Mercurial > sdl-ios-xcode
annotate src/thread/linux/SDL_syscond.c @ 244:dc660aee7d7d
Fixed timeout in Linux condition variable implementation
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Fri, 23 Nov 2001 17:11:05 +0000 |
| parents | 74212992fb08 |
| children | e8157fcb3114 |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 2 SDL - Simple DirectMedia Layer | |
| 3 Copyright (C) 1997, 1998, 1999, 2000, 2001 Sam Lantinga | |
| 4 | |
| 5 This library is free software; you can redistribute it and/or | |
| 6 modify it under the terms of the GNU Library General Public | |
| 7 License as published by the Free Software Foundation; either | |
| 8 version 2 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 Library General Public License for more details. | |
| 14 | |
| 15 You should have received a copy of the GNU Library General Public | |
| 16 License along with this library; if not, write to the Free | |
| 17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
| 18 | |
| 19 Sam Lantinga | |
| 20 slouken@devolution.com | |
| 21 */ | |
| 22 | |
| 23 #ifdef SAVE_RCSID | |
| 24 static char rcsid = | |
| 25 "@(#) $Id$"; | |
| 26 #endif | |
| 27 | |
| 28 #ifdef linux | |
| 29 /* Look to see if glibc is available, and if so, what version */ | |
| 30 #include <features.h> | |
| 31 | |
| 32 #if (__GLIBC__ == 2) && (__GLIBC_MINOR__ == 0) | |
| 33 #warning Working around a bug in glibc 2.0 pthreads | |
| 34 #undef SDL_USE_PTHREADS | |
| 35 /* The bug is actually a problem where threads are suspended, but don't | |
| 36 wake up when the thread manager sends them a signal. This is a problem | |
| 37 with thread creation too, but it happens less often. :-/ | |
| 38 We avoid this by using System V IPC for mutexes. | |
| 39 */ | |
| 40 #endif /* glibc 2.0 */ | |
| 41 #endif /* linux */ | |
| 42 | |
| 43 #ifdef SDL_USE_PTHREADS | |
| 44 | |
| 45 #include <sys/time.h> | |
| 46 #include <unistd.h> | |
| 47 #include <errno.h> | |
| 48 #include <stdlib.h> | |
| 49 #include <pthread.h> | |
| 50 | |
| 51 #include "SDL_error.h" | |
| 52 #include "SDL_thread.h" | |
| 53 #include "SDL_sysmutex_c.h" | |
| 54 | |
| 55 | |
| 56 #if defined(PTHREAD_NO_RECURSIVE_MUTEX) && !defined(__bsdi__) | |
| 57 #error You need to use the generic condition variable implementation | |
| 58 #endif | |
| 59 | |
| 60 struct SDL_cond | |
| 61 { | |
| 62 pthread_cond_t cond; | |
| 63 }; | |
| 64 | |
| 65 /* Create a condition variable */ | |
| 66 SDL_cond * SDL_CreateCond(void) | |
| 67 { | |
| 68 SDL_cond *cond; | |
| 69 | |
| 70 cond = (SDL_cond *) malloc(sizeof(SDL_cond)); | |
| 71 if ( cond ) { | |
| 72 if ( pthread_cond_init(&cond->cond, NULL) < 0 ) { | |
| 73 SDL_SetError("pthread_cond_init() failed"); | |
| 74 free(cond); | |
| 75 cond = NULL; | |
| 76 } | |
| 77 } | |
| 78 return(cond); | |
| 79 } | |
| 80 | |
| 81 /* Destroy a condition variable */ | |
| 82 void SDL_DestroyCond(SDL_cond *cond) | |
| 83 { | |
| 84 if ( cond ) { | |
| 85 pthread_cond_destroy(&cond->cond); | |
| 86 free(cond); | |
| 87 } | |
| 88 } | |
| 89 | |
| 90 /* Restart one of the threads that are waiting on the condition variable */ | |
| 91 int SDL_CondSignal(SDL_cond *cond) | |
| 92 { | |
| 93 int retval; | |
| 94 | |
| 95 if ( ! cond ) { | |
| 96 SDL_SetError("Passed a NULL condition variable"); | |
| 97 return -1; | |
| 98 } | |
| 99 | |
| 100 retval = 0; | |
| 101 if ( pthread_cond_signal(&cond->cond) != 0 ) { | |
| 102 SDL_SetError("pthread_cond_signal() failed"); | |
| 103 retval = -1; | |
| 104 } | |
| 105 return retval; | |
| 106 } | |
| 107 | |
| 108 /* Restart all threads that are waiting on the condition variable */ | |
| 109 int SDL_CondBroadcast(SDL_cond *cond) | |
| 110 { | |
| 111 int retval; | |
| 112 | |
| 113 if ( ! cond ) { | |
| 114 SDL_SetError("Passed a NULL condition variable"); | |
| 115 return -1; | |
| 116 } | |
| 117 | |
| 118 retval = 0; | |
| 119 if ( pthread_cond_broadcast(&cond->cond) != 0 ) { | |
| 120 SDL_SetError("pthread_cond_broadcast() failed"); | |
| 121 retval = -1; | |
| 122 } | |
| 123 return retval; | |
| 124 } | |
| 125 | |
| 126 int SDL_CondWaitTimeout(SDL_cond *cond, SDL_mutex *mutex, Uint32 ms) | |
| 127 { | |
| 128 int retval; | |
| 129 struct timeval delta; | |
| 130 struct timespec abstime; | |
| 131 | |
| 132 if ( ! cond ) { | |
| 133 SDL_SetError("Passed a NULL condition variable"); | |
| 134 return -1; | |
| 135 } | |
| 136 | |
| 137 gettimeofday(&delta, NULL); | |
| 138 | |
| 139 abstime.tv_sec = delta.tv_sec + (ms/1000); | |
|
244
dc660aee7d7d
Fixed timeout in Linux condition variable implementation
Sam Lantinga <slouken@libsdl.org>
parents:
0
diff
changeset
|
140 abstime.tv_nsec = (delta.tv_usec + (ms%1000) * 1000) * 1000; |
|
dc660aee7d7d
Fixed timeout in Linux condition variable implementation
Sam Lantinga <slouken@libsdl.org>
parents:
0
diff
changeset
|
141 if ( abstime.tv_nsec > 1000000000 ) { |
| 0 | 142 abstime.tv_sec += 1; |
|
244
dc660aee7d7d
Fixed timeout in Linux condition variable implementation
Sam Lantinga <slouken@libsdl.org>
parents:
0
diff
changeset
|
143 abstime.tv_nsec -= 1000000000; |
| 0 | 144 } |
| 145 | |
| 146 tryagain: | |
| 147 retval = pthread_cond_timedwait(&cond->cond, &mutex->id, &abstime); | |
| 148 switch (retval) { | |
| 149 case EINTR: | |
| 150 goto tryagain; | |
| 151 break; | |
| 152 case ETIMEDOUT: | |
| 153 retval = SDL_MUTEX_TIMEDOUT; | |
| 154 break; | |
| 155 case 0: | |
| 156 break; | |
| 157 default: | |
| 158 SDL_SetError("pthread_cond_timedwait() failed"); | |
| 159 retval = -1; | |
| 160 break; | |
| 161 } | |
| 162 return retval; | |
| 163 } | |
| 164 | |
| 165 /* Wait on the condition variable, unlocking the provided mutex. | |
| 166 The mutex must be locked before entering this function! | |
| 167 */ | |
| 168 int SDL_CondWait(SDL_cond *cond, SDL_mutex *mutex) | |
| 169 { | |
| 170 int retval; | |
| 171 | |
| 172 if ( ! cond ) { | |
| 173 SDL_SetError("Passed a NULL condition variable"); | |
| 174 return -1; | |
| 175 } | |
| 176 | |
| 177 retval = 0; | |
| 178 if ( pthread_cond_wait(&cond->cond, &mutex->id) != 0 ) { | |
| 179 SDL_SetError("pthread_cond_wait() failed"); | |
| 180 retval = -1; | |
| 181 } | |
| 182 return retval; | |
| 183 } | |
| 184 | |
| 185 #else /* Use semaphore implementation */ | |
| 186 | |
| 187 #include "generic/SDL_syscond.c" | |
| 188 | |
| 189 #endif /* SDL_USE_PTHREADS */ |