xref: /aoo41x/main/sal/osl/unx/semaphor.c (revision cdf0e10c)

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 *
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 *
 * Copyright 2000, 2010 Oracle and/or its affiliates.
 *
 * OpenOffice.org - a multi-platform office productivity suite
 *
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 *
 * 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.
 *
 ************************************************************************/


#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 */