1.. _module-pw_chrono_stl: 2 3------------- 4pw_chrono_stl 5------------- 6.. pigweed-module:: 7 :name: pw_chrono_stl 8 9``pw_chrono_stl`` is a collection of ``pw_chrono`` backends that are implemented 10using STL's ``std::chrono`` library. 11 12SystemClock backend 13------------------- 14The STL based ``pw_chrono_stl:system_clock`` backend target implements the 15``pw_chrono:system_clock`` facade by using the ``std::chrono::steady_clock``. 16Note that the ``std::chrono::system_clock`` cannot be used as this is not always 17a monotonic clock source. 18 19See the documentation for ``pw_chrono`` for further details. 20 21SystemTimer backend 22------------------- 23The STL based ``pw_chrono_stl:system_timer`` backend target implements the 24``pw_chrono:system_timer`` facade by spawning a detached thread for every single 25``InvokeAt()`` and ``InvokeAfter()`` call. This thread simply sleeps until the 26desired ``expiration_deadline`` and invokes the user's ``ExpiryCallback`` if it 27wasn't cancelled. 28 29.. Warning:: 30 Although fully functional, the current implementation is NOT efficient! 31 32See the documentation for ``pw_chrono`` for further details. 33 34Build targets 35------------- 36The GN build for ``pw_chrono_stl`` has one target: ``system_clock``. 37The ``system_clock`` target provides the 38``pw_chrono_backend/system_clock_config.h`` and 39``pw_chrono_backend/system_clock_inline.h`` headers and the backend for the 40``pw_chrono:system_clock``. 41