mstate ms = (mstate)msp; |
4803 | if (ok_magic(ms)) { |
4804 | result = ms->footprint; |
4805 | } |
4806 | USAGE_ERROR_ACTION(ms,ms); |
4807 | return result; |
4808 | } |
4809 | |
4810 | |
4811 | size_t mspace_max_footprint(mspace msp) { |
4812 | size_t result; |
4813 | mstate ms = (mstate)msp; |
4814 | if (ok_magic(ms)) { |
4815 | result = ms->max_footprint; |
4816 | } |
4817 | USAGE_ERROR_ACTION(ms,ms); |
4818 | return result; |
4819 | } |
4820 | |
4821 | |
4822 | #if !NO_MALLINFO |
4823 | struct mallinfo mspace_mallinfo(mspace msp) { |
4824 | mstate ms = (mstate)msp; |
4825 | if (!ok_magic(ms)) { |
4826 | USAGE_ERROR_ACTION(ms,ms); |
4827 | } |
4828 | return internal_mallinfo(ms); |
4829 | } |
4830 | #endif /* NO_MALLINFO */ |
4831 | |
4832 | int mspace_mallopt(int param_number, int value) { |
4833 | return change_mparam(param_number, value); |
4834 | } |
4835 | |
4836 | #endif /* MSPACES */ |
4837 | |
4838 | /* -------------------- Alternative MORECORE functions ------------------- */ |
4839 | |
4840 | /* |
4841 | Guidelines for creating a custom version of MORECORE: |
4842 | |
4843 | * For best performance, MORECORE should allocate in multiples of pagesize. |
4844 | * MORECORE may allocate more memory than requested. (Or even less, |
4845 | but this will usually result in a malloc failure.) |
4846 | * MORECORE must not allocate memory when given argument zero, but |
4847 | instead return one past the end address of memory from previous |
4848 | nonzero call. |
4849 | * For best performance, consecutive calls to MORECORE with positive |
4850 | arguments should return increasing addresses, indicating that |
4851 | space has been contiguously extended. |
4852 | * Even though consecutive calls to MORECORE need not return contiguous |
4853 | addresses, it must be OK for malloc'ed chunks to span multiple |
4854 | regions in those cases where they do happen to be contiguous. |
4855 | * MORECORE need not handle negative arguments -- it may instead |
4856 | just return MFAIL when given negative arguments. |
4857 | Negative arguments are always multiples of pagesize. MORECORE |
4858 | must not misinterpret negative args as large positive unsigned |
4859 | args. You can suppress all such calls from even occurring by defining |
4860 | MORECORE_CANNOT_TRIM, |
4861 | |
4862 | As an example alternative MORECORE, here is a custom allocator |
4863 | kindly contributed for pre-OSX macOS. It uses virtually but not |
4864 | necessarily physically contiguous non-paged memory (locked in, |
4865 | present and won't get swapped out). You can use it by uncommenting |
4866 | this section, adding some #includes, and setting up the appropriate |
4867 | defines above: |
4868 | |
4869 | #define MORECORE osMoreCore |
4870 | |
4871 | There is also a shutdown routine that should somehow be called for |
4872 | cleanup upon program exit. |
4873 | |
4874 | #define MAX_POOL_ENTRIES 100 |
4875 | #define MINIMUM_MORECORE_SIZE (64 * 1024U) |
4876 | static int next_os_pool; |
4877 | void *our_os_pools[MAX_POOL_ENTRIES]; |
4878 | |
4879 | void *osMoreCore(int size) |
4880 | { |
4881 | void *ptr = 0; |
4882 | static void *sbrk_top = 0; |
4883 | |
4884 | if (size > 0) |
4885 | { |
4886 | if (size < MINIMUM_MORECORE_SIZE) |
4887 | size = MINIMUM_MORECORE_SIZE; |
4888 | if (CurrentExecutionLevel() == kTaskLevel) |
4889 | ptr = PoolAllocateResident(size + RM_PAGE_SIZE, 0); |
4890 | if (ptr == 0) |
4891 | { |
4892 | return (void *) MFAIL; |
4893 | } |
4894 | // save ptrs so they can be freed during cleanup |
4895 | our_os_pools[next_os_pool] = ptr; |
4896 | next_os_pool++; |
4897 | ptr = (void *) ((((size_t) ptr) + RM_PAGE_MASK) & ~RM_PAGE_MASK); |
4898 | sbrk_top = (char *) ptr + size; |
4899 | return ptr; |
4900 | } |
4901 | else if (size < 0) |
4902 | { |
4903 | // we don't currently support shrink behavior |
4904 | return (void *) MFAIL; |
4905 | } |
4906 | else |
4907 | { |
4908 | return sbrk_top; |
4909 | } |
4910 | } |
4911 | |
4912 | // cleanup any allocated memory pools |
4913 | // called as last thing before shutting down driver |
4914 | |
4915 | void osCleanupMem(void) |
4916 | { |
4917 | void **ptr; |
4918 | |
4919 | for (ptr = our_os_pools; ptr < &our_os_pools[MAX_POOL_ENTRIES]; ptr++) |
4920 | if (*ptr) |
4921 | { |
4922 | PoolDeallocate(*ptr); |
4923 | *ptr = 0; |
4924 | } |
4925 | } |
4926 | |
4927 | */ |
4928 | |
4929 | |
4930 | /* ----------------------------------------------------------------------- |
4931 | History: |
4932 | V2.8.3 Thu Sep 22 11:16:32 2005 Doug Lea (dl at gee) |
4933 | * Add max_footprint functions |
4934 | * Ensure all appropriate literals are size_t |
4935 | * Fix conditional compilation problem for some #define settings |
4936 | * Avoid concatenating segments with the one provided |
4937 | in create_mspace_with_base |
4938 | * Rename some variables to avoid compiler shadowing warnings |
4939 | * Use explicit lock initialization. |
4940 | * Better handling of sbrk interference. |
4941 | * Simplify and fix segment insertion, trimming and mspace_destroy |
4942 | * Reinstate REALLOC_ZERO_BYTES_FREES option from 2.7.x |
4943 | * Thanks especially to Dennis Flanagan for help on these. |
4944 | |
4945 | V2.8.2 Sun Jun 12 16:01:10 2005 Doug Lea (dl at gee) |
4946 | * Fix memalign brace error. |
4947 | |
4948 | V2.8.1 Wed Jun 8 16:11:46 2005 Doug Lea (dl at gee) |
4949 | * Fix improper #endif nesting in C++ |
4950 | * Add explicit casts needed for C++ |
4951 | |
4952 | V2.8.0 Mon May 30 14:09:02 2005 Doug Lea (dl at gee) |
4953 | * Use trees for large bins |
4954 | * Support mspaces |
4955 | * Use segments to unify sbrk-based and mmap-based system allocation, |
4956 | removing need for emulation on most platforms without sbrk. |
4957 | * Default safety checks |
4958 | * Optional footer checks. Thanks to William Robertson for the idea. |
4959 | * Internal code refactoring |
4960 | * Incorporate suggestions and platform-specific changes. |
4961 | Thanks to Dennis Flanagan, Colin Plumb, Niall Douglas, |
4962 | Aaron Bachmann, Emery Berger, and others. |
4963 | * Speed up non-fastbin processing enough to remove fastbins. |
4964 | * Remove useless cfree() to avoid conflicts with other apps. |
4965 | * Remove internal memcpy, memset. Compilers handle builtins better. |
4966 | * Remove some options that no one ever used and rename others. |
4967 | |
4968 | V2.7.2 Sat Aug 17 09:07:30 2002 Doug Lea (dl at gee) |
4969 | * Fix malloc_state bitmap array misdeclaration |
4970 | |
4971 | V2.7.1 Thu Jul 25 10:58:03 2002 Doug Lea (dl at gee) |
4972 | * Allow tuning of FIRST_SORTED_BIN_SIZE |
4973 | * Use PTR_UINT as type for all ptr->int casts. Thanks to John Belmonte. |
4974 | * Better detection and support for non-contiguousness of MORECORE. |
4975 | Thanks to Andreas Mueller, Conal Walsh, and Wolfram Gloger |
4976 | * Bypass most of malloc if no frees. Thanks To Emery Berger. |
4977 | * Fix freeing of old top non-contiguous chunk im sysmalloc. |
4978 | * Raised default trim and map thresholds to 256K. |
4979 | * Fix mmap-related #defines. Thanks to Lubos Lunak. |
4980 | * Fix copy macros; added LACKS_FCNTL_H. Thanks to Neal Walfield. |
4981 | * Branch-free bin calculation |
4982 | * Default trim and mmap thresholds now 256K. |
4983 | |
4984 | V2.7.0 Sun Mar 11 14:14:06 2001 Doug Lea (dl at gee) |
4985 | * Introduce independent_comalloc and independent_calloc. |
4986 | Thanks to Michael Pachos for motivation and help. |
4987 | * Make optional .h file available |
4988 | * Allow > 2GB requests on 32bit systems. |
4989 | * new WIN32 sbrk, mmap, munmap, lock code from <Walter@GeNeSys-e.de>. |
4990 | Thanks also to Andreas Mueller <a.mueller at paradatec.de>, |
4991 | and Anonymous. |
4992 | * Allow override of MALLOC_ALIGNMENT (Thanks to Ruud Waij for |
4993 | helping test this.) |
4994 | * memalign: check alignment arg |
4995 | * realloc: don't try to shift chunks backwards, since this |
4996 | leads to more fragmentation in some programs and doesn't |
4997 | seem to help in any others. |
4998 | * Collect all cases in malloc requiring system memory into sysmalloc |
4999 | * Use mmap as backup to sbrk |
5000 | * Place all internal state in malloc_state |
5001 | * Introduce fastbins (although similar to 2.5.1) |
5002 | * Many minor tunings and cosmetic improvements |
5003 | * Introduce USE_PUBLIC_MALLOC_WRAPPERS, USE_MALLOC_LOCK |
5004 | * Introduce MALLOC_FAILURE_ACTION, MORECORE_CONTIGUOUS |
5005 | Thanks to Tony E. Bennett <tbennett@nvidia.com> and others. |
5006 | * Include errno.h to support default failure action. |
5007 | |
5008 | V2.6.6 Sun Dec 5 07:42:19 1999 Doug Lea (dl at gee) |
5009 | * return null for negative arguments |
5010 | * Added Several WIN32 cleanups from Martin C. Fong <mcfong at yahoo.com> |
5011 | * Add 'LACKS_SYS_PARAM_H' for those systems without 'sys/param.h' |
5012 | (e.g. WIN32 platforms) |
5013 | * Cleanup header file inclusion for WIN32 platforms |
5014 | * Cleanup code to avoid Microsoft Visual C++ compiler complaints |
5015 | * Add 'USE_DL_PREFIX' to quickly allow co-existence with existing |
5016 | memory allocation routines |
5017 | * Set 'malloc_getpagesize' for WIN32 platforms (needs more work) |
5018 | * Use 'assert' rather than 'ASSERT' in WIN32 code to conform to |
5019 | usage of 'assert' in non-WIN32 code |
5020 | * Improve WIN32 'sbrk()' emulation's 'findRegion()' routine to |
5021 | avoid infinite loop |
5022 | * Always call 'fREe()' rather than 'free()' |
5023 | |
5024 | V2.6.5 Wed Jun 17 15:57:31 1998 Doug Lea (dl at gee) |
5025 | * Fixed ordering problem with boundary-stamping |
5026 | |
5027 | V2.6.3 Sun May 19 08:17:58 1996 Doug Lea (dl at gee) |
5028 | * Added pvalloc, as recommended by H.J. Liu |
5029 | * Added 64bit pointer support mainly from Wolfram Gloger |
5030 | * Added anonymously donated WIN32 sbrk emulation |
5031 | * Malloc, calloc, getpagesize: add optimizations from Raymond Nijssen |
5032 | * malloc_extend_top: fix mask error that caused wastage after |
5033 | foreign sbrks |
5034 | * Add linux mremap support code from HJ Liu |
5035 | |
5036 | V2.6.2 Tue Dec 5 06:52:55 1995 Doug Lea (dl at gee) |
5037 | * Integrated most documentation with the code. |
5038 | * Add support for mmap, with help from |
5039 | Wolfram Gloger (Gloger@lrz.uni-muenchen.de). |
5040 | * Use last_remainder in more cases. |
5041 | * Pack bins using idea from colin@nyx10.cs.du.edu |
5042 | * Use ordered bins instead of best-fit threshhold |
5043 | * Eliminate block-local decls to simplify tracing and debugging. |
5044 | * Support another case of realloc via move into top |
5045 | * Fix error occuring when initial sbrk_base not word-aligned. |
5046 | * Rely on page size for units instead of SBRK_UNIT to |
5047 | avoid surprises about sbrk alignment conventions. |
5048 | * Add mallinfo, mallopt. Thanks to Raymond Nijssen |
5049 | (raymond@es.ele.tue.nl) for the suggestion. |
5050 | * Add `pad' argument to malloc_trim and top_pad mallopt parameter. |
5051 | * More precautions for cases where other routines call sbrk, |
5052 | courtesy of Wolfram Gloger (Gloger@lrz.uni-muenchen.de). |
5053 | * Added macros etc., allowing use in linux libc from |
5054 | H.J. Lu (hjl@gnu.ai.mit.edu) |
5055 | * Inverted this history list |
5056 | |
5057 | V2.6.1 Sat Dec 2 14:10:57 1995 Doug Lea (dl at gee) |
5058 | * Re-tuned and fixed to behave more nicely with V2.6.0 changes. |
5059 | * Removed all preallocation code since under current scheme |
5060 | the work required to undo bad preallocations exceeds |
5061 | the work saved in good cases for most test programs. |
5062 | * No longer use return list or unconsolidated bins since |
5063 | no scheme using them consistently outperforms those that don't |
5064 | given above changes. |
5065 | * Use best fit for very large chunks to prevent some worst-cases. |
5066 | * Added some support for debugging |
5067 | |
5068 | V2.6.0 Sat Nov 4 07:05:23 1995 Doug Lea (dl at gee) |
5069 | * Removed footers when chunks are in use. Thanks to |
5070 | Paul Wilson (wilson@cs.texas.edu) for the suggestion. |
5071 | |
5072 | V2.5.4 Wed Nov 1 07:54:51 1995 Doug Lea (dl at gee) |
5073 | * Added malloc_trim, with help from Wolfram Gloger |
5074 | (wmglo@Dent.MED.Uni-Muenchen.DE). |
5075 | |
5076 | V2.5.3 Tue Apr 26 10:16:01 1994 Doug Lea (dl at g) |
5077 | |
5078 | V2.5.2 Tue Apr 5 16:20:40 1994 Doug Lea (dl at g) |
5079 | * realloc: try to expand in both directions |
5080 | * malloc: swap order of clean-bin strategy; |
5081 | * realloc: only conditionally expand backwards |
5082 | * Try not to scavenge used bins |
5083 | * Use bin counts as a guide to preallocation |
5084 | * Occasionally bin return list chunks in first scan |
5085 | * Add a few optimizations from colin@nyx10.cs.du.edu |
5086 | |
5087 | V2.5.1 Sat Aug 14 15:40:43 1993 Doug Lea (dl at g) |
5088 | * faster bin computation & slightly different binning |
5089 | * merged all consolidations to one part of malloc proper |
5090 | (eliminating old malloc_find_space & malloc_clean_bin) |
5091 | * Scan 2 returns chunks (not just 1) |
5092 | * Propagate failure in realloc if malloc returns 0 |
5093 | * Add stuff to allow compilation on non-ANSI compilers |
5094 | from kpv@research.att.com |
5095 | |
5096 | V2.5 Sat Aug 7 07:41:59 1993 Doug Lea (dl at g.oswego.edu) |
5097 | * removed potential for odd address access in prev_chunk |
5098 | * removed dependency on getpagesize.h |
5099 | * misc cosmetics and a bit more internal documentation |
5100 | * anticosmetics: mangled names in macros to evade debugger strangeness |
5101 | * tested on sparc, hp-700, dec-mips, rs6000 |
5102 | with gcc & native cc (hp, dec only) allowing |
5103 | Detlefs & Zorn comparison study (in SIGPLAN Notices.) |
5104 | |
5105 | Trial version Fri Aug 28 13:14:29 1992 Doug Lea (dl at g.oswego.edu) |
5106 | * Based loosely on libg++-1.2X malloc. (It retains some of the overall |
5107 | structure of old version, but most details differ.) |
5108 | |
5109 | */ |
5110 | |
5111 | #endif /* !HAVE_MALLOC */ |