Mercurial > sdl-ios-xcode
view src/thread/SDL_thread.c @ 3468:789b97008d8a
My first OpenGL shader! Momma will be so proud!
This shader implements the software renderer mask semantics where the source pixel is multiplied by the color and alpha modulation values and then any pixel with non-zero alpha is fully opaque.
The OpenGL renderer on Mac OS X now passes all the automated render tests! :)
author | Sam Lantinga <slouken@libsdl.org> |
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date | Sat, 21 Nov 2009 05:29:31 +0000 |
parents | 34a4a01da79c |
children | 0d1b16ee0bca |
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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" /* System independent thread management routines for SDL */ #include "SDL_mutex.h" #include "SDL_thread.h" #include "SDL_thread_c.h" #include "SDL_systhread.h" #define ARRAY_CHUNKSIZE 32 /* The array of threads currently active in the application (except the main thread) The manipulation of an array here is safer than using a linked list. */ static int SDL_maxthreads = 0; static int SDL_numthreads = 0; static SDL_Thread **SDL_Threads = NULL; static SDL_mutex *thread_lock = NULL; int SDL_ThreadsInit(void) { int retval; retval = 0; thread_lock = SDL_CreateMutex(); if (thread_lock == NULL) { retval = -1; } return (retval); } /* This should never be called... If this is called by SDL_Quit(), we don't know whether or not we should clean up threads here. If any threads are still running after this call, they will no longer have access to any per-thread data. */ void SDL_ThreadsQuit(void) { SDL_mutex *mutex; mutex = thread_lock; thread_lock = NULL; if (mutex != NULL) { SDL_DestroyMutex(mutex); } } /* Routines for manipulating the thread list */ static void SDL_AddThread(SDL_Thread * thread) { /* WARNING: If the very first threads are created simultaneously, then there could be a race condition causing memory corruption. In practice, this isn't a problem because by definition there is only one thread running the first time this is called. */ if (!thread_lock) { if (SDL_ThreadsInit() < 0) { return; } } SDL_mutexP(thread_lock); /* Expand the list of threads, if necessary */ #ifdef DEBUG_THREADS printf("Adding thread (%d already - %d max)\n", SDL_numthreads, SDL_maxthreads); #endif if (SDL_numthreads == SDL_maxthreads) { SDL_Thread **threads; threads = (SDL_Thread **) SDL_realloc(SDL_Threads, (SDL_maxthreads + ARRAY_CHUNKSIZE) * (sizeof *threads)); if (threads == NULL) { SDL_OutOfMemory(); goto done; } SDL_maxthreads += ARRAY_CHUNKSIZE; SDL_Threads = threads; } SDL_Threads[SDL_numthreads++] = thread; done: SDL_mutexV(thread_lock); } static void SDL_DelThread(SDL_Thread * thread) { int i; if (!thread_lock) { return; } SDL_mutexP(thread_lock); for (i = 0; i < SDL_numthreads; ++i) { if (thread == SDL_Threads[i]) { break; } } if (i < SDL_numthreads) { if (--SDL_numthreads > 0) { while (i < SDL_numthreads) { SDL_Threads[i] = SDL_Threads[i + 1]; ++i; } } else { SDL_maxthreads = 0; SDL_free(SDL_Threads); SDL_Threads = NULL; } #ifdef DEBUG_THREADS printf("Deleting thread (%d left - %d max)\n", SDL_numthreads, SDL_maxthreads); #endif } SDL_mutexV(thread_lock); #if 0 /* There could be memory corruption if another thread is starting */ if (SDL_Threads == NULL) { SDL_ThreadsQuit(); } #endif } /* The default (non-thread-safe) global error variable */ static SDL_error SDL_global_error; /* Routine to get the thread-specific error variable */ SDL_error * SDL_GetErrBuf(void) { SDL_error *errbuf; errbuf = &SDL_global_error; if (SDL_Threads) { int i; Uint32 this_thread; this_thread = SDL_ThreadID(); SDL_mutexP(thread_lock); for (i = 0; i < SDL_numthreads; ++i) { if (this_thread == SDL_Threads[i]->threadid) { errbuf = &SDL_Threads[i]->errbuf; break; } } SDL_mutexV(thread_lock); } return (errbuf); } /* Arguments and callback to setup and run the user thread function */ typedef struct { int (SDLCALL * func) (void *); void *data; SDL_Thread *info; SDL_sem *wait; } thread_args; void SDL_RunThread(void *data) { thread_args *args; int (SDLCALL * userfunc) (void *); void *userdata; int *statusloc; /* Perform any system-dependent setup - this function cannot fail, and cannot use SDL_SetError() */ SDL_SYS_SetupThread(); /* Get the thread id */ args = (thread_args *) data; args->info->threadid = SDL_ThreadID(); /* Figure out what function to run */ userfunc = args->func; userdata = args->data; statusloc = &args->info->status; /* Wake up the parent thread */ SDL_SemPost(args->wait); /* Run the function */ *statusloc = userfunc(userdata); } #ifdef SDL_PASSED_BEGINTHREAD_ENDTHREAD #undef SDL_CreateThread DECLSPEC SDL_Thread *SDLCALL SDL_CreateThread(int (SDLCALL * fn) (void *), void *data, pfnSDL_CurrentBeginThread pfnBeginThread, pfnSDL_CurrentEndThread pfnEndThread) #else DECLSPEC SDL_Thread *SDLCALL SDL_CreateThread(int (SDLCALL * fn) (void *), void *data) #endif { SDL_Thread *thread; thread_args *args; int ret; /* Allocate memory for the thread info structure */ thread = (SDL_Thread *) SDL_malloc(sizeof(*thread)); if (thread == NULL) { SDL_OutOfMemory(); return (NULL); } SDL_memset(thread, 0, (sizeof *thread)); thread->status = -1; /* Set up the arguments for the thread */ args = (thread_args *) SDL_malloc(sizeof(*args)); if (args == NULL) { SDL_OutOfMemory(); SDL_free(thread); return (NULL); } args->func = fn; args->data = data; args->info = thread; args->wait = SDL_CreateSemaphore(0); if (args->wait == NULL) { SDL_free(thread); SDL_free(args); return (NULL); } /* Add the thread to the list of available threads */ SDL_AddThread(thread); /* Create the thread and go! */ #ifdef SDL_PASSED_BEGINTHREAD_ENDTHREAD ret = SDL_SYS_CreateThread(thread, args, pfnBeginThread, pfnEndThread); #else ret = SDL_SYS_CreateThread(thread, args); #endif if (ret >= 0) { /* Wait for the thread function to use arguments */ SDL_SemWait(args->wait); } else { /* Oops, failed. Gotta free everything */ SDL_DelThread(thread); SDL_free(thread); thread = NULL; } SDL_DestroySemaphore(args->wait); SDL_free(args); /* Everything is running now */ return (thread); } void SDL_WaitThread(SDL_Thread * thread, int *status) { if (thread) { SDL_SYS_WaitThread(thread); if (status) { *status = thread->status; } SDL_DelThread(thread); SDL_free(thread); } } Uint32 SDL_GetThreadID(SDL_Thread * thread) { Uint32 id; if (thread) { id = thread->threadid; } else { id = SDL_ThreadID(); } return (id); } void SDL_KillThread(SDL_Thread * thread) { /* This is a no-op in SDL 1.3 and later. */ } /* vi: set ts=4 sw=4 expandtab: */