static signed portBASE_TYPE prvUnlockQueue( xQueueHandle pxQueue )
{
signed portBASE_TYPE xYieldRequired = pdFALSE;
/* THIS FUNCTION MUST BE CALLED WITH THE SCHEDULER SUSPENDED. */
/* The lock counts contains the number of extra data items placed or
removed from the queue while the queue was locked. When a queue is
locked items can be added or removed, but the event lists cannot be
updated. */
taskENTER_CRITICAL();
{
--( pxQueue->xTxLock );
/* See if data was added to the queue while it was locked. */
if( pxQueue->xTxLock > queueUNLOCKED )
{
pxQueue->xTxLock = queueUNLOCKED;
/* Data was posted while the queue was locked. Are any tasks
blocked waiting for data to become available? */
if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) )
{
/* Tasks that are removed from the event list will get added to
the pending ready list as the scheduler is still suspended. */
if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) != pdFALSE )
{
/* The task waiting has a higher priority so record that a
context switch is required. */
xYieldRequired = pdTRUE;
}
}
}
}
taskEXIT_CRITICAL();
/* Do the same for the Rx lock. */
taskENTER_CRITICAL();
{
--( pxQueue->xRxLock );
if( pxQueue->xRxLock > queueUNLOCKED )
{
pxQueue->xRxLock = queueUNLOCKED;
if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToSend ) ) )
{
if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToSend ) ) != pdFALSE )
{
xYieldRequired = pdTRUE;
}
}
}
}
taskEXIT_CRITICAL();
return xYieldRequired;
}
signed portBASE_TYPE xQueueReceiveFromISR( xQueueHandle pxQueue, void *pvBuffer, signed portBASE_TYPE *pxTaskWoken )
{
signed portBASE_TYPE xReturn;
/* We cannot block from an ISR, so check there is data available. */
if( pxQueue->uxMessagesWaiting > ( unsigned portBASE_TYPE ) 0 )
{
/* Copy the data from the queue. */
pxQueue->pcReadFrom += pxQueue->uxItemSize;
if( pxQueue->pcReadFrom >= pxQueue->pcTail )
{
pxQueue->pcReadFrom = pxQueue->pcHead;
}
--( pxQueue->uxMessagesWaiting );
if(pvBuffer != (void*)0UL)
{
memcpy( ( void * ) pvBuffer, ( void * ) pxQueue->pcReadFrom, ( unsigned ) pxQueue->uxItemSize );
}
/* If the queue is locked we will not modify the event list. Instead
we update the lock count so the task that unlocks the queue will know
that an ISR has removed data while the queue was locked. */
if( pxQueue->xRxLock == queueUNLOCKED )
{
/* We only want to wake one task per ISR, so check that a task has
not already been woken. */
if( !( *pxTaskWoken ) )
{
if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToSend ) ) )
{
if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToSend ) ) != pdFALSE )
{
/* The task waiting has a higher priority than us so
force a context switch. */
*pxTaskWoken = pdTRUE;
}
}
}
}
else
{
/* Increment the lock count so the task that unlocks the queue
knows that data was removed while it was locked. */
++( pxQueue->xRxLock );
}
xReturn = pdPASS;
}
else
{
xReturn = pdFAIL;
}
return xReturn;
}
signed portBASE_TYPE xQueueGenericSendFromISR( xQueueHandle pxQueue, const void * const pvItemToQueue, signed portBASE_TYPE *pxHigherPriorityTaskWoken, portBASE_TYPE xCopyPosition )
{
signed portBASE_TYPE xReturn;
unsigned portBASE_TYPE uxSavedInterruptStatus;
/* Similar to xQueueGenericSend, except we don't block if there is no room
in the queue. Also we don't directly wake a task that was blocked on a
queue read, instead we return a flag to say whether a context switch is
required or not (i.e. has a task with a higher priority than us been woken
by this post). */
uxSavedInterruptStatus = portSET_INTERRUPT_MASK_FROM_ISR();
{
if( pxQueue->uxMessagesWaiting < pxQueue->uxLength )
{
traceQUEUE_SEND_FROM_ISR( pxQueue );
prvCopyDataToQueue( pxQueue, pvItemToQueue, xCopyPosition );
/* If the queue is locked we do not alter the event list. This will
be done when the queue is unlocked later. */
if( pxQueue->xTxLock == queueUNLOCKED )
{
if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) )
{
if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) != pdFALSE )
{
/* The task waiting has a higher priority so record that a
context switch is required. */
*pxHigherPriorityTaskWoken = pdTRUE;
}
}
}
else
{
/* Increment the lock count so the task that unlocks the queue
knows that data was posted while it was locked. */
++( pxQueue->xTxLock );
}
xReturn = pdPASS;
}
else
{
traceQUEUE_SEND_FROM_ISR_FAILED( pxQueue );
xReturn = errQUEUE_FULL;
}
}
portCLEAR_INTERRUPT_MASK_FROM_ISR( uxSavedInterruptStatus );
return xReturn;
}
signed portBASE_TYPE xQueueReceiveFromISR( xQueueHandle pxQueue, void * const pvBuffer, signed portBASE_TYPE *pxTaskWoken )
{
signed portBASE_TYPE xReturn;
unsigned portBASE_TYPE uxSavedInterruptStatus;
uxSavedInterruptStatus = portSET_INTERRUPT_MASK_FROM_ISR();
{
/* We cannot block from an ISR, so check there is data available. */
if( pxQueue->uxMessagesWaiting > ( unsigned portBASE_TYPE ) 0 )
{
traceQUEUE_RECEIVE_FROM_ISR( pxQueue );
prvCopyDataFromQueue( pxQueue, pvBuffer );
--( pxQueue->uxMessagesWaiting );
/* If the queue is locked we will not modify the event list. Instead
we update the lock count so the task that unlocks the queue will know
that an ISR has removed data while the queue was locked. */
if( pxQueue->xRxLock == queueUNLOCKED )
{
if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToSend ) ) )
{
if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToSend ) ) != pdFALSE )
{
/* The task waiting has a higher priority than us so
force a context switch. */
*pxTaskWoken = pdTRUE;
}
}
}
else
{
/* Increment the lock count so the task that unlocks the queue
knows that data was removed while it was locked. */
++( pxQueue->xRxLock );
}
xReturn = pdPASS;
}
else
{
xReturn = pdFAIL;
traceQUEUE_RECEIVE_FROM_ISR_FAILED( pxQueue );
}
}
portCLEAR_INTERRUPT_MASK_FROM_ISR( uxSavedInterruptStatus );
return xReturn;
}
static Void callback_ToHost(VirtQueue_Handle vq)
{
UInt16 avail;
int i;
Bool doSwitch[portNUM_PROCESSORS];
unsigned portBASE_TYPE curCpu = portGetCurrentCPU();
taskENTER_CRITICAL_NOT_RECURSIVE_FROM_ISR(&virtQueLock);
if(listLIST_IS_EMPTY(&availBufList) != pdFALSE){
taskEXIT_CRITICAL_NOT_RECURSIVE_FROM_ISR(&virtQueLock);
return;
}
if((avail = GET_AVAIL_COUNT(vq)) == 0){
taskEXIT_CRITICAL_NOT_RECURSIVE_FROM_ISR(&virtQueLock);
return;
}
memset(doSwitch, FALSE, sizeof(doSwitch));
do{
signed portBASE_TYPE ret;
/* Because this function is not an application code, */
/* there is not the problem with using xTaskRemoveFromEventList. */
ret = xTaskRemoveFromEventList(&availBufList, pdFALSE);
if(ret >= 0){
doSwitch[ret] = TRUE;
}
}
while(--avail > 0);
taskEXIT_CRITICAL_NOT_RECURSIVE_FROM_ISR(&virtQueLock);
for(i = 0; i < portNUM_PROCESSORS; i++){
if(doSwitch[i]){
if(i == (int)curCpu){
vPortYieldFromISR();
}
else{
portINTERRUPT_CORE(i);
}
}
}
}
signed portBASE_TYPE xQueueSendFromISR( xQueueHandle pxQueue, const void *pvItemToQueue, signed portBASE_TYPE xTaskPreviouslyWoken )
{
/* Similar to xQueueSend, except we don't block if there is no room in the
queue. Also we don't directly wake a task that was blocked on a queue
read, instead we return a flag to say whether a context switch is required
or not (i.e. has a task with a higher priority than us been woken by this
post). */
if( pxQueue->uxMessagesWaiting < pxQueue->uxLength )
{
prvCopyQueueData( pxQueue, pvItemToQueue );
/* If the queue is locked we do not alter the event list. This will
be done when the queue is unlocked later. */
if( pxQueue->xTxLock == queueUNLOCKED )
{
/* We only want to wake one task per ISR, so check that a task has
not already been woken. */
if( !xTaskPreviouslyWoken )
{
if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) )
{
if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) != pdFALSE )
{
/* The task waiting has a higher priority so record that a
context switch is required. */
return pdTRUE;
}
}
}
}
else
{
/* Increment the lock count so the task that unlocks the queue
knows that data was posted while it was locked. */
++( pxQueue->xTxLock );
}
}
return xTaskPreviouslyWoken;
}
signed portBASE_TYPE xMutexGive( xMutexHandle pxMutex, portBASE_TYPE Release )
{
portENTER_CRITICAL( );
if ( pxMutex->pxOwner != xTaskGetCurrentTaskHandle( ) )
{
portEXIT_CRITICAL( );
return pdFALSE;
}
if ( Release )
pxMutex->uxCount = 0;
else
{
if ( --pxMutex->uxCount != 0 )
{
portEXIT_CRITICAL( );
return pdFALSE;
}
}
if( !listLIST_IS_EMPTY( &pxMutex->xTasksWaitingToTake ) )
{
pxMutex->pxOwner = (xTaskHandle) listGET_OWNER_OF_HEAD_ENTRY( ( &pxMutex->xTasksWaitingToTake ) );
pxMutex->uxCount = 1;
if( xTaskRemoveFromEventList( &pxMutex->xTasksWaitingToTake ) == pdTRUE )
taskYIELD( );
}
else
{
pxMutex->pxOwner = NULL;
}
portEXIT_CRITICAL( );
return pdTRUE;
}
signed portBASE_TYPE xQueueGenericReceive( xQueueHandle pxQueue, void * const pvBuffer, portTickType xTicksToWait, portBASE_TYPE xJustPeeking )
{
signed portBASE_TYPE xReturn = pdTRUE;
xTimeOutType xTimeOut;
signed portCHAR *pcOriginalReadPosition;
do
{
/* If there are no messages in the queue we may have to block. */
if( xTicksToWait > ( portTickType ) 0 )
{
vTaskSuspendAll();
prvLockQueue( pxQueue );
if( xReturn == pdTRUE )
{
/* This is the first time through - we need to capture the
time while the scheduler is locked to ensure we attempt to
block at least once. */
vTaskSetTimeOutState( &xTimeOut );
}
if( prvIsQueueEmpty( pxQueue ) )
{
/* Need to call xTaskCheckForTimeout again as time could
have passed since it was last called if this is not the
first time around this loop. */
if( xTaskCheckForTimeOut( &xTimeOut, &xTicksToWait ) == pdFALSE )
{
traceBLOCKING_ON_QUEUE_RECEIVE( pxQueue );
#if ( configUSE_MUTEXES == 1 )
{
if( pxQueue->uxQueueType == queueQUEUE_IS_MUTEX )
{
portENTER_CRITICAL();
vTaskPriorityInherit( ( void * ) pxQueue->pxMutexHolder );
portEXIT_CRITICAL();
}
}
#endif
vTaskPlaceOnEventList( &( pxQueue->xTasksWaitingToReceive ), xTicksToWait );
prvUnlockQueue( pxQueue );
if( !xTaskResumeAll() )
{
taskYIELD();
}
}
else
{
prvUnlockQueue( pxQueue );
( void ) xTaskResumeAll();
}
}
else
{
prvUnlockQueue( pxQueue );
( void ) xTaskResumeAll();
}
}
/* The two tasks are blocked on the queue, the low priority task is polling/running. */
/* An interrupt occurs here - which unblocks the HP tasks, but they do not run. */
taskENTER_CRITICAL();
{
/* Because the interrupt occurred the LP task manages to grab the data as the other two tasks are not yet running. */
if( pxQueue->uxMessagesWaiting > ( unsigned portBASE_TYPE ) 0 )
{
/* Remember our read position in case we are just peeking. */
pcOriginalReadPosition = pxQueue->pcReadFrom;
prvCopyDataFromQueue( pxQueue, pvBuffer );
if( xJustPeeking == pdFALSE )
{
traceQUEUE_RECEIVE( pxQueue );
/* We are actually removing data. */
--( pxQueue->uxMessagesWaiting );
#if ( configUSE_MUTEXES == 1 )
{
if( pxQueue->uxQueueType == queueQUEUE_IS_MUTEX )
{
/* Record the information required to implement
priority inheritance should it become necessary. */
pxQueue->pxMutexHolder = xTaskGetCurrentTaskHandle();
}
}
#endif
if( listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToSend ) ) == pdFALSE )
{
if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToSend ) ) == pdTRUE )
{
taskYIELD();
}
}
}
else
{
traceQUEUE_PEEK( pxQueue );
/* We are not removing the data, so reset our read
pointer. */
pxQueue->pcReadFrom = pcOriginalReadPosition;
/* The data is being left in the queue, so see if there are
any other tasks waiting for the data. */
if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) )
{
/* Tasks that are removed from the event list will get added to
the pending ready list as the scheduler is still suspended. */
if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) != pdFALSE )
{
/* The task waiting has a higher priority than this task. */
taskYIELD();
}
}
}
xReturn = pdPASS;
}
else
{
xReturn = errQUEUE_EMPTY;
}
}
taskEXIT_CRITICAL();
if( xReturn == errQUEUE_EMPTY )
{
if( xTicksToWait > ( portTickType ) 0 )
{
if( xTaskCheckForTimeOut( &xTimeOut, &xTicksToWait ) == pdFALSE )
{
xReturn = queueERRONEOUS_UNBLOCK;
}
else
{
traceQUEUE_RECEIVE_FAILED( pxQueue );
}
}
else
{
traceQUEUE_RECEIVE_FAILED( pxQueue );
}
}
} while( xReturn == queueERRONEOUS_UNBLOCK );
return xReturn;
}
signed portBASE_TYPE xQueueAltGenericReceive( xQueueHandle pxQueue, void * const pvBuffer, portTickType xTicksToWait, portBASE_TYPE xJustPeeking )
{
signed portBASE_TYPE xReturn = pdTRUE;
xTimeOutType xTimeOut;
signed portCHAR *pcOriginalReadPosition;
/* The source code that implements the alternative (Alt) API is
simpler because it makes more use of critical sections. This is
the approach taken by many other RTOSes, but FreeRTOS.org has the
preferred fully featured API too. The fully featured API has more
complex code that takes longer to execute, but makes less use of
critical sections. */
do
{
/* If there are no messages in the queue we may have to block. */
if( xTicksToWait > ( portTickType ) 0 )
{
portENTER_CRITICAL();
{
if( xReturn == pdPASS )
{
/* This is the first time through - capture the time
inside the critical section to ensure we attempt to
block at least once. */
vTaskSetTimeOutState( &xTimeOut );
}
if( prvIsQueueEmpty( pxQueue ) )
{
/* Need to call xTaskCheckForTimeout again as time could
have passed since it was last called if this is not the
first time around this loop. */
if( xTaskCheckForTimeOut( &xTimeOut, &xTicksToWait ) == pdFALSE )
{
traceBLOCKING_ON_QUEUE_RECEIVE( pxQueue );
#if ( configUSE_MUTEXES == 1 )
{
if( pxQueue->uxQueueType == queueQUEUE_IS_MUTEX )
{
vTaskPriorityInherit( ( void * ) pxQueue->pxMutexHolder );
}
}
#endif
vTaskPlaceOnEventList( &( pxQueue->xTasksWaitingToReceive ), xTicksToWait );
taskYIELD();
}
}
}
portEXIT_CRITICAL();
}
taskENTER_CRITICAL();
{
if( pxQueue->uxMessagesWaiting > ( unsigned portBASE_TYPE ) 0 )
{
/* Remember our read position in case we are just peeking. */
pcOriginalReadPosition = pxQueue->pcReadFrom;
prvCopyDataFromQueue( pxQueue, pvBuffer );
if( xJustPeeking == pdFALSE )
{
traceQUEUE_RECEIVE( pxQueue );
/* We are actually removing data. */
--( pxQueue->uxMessagesWaiting );
#if ( configUSE_MUTEXES == 1 )
{
if( pxQueue->uxQueueType == queueQUEUE_IS_MUTEX )
{
/* Record the information required to implement
priority inheritance should it become necessary. */
pxQueue->pxMutexHolder = xTaskGetCurrentTaskHandle();
}
}
#endif
if( listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToSend ) ) == pdFALSE )
{
if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToSend ) ) == pdTRUE )
{
taskYIELD();
}
}
}
else
{
traceQUEUE_PEEK( pxQueue );
/* We are not removing the data, so reset our read
pointer. */
pxQueue->pcReadFrom = pcOriginalReadPosition;
/* The data is being left in the queue, so see if there are
any other tasks waiting for the data. */
if( !listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) )
{
/* Tasks that are removed from the event list will get added to
the pending ready list as the scheduler is still suspended. */
if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) != pdFALSE )
{
/* The task waiting has a higher priority that this task. */
taskYIELD();
}
}
}
xReturn = pdPASS;
}
else
{
xReturn = errQUEUE_EMPTY;
}
}
taskEXIT_CRITICAL();
if( xReturn == errQUEUE_EMPTY )
{
if( xTicksToWait > ( portTickType ) 0 )
{
if( xTaskCheckForTimeOut( &xTimeOut, &xTicksToWait ) == pdFALSE )
{
xReturn = queueERRONEOUS_UNBLOCK;
}
else
{
traceQUEUE_RECEIVE_FAILED( pxQueue );
}
}
else
{
traceQUEUE_RECEIVE_FAILED( pxQueue );
}
}
} while( xReturn == queueERRONEOUS_UNBLOCK );
return xReturn;
}
signed portBASE_TYPE xQueueAltGenericSend( xQueueHandle pxQueue, const void * const pvItemToQueue, portTickType xTicksToWait, portBASE_TYPE xCopyPosition )
{
signed portBASE_TYPE xReturn = pdPASS;
xTimeOutType xTimeOut;
/* The source code that implements the alternative (Alt) API is
simpler because it makes more use of critical sections. This is
the approach taken by many other RTOSes, but FreeRTOS.org has the
preferred fully featured API too. The fully featured API has more
complex code that takes longer to execute, but makes less use of
critical sections. */
do
{
/* If xTicksToWait is zero then we are not going to block even
if there is no room in the queue to post. */
if( xTicksToWait > ( portTickType ) 0 )
{
portENTER_CRITICAL();
{
if( xReturn == pdPASS )
{
/* This is the first time through - capture the time
inside the critical section to ensure we attempt to
block at least once. */
vTaskSetTimeOutState( &xTimeOut );
}
if( prvIsQueueFull( pxQueue ) )
{
/* Need to call xTaskCheckForTimeout again as time could
have passed since it was last called if this is not the
first time around this loop. */
if( xTaskCheckForTimeOut( &xTimeOut, &xTicksToWait ) == pdFALSE )
{
traceBLOCKING_ON_QUEUE_SEND( pxQueue );
vTaskPlaceOnEventList( &( pxQueue->xTasksWaitingToSend ), xTicksToWait );
/* This will exit the critical section, then re-enter when
the task next runs. */
taskYIELD();
}
}
}
portEXIT_CRITICAL();
}
/* Higher priority tasks and interrupts can execute during
this time and could possible refill the queue - even if we
unblocked because space became available. */
taskENTER_CRITICAL();
{
/* Is there room on the queue now? To be running we must be
the highest priority task wanting to access the queue. */
if( pxQueue->uxMessagesWaiting < pxQueue->uxLength )
{
traceQUEUE_SEND( pxQueue );
prvCopyDataToQueue( pxQueue, pvItemToQueue, xCopyPosition );
xReturn = pdPASS;
/* If there was a task waiting for data to arrive on the
queue then unblock it now. */
if( listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) == pdFALSE )
{
if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) == pdTRUE )
{
/* The unblocked task has a priority higher than
our own so yield immediately. */
taskYIELD();
}
}
}
else
{
/* Setting xReturn to errQUEUE_FULL will force its timeout
to be re-evaluated. This is necessary in case interrupts
and higher priority tasks accessed the queue between this
task being unblocked and subsequently attempting to write
to the queue. */
xReturn = errQUEUE_FULL;
}
}
taskEXIT_CRITICAL();
if( xReturn == errQUEUE_FULL )
{
if( xTicksToWait > ( portTickType ) 0 )
{
if( xTaskCheckForTimeOut( &xTimeOut, &xTicksToWait ) == pdFALSE )
{
xReturn = queueERRONEOUS_UNBLOCK;
}
else
{
traceQUEUE_SEND_FAILED( pxQueue );
}
}
else
{
traceQUEUE_SEND_FAILED( pxQueue );
}
}
}
while( xReturn == queueERRONEOUS_UNBLOCK );
return xReturn;
}
signed portBASE_TYPE xQueueGenericSend( xQueueHandle pxQueue, const void * const pvItemToQueue, portTickType xTicksToWait, portBASE_TYPE xCopyPosition )
{
signed portBASE_TYPE xReturn = pdTRUE;
xTimeOutType xTimeOut;
do
{
/* If xTicksToWait is zero then we are not going to block even
if there is no room in the queue to post. */
if( xTicksToWait > ( portTickType ) 0 )
{
vTaskSuspendAll();
prvLockQueue( pxQueue );
if( xReturn == pdTRUE )
{
/* This is the first time through - we need to capture the
time while the scheduler is locked to ensure we attempt to
block at least once. */
vTaskSetTimeOutState( &xTimeOut );
}
if( prvIsQueueFull( pxQueue ) )
{
/* Need to call xTaskCheckForTimeout again as time could
have passed since it was last called if this is not the
first time around this loop. */
if( xTaskCheckForTimeOut( &xTimeOut, &xTicksToWait ) == pdFALSE )
{
traceBLOCKING_ON_QUEUE_SEND( pxQueue );
vTaskPlaceOnEventList( &( pxQueue->xTasksWaitingToSend ), xTicksToWait );
/* Unlocking the queue means queue events can effect the
event list. It is possible that interrupts occurring now
remove this task from the event list again - but as the
scheduler is suspended the task will go onto the pending
ready last instead of the actual ready list. */
prvUnlockQueue( pxQueue );
/* Resuming the scheduler will move tasks from the pending
ready list into the ready list - so it is feasible that this
task is already in a ready list before it yields - in which
case the yield will not cause a context switch unless there
is also a higher priority task in the pending ready list. */
if( !xTaskResumeAll() )
{
taskYIELD();
}
}
else
{
prvUnlockQueue( pxQueue );
( void ) xTaskResumeAll();
}
}
else
{
/* The queue was not full so we can just unlock the
scheduler and queue again before carrying on. */
prvUnlockQueue( pxQueue );
( void ) xTaskResumeAll();
}
}
/* Higher priority tasks and interrupts can execute during
this time and could possible refill the queue - even if we
unblocked because space became available. */
taskENTER_CRITICAL();
{
/* Is there room on the queue now? To be running we must be
the highest priority task wanting to access the queue. */
if( pxQueue->uxMessagesWaiting < pxQueue->uxLength )
{
traceQUEUE_SEND( pxQueue );
prvCopyDataToQueue( pxQueue, pvItemToQueue, xCopyPosition );
xReturn = pdPASS;
/* If there was a task waiting for data to arrive on the
queue then unblock it now. */
if( listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) == pdFALSE )
{
if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) == pdTRUE )
{
/* The unblocked task has a priority higher than
our own so yield immediately. */
taskYIELD();
}
}
}
else
{
/* Setting xReturn to errQUEUE_FULL will force its timeout
to be re-evaluated. This is necessary in case interrupts
and higher priority tasks accessed the queue between this
task being unblocked and subsequently attempting to write
to the queue. */
xReturn = errQUEUE_FULL;
}
}
taskEXIT_CRITICAL();
if( xReturn == errQUEUE_FULL )
{
if( xTicksToWait > ( portTickType ) 0 )
{
if( xTaskCheckForTimeOut( &xTimeOut, &xTicksToWait ) == pdFALSE )
{
xReturn = queueERRONEOUS_UNBLOCK;
}
else
{
traceQUEUE_SEND_FAILED( pxQueue );
}
}
else
{
traceQUEUE_SEND_FAILED( pxQueue );
}
}
}
while( xReturn == queueERRONEOUS_UNBLOCK );
return xReturn;
}