| 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 | } |