// %flair:license{
// This file is part of the Flair framework distributed under the
// CECILL-C License, Version 1.0.
// %flair:license}
//  created:    2016/11/16
//  filename:   Semaphore_impl.cpp
//
//  author:     Thomas Fuhrmann
//              Copyright Heudiasyc UMR UTC/CNRS 7253
//
//  version:    $Id: $
//
//  purpose:    Class defining a semaphore implementation
//
//
/*********************************************************************/

#include "Semaphore.h"
#include "Semaphore_impl.h"

#include <string.h>
#include <time.h>

using std::string;
using namespace flair::core;

Semaphore_impl::Semaphore_impl(Semaphore *self, string name, uint32_t initialValue, Semaphore::Type &type):type(type) {
  this->self = self;
  int status;
	
#ifdef __XENO__
  status = rt_sem_create(&semaphore, NULL, initialValue, S_FIFO);
#else
  if (type==Semaphore::Type::named) {
    sem_name = "/" + name;
    semaphore=sem_open(sem_name.c_str(),O_CREAT, 0666, initialValue);
    if (semaphore==SEM_FAILED) status=errno; else status=0;
  } else { //anonymous
    semaphore=new sem_t;
    status = sem_init(semaphore, 0, initialValue);
  }
#endif
  if (status != 0) {
    char errorMsg[256];
    self->Err("error creating semaphore (%s)\n", strerror_r(-status, errorMsg, sizeof(errorMsg)));
  }
}

Semaphore_impl::~Semaphore_impl() {
  int status;
	
#ifdef __XENO__
  status = rt_sem_delete(&semaphore);
#else
  if (type==Semaphore::Type::named) {
    status=sem_close(semaphore);
    sem_unlink(sem_name.c_str());
  } else { //anonymous
    status = sem_destroy(semaphore);
  }
#endif
  if (status != 0) {
    char errorMsg[256];
    self->Err("error destroying semaphore (%s)\n", strerror_r(-status, errorMsg, sizeof(errorMsg)));
  }
}

bool Semaphore_impl::TryGetSemaphore() {
#ifdef __XENO__
  return !rt_sem_p(&semaphore, TM_NONBLOCK);
#else
  return !sem_trywait(semaphore);
#endif
}

bool Semaphore_impl::GetSemaphore(Time timeout) {
  int status;
  bool returnValue = true;
#ifdef __XENO__
  status = rt_sem_p(&semaphore, timeout);
#else
  if (timeout != 0) {
    struct timespec semTimeout;
    clock_gettime(CLOCK_REALTIME, &semTimeout);
    semTimeout.tv_sec += timeout / 1000000000ULL;
    semTimeout.tv_nsec += timeout % 1000000000ULL;
    if (semTimeout.tv_nsec >= 1000000000ULL) {
    	semTimeout.tv_sec++;
    	semTimeout.tv_nsec -= 1000000000ULL;
    }
    status = sem_timedwait(semaphore, &semTimeout);
  } else {
    status = sem_wait(semaphore);
  }
#endif
  	if (status != 0) {
  		if (errno == ETIMEDOUT) {
#ifdef DEBUG
  		  	self->Warn("warning : semaphore timedout\n");
#endif
  		} else {
					char errorMsg[256];
  		    self->Err("error getting the semaphore (%s)\n", strerror_r(-status, errorMsg, sizeof(errorMsg)));
  		}
    returnValue = false;
  }
  return returnValue;
}

bool Semaphore_impl::ReleaseSemaphore(void) {
  int status;
  bool returnValue = true;
#ifdef __XENO__
  status = rt_sem_v(&semaphore);
#else
  status = sem_post(semaphore);
#endif
  if (status != 0) {
		char errorMsg[256];
    self->Err("error releasing the semaphore (%s)\n", strerror_r(-status, errorMsg, sizeof(errorMsg)));
    returnValue = false;
  }
  return returnValue;
}