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Resume after Delay without Suspend possible?

Posted by Asier Gonzalez on February 2, 2009
I know that this question may be a stupid question, but as nowdays i still have not the development kit in orden to testing it, i need to know as I`m making the design.
I am going to have a task (task 1), which is going to executes periodically, so i´m going to use vTaskDelayUntil() but i want it to resume it from another task(task 2) if i have one interrupt.
I have to Suspend task 1 before Resuming it OR if I call vTaskResume from task 2 while the task 1 is Delayed (without calling vTaskSuspend) it will be enough and the task 1 will be ready to execute.


RE: Resume after Delay without Suspend possib

Posted by MEdwards on February 2, 2009
Once a task has called vTaskDelayUntil() there is no way of making the task execute again until after the delay period has expired (unless you write your own function to do this which would actually be very easy). A task can only be resumed by a call to vTaskResume() if it has been suspended by a call to vTaskSuspend().

I think the best thing for you would be to replace the call to vTaskDelayUntil() with a pend on a binary semaphore. The pend can have a timeout just like the call to vTaskDelayUntil(). If an interrupt executes and sends the semaphore the task will immediately unblock even if the block time has not expired.

I recommend you read http://www.freertos.org/Documentation for a full understanding.

RE: Resume after Delay without Suspend possib

Posted by Asier Gonzalez on February 2, 2009
OK, thanks. Your opinion has been very useful as i haven´t though about using a binary semaphore in order to synchronizing the interrupt with the task.
Anyway, if i want to Resume a task , which has been blocked for a period of time,from another task rather than from an interrupt, it can be suspended before and then resumed, isn´t it?


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