When the buffer is full, Thread A gets pended (blocked).
If Thread B later calls the get function, it will unpend Thread A,
allowing it to resume and put the message into the queue.
In this situation, we need to know whether Thread A should
continue with put to front or put to end.
In order to resolve this issue, we don't allow set timeout
parameter for `k_msgq_put_front` and this parameter is always
`K_NO_WAIT`.
Signed-off-by: TaiJu Wu <tjwu1217@gmail.com>
this commit adds a sample code to illustrate the base usage
of message queues. a producer and a consumer thread work
together, exchanging messages in a FIFO (for normal payloads)
and LIFO (for higher priority payloads) schemes.
Signed-off-by: Alexander Paschoaletto <axelpinheiro@gmail.com>
