Mercurial > sdl-ios-xcode
view src/thread/os2/SDL_syssem.c @ 4347:38f22ed3a433 SDL-1.2
Option to fix bug #851
For some people setting the period size works better (and is what SDL 1.2.13 did), but for most people it's the same or worse. You can use an environment variable to pick which one you want.
author | Sam Lantinga <slouken@libsdl.org> |
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date | Sat, 17 Oct 2009 06:55:17 +0000 |
parents | a1b03ba2fcd0 |
children |
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/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2009 Sam Lantinga This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA Sam Lantinga slouken@libsdl.org */ #include "SDL_config.h" /* Semaphore functions using the OS/2 API */ #define INCL_DOS #define INCL_DOSERRORS #define INCL_DOSSEMAPHORES #include <os2.h> #include "SDL_thread.h" #include "SDL_timer.h" struct SDL_semaphore { HMTX id; HEV changed; Uint32 value; }; /* Create a semaphore */ DECLSPEC SDL_sem * SDLCALL SDL_CreateSemaphore(Uint32 initial_value) { SDL_sem *sem; ULONG ulrc; /* Allocate sem memory */ sem = (SDL_sem *)SDL_malloc(sizeof(*sem)); if ( sem ) { /* Create the mutex semaphore */ ulrc = DosCreateMutexSem(NULL,&(sem->id),0,TRUE); if ( ulrc ) { SDL_SetError("Couldn't create semaphore"); SDL_free(sem); sem = NULL; } else { DosCreateEventSem(NULL, &(sem->changed), 0, FALSE); sem->value = initial_value; DosReleaseMutexSem(sem->id); } } else { SDL_OutOfMemory(); } return(sem); } /* Free the semaphore */ DECLSPEC void SDLCALL SDL_DestroySemaphore(SDL_sem *sem) { if ( sem ) { if ( sem->id ) { DosCloseEventSem(sem->changed); DosCloseMutexSem(sem->id); sem->id = 0; } SDL_free(sem); } } DECLSPEC int SDLCALL SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout) { ULONG ulrc; if ( ! sem ) { SDL_SetError("Passed a NULL sem"); return -1; } if ( timeout == SDL_MUTEX_MAXWAIT ) { while (1) { ulrc = DosRequestMutexSem(sem->id, SEM_INDEFINITE_WAIT); if (ulrc) { /* if error waiting mutex */ SDL_SetError("DosRequestMutexSem() failed"); return -1; } else if (sem->value) { sem->value--; DosReleaseMutexSem(sem->id); return 0; } else { ULONG ulPostCount; DosResetEventSem(sem->changed, &ulPostCount); DosReleaseMutexSem(sem->id); /* continue waiting until somebody posts the semaphore */ DosWaitEventSem(sem->changed, SEM_INDEFINITE_WAIT); } } } else if ( timeout == 0 ) { ulrc = DosRequestMutexSem(sem->id, SEM_INDEFINITE_WAIT); if (ulrc==NO_ERROR) { if (sem->value) { sem->value--; DosReleaseMutexSem(sem->id); return 0; } else { DosReleaseMutexSem(sem->id); return SDL_MUTEX_TIMEDOUT; } } else { SDL_SetError("DosRequestMutexSem() failed"); return -1; } } else { ulrc = DosRequestMutexSem(sem->id, SEM_INDEFINITE_WAIT); if (ulrc) { /* if error waiting mutex */ SDL_SetError("DosRequestMutexSem() failed"); return -1; } else if (sem->value) { sem->value--; DosReleaseMutexSem(sem->id); return 0; } else { ULONG ulPostCount; DosResetEventSem(sem->changed, &ulPostCount); DosReleaseMutexSem(sem->id); /* continue waiting until somebody posts the semaphore */ ulrc = DosWaitEventSem(sem->changed, timeout); if (ulrc==NO_ERROR) return 0; else return SDL_MUTEX_TIMEDOUT; } } /* never reached */ return -1; } DECLSPEC int SDLCALL SDL_SemTryWait(SDL_sem *sem) { return SDL_SemWaitTimeout(sem, 0); } DECLSPEC int SDLCALL SDL_SemWait(SDL_sem *sem) { return SDL_SemWaitTimeout(sem, SDL_MUTEX_MAXWAIT); } /* Returns the current count of the semaphore */ DECLSPEC Uint32 SDLCALL SDL_SemValue(SDL_sem *sem) { if ( ! sem ) { SDL_SetError("Passed a NULL sem"); return 0; } return sem->value; } DECLSPEC int SDLCALL SDL_SemPost(SDL_sem *sem) { if ( ! sem ) { SDL_SetError("Passed a NULL sem"); return -1; } if ( DosRequestMutexSem(sem->id,SEM_INDEFINITE_WAIT) ) { SDL_SetError("DosRequestMutexSem() failed"); return -1; } sem->value++; DosPostEventSem(sem->changed); DosReleaseMutexSem(sem->id); return 0; }