diff options
Diffstat (limited to 'distrib/sdl-1.2.15/src/thread/riscos/SDL_sysmutex.c')
| -rw-r--r-- | distrib/sdl-1.2.15/src/thread/riscos/SDL_sysmutex.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/distrib/sdl-1.2.15/src/thread/riscos/SDL_sysmutex.c b/distrib/sdl-1.2.15/src/thread/riscos/SDL_sysmutex.c new file mode 100644 index 0000000..e9ac139 --- /dev/null +++ b/distrib/sdl-1.2.15/src/thread/riscos/SDL_sysmutex.c @@ -0,0 +1,153 @@ +/* + SDL - Simple DirectMedia Layer + Copyright (C) 1997-2012 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" + +/* RISC OS implementations uses pthreads based on linux code */ + +#include "SDL_thread.h" + +#if SDL_THREADS_DISABLED +#include "../generic/SDL_sysmutex.c" +#else + +#include <pthread.h> + +struct SDL_mutex { + pthread_mutex_t id; +#if SDL_THREAD_PTHREAD_NO_RECURSIVE_MUTEX + int recursive; + pthread_t owner; +#endif +}; + +SDL_mutex *SDL_CreateMutex (void) +{ + SDL_mutex *mutex; + pthread_mutexattr_t attr; + + /* Allocate the structure */ + mutex = (SDL_mutex *)SDL_calloc(1, sizeof(*mutex)); + if ( mutex ) { + pthread_mutexattr_init(&attr); +#if SDL_THREAD_PTHREAD_NO_RECURSIVE_MUTEX + /* No extra attributes necessary */ +#else + pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE); +#endif /* SDL_THREAD_PTHREAD_NO_RECURSIVE_MUTEX */ + if ( pthread_mutex_init(&mutex->id, &attr) != 0 ) { + SDL_SetError("pthread_mutex_init() failed"); + SDL_free(mutex); + mutex = NULL; + } + } else { + SDL_OutOfMemory(); + } + return(mutex); +} + +void SDL_DestroyMutex(SDL_mutex *mutex) +{ + if ( mutex ) { + pthread_mutex_destroy(&mutex->id); + SDL_free(mutex); + } +} + +/* Lock the mutex */ +int SDL_mutexP(SDL_mutex *mutex) +{ + int retval; +#if SDL_THREAD_PTHREAD_NO_RECURSIVE_MUTEX + pthread_t this_thread; +#endif + + if ( mutex == NULL ) { + SDL_SetError("Passed a NULL mutex"); + return -1; + } + + retval = 0; +#if SDL_THREAD_PTHREAD_NO_RECURSIVE_MUTEX + this_thread = pthread_self(); + 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. + */ + if ( pthread_mutex_lock(&mutex->id) == 0 ) { + mutex->owner = this_thread; + mutex->recursive = 0; + } else { + SDL_SetError("pthread_mutex_lock() failed"); + retval = -1; + } + } +#else + if ( pthread_mutex_lock(&mutex->id) < 0 ) { + SDL_SetError("pthread_mutex_lock() failed"); + retval = -1; + } +#endif + return retval; +} + +int SDL_mutexV(SDL_mutex *mutex) +{ + int retval; + + if ( mutex == NULL ) { + SDL_SetError("Passed a NULL mutex"); + return -1; + } + + retval = 0; +#if SDL_THREAD_PTHREAD_NO_RECURSIVE_MUTEX + /* We can only unlock the mutex if we own it */ + if ( pthread_self() == mutex->owner ) { + 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; + pthread_mutex_unlock(&mutex->id); + } + } else { + SDL_SetError("mutex not owned by this thread"); + retval = -1; + } + +#else + if ( pthread_mutex_unlock(&mutex->id) < 0 ) { + SDL_SetError("pthread_mutex_unlock() failed"); + retval = -1; + } +#endif /* SDL_THREAD_PTHREAD_NO_RECURSIVE_MUTEX */ + + return retval; +} +#endif |