Commit | Line | Data |
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3719602c PC |
1 | /* |
2 | libco.sjlj (2008-01-28) | |
3 | author: Nach | |
4 | license: public domain | |
5 | */ | |
6 | ||
7 | /* | |
8 | * Note this was designed for UNIX systems. Based on ideas expressed in a paper | |
9 | * by Ralf Engelschall. | |
10 | * For SJLJ on other systems, one would want to rewrite springboard() and | |
11 | * co_create() and hack the jmb_buf stack pointer. | |
12 | */ | |
13 | ||
14 | #define LIBCO_C | |
15 | #include <libco.h> | |
16 | #include <stdlib.h> | |
17 | #include <signal.h> | |
18 | #include <setjmp.h> | |
19 | ||
20 | #ifdef __cplusplus | |
21 | extern "C" { | |
22 | #endif | |
23 | ||
24 | typedef struct | |
25 | { | |
26 | sigjmp_buf context; | |
27 | void (*coentry)(void); | |
28 | void *stack; | |
29 | } cothread_struct; | |
30 | ||
31 | static thread_local cothread_struct co_primary; | |
32 | static thread_local cothread_struct *creating, *co_running = 0; | |
33 | ||
34 | static void springboard(int ignored) | |
35 | { | |
36 | if (sigsetjmp(creating->context, 0)) | |
37 | co_running->coentry(); | |
38 | } | |
39 | ||
40 | cothread_t co_active(void) | |
41 | { | |
42 | if (!co_running) | |
43 | co_running = &co_primary; | |
44 | return (cothread_t)co_running; | |
45 | } | |
46 | ||
47 | cothread_t co_create(unsigned int size, void (*coentry)(void)) | |
48 | { | |
49 | cothread_struct *thread; | |
50 | if (!co_running) | |
51 | co_running = &co_primary; | |
52 | ||
53 | if ((thread = (cothread_struct*)malloc(sizeof(cothread_struct)))) | |
54 | { | |
55 | stack_t stack; | |
56 | stack_t old_stack; | |
57 | ||
58 | thread->coentry = thread->stack = 0; | |
59 | ||
60 | stack.ss_flags = 0; | |
61 | stack.ss_size = size; | |
62 | thread->stack = stack.ss_sp = malloc(size); | |
63 | ||
64 | if (stack.ss_sp && !sigaltstack(&stack, &old_stack)) | |
65 | { | |
66 | struct sigaction old_handler = {{0}}; | |
67 | struct sigaction handler = {{0}}; | |
68 | handler.sa_handler = springboard; | |
69 | handler.sa_flags = SA_ONSTACK; | |
70 | sigemptyset(&handler.sa_mask); | |
71 | creating = thread; | |
72 | ||
73 | if (!sigaction(SIGUSR1, &handler, &old_handler)) | |
74 | { | |
75 | if (!raise(SIGUSR1)) | |
76 | thread->coentry = coentry; | |
77 | sigaltstack(&old_stack, 0); | |
78 | sigaction(SIGUSR1, &old_handler, 0); | |
79 | } | |
80 | } | |
81 | ||
82 | if (thread->coentry != coentry) | |
83 | { | |
84 | co_delete(thread); | |
85 | thread = 0; | |
86 | } | |
87 | } | |
88 | ||
89 | return (cothread_t)thread; | |
90 | } | |
91 | ||
92 | void co_delete(cothread_t cothread) | |
93 | { | |
94 | if (cothread) | |
95 | { | |
96 | if (((cothread_struct*)cothread)->stack) | |
97 | free(((cothread_struct*)cothread)->stack); | |
98 | free(cothread); | |
99 | } | |
100 | } | |
101 | ||
102 | void co_switch(cothread_t cothread) | |
103 | { | |
104 | if (!sigsetjmp(co_running->context, 0)) | |
105 | { | |
106 | co_running = (cothread_struct*)cothread; | |
107 | siglongjmp(co_running->context, 1); | |
108 | } | |
109 | } | |
110 | ||
111 | #ifdef __cplusplus | |
112 | } | |
113 | #endif |