Mercurial > sdl-ios-xcode
view src/thread/nds/SDL_syssem.c @ 3202:3aa519a5c676
I've made so many changes I don't dare continue until I check the current stuff in.
/test/testatomic.c performs absolutely basic tests to show that the function work as expected. Need a second test to do more detailed tests.
/include/SDL_atomic.h provides declarations for all included functions.
/src/atomic/linux/SDL_atomic.c provided all the functions. On a generic built the 64 bit functions work, but they are emulated. On a build for -march=pentium and above the 64 bit functions use native instructions
/src/atomic/dummy/SDL_atomic.c emulates all the operations using SDL_mutex.h.
/src/atomic/win32/SDL_atomic.c is a copy of dummy
/src/atomic/macosx/SDL_atomic.s is a copy of dummy
These versions of SDL_atomic.c provide a frame work for building the library with a mixture of native and emulated functions. This allows the whole library to be provided on all platforms. (I hope.)
I hope this fits with the SDL philosophy of either providing a common subset or emulating when the platform is missing a feature.
I have not added dummy, macosx, or win32 to the build. They are there as place holders for future work.
I have modified congifure.in to compile sources in /src/atomic/linux. (The SDL configure.in file is an amazing piece of work and I hope I didn't mess it up. :-)
author | Bob Pendleton <bob@pendleton.com> |
---|---|
date | Mon, 29 Jun 2009 19:54:43 +0000 |
parents | 99210400e8b9 |
children | f7b03b6838cb |
line wrap: on
line source
/* 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 Library General Public License as published by the Free Software Foundation; either version 2 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 Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with this library; if not, write to the Free Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA Sam Lantinga slouken@devolution.com */ #ifdef SAVE_RCSID static char rcsid = "@(#) $Id: SDL_syssem.c,v 1.2 2001/04/26 16:50:18 hercules Exp $"; #endif /* An implementation of semaphores using mutexes and condition variables */ #include <stdlib.h> #include "SDL_error.h" #include "SDL_timer.h" #include "SDL_thread.h" #include "SDL_systhread_c.h" #ifdef DISABLE_THREADS SDL_sem * SDL_CreateSemaphore(Uint32 initial_value) { SDL_SetError("SDL not configured with thread support"); return (SDL_sem *) 0; } void SDL_DestroySemaphore(SDL_sem * sem) { return; } int SDL_SemTryWait(SDL_sem * sem) { SDL_SetError("SDL not configured with thread support"); return -1; } int SDL_SemWaitTimeout(SDL_sem * sem, Uint32 timeout) { SDL_SetError("SDL not configured with thread support"); return -1; } int SDL_SemWait(SDL_sem * sem) { SDL_SetError("SDL not configured with thread support"); return -1; } Uint32 SDL_SemValue(SDL_sem * sem) { return 0; } int SDL_SemPost(SDL_sem * sem) { SDL_SetError("SDL not configured with thread support"); return -1; } #else struct SDL_semaphore { Uint32 count; Uint32 waiters_count; SDL_mutex *count_lock; SDL_cond *count_nonzero; }; SDL_sem * SDL_CreateSemaphore(Uint32 initial_value) { SDL_sem *sem; sem = (SDL_sem *) malloc(sizeof(*sem)); if (!sem) { SDL_OutOfMemory(); return (0); } sem->count = initial_value; sem->waiters_count = 0; sem->count_lock = SDL_CreateMutex(); sem->count_nonzero = SDL_CreateCond(); if (!sem->count_lock || !sem->count_nonzero) { SDL_DestroySemaphore(sem); return (0); } return (sem); } /* WARNING: You cannot call this function when another thread is using the semaphore. */ void SDL_DestroySemaphore(SDL_sem * sem) { if (sem) { sem->count = 0xFFFFFFFF; while (sem->waiters_count > 0) { SDL_CondSignal(sem->count_nonzero); SDL_Delay(10); } SDL_DestroyCond(sem->count_nonzero); SDL_mutexP(sem->count_lock); SDL_mutexV(sem->count_lock); SDL_DestroyMutex(sem->count_lock); free(sem); } } int SDL_SemTryWait(SDL_sem * sem) { int retval; if (!sem) { SDL_SetError("Passed a NULL semaphore"); return -1; } retval = SDL_MUTEX_TIMEDOUT; SDL_LockMutex(sem->count_lock); if (sem->count > 0) { --sem->count; retval = 0; } SDL_UnlockMutex(sem->count_lock); return retval; } int SDL_SemWaitTimeout(SDL_sem * sem, Uint32 timeout) { int retval; if (!sem) { SDL_SetError("Passed a NULL semaphore"); return -1; } /* A timeout of 0 is an easy case */ if (timeout == 0) { return SDL_SemTryWait(sem); } SDL_LockMutex(sem->count_lock); ++sem->waiters_count; retval = 0; while ((sem->count == 0) && (retval != SDL_MUTEX_TIMEDOUT)) { retval = SDL_CondWaitTimeout(sem->count_nonzero, sem->count_lock, timeout); } --sem->waiters_count; --sem->count; SDL_UnlockMutex(sem->count_lock); return retval; } int SDL_SemWait(SDL_sem * sem) { return SDL_SemWaitTimeout(sem, SDL_MUTEX_MAXWAIT); } Uint32 SDL_SemValue(SDL_sem * sem) { Uint32 value; value = 0; if (sem) { SDL_LockMutex(sem->count_lock); value = sem->count; SDL_UnlockMutex(sem->count_lock); } return value; } int SDL_SemPost(SDL_sem * sem) { if (!sem) { SDL_SetError("Passed a NULL semaphore"); return -1; } SDL_LockMutex(sem->count_lock); if (sem->waiters_count > 0) { SDL_CondSignal(sem->count_nonzero); } ++sem->count; SDL_UnlockMutex(sem->count_lock); return 0; } #endif /* DISABLE_THREADS */