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 | /* |
25 | * GNU pth conditions variables |
26 | * |
27 | * Patrice Mandin |
28 | */ |
29 | |
30 | #include <pth.h> |
31 | |
32 | #include "SDL_thread.h" |
33 | #include "SDL_sysmutex_c.h" |
34 | |
35 | struct SDL_cond |
36 | { |
37 | pth_cond_t condpth_p; |
38 | }; |
39 | |
40 | /* Create a condition variable */ |
41 | SDL_cond * SDL_CreateCond(void) |
42 | { |
43 | SDL_cond *cond; |
44 | |
45 | cond = (SDL_cond *) SDL_malloc(sizeof(SDL_cond)); |
46 | if ( cond ) { |
47 | if ( pth_cond_init(&(cond->condpth_p)) < 0 ) { |
48 | SDL_SetError("pthread_cond_init() failed"); |
49 | SDL_free(cond); |
50 | cond = NULL; |
51 | } |
52 | } else { |
53 | SDL_OutOfMemory(); |
54 | } |
55 | return(cond); |
56 | } |
57 | |
58 | /* Destroy a condition variable */ |
59 | void SDL_DestroyCond(SDL_cond *cond) |
60 | { |
61 | if ( cond ) { |
62 | SDL_free(cond); |
63 | } |
64 | } |
65 | |
66 | /* Restart one of the threads that are waiting on the condition variable */ |
67 | int SDL_CondSignal(SDL_cond *cond) |
68 | { |
69 | int retval; |
70 | |
71 | if ( ! cond ) { |
72 | SDL_SetError("Passed a NULL condition variable"); |
73 | return -1; |
74 | } |
75 | |
76 | retval = 0; |
77 | if ( pth_cond_notify(&(cond->condpth_p), FALSE) != 0 ) { |
78 | SDL_SetError("pth_cond_notify() failed"); |
79 | retval = -1; |
80 | } |
81 | return retval; |
82 | } |
83 | |
84 | /* Restart all threads that are waiting on the condition variable */ |
85 | int SDL_CondBroadcast(SDL_cond *cond) |
86 | { |
87 | int retval; |
88 | |
89 | if ( ! cond ) { |
90 | SDL_SetError("Passed a NULL condition variable"); |
91 | return -1; |
92 | } |
93 | |
94 | retval = 0; |
95 | if ( pth_cond_notify(&(cond->condpth_p), TRUE) != 0 ) { |
96 | SDL_SetError("pth_cond_notify() failed"); |
97 | retval = -1; |
98 | } |
99 | return retval; |
100 | } |
101 | |
102 | /* Wait on the condition variable for at most 'ms' milliseconds. |
103 | The mutex must be locked before entering this function! |
104 | The mutex is unlocked during the wait, and locked again after the wait. |
105 | |
106 | Typical use: |
107 | |
108 | Thread A: |
109 | SDL_LockMutex(lock); |
110 | while ( ! condition ) { |
111 | SDL_CondWait(cond); |
112 | } |
113 | SDL_UnlockMutex(lock); |
114 | |
115 | Thread B: |
116 | SDL_LockMutex(lock); |
117 | ... |
118 | condition = true; |
119 | ... |
120 | SDL_UnlockMutex(lock); |
121 | */ |
122 | int SDL_CondWaitTimeout(SDL_cond *cond, SDL_mutex *mutex, Uint32 ms) |
123 | { |
124 | int retval; |
125 | pth_event_t ev; |
126 | int sec; |
127 | |
128 | if ( ! cond ) { |
129 | SDL_SetError("Passed a NULL condition variable"); |
130 | return -1; |
131 | } |
132 | |
133 | retval = 0; |
134 | |
135 | sec = ms/1000; |
136 | ev = pth_event(PTH_EVENT_TIME, pth_timeout(sec,(ms-sec*1000)*1000)); |
137 | |
138 | if ( pth_cond_await(&(cond->condpth_p), &(mutex->mutexpth_p), ev) != 0 ) { |
139 | SDL_SetError("pth_cond_await() failed"); |
140 | retval = -1; |
141 | } |
142 | |
143 | pth_event_free(ev, PTH_FREE_ALL); |
144 | |
145 | return retval; |
146 | } |
147 | |
148 | /* Wait on the condition variable forever */ |
149 | int SDL_CondWait(SDL_cond *cond, SDL_mutex *mutex) |
150 | { |
151 | int retval; |
152 | |
153 | if ( ! cond ) { |
154 | SDL_SetError("Passed a NULL condition variable"); |
155 | return -1; |
156 | } |
157 | |
158 | retval = 0; |
159 | if ( pth_cond_await(&(cond->condpth_p), &(mutex->mutexpth_p), NULL) != 0 ) { |
160 | SDL_SetError("pth_cond_await() failed"); |
161 | retval = -1; |
162 | } |
163 | return retval; |
164 | } |