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/*******************************************************************************
* Copyright (C) ST-Ericsson SA 2011
* License terms: 3-clause BSD license
******************************************************************************/
#include <sys/errno.h>
#include <semaphore.h>
#include <sys/time.h>
#include <fcntl.h>
#include "Types.h"
#include "CSemaphore.h"
#include "OS.h"
CSemaphore::CSemaphore(unsigned int initial_count)
{
#if defined(__APPLE__)
char sem_name[SEM_NAME_MAX_LENGTH];
int sem_nr = 1;
while (sem_nr <= SEM_MAX_NR) {
snprintf(sem_name, SEM_NAME_MAX_LENGTH, "lcdriversem_%d", sem_nr);
/* open semaphore with "rw" permissions for everyone - 0666 */
m_semaphore = sem_open(sem_name, O_CREAT | O_EXCL, 0666 , 0);
if (m_semaphore != SEM_FAILED) {
break;
}
sem_nr++;
}
#elif defined(__linux__)
sem_init(&m_semaphore, 0, initial_count);
#endif
}
CSemaphore::~CSemaphore()
{
#if defined(__APPLE__)
sem_close(m_semaphore);
#elif defined(__linux__)
sem_destroy(&m_semaphore);
#endif
}
bool CSemaphore::Release(unsigned int count)
{
if (!count) {
return false;
}
for (unsigned int i = 0; i < count; ++i) {
#if defined(__APPLE__)
if (sem_post(m_semaphore)) {
#elif defined(__linux__)
if (sem_post(&m_semaphore)) {
#endif
return false;
}
}
return true;
}
DWORD CSemaphore::Wait(DWORD timeout)
{
#if defined(__APPLE__)
if (INFINITE == timeout) {
sem_wait(m_semaphore);
} else {
struct timeval curr_time, start_time;
DWORD dwTimePassed = 0;
int ret;
gettimeofday(&start_time, NULL);
/* Try to lock the semaphore */
ret = sem_trywait(m_semaphore);
if (ret != 0) {
while (dwTimePassed < timeout) {
/* Sleep 1ms */
OS::Sleep(1);
/* Try to lock the semaphore again*/
ret = sem_trywait(m_semaphore);
if (ret == 0) {
return WAIT_OBJECT_0;
}
gettimeofday(&curr_time, NULL);
dwTimePassed = 1000 * (curr_time.tv_sec - start_time.tv_sec) + \
(curr_time.tv_usec - start_time.tv_usec) / 1000;
}
return WAIT_TIMEOUT;
}
}
return WAIT_OBJECT_0;
#elif defined(__linux__)
if (INFINITE == timeout) {
sem_wait(&m_semaphore);
} else {
timespec absoulute_time = OS::GetAbsoluteTime(timeout);
int ret;
/* coverity[returned_null] */
while (-1 == (ret = sem_timedwait(&m_semaphore, &absoulute_time)) && errno == EINTR);
if (0 != ret) {
return WAIT_TIMEOUT;
}
}
return WAIT_OBJECT_0;
#endif
}
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