semaphore.c

xenomai 很好的linux实时补丁

/*
 * Copyright (C) 2005 Philippe Gerum <[e-mail]>.
 *
 * 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 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
 */

#include <stdlib.h>             /* For malloc & free. */
#include <stdarg.h>
#include <errno.h>
#include <fcntl.h>              /* For O_CREAT. */
#include <pthread.h>            /* For pthread_setcanceltype. */
#include <posix/syscall.h>
#include <semaphore.h>

extern int __pse51_muxid;

int __wrap_sem_init (sem_t *sem,
		     int pshared,
		     unsigned value)
{
    union __xeno_sem *_sem = (union __xeno_sem *)sem;
    int err;

    err = -XENOMAI_SKINCALL3(__pse51_muxid,
			     __pse51_sem_init,
			     &_sem->shadow_sem,
			     pshared,
			     value);
    if (!err)
	return 0;

    errno = err;

    return -1;
}

int __wrap_sem_destroy (sem_t *sem)

{
    union __xeno_sem *_sem = (union __xeno_sem *)sem;
    int err;

    err = -XENOMAI_SKINCALL1(__pse51_muxid,
			     __pse51_sem_destroy,
			     &_sem->shadow_sem);
    if (!err)
	return 0;

    errno = err;

    return -1;
}

int __wrap_sem_post (sem_t *sem)

{
    union __xeno_sem *_sem = (union __xeno_sem *)sem;
    int err;

    err = -XENOMAI_SKINCALL1(__pse51_muxid,
			     __pse51_sem_post,
			     &_sem->shadow_sem);
    if (!err)
	return 0;

    errno = err;

    return -1;
}

int __wrap_sem_wait (sem_t *sem)

{
    union __xeno_sem *_sem = (union __xeno_sem *)sem;
    int err, oldtype;

    pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, &oldtype);

    err = -XENOMAI_SKINCALL1(__pse51_muxid,
			     __pse51_sem_wait,
			     &_sem->shadow_sem);

    pthread_setcanceltype(oldtype, NULL);

    if (!err)
	return 0;

    errno = err;

    return -1;
}

int __wrap_sem_timedwait (sem_t *sem, const struct timespec *ts)

{
    union __xeno_sem *_sem = (union __xeno_sem *)sem;
    int err, oldtype;

    pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, &oldtype);

    err = -XENOMAI_SKINCALL2(__pse51_muxid,
			     __pse51_sem_timedwait,
			     &_sem->shadow_sem,
                             ts);

    pthread_setcanceltype(oldtype, NULL);

    if (!err)
	return 0;

    errno = err;

    return -1;
}

int __wrap_sem_trywait (sem_t *sem)

{
    union __xeno_sem *_sem = (union __xeno_sem *)sem;
    int err;

    err = -XENOMAI_SKINCALL1(__pse51_muxid,
			     __pse51_sem_trywait,
			     &_sem->shadow_sem);
    if (!err)
	return 0;

    errno = err;

    return -1;
}

int __wrap_sem_getvalue (sem_t *sem, int *sval)

{
    union __xeno_sem *_sem = (union __xeno_sem *)sem;
    int err;

    err = -XENOMAI_SKINCALL2(__pse51_muxid,
			     __pse51_sem_getvalue,
			     &_sem->shadow_sem,
			     sval);
    if (!err)
	return 0;

    errno = err;

    return -1;
}

sem_t *__wrap_sem_open (const char *name, int oflags, ...)
{
    union __xeno_sem *sem, *rsem;
    unsigned value = 0;
    mode_t mode = 0;
    va_list ap;
    int err;

    if((oflags & O_CREAT))
        {
        va_start(ap, oflags);
        mode = va_arg(ap, int);
        value = va_arg(ap, unsigned);
        va_end(ap);
        }

    rsem = sem = (union __xeno_sem *) malloc(sizeof(*sem));

    if (!rsem)
        {
        err = ENOSPC;
        goto error;
        }

    err = -XENOMAI_SKINCALL5(__pse51_muxid,
                             __pse51_sem_open,
                             &rsem,
                             name,
                             oflags,
                             mode,
                             value);

    if (!err)
        {
        if (rsem != sem)
            free(sem);
        return &rsem->native_sem;
        }

    free(sem);
  error:
    errno = err;
    return SEM_FAILED;
}

int __wrap_sem_close (sem_t *sem)
{
    union __xeno_sem *_sem = (union __xeno_sem *)sem;
    int err, closed;

    err = -XENOMAI_SKINCALL2(__pse51_muxid,
                             __pse51_sem_close,
                             &_sem->shadow_sem,
			     &closed);

    if (!err)
        {
	if(closed)
            free(sem);
        return 0;
	}

    errno = err;
    return -1;
}

int __wrap_sem_unlink (const char *name)
{
    int err;

    err = -XENOMAI_SKINCALL1(__pse51_muxid, 
		    	     __pse51_sem_unlink, 
			     name);

    if (!err)
        return 0;

    errno = err;
    return -1;
}