34efba28b1
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>
53 lines
1.4 KiB
ReStructuredText
53 lines
1.4 KiB
ReStructuredText
.. zephyr:code-sample:: msg_queue
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:name: Message Queue
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Implements a basic message queue producer/consumer thread pair.
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Overview
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********
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A sample demonstrating the basic usage of Zephyr message queues.
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A producer thread sends both normal and urgent messages to be retrieved
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by a consumer thread.
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Building and Running
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********************
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This application can be built and executed on QEMU as follows:
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.. zephyr-app-commands::
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:zephyr-app: samples/kernel/msg_queue
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:host-os: unix
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:board: qemu_x86
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:goals: run
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:compact:
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To build for another board target, replace "qemu_x86" above with it.
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Sample Output
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=============
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Every normal message is put at the end of the queue, and they are delivered
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in FIFO order. Every "urgent" message is put at the beginning of the queue,
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and it is delivered first as long as no other "urgent" message comes in after
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it.
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In this sample, one producer thread sends 1 urgent message for each 2 normal
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ones. Note that message C is the first retrieved because it was the last one
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sent as "urgent".
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.. code-block:: console
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[producer] sending: 0
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[producer] sending: 1
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[producer] sending: A (urgent)
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[producer] sending: 2
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[producer] sending: 3
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[producer] sending: B (urgent)
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[producer] sending: 4
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[producer] sending: 5
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[producer] sending: C (urgent)
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[consumer] got sequence: CBA012345
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Exit QEMU by pressing :kbd:`CTRL+A` :kbd:`x`.
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