Mercurial > sdl-ios-xcode
view src/thread/generic/SDL_sysmutex.c @ 2847:7d020441fa81
Don't hardcode RECT for fragment program texture targets.
Now we can generate what a given system needs when compiling the shader.
author | Ryan C. Gordon <icculus@icculus.org> |
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date | Sun, 07 Dec 2008 07:06:34 +0000 |
parents | c121d94672cb |
children | 99210400e8b9 |
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/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2006 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" /* An implementation of mutexes using semaphores */ #include "SDL_thread.h" #include "SDL_systhread_c.h" struct SDL_mutex { int recursive; Uint32 owner; SDL_sem *sem; }; /* Create a mutex */ SDL_mutex * SDL_CreateMutex(void) { SDL_mutex *mutex; /* Allocate mutex memory */ mutex = (SDL_mutex *) SDL_malloc(sizeof(*mutex)); if (mutex) { /* Create the mutex semaphore, with initial value 1 */ mutex->sem = SDL_CreateSemaphore(1); mutex->recursive = 0; mutex->owner = 0; if (!mutex->sem) { SDL_free(mutex); mutex = NULL; } } else { SDL_OutOfMemory(); } return mutex; } /* Free the mutex */ void SDL_DestroyMutex(SDL_mutex * mutex) { if (mutex) { if (mutex->sem) { SDL_DestroySemaphore(mutex->sem); } SDL_free(mutex); } } /* Lock the semaphore */ int SDL_mutexP(SDL_mutex * mutex) { #if SDL_THREADS_DISABLED return 0; #else Uint32 this_thread; if (mutex == NULL) { SDL_SetError("Passed a NULL mutex"); return -1; } this_thread = SDL_ThreadID(); if (mutex->owner == this_thread) { ++mutex->recursive; } else { /* The order of operations is important. We set the locking thread id after we obtain the lock so unlocks from other threads will fail. */ SDL_SemWait(mutex->sem); mutex->owner = this_thread; mutex->recursive = 0; } return 0; #endif /* SDL_THREADS_DISABLED */ } /* Unlock the mutex */ int SDL_mutexV(SDL_mutex * mutex) { #if SDL_THREADS_DISABLED return 0; #else if (mutex == NULL) { SDL_SetError("Passed a NULL mutex"); return -1; } /* If we don't own the mutex, we can't unlock it */ if (SDL_ThreadID() != mutex->owner) { SDL_SetError("mutex not owned by this thread"); return -1; } if (mutex->recursive) { --mutex->recursive; } else { /* The order of operations is important. First reset the owner so another thread doesn't lock the mutex and set the ownership before we reset it, then release the lock semaphore. */ mutex->owner = 0; SDL_SemPost(mutex->sem); } return 0; #endif /* SDL_THREADS_DISABLED */ } /* vi: set ts=4 sw=4 expandtab: */