Queue set and semaphore behavior question

rrrum wrote on Thursday, May 19, 2016:


Suppose I have created queue set “xQueueSetTest” with one queue and semaphore. Then in a task I call

xActivatedMember = xQueueSelectFromSet( xQueueSetTest, portMAX_DELAY );

which will block the task. If semaphore is signaled from some other task, the task unblocks but in subsequent code I don’t call

xSemaphoreTake( xActivatedMember, 0 );

If the task is executed again and arrives at xQueueSelectFromSet will it exit immediately since semaphore is still signaled?

Is my understanding correct or the behavior will be again blocked task?



rtel wrote on Thursday, May 19, 2016:

No - the task will block again and that will be a logic error. If a
task is blocked on a queue set and leaves the blocked state because an
item was posted to a queue or semaphore in that set then the unblocked
task MUST them remove the item from the queue or semaphore.