// Copyright CERN and copyright holders of ALICE O2. This software is

// distributed under the terms of the GNU General Public License v3 (GPL

// Version 3), copied verbatim in the file "COPYING".

//

// See http://alice-o2.web.cern.ch/license for full licensing information.

//

// In applying this license CERN does not waive the privileges and immunities

// granted to it by virtue of its status as an Intergovernmental Organization

// or submit itself to any jurisdiction.

/// \file qsem.cxx

/// \author David Rohr

#include <cerrno>

#include <cstdio>

#include "qsem.h"

#ifndef STD_OUT

#define STD_OUT stdout

#endif

qSem::qSem(int num)

{

max = num;

if (sem_init(&sem, 0, num)) {

fprintf(STD_OUT, "Error initializing semaphore");

}

}

qSem::~qSem()

{

if (sem_destroy(&sem)) {

fprintf(STD_OUT, "Error destroying semaphore");

}

}

int qSem::Lock()

{

int retVal;

if ((retVal = sem_wait(&sem))) {

fprintf(STD_OUT, "Error locking semaphore");

}

return (retVal);

}

int qSem::Unlock()

{

int retVal;

if ((retVal = sem_post(&sem))) {

fprintf(STD_OUT, "Error unlocking semaphire");

}

return (retVal);

}

int qSem::Trylock()

{

int retVal = sem_trywait(&sem);

if (retVal) {

if (errno == EAGAIN) {

return (EBUSY);

}

return (-1);

}

return (0);

}

#ifndef _WIN32

int qSem::Query()

{

int value;

if (sem_getvalue(&sem, &value) != 0) {

value = -1;

}

return (value);

}

#endif