C++ semGive函数代码示例

static struct event_info * event_info_alloc(int event) {
    int nxt;
    struct event_info * info;
    SPIN_LOCK_ISR_TAKE(&events_lock);
    if (events_buf_overflow) {
        SPIN_LOCK_ISR_GIVE(&events_lock);
        return NULL;
    }
    info = events + events_inp;
    nxt = (events_inp + 1) % MAX_EVENTS;
    if (nxt == events_out) {
        events_buf_overflow = 1;
        semGive(events_signal);
        SPIN_LOCK_ISR_GIVE(&events_lock);
        return NULL;
    }
    memset(info, 0, sizeof(struct event_info));
    info->event = event;
    events_inp = nxt;
    events_cnt++;
    return info;
}

STATUS ti81xxSpiChannelConfig
    (
    int module,     /* SPI module number */
    int channel,    /* SPI channel number */
    int cfgValue    /* SPI channel configure value */
    )
    {
    if (ti81xxMcSpiSanityCheck(module, channel) == ERROR)
        {
        TI81XX_SPI_LOG("%s : invalid parameter.\n", __FUNCTION__, 0, 0, 0, 0, 0);
        return (ERROR);
        }

    semTake(mcSpiSem[module], WAIT_FOREVER);

    TI81XX_SPI_REGISTER_WRITE(module, MCSPI_CHxCONF(channel), cfgValue);

    semGive(mcSpiSem[module]);

    return (OK);

    }

/*!*****************************************************************************
*******************************************************************************
\note  send_misc_sensors
\date  Nov. 2007
   
\remarks 

sends the entire misc_sim_sensors to shared memory
	

*******************************************************************************
Function Parameters: [in]=input,[out]=output

none

******************************************************************************/
int 
send_misc_sensors(void)
{
  
  int i;

  if (semTake(sm_misc_sim_sensor_sem,ns2ticks(TIME_OUT_NS)) == ERROR) {
    
    ++simulation_servo_errors;
    return FALSE;

  } 

  for (i=1; i<=n_misc_sensors; ++i)
    sm_misc_sim_sensor->value[i] = misc_sim_sensor[i];

  sm_misc_sim_sensor->ts = simulation_servo_time;
  
  semGive(sm_misc_sim_sensor_sem);

  return TRUE;
}

void Semaphore::give()
{
#if defined (PTHREADS)
	if (sem_post(sem))
	{
		throw Exception("Could not release semaphore", errno, __FILE__, __LINE__);
	}

#elif defined(VXWORKS)
	if (semGive(sem))
	{
		throw Exception("Could not release semaphore", -1, __FILE__, __LINE__);
	}

#elif defined(_WINDOWS)
	if (! ReleaseSemaphore(sem,1,NULL))
	{
		throw Exception("Could not release semaphore", GetLastError(), __FILE__, __LINE__);
	}

#endif
}

STATUS virtualStackNumGet
    (
    VSID vsid,
    int *num
    )
    {
    
    if ((vsid == NULL) && (num == NULL))
        return (ERROR);

    semTake (vsTblLock, WAIT_FOREVER);
    
    for (*num = 0; (*num < VSID_MAX) && (vsTbl[*num] != vsid); (*num)++);

    semGive(vsTblLock);

    if ( vsTbl[*num] != vsid )
	return (ERROR);

    return OK;

    }

//------------------------------------------------------------------------------
// Function:    ShbIpcStopSignalingNewData
//
// Description: Stop signaling of new data (called from reading process)
//
// Parameters:  pShbInstance_p        pointer to shared buffer instance
//
// Return:      tShbError      = error code
//------------------------------------------------------------------------------
tShbError ShbIpcStopSignalingNewData(tShbInstance pShbInstance_p)
{
    tShbMemInst         *pShbMemInst;
    tShbMemHeader       *pShbMemHeader;
    tShbError           ShbError;
    INT                 iRetVal = -1;

    if (pShbInstance_p == NULL)
    {
        return (kShbInvalidArg);
    }

    pShbMemHeader = ShbIpcGetShbMemHeader (pShbInstance_p);
    pShbMemInst = ShbIpcGetShbMemInst (pShbInstance_p);

    ShbError = kShbOk;

    if (!pShbMemInst->m_fNewDataThreadStarted)
    {
        ShbError = kShbBufferAlreadyCompleted;
        goto Exit;
    }

    //set termination flag and signal new data to terminate thread
    pShbMemInst->m_fThreadTermFlag = TRUE;
    semGive(pShbMemHeader->m_semNewData);

    iRetVal = semTake(pShbMemHeader->m_semStopSignalingNewData,
    		          TIMEOUT_WAITING_THREAD);
    if (iRetVal == ERROR)
    {
        EPL_DBGLVL_ERROR_TRACE("%s() Stop Sem TIMEOUT %d (%s)\n", __func__,
        		                iRetVal, strerror(errno));
    }

Exit:

    return (ShbError);
}

int devClose(myDev * dev)
{
	fifo * i = NULL; 
	fifo * temp = NULL;
	if(dev==NULL)
	{
		errnoSet(NOT_OPEN);
		return -1;
	}
	//Prevent anyone from accessing this device while we're modifying it :
	if(semTake(dev->semMData,WAIT_FOREVER)==-1)
	{
		errnoSet(SEM_ERR);
		return -1;
	}
	if (dev->openned == 0)
	{
		errnoSet(NOT_OPEN);
		return -1;
	} else {
		//Find fifo corresponding to this task in drv->listFifo and deallocate it
		if (dev->firstFifo->taskId==taskIdSelf())
		{
			temp=dev->firstFifo;
			dev->firstFifo=temp->nextFifo;
			deleteFifo(temp);
			free(temp);
		} else {
			for (i=dev->firstFifo;i->nextFifo->taskId==taskIdSelf();i=i->nextFifo);
			temp=i->nextFifo;
			i->nextFifo=temp->nextFifo;
			deleteFifo(temp);
			free(temp);
		}
		dev->openned--;
	}
	semGive(dev->semMData);
	return 0;
}

BST_ERR_ENUM_UINT8  BST_OS_PalSendSem(
    BST_OS_PAL_SEM_T    stSemHandle,
    BST_VOID           *pvArg )
{
    if( BST_PAL_IsSemInValid( stSemHandle ) )
    {
        return BST_ERR_ILLEGAL_PARAM;
    }

#if (VOS_RTOSCK == VOS_OS_VER)
    if( VOS_OK == VOS_SmV(stSemHandle) )
#else
    if( OK == semGive(stSemHandle) )
#endif
    {
        return BST_NO_ERROR_MSG;
    }
    else
    {
        return BST_ERR_ILLEGAL_PARAM;
    }
}

/* Move execution to netJob. returns 0 if successful. */
int ssh_netjob_synchronous_invoke(FUNCPTR function, void *context)
{
  STATUS stat;
  SEMAPHORE *s;

  s = semBCreate(SEM_Q_PRIORITY, SEM_FULL);
  if (!s) return 2;
  
  semTake(s, WAIT_FOREVER);
  stat = netJobAdd(function, (int)context, (int)s, 0, 0, 0);

  if (stat == OK) 
    {
      semTake(s, WAIT_FOREVER);
      semDelete(s);
      return 0;
    }

  semGive(s);
  semDelete(s);
  return 1;
}

/******************************************************************************
*
* m2SysGroupInfoSet - set system-group MIB-II variables to new values
*
* This routine sets one or more variables in the system group as specified in
* the input structure at <pSysInfo> and the bit field parameter <varToSet>.
*
* RETURNS: 
* OK, or ERROR if <pSysInfo> is not a valid pointer, or <varToSet> has an 
* invalid bit field.
*
* ERRNO:
*  S_m2Lib_INVALID_PARAMETER
*  S_m2Lib_INVALID_VAR_TO_SET
*
* SEE ALSO: m2SysInit(), m2SysGroupInfoGet(), m2SysDelete()
*/
STATUS m2SysGroupInfoSet
    (
    unsigned int varToSet,		/* bit field of variables to set */
    M2_SYSTEM * pSysInfo		/* pointer to the system structure */
    )
    {
 
    /* Validate Pointer to System structure and bit field in varToSet */
 
    if (pSysInfo == NULL ||
        (varToSet & (M2SYSNAME | M2SYSCONTACT | M2SYSLOCATION)) == 0)
	{
	if (pSysInfo == NULL)
	    errnoSet (S_m2Lib_INVALID_PARAMETER);
	else
	    errnoSet (S_m2Lib_INVALID_VAR_TO_SET);

        return (ERROR);
	}
 
    /* Set requested variables */
 
    semTake (m2SystemSem, WAIT_FOREVER);
 
    if (varToSet & M2SYSNAME)
        strcpy ((char *) m2SystemVars.sysName, (char *) pSysInfo->sysName);
 
    if (varToSet & M2SYSCONTACT)
        strcpy ((char *) m2SystemVars.sysContact, (char *)pSysInfo->sysContact);
 
    if (varToSet & M2SYSLOCATION)
        strcpy ((char *) m2SystemVars.sysLocation, 
		(char *) pSysInfo->sysLocation);
 
    semGive (m2SystemSem);
 
    return (OK);
    }

int _tmain(int argc, _TCHAR* argv[])
{
	classLibInit();
	memPartLibInit(memBuf, MEM_LEN);

	char* a1 = (char*)memPartAlloc(memSysPartId, 10);
	char* a2 = (char*)memPartAlloc(memSysPartId, 45);
	memPartFree(memSysPartId, a1);
	memPartFree(memSysPartId, a2);

	a1 = (char*)memPartAlloc(memSysPartId, 10);
	a2 = (char*)memPartAlloc(memSysPartId, 45);

	memPartFree(memSysPartId, a2);
	memPartFree(memSysPartId, a1);

	a1 = (char*)memPartAlloc(memSysPartId, 10);
	a2 = (char*)memPartAlloc(memSysPartId, 12);
	char* a3 = (char*)memPartAlloc(memSysPartId, 45);

	memPartFree(memSysPartId, a2);

	char* a4 = (char*)memPartAlloc(memSysPartId, 12);

	testQueue();

	SEM_ID semId = semMCreate(0);

	int c = 0;
	semTake(semId, WAIT_FOREVER);
	c++;
	semGive(semId);

	semDelete(semId);

	gets(a1);
	return 0;
}

/* Function: DisconnectFromHost ================================================
 * Abstract:
 *  Disconnect from the host.
 */
PRIVATE void DisconnectFromHost(int_T numSampTimes)
{
    int i;

    for (i=0; i<NUM_UPINFOS; i++) {
        UploadPrepareForFinalFlush(i);

#if defined(VXWORKS)
        /*
         * UploadPrepareForFinalFlush() has already called semGive(uploadSem)
         * two times.  Now the server thread will wait until the upload thread
         * has processed all of the data in the buffers for the final upload
         * and exhausted the uploadSem semaphores.  If the server thread
         * attempts to call UploadServerWork() while the upload thread is in
         * the middle of processing the buffers, the target code may crash
         * with a NULL pointer exception (the buffers are destroyed after
         * calling UploadLogInfoTerm).
         */
        while(semTake(uploadSem, NO_WAIT) != ERROR) {
            semGive(uploadSem);
            taskDelay(1000);
        }
#else
#ifndef EXTMODE_DISABLESIGNALMONITORING
        if (host_upstatus_is_uploading) {
            UploadServerWork(i, numSampTimes);
        }
#endif
#endif

        UploadLogInfoTerm(i, numSampTimes);
    }
    
    connected       = false;
    commInitialized = false;
    
    ExtCloseConnection(extUD);
} /* end DisconnectFromHost */

/**
 * ProcessQueue is called whenever there is a timer interrupt.
 * We need to wake up and process the current top item in the timer queue as long
 * as its scheduled time is after the current time. Then the item is removed or 
 * rescheduled (repetitive events) in the queue.
 */
void Notifier::ProcessQueue(uint32_t mask, void *params)
{
    Notifier *current;
    while (true)                // keep processing past events until no more
    {
        {
            Synchronized sync(queueSemaphore);
            double currentTime = GetClock();
            current = timerQueueHead;
            if (current == NULL || current->m_expirationTime > currentTime)
            {
                break;        // no more timer events to process
            }
            // need to process this entry
            timerQueueHead = current->m_nextEvent;
            if (current->m_periodic)
            {
                // if periodic, requeue the event
                // compute when to put into queue
                current->InsertInQueue(true);
            }
            else
            {
                // not periodic; removed from queue
                current->m_queued = false;
            }
            // Take handler semaphore while holding queue semaphore to make sure
            //  the handler will execute to completion in case we are being deleted.
            semTake(current->m_handlerSemaphore, WAIT_FOREVER);
        }

        current->m_handler(current->m_param);    // call the event handler
        semGive(current->m_handlerSemaphore);
    }
    // reschedule the first item in the queue
    Synchronized sync(queueSemaphore);
    UpdateAlarm();
}

int drvRemove()
{
	myDev * i = first;
	myDev * drv;
	if (semMAdmin == 0)
	{
		errnoSet(NOT_INSTALLED);
		return -1;
	}
	if (semTake(semMAdmin,WAIT_FOREVER)==-1)
	{
		errnoSet(SEM_ERR);
		return -1;
	}
	if (iosDrvRemove(numPilote,1) == -1) //And force closure of open files
	{
		errnoSet(REMOVE_ERROR);
		semGive(semMAdmin);
		return -1;
	}
	taskDelete(tMsgDispatchID);
	msgQDelete(isrmq);
	//Delete all devices  : 
	while (i!=NULL)
	{
		drv = i;
		i = drv->next;
		iosDevDelete((DEV_HDR*)drv);
		semTake(drv->semMData,WAIT_FOREVER); //Let pending ops finish
		semDelete(drv->semMData);
		free(drv);
	}
	numPilote = -1;
	first = NULL;
	semDelete(semMAdmin);
	semMAdmin=0;
	return 0;
}

/*!*****************************************************************************
 *******************************************************************************
\note  receive_misc_sensors
\date  Nov. 2007   
\remarks 

        receives the entire misc_sim_sensors from shared memory
	

 *******************************************************************************
 Function Parameters: [in]=input,[out]=output

     none

 ******************************************************************************/
static int 
receive_misc_sensors(void)
{
  
  int i;

  if (n_misc_sensors <= 0)
    return TRUE;

  if (semTake(sm_misc_sim_sensor_sem,ns2ticks(TIME_OUT_NS)) == ERROR) {
    
    ++motor_servo_errors;
    return FALSE;

  } 

  for (i=1; i<=n_misc_sensors; ++i)
    misc_sim_sensor[i] = sm_misc_sim_sensor->value[i];
  
  semGive(sm_misc_sim_sensor_sem);

  return TRUE;
}