6f5c26d71e
Add readme for the sample for conditional variables in kernel. Signed-off-by: Aastha Grover <aastha.grover@intel.com>
66 lines
2.5 KiB
ReStructuredText
66 lines
2.5 KiB
ReStructuredText
.. _samples_kernel_condvar:
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Condition Variables
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###################
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Overview
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********
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This sample demonstrates the usage of condition variables in a
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multithreaded application. Condition variables are used with a mutex
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to signal changing states (conditions) from one thread to another
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thread. A thread uses a condition variable to wait for a condition to
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become true. Different threads alternate between their entry point
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function execution based on when they signal the other thread that is
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pending on the condition variable. The sample can be used with any
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:ref:`supported board <boards>` and prints the sample output shown to
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the console.
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Building and Running
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********************
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This application can be built and executed on Native Posix as follows:
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.. zephyr-app-commands::
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:zephyr-app: samples/kernel/condition_variables/condvar
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:host-os: unix
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:board: native_posix
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:goals: run
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:compact:
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To build for another board, change "native_posix" above to that board's name.
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Sample Output
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=============
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.. code-block:: console
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Starting watch_count: thread 1
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watch_count: thread 1 Count= 0. Going into wait...
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inc_count: thread 2, count = 1, unlocking mutex
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inc_count: thread 3, count = 2, unlocking mutex
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inc_count: thread 2, count = 3, unlocking mutex
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inc_count: thread 3, count = 4, unlocking mutex
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inc_count: thread 2, count = 5, unlocking mutex
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inc_count: thread 3, count = 6, unlocking mutex
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inc_count: thread 2, count = 7, unlocking mutex
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inc_count: thread 3, count = 8, unlocking mutex
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inc_count: thread 2, count = 9, unlocking mutex
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inc_count: thread 3, count = 10, unlocking mutex
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inc_count: thread 2, count = 11, unlocking mutex
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inc_count: thread 3, count = 12 Threshold reached.Just sent signal.
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inc_count: thread 3, count = 12, unlocking mutex
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watch_count: thread 1 Condition signal received. Count= 12
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watch_count: thread 1 Updating the value of count...
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watch_count: thread 1 count now = 137.
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watch_count: thread 1 Unlocking mutex.
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inc_count: thread 2, count = 138, unlocking mutex
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inc_count: thread 3, count = 139, unlocking mutex
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inc_count: thread 2, count = 140, unlocking mutex
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inc_count: thread 3, count = 141, unlocking mutex
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inc_count: thread 2, count = 142, unlocking mutex
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inc_count: thread 3, count = 143, unlocking mutex
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inc_count: thread 2, count = 144, unlocking mutex
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inc_count: thread 3, count = 145, unlocking mutex
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Main(): Waited and joined with 3 threads. Final value of count = 145. Done.
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