/*

SDL - Simple DirectMedia Layer

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 =

"@(#) $Id$";

#endif

#include <stdlib.h>

#include "SDL_error.h"

#include "SDL_thread.h"

#include "SDL_timer.h"

#ifdef SDL_USE_PTHREADS

#include <stdio.h>

#include <stdlib.h>

#include <unistd.h> /* For getpid() */

#include <pthread.h>

/*

* This is semaphore.h inlined here so that BSD/OS POSIX semaphore are

* completely selfcontained without requiring any additional include files

* or libraries not present in the stock system

*/

/* semaphore.h: POSIX 1003.1b semaphores */

/*-

* Copyright (c) 1996, 1997

* HD Associates, Inc. All rights reserved.

*

* Redistribution and use in source and binary forms, with or without

* modification, are permitted provided that the following conditions

* are met:

* 1. Redistributions of source code must retain the above copyright

* notice, this list of conditions and the following disclaimer.

* 2. Redistributions in binary form must reproduce the above copyright

* notice, this list of conditions and the following disclaimer in the

* documentation and/or other materials provided with the distribution.

* 3. All advertising materials mentioning features or use of this software

* must display the following acknowledgement:

* This product includes software developed by HD Associates, Inc

* 4. Neither the name of the author nor the names of any co-contributors

* may be used to endorse or promote products derived from this software

* without specific prior written permission.

*

* THIS SOFTWARE IS PROVIDED BY HD ASSOCIATES AND CONTRIBUTORS ``AS IS'' AND

* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

* ARE DISCLAIMED. IN NO EVENT SHALL HD ASSOCIATES OR CONTRIBUTORS BE LIABLE

* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

* SUCH DAMAGE.

*

* $FreeBSD: src/sys/posix4/semaphore.h,v 1.6 2000/01/20 07:55:42 jasone Exp $

*/

#include <machine/limits.h>

#include <sys/types.h>

#include <fcntl.h>

/* Opaque type definition. */

struct sem;

typedef struct sem *sem_t;

#define SEM_FAILED ((sem_t *)0)

#define SEM_VALUE_MAX UINT_MAX

#include <sys/cdefs.h>

__BEGIN_DECLS

int sem_init __P((sem_t *, int, unsigned int));

int sem_destroy __P((sem_t *));

sem_t *sem_open __P((const char *, int, ...));

int sem_close __P((sem_t *));

int sem_unlink __P((const char *));

int sem_wait __P((sem_t *));

int sem_trywait __P((sem_t *));

int sem_post __P((sem_t *));

int sem_getvalue __P((sem_t *, int *));

__END_DECLS

/* END of inlined semaphore.h */

/* Wrapper around POSIX 1003.1b semaphores */

struct SDL_semaphore {

sem_t *sem;

sem_t sem_data;

};

/* Create a semaphore, initialized with value */

SDL_sem *SDL_CreateSemaphore(Uint32 initial_value)

{

SDL_sem *sem = (SDL_sem *) malloc(sizeof(SDL_sem));

if ( sem ) {

if ( sem_init(&sem->sem_data, 0, initial_value) < 0 ) {

SDL_SetError("sem_init() failed");

free(sem);

sem = NULL;

} else {

sem->sem = &sem->sem_data;

}

} else {

SDL_OutOfMemory();

}

return sem;

}

void SDL_DestroySemaphore(SDL_sem *sem)

{

if ( sem ) {

sem_destroy(sem->sem);

free(sem);

}

}

int SDL_SemTryWait(SDL_sem *sem)

{

int retval;

if ( ! sem ) {

SDL_SetError("Passed a NULL semaphore");

return -1;

}

retval = SDL_MUTEX_TIMEDOUT;

if ( sem_trywait(sem->sem) == 0 )

retval = 0;

return retval;

}

int SDL_SemWait(SDL_sem *sem)

{

int retval;

if ( ! sem ) {

SDL_SetError("Passed a NULL semaphore");

return -1;

}

retval = sem_wait(sem->sem);

if ( retval < 0 ) {

SDL_SetError("sem_wait() failed");

}

return retval;

}

int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout)

{

int retval;

if ( ! sem ) {

SDL_SetError("Passed a NULL semaphore");

return -1;

}

/* Try the easy cases first */

if ( timeout == 0 ) {

return SDL_SemTryWait(sem);

}

if ( timeout == SDL_MUTEX_MAXWAIT ) {

return SDL_SemWait(sem);

}

/* Ack! We have to busy wait... */

timeout += SDL_GetTicks();

do {

retval = SDL_SemTryWait(sem);

if ( retval == 0 ) {

break;

}

SDL_Delay(1);

} while ( SDL_GetTicks() < timeout );

return retval;

}

Uint32 SDL_SemValue(SDL_sem *sem)

{

int ret = 0;

if ( sem ) {

sem_getvalue(sem->sem, &ret);

if ( ret < 0 ) {

ret = 0;

}

}

return (Uint32)ret;

}

int SDL_SemPost(SDL_sem *sem)

{

int retval;

if ( ! sem ) {

SDL_SetError("Passed a NULL semaphore");

return -1;

}

retval = sem_post(sem->sem);

if ( retval < 0 ) {

SDL_SetError("sem_post() failed");

}

return retval;

}

/*

* BEGIN inlined uthread_sem.c. This is done here so that no extra libraries

* or include files not present in BSD/OS are required

*/

/*

* Copyright (C) 2000 Jason Evans <jasone@freebsd.org>.

* All rights reserved.

*

* Redistribution and use in source and binary forms, with or without

* modification, are permitted provided that the following conditions

* are met:

* 1. Redistributions of source code must retain the above copyright

* notice(s), this list of conditions and the following disclaimer as

* the first lines of this file unmodified other than the possible

* addition of one or more copyright notices.

* 2. Redistributions in binary form must reproduce the above copyright

* notice(s), this list of conditions and the following disclaimer in

* the documentation and/or other materials provided with the

* distribution.

*

* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY

* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE

* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR

* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,

* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE

* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,

* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

*

* $FreeBSD: src/lib/libc_r/uthread/uthread_sem.c,v 1.3.2.1 2000/07/18 02:05:57 jasone Exp $

*/

#include <errno.h>

#include <pthread.h>

/* Begin thread_private.h kluge */

/*

* These come out of (or should go into) thread_private.h - rather than have

* to copy (or symlink) the files from the source tree these definitions are

* inlined here. Obviously these go away when this module is part of libc.

*/

struct sem {

#define SEM_MAGIC ((u_int32_t) 0x09fa4012)

u_int32_t magic;

pthread_mutex_t lock;

pthread_cond_t gtzero;

u_int32_t count;

u_int32_t nwaiters;

};

extern pthread_once_t _thread_init_once;

extern int _threads_initialized;

extern void _thread_init __P((void));

#define THREAD_INIT() \

(void) pthread_once(&_thread_init_once, _thread_init)

#define THREAD_SAFE() \

(_threads_initialized != 0)

#define _SEM_CHECK_VALIDITY(sem) \

if ((*(sem))->magic != SEM_MAGIC) { \

errno = EINVAL; \

retval = -1; \

goto RETURN; \

}

/* End thread_private.h kluge */

int

sem_init(sem_t *sem, int pshared, unsigned int value)

{

int retval;

if (!THREAD_SAFE())

THREAD_INIT();

/*

* Range check the arguments.

*/

if (pshared != 0) {

/*

* The user wants a semaphore that can be shared among

* processes, which this implementation can't do. Sounds like a

* permissions problem to me (yeah right).

*/

errno = EPERM;

retval = -1;

goto RETURN;

}

if (value > SEM_VALUE_MAX) {

errno = EINVAL;

retval = -1;

goto RETURN;

}

*sem = (sem_t)malloc(sizeof(struct sem));

if (*sem == NULL) {

errno = ENOSPC;

retval = -1;

goto RETURN;

}

/*

* Initialize the semaphore.

*/

if (pthread_mutex_init(&(*sem)->lock, NULL) != 0) {

free(*sem);

errno = ENOSPC;

retval = -1;

goto RETURN;

}

if (pthread_cond_init(&(*sem)->gtzero, NULL) != 0) {

pthread_mutex_destroy(&(*sem)->lock);

free(*sem);

errno = ENOSPC;

retval = -1;

goto RETURN;

}

(*sem)->count = (u_int32_t)value;

(*sem)->nwaiters = 0;

(*sem)->magic = SEM_MAGIC;

retval = 0;

RETURN:

return retval;

}

int

sem_destroy(sem_t *sem)

{

int retval;

_SEM_CHECK_VALIDITY(sem);

/* Make sure there are no waiters. */

pthread_mutex_lock(&(*sem)->lock);

if ((*sem)->nwaiters > 0) {

pthread_mutex_unlock(&(*sem)->lock);

errno = EBUSY;

retval = -1;

goto RETURN;

}

pthread_mutex_unlock(&(*sem)->lock);

pthread_mutex_destroy(&(*sem)->lock);

pthread_cond_destroy(&(*sem)->gtzero);

(*sem)->magic = 0;

free(*sem);

retval = 0;

RETURN:

return retval;

}

sem_t *

sem_open(const char *name, int oflag, ...)

{

errno = ENOSYS;

return SEM_FAILED;

}

int

sem_close(sem_t *sem)

{

errno = ENOSYS;

return -1;

}

int

sem_unlink(const char *name)

{

errno = ENOSYS;

return -1;

}

int

sem_wait(sem_t *sem)

{

int retval;

pthread_testcancel();

_SEM_CHECK_VALIDITY(sem);

pthread_mutex_lock(&(*sem)->lock);

while ((*sem)->count == 0) {

(*sem)->nwaiters++;

pthread_cond_wait(&(*sem)->gtzero, &(*sem)->lock);

(*sem)->nwaiters--;

}

(*sem)->count--;

pthread_mutex_unlock(&(*sem)->lock);

retval = 0;

RETURN:

pthread_testcancel();

return retval;

}

int

sem_trywait(sem_t *sem)

{

int retval;

_SEM_CHECK_VALIDITY(sem);

pthread_mutex_lock(&(*sem)->lock);

if ((*sem)->count > 0) {

(*sem)->count--;

retval = 0;

} else {

errno = EAGAIN;

retval = -1;

}

pthread_mutex_unlock(&(*sem)->lock);

RETURN:

return retval;

}

int

sem_post(sem_t *sem)

{

int retval;

_SEM_CHECK_VALIDITY(sem);

pthread_mutex_lock(&(*sem)->lock);

(*sem)->count++;

if ((*sem)->nwaiters > 0) {

/*

* We must use pthread_cond_broadcast() rather than

* pthread_cond_signal() in order to assure that the highest

* priority thread is run by the scheduler, since

* pthread_cond_signal() signals waiting threads in FIFO order.

*/

pthread_cond_broadcast(&(*sem)->gtzero);

}

pthread_mutex_unlock(&(*sem)->lock);

retval = 0;

RETURN:

return retval;

}

int

sem_getvalue(sem_t *sem, int *sval)

{

int retval;

_SEM_CHECK_VALIDITY(sem);

pthread_mutex_lock(&(*sem)->lock);

*sval = (int)(*sem)->count;

pthread_mutex_unlock(&(*sem)->lock);

retval = 0;

RETURN:

return retval;

}

/* END of inlined uthread_sem.c */

#endif /* SDL_USE_PTHREADS */