| 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 | /* 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 */ |
| 49 | sem = (SDL_sem *)SDL_malloc(sizeof(*sem)); |
| 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"); |
| 55 | SDL_free(sem); |
| 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 | } |
| 78 | SDL_free(sem); |
| 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 | } |