| 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 | #include <sys/time.h> |
| 25 | #include <unistd.h> |
| 26 | #include <errno.h> |
| 27 | #include <pthread.h> |
| 28 | |
| 29 | #include "SDL_thread.h" |
| 30 | #include "SDL_sysmutex_c.h" |
| 31 | |
| 32 | struct SDL_cond |
| 33 | { |
| 34 | pthread_cond_t cond; |
| 35 | }; |
| 36 | |
| 37 | /* Create a condition variable */ |
| 38 | SDL_cond * SDL_CreateCond(void) |
| 39 | { |
| 40 | SDL_cond *cond; |
| 41 | |
| 42 | cond = (SDL_cond *) SDL_malloc(sizeof(SDL_cond)); |
| 43 | if ( cond ) { |
| 44 | if ( pthread_cond_init(&cond->cond, NULL) < 0 ) { |
| 45 | SDL_SetError("pthread_cond_init() failed"); |
| 46 | SDL_free(cond); |
| 47 | cond = NULL; |
| 48 | } |
| 49 | } |
| 50 | return(cond); |
| 51 | } |
| 52 | |
| 53 | /* Destroy a condition variable */ |
| 54 | void SDL_DestroyCond(SDL_cond *cond) |
| 55 | { |
| 56 | if ( cond ) { |
| 57 | pthread_cond_destroy(&cond->cond); |
| 58 | SDL_free(cond); |
| 59 | } |
| 60 | } |
| 61 | |
| 62 | /* Restart one of the threads that are waiting on the condition variable */ |
| 63 | int SDL_CondSignal(SDL_cond *cond) |
| 64 | { |
| 65 | int retval; |
| 66 | |
| 67 | if ( ! cond ) { |
| 68 | SDL_SetError("Passed a NULL condition variable"); |
| 69 | return -1; |
| 70 | } |
| 71 | |
| 72 | retval = 0; |
| 73 | if ( pthread_cond_signal(&cond->cond) != 0 ) { |
| 74 | SDL_SetError("pthread_cond_signal() failed"); |
| 75 | retval = -1; |
| 76 | } |
| 77 | return retval; |
| 78 | } |
| 79 | |
| 80 | /* Restart all threads that are waiting on the condition variable */ |
| 81 | int SDL_CondBroadcast(SDL_cond *cond) |
| 82 | { |
| 83 | int retval; |
| 84 | |
| 85 | if ( ! cond ) { |
| 86 | SDL_SetError("Passed a NULL condition variable"); |
| 87 | return -1; |
| 88 | } |
| 89 | |
| 90 | retval = 0; |
| 91 | if ( pthread_cond_broadcast(&cond->cond) != 0 ) { |
| 92 | SDL_SetError("pthread_cond_broadcast() failed"); |
| 93 | retval = -1; |
| 94 | } |
| 95 | return retval; |
| 96 | } |
| 97 | |
| 98 | int SDL_CondWaitTimeout(SDL_cond *cond, SDL_mutex *mutex, Uint32 ms) |
| 99 | { |
| 100 | int retval; |
| 101 | struct timeval delta; |
| 102 | struct timespec abstime; |
| 103 | |
| 104 | if ( ! cond ) { |
| 105 | SDL_SetError("Passed a NULL condition variable"); |
| 106 | return -1; |
| 107 | } |
| 108 | |
| 109 | gettimeofday(&delta, NULL); |
| 110 | |
| 111 | abstime.tv_sec = delta.tv_sec + (ms/1000); |
| 112 | abstime.tv_nsec = (delta.tv_usec + (ms%1000) * 1000) * 1000; |
| 113 | if ( abstime.tv_nsec > 1000000000 ) { |
| 114 | abstime.tv_sec += 1; |
| 115 | abstime.tv_nsec -= 1000000000; |
| 116 | } |
| 117 | |
| 118 | tryagain: |
| 119 | retval = pthread_cond_timedwait(&cond->cond, &mutex->id, &abstime); |
| 120 | switch (retval) { |
| 121 | case EINTR: |
| 122 | goto tryagain; |
| 123 | break; |
| 124 | case ETIMEDOUT: |
| 125 | retval = SDL_MUTEX_TIMEDOUT; |
| 126 | break; |
| 127 | case 0: |
| 128 | break; |
| 129 | default: |
| 130 | SDL_SetError("pthread_cond_timedwait() failed"); |
| 131 | retval = -1; |
| 132 | break; |
| 133 | } |
| 134 | return retval; |
| 135 | } |
| 136 | |
| 137 | /* Wait on the condition variable, unlocking the provided mutex. |
| 138 | The mutex must be locked before entering this function! |
| 139 | */ |
| 140 | int SDL_CondWait(SDL_cond *cond, SDL_mutex *mutex) |
| 141 | { |
| 142 | int retval; |
| 143 | |
| 144 | if ( ! cond ) { |
| 145 | SDL_SetError("Passed a NULL condition variable"); |
| 146 | return -1; |
| 147 | } |
| 148 | |
| 149 | retval = 0; |
| 150 | if ( pthread_cond_wait(&cond->cond, &mutex->id) != 0 ) { |
| 151 | SDL_SetError("pthread_cond_wait() failed"); |
| 152 | retval = -1; |
| 153 | } |
| 154 | return retval; |
| 155 | } |