Function xQueueGenericSendFromISR

queue.c:987–1151

/*-----------------------------------------------------------*/

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 )
                        {