do we need mutexes while using queues?

[ritu_2178811]

Hello,

Queues are meant to send data between threads so I guess there is already a synchronization mechanisim inside but since I didn't see it in the documentation. I wanted to ask.

do queues in wiced sdk have internal synchronization mechanism? or should we use a mutex

thanks

[Anonymous · Accepted solution]

I found a queston about ThreadX at here : multithreading - access a threadx-queue concurrently - Stack Overflow

This maybe a fundemental for embedded programming, but I thing it should written at docs (not shown at 5.0.1 doc).

Another question, how can I find which backend I am using (ThreadX, RTOS, etc) ?

[AxLi_1746341]

riforifo wrote:

Hello,

Queues are meant to send data between threads so I guess there is already a synchronization mechanisim inside but since I didn't see it in the documentation. I wanted to ask.

do queues in wiced sdk have internal synchronization mechanism? or should we use a mutex

thanks

Both ThreadX and FreeRTOS provide thread safe APIs to access the queue.

However, the WICED API level is racy for ThreadX build because it directly

dereferences the data structure in the RTOS.

e.g. wiced_rtos_get_queue_occupancy/wiced_rtos_is_queue_empty/wiced_rtos_is_queue_full

Add locking does not help, because the RTOS does not hold the lock adding by WICED API layer while accessing the data structure.

It's simply buggy.