Mercurial > sdl-ios-xcode
annotate src/thread/os2/SDL_syssem.c @ 5107:99acf3d856cb SDL-1.2
Colin Leroy 2011-01-26 04:24:20 PST
the pthread implementation of SDL_SemWaitTimeout() uses busy waiting, while
pthread's sem_timedwait() does work. Attached are patches that make use of it
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Thu, 27 Jan 2011 00:33:26 -0800 |
| parents | a1b03ba2fcd0 |
| children |
| rev | line source |
|---|---|
| 1190 | 1 /* |
| 2 SDL - Simple DirectMedia Layer | |
| 4159 | 3 Copyright (C) 1997-2009 Sam Lantinga |
| 1190 | 4 |
| 5 This library is free software; you can redistribute it and/or | |
|
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6 modify it under the terms of the GNU Lesser General Public |
| 1190 | 7 License as published by the Free Software Foundation; either |
|
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8 version 2.1 of the License, or (at your option) any later version. |
| 1190 | 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 | |
|
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13 Lesser General Public License for more details. |
| 1190 | 14 |
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15 You should have received a copy of the GNU Lesser General Public |
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c9b51268668f
Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents:
1190
diff
changeset
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16 License along with this library; if not, write to the Free Software |
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c9b51268668f
Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents:
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changeset
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17 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| 1190 | 18 |
| 19 Sam Lantinga | |
| 20 slouken@libsdl.org | |
| 21 */ | |
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22 #include "SDL_config.h" |
| 1190 | 23 |
| 24 /* Semaphore functions using the OS/2 API */ | |
| 25 | |
| 26 #define INCL_DOS | |
| 27 #define INCL_DOSERRORS | |
| 28 #define INCL_DOSSEMAPHORES | |
| 29 #include <os2.h> | |
| 30 | |
| 31 #include "SDL_thread.h" | |
| 32 #include "SDL_timer.h" | |
| 33 | |
| 34 | |
| 35 struct SDL_semaphore { | |
| 36 HMTX id; | |
| 37 HEV changed; | |
| 38 Uint32 value; | |
| 39 }; | |
| 40 | |
| 41 | |
| 42 /* Create a semaphore */ | |
| 43 DECLSPEC SDL_sem * SDLCALL SDL_CreateSemaphore(Uint32 initial_value) | |
| 44 { | |
| 45 SDL_sem *sem; | |
| 46 ULONG ulrc; | |
| 47 | |
| 48 /* Allocate sem memory */ | |
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49 sem = (SDL_sem *)SDL_malloc(sizeof(*sem)); |
| 1190 | 50 if ( sem ) { |
| 51 /* Create the mutex semaphore */ | |
| 52 ulrc = DosCreateMutexSem(NULL,&(sem->id),0,TRUE); | |
| 53 if ( ulrc ) { | |
| 54 SDL_SetError("Couldn't create semaphore"); | |
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changeset
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55 SDL_free(sem); |
| 1190 | 56 sem = NULL; |
| 57 } else | |
| 58 { | |
| 59 DosCreateEventSem(NULL, &(sem->changed), 0, FALSE); | |
| 60 sem->value = initial_value; | |
| 61 DosReleaseMutexSem(sem->id); | |
| 62 } | |
| 63 } else { | |
| 64 SDL_OutOfMemory(); | |
| 65 } | |
| 66 return(sem); | |
| 67 } | |
| 68 | |
| 69 /* Free the semaphore */ | |
| 70 DECLSPEC void SDLCALL SDL_DestroySemaphore(SDL_sem *sem) | |
| 71 { | |
| 72 if ( sem ) { | |
| 73 if ( sem->id ) { | |
| 74 DosCloseEventSem(sem->changed); | |
| 75 DosCloseMutexSem(sem->id); | |
| 76 sem->id = 0; | |
| 77 } | |
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Sam Lantinga <slouken@libsdl.org>
parents:
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diff
changeset
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78 SDL_free(sem); |
| 1190 | 79 } |
| 80 } | |
| 81 | |
| 82 DECLSPEC int SDLCALL SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout) | |
| 83 { | |
| 84 ULONG ulrc; | |
| 85 | |
| 86 if ( ! sem ) { | |
| 87 SDL_SetError("Passed a NULL sem"); | |
| 88 return -1; | |
| 89 } | |
| 90 | |
| 91 if ( timeout == SDL_MUTEX_MAXWAIT ) { | |
| 92 while (1) { | |
| 93 ulrc = DosRequestMutexSem(sem->id, SEM_INDEFINITE_WAIT); | |
| 94 if (ulrc) { | |
| 95 /* if error waiting mutex */ | |
| 96 SDL_SetError("DosRequestMutexSem() failed"); | |
| 97 return -1; | |
| 98 } else if (sem->value) { | |
| 99 sem->value--; | |
| 100 DosReleaseMutexSem(sem->id); | |
| 101 return 0; | |
| 102 } else { | |
| 103 ULONG ulPostCount; | |
| 104 DosResetEventSem(sem->changed, &ulPostCount); | |
| 105 DosReleaseMutexSem(sem->id); | |
| 106 /* continue waiting until somebody posts the semaphore */ | |
| 107 DosWaitEventSem(sem->changed, SEM_INDEFINITE_WAIT); | |
| 108 } | |
| 109 } | |
| 110 } else | |
| 111 if ( timeout == 0 ) | |
| 112 { | |
| 113 ulrc = DosRequestMutexSem(sem->id, SEM_INDEFINITE_WAIT); | |
| 114 if (ulrc==NO_ERROR) | |
| 115 { | |
| 116 if (sem->value) | |
| 117 { | |
| 118 sem->value--; | |
| 119 DosReleaseMutexSem(sem->id); | |
| 120 return 0; | |
| 121 } else | |
| 122 { | |
| 123 DosReleaseMutexSem(sem->id); | |
| 124 return SDL_MUTEX_TIMEDOUT; | |
| 125 } | |
| 126 } else | |
| 127 { | |
| 128 SDL_SetError("DosRequestMutexSem() failed"); | |
| 129 return -1; | |
| 130 } | |
| 131 } else { | |
| 132 ulrc = DosRequestMutexSem(sem->id, SEM_INDEFINITE_WAIT); | |
| 133 if (ulrc) { | |
| 134 /* if error waiting mutex */ | |
| 135 SDL_SetError("DosRequestMutexSem() failed"); | |
| 136 return -1; | |
| 137 } else | |
| 138 if (sem->value) { | |
| 139 sem->value--; | |
| 140 DosReleaseMutexSem(sem->id); | |
| 141 return 0; | |
| 142 } else { | |
| 143 ULONG ulPostCount; | |
| 144 DosResetEventSem(sem->changed, &ulPostCount); | |
| 145 DosReleaseMutexSem(sem->id); | |
| 146 /* continue waiting until somebody posts the semaphore */ | |
| 147 ulrc = DosWaitEventSem(sem->changed, timeout); | |
| 148 if (ulrc==NO_ERROR) | |
| 149 return 0; | |
| 150 else | |
| 151 return SDL_MUTEX_TIMEDOUT; | |
| 152 } | |
| 153 } | |
| 154 /* never reached */ | |
| 155 return -1; | |
| 156 } | |
| 157 | |
| 158 DECLSPEC int SDLCALL SDL_SemTryWait(SDL_sem *sem) | |
| 159 { | |
| 160 return SDL_SemWaitTimeout(sem, 0); | |
| 161 } | |
| 162 | |
| 163 DECLSPEC int SDLCALL SDL_SemWait(SDL_sem *sem) | |
| 164 { | |
| 165 return SDL_SemWaitTimeout(sem, SDL_MUTEX_MAXWAIT); | |
| 166 } | |
| 167 | |
| 168 /* Returns the current count of the semaphore */ | |
| 169 DECLSPEC Uint32 SDLCALL SDL_SemValue(SDL_sem *sem) | |
| 170 { | |
| 171 if ( ! sem ) { | |
| 172 SDL_SetError("Passed a NULL sem"); | |
| 173 return 0; | |
| 174 } | |
| 175 return sem->value; | |
| 176 } | |
| 177 | |
| 178 DECLSPEC int SDLCALL SDL_SemPost(SDL_sem *sem) | |
| 179 { | |
| 180 if ( ! sem ) { | |
| 181 SDL_SetError("Passed a NULL sem"); | |
| 182 return -1; | |
| 183 } | |
| 184 if ( DosRequestMutexSem(sem->id,SEM_INDEFINITE_WAIT) ) { | |
| 185 SDL_SetError("DosRequestMutexSem() failed"); | |
| 186 return -1; | |
| 187 } | |
| 188 sem->value++; | |
| 189 DosPostEventSem(sem->changed); | |
| 190 DosReleaseMutexSem(sem->id); | |
| 191 return 0; | |
| 192 } |