int mq_close()

in FreeRTOS-Plus-POSIX/source/FreeRTOS_POSIX_mqueue.c [398:457]
38 lines of code
6 McCabe index (conditional complexity)

int mq_close( mqd_t mqdes )
{
    int iStatus = 0;
    QueueListElement_t * pxMessageQueue = ( QueueListElement_t * ) mqdes;
    BaseType_t xQueueRemoved = pdFALSE;

    /* Initialize the queue list, if needed. */
    prvInitializeQueueList();

    /* Lock the mutex that guards access to the queue list. This call will
     * never fail because it blocks forever. */
    ( void ) xSemaphoreTake( ( SemaphoreHandle_t ) &xQueueListMutex, portMAX_DELAY );

    /* Attempt to find the message queue based on the given descriptor. */
    if( prvFindQueueInList( NULL, NULL, mqdes ) == pdTRUE )
    {
        /* Decrement the number of open descriptors. */
        if( pxMessageQueue->xOpenDescriptors > 0 )
        {
            pxMessageQueue->xOpenDescriptors--;
        }

        /* Check if the queue has any more open descriptors. */
        if( pxMessageQueue->xOpenDescriptors == 0 )
        {
            /* If no open descriptors remain and mq_unlink has already been called,
             * remove the queue. */
            if( pxMessageQueue->xPendingUnlink == pdTRUE )
            {
                listREMOVE( &pxMessageQueue->xLink );

                /* Set the flag to delete the queue. Deleting the queue is deferred
                 * until xQueueListMutex is released. */
                xQueueRemoved = pdTRUE;
            }
            /* Otherwise, wait for the call to mq_unlink. */
            else
            {
                pxMessageQueue->xPendingUnlink = pdTRUE;
            }
        }
    }
    else
    {
        /* Queue not found; bad descriptor. */
        errno = EBADF;
        iStatus = -1;
    }

    /* Release the mutex protecting the queue list. */
    ( void ) xSemaphoreGive( ( SemaphoreHandle_t ) &xQueueListMutex );

    /* Delete all resources used by the queue if needed. */
    if( xQueueRemoved == pdTRUE )
    {
        prvDeleteMessageQueue( pxMessageQueue );
    }

    return iStatus;
}