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Change-Id: If6187640e8b53d6334cecbfc6439490add871e84 Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/40440 Commit-Queue: Auto-Submit <auto-submit@pigweed.google.com.iam.gserviceaccount.com> Pigweed-Auto-Submit: Ewout van Bekkum <ewout@google.com> Reviewed-by: Keir Mierle <keir@google.com>
34 lines
1.1 KiB
ReStructuredText
34 lines
1.1 KiB
ReStructuredText
.. _module-pw_chrono_threadx:
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-----------------
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pw_chrono_threadx
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-----------------
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``pw_chrono_threadx`` is a collection of ``pw_chrono`` backends that are
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implemented using ThreadX.
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.. warning::
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This module is under construction, not ready for use, and the documentation
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is incomplete.
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SystemClock backend
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-------------------
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The ThreadX based ``system_clock`` backend implements the
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``pw_chrono:system_clock`` facade by using ``tx_time_get()``. An
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InterruptSpinLock is used to manage overflows in a thread and interrupt safe
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manner to produce a signed 64 bit timestamp.
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The ``SystemClock::now()`` must be used more than once per overflow of the
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native ThreadX ``tx_time_get()`` overflow. Note that this duration may vary if
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``tx_time_set()`` is used.
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.. warning::
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Note that this is not compatible with TX_NO_TIMER as this disables
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``tx_time_get()``.
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Build targets
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-------------
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The GN build for ``pw_chrono_threadx`` has one target: ``system_clock``.
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The ``system_clock`` target provides the
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``pw_chrono_backend/system_clock_config.h`` and ``pw_chrono_threadx/config.h``
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headers and the backend for the ``pw_chrono:system_clock``.
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