/*************************************************************************
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * Copyright 2008 by Sun Microsystems, Inc.
 *
 * OpenOffice.org - a multi-platform office productivity suite
 *
 * $RCSfile: mutex.c,v $
 * $Revision: 1.15 $
 *
 * This file is part of OpenOffice.org.
 *
 * OpenOffice.org is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License version 3
 * only, as published by the Free Software Foundation.
 *
 * OpenOffice.org is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License version 3 for more details
 * (a copy is included in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU Lesser General Public License
 * version 3 along with OpenOffice.org.  If not, see
 * <http://www.openoffice.org/license.html>
 * for a copy of the LGPLv3 License.
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 ************************************************************************/

#include "system.h"

#include <osl/mutex.h>
#include <osl/diagnose.h>

#include <pthread.h>
#include <stdlib.h>

#if defined LINUX /* bad hack */
int pthread_mutexattr_setkind_np(pthread_mutexattr_t *, int);
#define pthread_mutexattr_settype pthread_mutexattr_setkind_np
#define PTHREAD_MUTEX_RECURSIVE PTHREAD_MUTEX_RECURSIVE_NP
#endif

/*
    Implementation notes:
    oslMutex hides a pointer to the oslMutexImpl structure, which
    ist needed to manage recursive locks on a mutex.

*/

typedef struct _oslMutexImpl
{
    pthread_mutex_t mutex;
} oslMutexImpl;


/*****************************************************************************/
/* osl_createMutex */
/*****************************************************************************/
oslMutex SAL_CALL osl_createMutex()
{
    oslMutexImpl* pMutex = (oslMutexImpl*) malloc(sizeof(oslMutexImpl));
    pthread_mutexattr_t aMutexAttr;
    int nRet=0;

    OSL_ASSERT(pMutex);

    if ( pMutex == 0 )
    {
        return 0;
    }

    pthread_mutexattr_init(&aMutexAttr);

    nRet = pthread_mutexattr_settype(&aMutexAttr, PTHREAD_MUTEX_RECURSIVE);

    nRet = pthread_mutex_init(&(pMutex->mutex), &aMutexAttr);
    if ( nRet != 0 )
    {
        OSL_TRACE("osl_createMutex : mutex init failed. Errno: %d; %s\n",
                  nRet, strerror(nRet));

        free(pMutex);
        pMutex = 0;
    }

    pthread_mutexattr_destroy(&aMutexAttr);

    return (oslMutex) pMutex;
}

/*****************************************************************************/
/* osl_destroyMutex */
/*****************************************************************************/
void SAL_CALL osl_destroyMutex(oslMutex Mutex)
{
    oslMutexImpl* pMutex = (oslMutexImpl*) Mutex;

    OSL_ASSERT(pMutex);

    if ( pMutex != 0 )
    {
        int nRet=0;

        nRet = pthread_mutex_destroy(&(pMutex->mutex));
        if ( nRet != 0 )
        {
            OSL_TRACE("osl_destroyMutex : mutex destroy failed. Errno: %d; %s\n",
                      nRet, strerror(nRet));
        }

        free(pMutex);
    }

    return;
}

/*****************************************************************************/
/* osl_acquireMutex */
/*****************************************************************************/
sal_Bool SAL_CALL osl_acquireMutex(oslMutex Mutex)
{
    oslMutexImpl* pMutex = (oslMutexImpl*) Mutex;

    OSL_ASSERT(pMutex);

    if ( pMutex != 0 )
    {
        int nRet=0;

        nRet = pthread_mutex_lock(&(pMutex->mutex));
        if ( nRet != 0 )
        {
            OSL_TRACE("osl_acquireMutex : mutex lock failed. Errno: %d; %s\n",
                      nRet, strerror(nRet));
            return sal_False;
        }
        return sal_True;
    }

    /* not initialized */
    return sal_False;
}

/*****************************************************************************/
/* osl_tryToAcquireMutex */
/*****************************************************************************/
sal_Bool SAL_CALL osl_tryToAcquireMutex(oslMutex Mutex)
{
    oslMutexImpl* pMutex = (oslMutexImpl*) Mutex;

    OSL_ASSERT(pMutex);

    if ( pMutex )
    {
        int nRet = 0;
        nRet = pthread_mutex_trylock(&(pMutex->mutex));
        if ( nRet != 0  )
            return sal_False;

        return sal_True;
    }

    /* not initialized */
    return sal_False;
}

/*****************************************************************************/
/* osl_releaseMutex */
/*****************************************************************************/
sal_Bool SAL_CALL osl_releaseMutex(oslMutex Mutex)
{
    oslMutexImpl* pMutex = (oslMutexImpl*) Mutex;

    OSL_ASSERT(pMutex);

    if ( pMutex )
    {
        int nRet=0;
        nRet = pthread_mutex_unlock(&(pMutex->mutex));
        if ( nRet != 0 )
        {
            OSL_TRACE("osl_releaseMutex : mutex unlock failed. Errno: %d; %s\n",
                      nRet, strerror(nRet));
            return sal_False;
        }

        return sal_True;
    }

    /* not initialized */
    return sal_False;
}

/*****************************************************************************/
/* osl_getGlobalMutex */
/*****************************************************************************/

static oslMutexImpl globalMutexImpl;

static void globalMutexInitImpl(void) {
    pthread_mutexattr_t attr;
    if (pthread_mutexattr_init(&attr) != 0 ||
        pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE) ||
        pthread_mutex_init(&globalMutexImpl.mutex, &attr) != 0 ||
        pthread_mutexattr_destroy(&attr) != 0)
    {
        abort();
    }
}

oslMutex * SAL_CALL osl_getGlobalMutex()
{
    /* necessary to get a "oslMutex *" */
    static oslMutex globalMutex = (oslMutex) &globalMutexImpl;

    static pthread_once_t once = PTHREAD_ONCE_INIT;
    if (pthread_once(&once, &globalMutexInitImpl) != 0) {
        abort();
    }

    return &globalMutex;
}