Add test for timer start delayed past expiration (FreeRTOS#557)

Co-authored-by: Dan Good <[email protected]>
Co-authored-by: RichardBarry <[email protected]>

FreeRTOS/Demo/Common/Minimal/TimerDemo.c

@@ -686,6 +686,8 @@ uint8_t ucTimer;
 
 static void prvTest7_CheckBacklogBehaviour( void )
 {
+UBaseType_t uxOriginalPriority;
+
 	/* Use the first auto-reload timer to test stopping a timer from a
 	backlogged callback. */
 
@@ -734,6 +736,55 @@ static void prvTest7_CheckBacklogBehaviour( void )
 	/* Clear the reload count for the timer used in this test. */
 	ucAutoReloadTimerCounters[ 0 ] = ( uint8_t ) 0;
 
+
+	/* Verify a one-shot timer is marked as inactive if the timer task processes
+	the start or reset request after the expiration time has passed. */
+
+	/* The timer has not been started yet! */
+	if( xTimerIsTimerActive( xOneShotTimer ) != pdFALSE )
+	{
+		xTestStatus = pdFAIL;
+		configASSERT( xTestStatus );
+	}
+
+	/* Use the timer period specific to backlogged timers because it reduces
+	the impact on other tests that might be running when xTaskCatchUpTicks()
+	creates the backlog, below. */
+	xTimerChangePeriod( xOneShotTimer, tmrdemoBACKLOG_TIMER_PERIOD, tmrdemoDONT_BLOCK );
+
+	/* Temporarily give this task maximum priority so it can cause the timer
+	task to delay its processing of the reset request below. */
+	uxOriginalPriority = uxTaskPriorityGet( NULL );
+	vTaskPrioritySet( NULL, ( configMAX_PRIORITIES - 1 ) );
+
+	/* Reset the timer.  The timer service won't process this request right
+	away as noted above. */
+	xTimerReset( xOneShotTimer, tmrdemoDONT_BLOCK );
+
+	/* Cause the timer period to elapse without giving an opportunity for the
+	timer service task to process the reset request. */
+	xTaskCatchUpTicks( tmrdemoBACKLOG_TIMER_PERIOD );
+
+	/* Return this task to its original priority.  The timer service task will
+	process the reset request immediately.  The timer task must handle the reset
+	request as if it were processed at the time of the request even though in
+	this test the processing occurs after the intended expiration time. */
+	vTaskPrioritySet( NULL, uxOriginalPriority );
+
+	/* The timer should now be inactive. */
+	if( xTimerIsTimerActive( xOneShotTimer ) != pdFALSE )
+	{
+		xTestStatus = pdFAIL;
+		configASSERT( xTestStatus );
+	}
+
+	/* Restore the standard timer period, and leave the timer inactive. */
+	xTimerChangePeriod( xOneShotTimer, tmrdemoONE_SHOT_TIMER_PERIOD, tmrdemoDONT_BLOCK );
+	xTimerStop( xOneShotTimer, tmrdemoDONT_BLOCK );
+
+	/* Clear the counter for the timer used in this test. */
+	ucOneShotTimerCounter = ( uint8_t ) 0;
+
 	if( xTestStatus == pdPASS )
 	{
 		/* No errors have been reported so increment the loop counter so the check