in queue.c [1047:1209]
BaseType_t xQueueGenericSendFromISR( QueueHandle_t xQueue,
const void * const pvItemToQueue,
BaseType_t * const pxHigherPriorityTaskWoken,
const BaseType_t xCopyPosition )
{
BaseType_t xReturn;
UBaseType_t uxSavedInterruptStatus;
Queue_t * const pxQueue = xQueue;
configASSERT( pxQueue );
configASSERT( !( ( pvItemToQueue == NULL ) && ( pxQueue->uxItemSize != ( UBaseType_t ) 0U ) ) );
configASSERT( !( ( xCopyPosition == queueOVERWRITE ) && ( pxQueue->uxLength != 1 ) ) );
/* RTOS ports that support interrupt nesting have the concept of a maximum
* system call (or maximum API call) interrupt priority. Interrupts that are
* above the maximum system call priority are kept permanently enabled, even
* when the RTOS kernel is in a critical section, but cannot make any calls to
* FreeRTOS API functions. If configASSERT() is defined in FreeRTOSConfig.h
* then portASSERT_IF_INTERRUPT_PRIORITY_INVALID() will result in an assertion
* failure if a FreeRTOS API function is called from an interrupt that has been
* assigned a priority above the configured maximum system call priority.
* Only FreeRTOS functions that end in FromISR can be called from interrupts
* that have been assigned a priority at or (logically) below the maximum
* system call interrupt priority. FreeRTOS maintains a separate interrupt
* safe API to ensure interrupt entry is as fast and as simple as possible.
* More information (albeit Cortex-M specific) is provided on the following
* link: https://www.FreeRTOS.org/RTOS-Cortex-M3-M4.html */
portASSERT_IF_INTERRUPT_PRIORITY_INVALID();
/* Similar to xQueueGenericSend, except without blocking if there is no room
* in the queue. Also don't directly wake a task that was blocked on a queue
* read, instead 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 ) || ( xCopyPosition == queueOVERWRITE ) )
{
const int8_t cTxLock = pxQueue->cTxLock;
const UBaseType_t uxPreviousMessagesWaiting = pxQueue->uxMessagesWaiting;
traceQUEUE_SEND_FROM_ISR( pxQueue );
/* Semaphores use xQueueGiveFromISR(), so pxQueue will not be a
* semaphore or mutex. That means prvCopyDataToQueue() cannot result
* in a task disinheriting a priority and prvCopyDataToQueue() can be
* called here even though the disinherit function does not check if
* the scheduler is suspended before accessing the ready lists. */
( void ) prvCopyDataToQueue( pxQueue, pvItemToQueue, xCopyPosition );
/* The event list is not altered if the queue is locked. This will
* be done when the queue is unlocked later. */
if( cTxLock == queueUNLOCKED )
{
#if ( configUSE_QUEUE_SETS == 1 )
{
if( pxQueue->pxQueueSetContainer != NULL )
{
if( ( xCopyPosition == queueOVERWRITE ) && ( uxPreviousMessagesWaiting != ( UBaseType_t ) 0 ) )
{
/* Do not notify the queue set as an existing item
* was overwritten in the queue so the number of items
* in the queue has not changed. */
mtCOVERAGE_TEST_MARKER();
}
else if( prvNotifyQueueSetContainer( pxQueue ) != pdFALSE )
{
/* The queue is a member of a queue set, and posting
* to the queue set caused a higher priority task to
* unblock. A context switch is required. */
if( pxHigherPriorityTaskWoken != NULL )
{
*pxHigherPriorityTaskWoken = pdTRUE;
}
else
{
mtCOVERAGE_TEST_MARKER();
}
}
else
{
mtCOVERAGE_TEST_MARKER();
}
}
else
{
if( listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) == pdFALSE )
{
if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) != pdFALSE )
{
/* The task waiting has a higher priority so
* record that a context switch is required. */
if( pxHigherPriorityTaskWoken != NULL )
{
*pxHigherPriorityTaskWoken = pdTRUE;
}
else
{
mtCOVERAGE_TEST_MARKER();
}
}
else
{
mtCOVERAGE_TEST_MARKER();
}
}
else
{
mtCOVERAGE_TEST_MARKER();
}
}
}
#else /* configUSE_QUEUE_SETS */
{
if( listLIST_IS_EMPTY( &( pxQueue->xTasksWaitingToReceive ) ) == pdFALSE )
{
if( xTaskRemoveFromEventList( &( pxQueue->xTasksWaitingToReceive ) ) != pdFALSE )
{
/* The task waiting has a higher priority so record that a
* context switch is required. */
if( pxHigherPriorityTaskWoken != NULL )
{
*pxHigherPriorityTaskWoken = pdTRUE;
}
else
{
mtCOVERAGE_TEST_MARKER();
}
}
else
{
mtCOVERAGE_TEST_MARKER();
}
}
else
{
mtCOVERAGE_TEST_MARKER();
}
/* Not used in this path. */
( void ) uxPreviousMessagesWaiting;
}
#endif /* configUSE_QUEUE_SETS */
}
else
{
/* Increment the lock count so the task that unlocks the queue
* knows that data was posted while it was locked. */
prvIncrementQueueTxLock( pxQueue, cTxLock );
}
xReturn = pdPASS;
}
else
{
traceQUEUE_SEND_FROM_ISR_FAILED( pxQueue );
xReturn = errQUEUE_FULL;
}
}
portCLEAR_INTERRUPT_MASK_FROM_ISR( uxSavedInterruptStatus );
return xReturn;
}