/*------------------------------------------------------------------------*/
/* Copyright (C) SIEMENS CORP., 2018 All rights reserved.*/
/* All rights reserved.                                                   */
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/* modification, are permitted provided that the following conditions     */
/* are met:                                                               */
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/* 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. Neither the name of the copyright holder nor the names of its       */
/* contributors may be used to endorse or promote products derived from   */
/* this software without specific prior written permission.               */
/* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS    */
/* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT      */
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/*------------------------------------------------------------------------*/
/*------------------------------------------------------------------------*/
/* Attention : Callbacks are running concurrent in other threads so all   */
/*             printf statements should be synchronized. But this sample  */
/*             application doesn't synchronize for simplicity  !          */
/*------------------------------------------------------------------------*/

#include "os/semaphores.h"

#include <stdlib.h>

#if defined(_WIN32)
#include <Windows.h>
#elif defined(__unix)
#include <semaphore.h>
#endif

typedef struct OsSemaphore
{
#if defined(_WIN32)
	HANDLE win_sem;
#elif defined(__unix)
	sem_t lin_sem;
#endif
}OsSemaphore;

/* Initialize the semaphore */
void SemaphoreCreate(Semaphore* sem, int value)
{
	sem->os_sem = (OsSemaphore*)malloc(sizeof(OsSemaphore));
#if defined(_WIN32)
	sem->os_sem->win_sem = CreateSemaphore(0, value, LONG_MAX, 0);
#elif defined(__unix)
	sem_init(&sem->os_sem->lin_sem, 0, value);
#endif
}

/* Deinitialize the semaphore */
void SemaphoreDelete(Semaphore* sem)
{
#if defined(_WIN32)
	CloseHandle(sem->os_sem->win_sem);
#elif defined(__unix)
	sem_destroy(&sem->os_sem->lin_sem);
#endif
}

/* Signal (increment) the semaphore */
void SemaphoreSignal(Semaphore* sem)
{
#if defined(_WIN32)
	ReleaseSemaphore(sem->os_sem->win_sem, 1, 0);
#elif defined(__unix)
	sem_post(&sem->os_sem->lin_sem);
#endif
}

/* Wait for the semaphore (and decrement it) */
void SemaphoreWait(Semaphore* sem)
{
#if defined(_WIN32)
	WaitForSingleObject(sem->os_sem->win_sem, INFINITE);
#elif defined(__unix)
	sem_wait(&sem->os_sem->lin_sem);
#endif
}

