semaphore.h

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/*
 *  The contents of this file are subject to the Mozilla Public License
 *  Version 1.0 (the "License"); you may not use this file except in
 *  compliance with the License. You may obtain a copy of the License
 *  at http://www.mozilla.org/MPL/
 *
 *  Software distributed under the License is distributed on an "AS IS"
 *  basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 *  the License for the specific language governing rights and
 *  limitations under the License.
 *
 *  The Original Code is legOS code, released October 17, 1999.
 *
 *  The Initial Developer of the Original Code is Markus L. Noga.
 *  Portions created by Markus L. Noga are Copyright (C) 1999
 *  Markus L. Noga. All Rights Reserved.
 *
 *  Contributor(s): Markus L. Noga <markus@noga.de>
 *                  Henner Zeller <H.Zeller@acm.org> (sem_timedwait())
 */

#ifndef __semaphore_h__
#define __semaphore_h__

#ifdef  __cplusplus
extern "C" {
#endif

#include <config.h>
#include <time.h> /* time_t */
#include <atomic.h>

#ifdef CONF_SEMAPHORES

//
// Definitions
//

typedef atomic_t sem_t;                         

#define EAGAIN  0xffff                          


//
// Functions
//


extern inline int sem_init(sem_t * sem, int pshared, unsigned int value)
{
  *sem = (sem_t) value;
  return 0;
}


extern int sem_wait(sem_t * sem);

extern int sem_timedwait(sem_t * sem,
                         const time_t abs_timeout);


extern int sem_trywait(sem_t * sem);


extern inline int sem_post(sem_t * sem) 
{ 
        atomic_inc(sem);
        return 0;
}

//
//
extern inline int sem_getvalue(sem_t * sem, int *sval)
{
  *sval = *sem;
  return 0;
}


extern inline int sem_destroy(sem_t * sem)
{
  return 0;
}

#endif // CONF_SEMAPHORES

#ifdef  __cplusplus
}
#endif

#endif // __semaphore_h__

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