xQueueOverwriteFromISR macro

QueueHandle_t xQueue; void vFunction( void *pvParameters ) { // Create a queue to hold one uint32_t value. It is strongly // recommended *not* to use xQueueOverwriteFromISR() on queues that can // contain more than one value, and doing so will trigger an assertion // if configASSERT() is defined. xQueue = xQueueCreate( 1, sizeof( uint32_t ) ); } void vAnInterruptHandler( void ) { // xHigherPriorityTaskWoken must be set to pdFALSE before it is used. BaseType_t xHigherPriorityTaskWoken = pdFALSE; uint32_t ulVarToSend, ulValReceived; // Write the value 10 to the queue using xQueueOverwriteFromISR(). ulVarToSend = 10; xQueueOverwriteFromISR( xQueue, &ulVarToSend, &xHigherPriorityTaskWoken ); // The queue is full, but calling xQueueOverwriteFromISR() again will still // pass because the value held in the queue will be overwritten with the // new value. ulVarToSend = 100; xQueueOverwriteFromISR( xQueue, &ulVarToSend, &xHigherPriorityTaskWoken ); // Reading from the queue will now return 100. // ... if( xHigherPrioritytaskWoken == pdTRUE ) { // Writing to the queue caused a task to unblock and the unblocked task // has a priority higher than or equal to the priority of the currently // executing task (the task this interrupt interrupted). Perform a context // switch so this interrupt returns directly to the unblocked task. portYIELD_FROM_ISR(); // or portEND_SWITCHING_ISR() depending on the port. } }