Cannot xQueueSend then crQUEUE_RECEIVE

korggy wrote on Saturday, September 08, 2007:

I just posted a bug that I couldn’t add to a queue in a Task using xQueueSend and then retrieve from the queue in a coroutine using crQUEUE_RECEIVE. The reply to the bug was “This is not a bug.  Unfortunately, tasks and co-routines cannot share a
queue or semaphore.” If this is the case, I think the documentation should be modified to reflect this restriction, perhaps referring to “Task Queue” and “Coroutine Queue”. Currently the documentation doesn’t differentiate between Queue types.

rtel wrote on Saturday, September 08, 2007:

I have to agree that the documentation was not as clear on this matter as it could be.  I have added:

"Note that co-routines can only send data to other co-routines. A co-routine cannot use a queue to send data to a task or visa versa"

to the crSEND and crRECEIVE pages, and:

" Note that an application can be designed using just tasks, just co-routines, or a mixture of both - however tasks and co-routines use different API functions and therefore a queue (or semaphore) cannot be used to pass data from a task to a co-routine or visa versa."

to the page describing the differences between tasks and co-routines.


korggy wrote on Saturday, September 08, 2007:

Thank you, that clarifies the issue and will be helpful to others.

sashiono wrote on Wednesday, September 12, 2007:

I feel that it greatly reduces the functionality of co-routines that you cannot passed data between queues from a co-routine to a task. What causes it limitation and it there a way to connect the queues between the two?