/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*************************************************************************
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * Copyright 2000, 2010 Oracle and/or its affiliates.
 *
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 *
 * 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/semaphor.h>
#include <osl/diagnose.h>

#ifndef OSL_USE_SYS_V_SEMAPHORE

/* This is the (default) POSIX thread-local semaphore variant */

/*
    Implemetation notes:
    The void* represented by oslSemaphore is used
    as a pointer to an sem_t struct
*/

/*****************************************************************************/
/* osl_createSemaphore  */
/*****************************************************************************/

oslSemaphore SAL_CALL osl_createSemaphore(sal_uInt32 initialCount) 
{
    int ret = 0;
    oslSemaphore Semaphore;

    Semaphore= malloc(sizeof(sem_t));

    OSL_ASSERT(Semaphore);		/* ptr valid? */

    if ( Semaphore == 0 )
    {
        return 0;
    }
    
    /* unnamed semaphore, not shared between processes */

       ret= sem_init((sem_t*)Semaphore, 0, initialCount);

    /* create failed? */
    if (ret != 0)
    {
        OSL_TRACE("osl_createSemaphore failed. Errno: %d; %s\n", 
                  errno, 
                  strerror(errno));

        free(Semaphore);
        Semaphore = NULL;
    }
    
    return Semaphore;
}

/*****************************************************************************/
/* osl_destroySemaphore  */
/*****************************************************************************/
void SAL_CALL osl_destroySemaphore(oslSemaphore Semaphore)
{
    if(Semaphore)			/* ptr valid? */
    {
        sem_destroy((sem_t*)Semaphore);
        free(Semaphore);
    }
}

/*****************************************************************************/
/* osl_acquireSemaphore  */
/*****************************************************************************/
sal_Bool SAL_CALL osl_acquireSemaphore(oslSemaphore Semaphore) {
    
    OSL_ASSERT(Semaphore != 0);	/* abort in debug mode */

    if (Semaphore != 0)		/* be tolerant in release mode */
    {
        return (sem_wait((sem_t*)Semaphore) == 0);
    }

    return sal_False;
}

/*****************************************************************************/
/* osl_tryToAcquireSemaphore  */
/*****************************************************************************/
sal_Bool SAL_CALL osl_tryToAcquireSemaphore(oslSemaphore Semaphore) {
    
    OSL_ASSERT(Semaphore != 0);	/* abort in debug mode */
    if (Semaphore != 0)		/* be tolerant in release mode */
    {
        return (sem_trywait((sem_t*)Semaphore) == 0);
    }

    return sal_False;
}

/*****************************************************************************/
/* osl_releaseSemaphore  */
/*****************************************************************************/
sal_Bool SAL_CALL osl_releaseSemaphore(oslSemaphore Semaphore) {

    OSL_ASSERT(Semaphore != 0);		/* abort in debug mode */
    
    if (Semaphore != 0)			/* be tolerant in release mode */
    {
        return (sem_post((sem_t*)Semaphore) == 0);
    }

    return sal_False;
}

#else /* OSL_USE_SYS_V_SEMAPHORE */

/*******************************************************************************/

/* This is the SYS V private semaphore variant */

/*
    Implemetation notes:
    The void* represented by oslSemaphore is used
    as a pointer to an osl_TSemImpl struct
*/


#if defined(NETBSD)
union semun {
        int     val;            /* value for SETVAL */
        struct  semid_ds *buf;  /* buffer for IPC_STAT & IPC_SET */
        u_short *array;         /* array for GETALL & SETALL */
};
#endif

typedef struct _osl_TSemImpl
{
  int m_Id;

} osl_TSemImpl;

/*****************************************************************************/
/* osl_createSemaphore  */
/*****************************************************************************/
oslSemaphore SAL_CALL osl_createSemaphore(sal_uInt32 initialCount) 
{
    union semun arg;
    
    oslSemaphore Semaphore;
    osl_TSemImpl* pSem;

    Semaphore= malloc(sizeof(osl_TSemImpl));
    OSL_POSTCOND(Semaphore, "malloc failed\n");		/* ptr valid? */

    pSem= (osl_TSemImpl*)Semaphore;


    /* unnamed (private) semaphore */

       pSem->m_Id= semget(IPC_PRIVATE, 1, 0666 | IPC_CREAT);


    /* create failed? */
    if (pSem->m_Id < 0)
    {
        OSL_TRACE("osl_createSemaphore failed (semget). Errno: %d; %s\n", 
               errno, 
               strerror(errno));

        free(Semaphore);
        return 0;
    }

    /* set initial count */

    arg.val= initialCount;

    if(semctl(pSem->m_Id, 0, SETVAL, arg) < 0)
    {
        OSL_TRACE("osl_createSemaphore failed (semctl(SETVAL)). Errno: %d; %s\n", 
               errno, 
               strerror(errno));

        if(semctl(pSem->m_Id, 0, IPC_RMID, arg) < 0)
        {
            OSL_TRACE("semctl(IPC_RMID) failed. Errno: %d; %s\n", errno, strerror(errno));
        }
        
        free(Semaphore);
        return 0;
    }
    
    
    return Semaphore;
}

/*****************************************************************************/
/* osl_destroySemaphore  */
/*****************************************************************************/
void SAL_CALL osl_destroySemaphore(oslSemaphore Semaphore) {
    
    if(Semaphore)			/* ptr valid? */
    {
        union semun arg;

        osl_TSemImpl* pSem= (osl_TSemImpl*)Semaphore;

        if(semctl(pSem->m_Id, 0, IPC_RMID, arg) < 0)

        {
            OSL_TRACE("osl_destroySemaphore failed. (semctl(IPC_RMID)). Errno: %d; %s\n", 
                   errno, 
                   strerror(errno));			
        }
        
        free(Semaphore);
    }
}

/*****************************************************************************/
/* osl_acquireSemaphore  */
/*****************************************************************************/
sal_Bool SAL_CALL osl_acquireSemaphore(oslSemaphore Semaphore) {
    
    /* abort in debug mode */
    OSL_PRECOND(Semaphore != 0, "Semaphore not created\n");	


    if (Semaphore != 0)		/* be tolerant in release mode */
    {
        struct sembuf op;
        osl_TSemImpl* pSem= (osl_TSemImpl*)Semaphore;

        op.sem_num= 0;
        op.sem_op= -1;
        op.sem_flg= SEM_UNDO;

        return semop(pSem->m_Id, &op, 1) >= 0;

    }

    return sal_False;
}

/*****************************************************************************/
/* osl_tryToAcquireSemaphore  */
/*****************************************************************************/
sal_Bool SAL_CALL osl_tryToAcquireSemaphore(oslSemaphore Semaphore) {
    
    /* abort in debug mode */
    OSL_PRECOND(Semaphore != 0, "Semaphore not created\n");	

    if (Semaphore != 0)		/* be tolerant in release mode */
    {
        struct sembuf op;
        osl_TSemImpl* pSem= (osl_TSemImpl*)Semaphore;

        op.sem_num= 0;
        op.sem_op= -1;
        op.sem_flg= SEM_UNDO | IPC_NOWAIT;

        return semop(pSem->m_Id, &op, 1) >= 0;
    }

    return sal_False;
}

/*****************************************************************************/
/* osl_releaseSemaphore  */
/*****************************************************************************/
sal_Bool SAL_CALL osl_releaseSemaphore(oslSemaphore Semaphore) 
{

    /* abort in debug mode */
    OSL_PRECOND(Semaphore != 0, "Semaphore not created\n");	
    
    if (Semaphore != 0)			/* be tolerant in release mode */
    {
        struct sembuf op;
        osl_TSemImpl* pSem= (osl_TSemImpl*)Semaphore;

        op.sem_num= 0;
        op.sem_op= 1;
        op.sem_flg= SEM_UNDO;

        return semop(pSem->m_Id, &op, 1) >= 0;
    }

    return sal_False;
}

#endif /* OSL_USE_SYS_V_SEMAPHORE */

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