// Copyright (c) 2005-2009 Nokia Corporation and/or its subsidiary(-ies).

// All rights reserved.

// This component and the accompanying materials are made available

// under the terms of "Eclipse Public License v1.0"

// which accompanies this distribution, and is available

// at the URL "http://www.eclipse.org/legal/epl-v10.html".

//

// Initial Contributors:

// Nokia Corporation - initial contribution.

//

// Contributors:

//

// Description:

// Name     : sem_trywait.cpp

// Part of  : PThread library

// sem_trywait call is implemented.

// Version:

//

#include <e32def.h>

#include <errno.h>

#include "semaphore.h"

#include "semaphoretypes.h"

#include "pthread.h"

EXPORT_C int sem_trywait (sem_t * sem)

{

    if (!sem || !(*sem))

    {

        errno = EINVAL;

        return -1;

    }

    _sem_t* gsem = *sem;

    if(gsem->iState != _sem_t::EInitialized)

    {

        errno = EINVAL;

        return -1;

    }

    if(gsem->iCount <=0)

    {

        errno = EAGAIN;

        return -1;

    }

    gsem->iMutex.Wait(); 

    if(gsem->iState != _sem_t::EInitialized) 

    { 

        errno = EINVAL; 

        return -1; 

    }

    //mutex still locked

    int retval=0;

    if(gsem->iCount > 0)

    {

        gsem->iCount--; 

        retval = 0;

    }

    else

    {

        errno = EAGAIN;

        retval = -1;

    }

    gsem->iMutex.Signal();

    return retval;

}//sem_trywait

//End of File