[sdl_omap.git] / src / thread / riscos / SDL_sysmutex.c

/*
    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"

/* 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
Commit	Line	Data
e14743d1	1	/*
	2	SDL - Simple DirectMedia Layer
	3	Copyright (C) 1997-2009 Sam Lantinga
	4
	5	This library is free software; you can redistribute it and/or
	6	modify it under the terms of the GNU Lesser General Public
	7	License as published by the Free Software Foundation; either
	8	version 2.1 of the License, or (at your option) any later version.
	9
	10	This library is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	Lesser General Public License for more details.
	14
	15	You should have received a copy of the GNU Lesser General Public
	16	License along with this library; if not, write to the Free Software
	17	Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	18
	19	Sam Lantinga
	20	slouken@libsdl.org
	21	*/
	22	#include "SDL_config.h"
	23
	24	/* RISC OS implementations uses pthreads based on linux code */
	25
	26	#include "SDL_thread.h"
	27
	28	#if SDL_THREADS_DISABLED
	29	#include "../generic/SDL_sysmutex.c"
	30	#else
	31
	32	#include <pthread.h>
	33
	34	struct SDL_mutex {
	35	pthread_mutex_t id;
	36	#if SDL_THREAD_PTHREAD_NO_RECURSIVE_MUTEX
	37	int recursive;
	38	pthread_t owner;
	39	#endif
	40	};
	41
	42	SDL_mutex *SDL_CreateMutex (void)
	43	{
	44	SDL_mutex *mutex;
	45	pthread_mutexattr_t attr;
	46
	47	/* Allocate the structure */
	48	mutex = (SDL_mutex )SDL_calloc(1, sizeof(mutex));
	49	if ( mutex ) {
	50	pthread_mutexattr_init(&attr);
	51	#if SDL_THREAD_PTHREAD_NO_RECURSIVE_MUTEX
	52	/* No extra attributes necessary */
	53	#else
	54	pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
	55	#endif /* SDL_THREAD_PTHREAD_NO_RECURSIVE_MUTEX */
	56	if ( pthread_mutex_init(&mutex->id, &attr) != 0 ) {
	57	SDL_SetError("pthread_mutex_init() failed");
	58	SDL_free(mutex);
	59	mutex = NULL;
	60	}
	61	} else {
	62	SDL_OutOfMemory();
	63	}
	64	return(mutex);
65	}
66
67	void SDL_DestroyMutex(SDL_mutex *mutex)
68	{
69	if ( mutex ) {
70	pthread_mutex_destroy(&mutex->id);
71	SDL_free(mutex);
72	}
73	}
74
75	/* Lock the mutex */
76	int SDL_mutexP(SDL_mutex *mutex)
77	{
78	int retval;
79	#if SDL_THREAD_PTHREAD_NO_RECURSIVE_MUTEX
80	pthread_t this_thread;
81	#endif
82
83	if ( mutex == NULL ) {
84	SDL_SetError("Passed a NULL mutex");
85	return -1;
86	}
87
88	retval = 0;
89	#if SDL_THREAD_PTHREAD_NO_RECURSIVE_MUTEX
90	this_thread = pthread_self();
91	if ( mutex->owner == this_thread ) {
92	++mutex->recursive;
93	} else {
94	/* The order of operations is important.
95	We set the locking thread id after we obtain the lock
96	so unlocks from other threads will fail.
97	*/
98	if ( pthread_mutex_lock(&mutex->id) == 0 ) {
99	mutex->owner = this_thread;
100	mutex->recursive = 0;
101	} else {
102	SDL_SetError("pthread_mutex_lock() failed");
103	retval = -1;
104	}
105	}
106	#else
107	if ( pthread_mutex_lock(&mutex->id) < 0 ) {
108	SDL_SetError("pthread_mutex_lock() failed");
109	retval = -1;
110	}
111	#endif
112	return retval;
113	}
114
115	int SDL_mutexV(SDL_mutex *mutex)
116	{
117	int retval;
118
119	if ( mutex == NULL ) {
120	SDL_SetError("Passed a NULL mutex");
121	return -1;
122	}
123
124	retval = 0;
125	#if SDL_THREAD_PTHREAD_NO_RECURSIVE_MUTEX
126	/* We can only unlock the mutex if we own it */
127	if ( pthread_self() == mutex->owner ) {
128	if ( mutex->recursive ) {
129	--mutex->recursive;
130	} else {
131	/* The order of operations is important.
132	First reset the owner so another thread doesn't lock
133	the mutex and set the ownership before we reset it,
134	then release the lock semaphore.
135	*/
136	mutex->owner = 0;
137	pthread_mutex_unlock(&mutex->id);
138	}
139	} else {
140	SDL_SetError("mutex not owned by this thread");
141	retval = -1;
142	}
143
144	#else
145	if ( pthread_mutex_unlock(&mutex->id) < 0 ) {
146	SDL_SetError("pthread_mutex_unlock() failed");
147	retval = -1;
148	}
149	#endif /* SDL_THREAD_PTHREAD_NO_RECURSIVE_MUTEX */
150
151	return retval;
152	}
153	#endif