kopia lustrzana https://github.com/micropython/micropython-lib
38 wiersze
1.6 KiB
ReStructuredText
38 wiersze
1.6 KiB
ReStructuredText
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uasyncio
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========
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uasyncio is MicroPython's asynchronous sheduling library, roughly
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modeled after CPython's asyncio.
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uasyncio doesn't use naive always-iterating scheduling algorithm,
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but performs a real time-based scheduling, which allows it (and
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thus the whole system) to sleep when there is nothing to do (actual
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implementation of that depends on I/O scheduling algorithm which
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actually performs the wait operation).
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Major conceptual differences to asyncio:
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* Avoids defining a notion of Future, and especially wrapping coroutines
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in Futures, like CPython asyncio does. uasyncio works directly with
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coroutines (and callbacks).
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* uasyncio uses wrap-around millisecond timebase (as native to all
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MicroPython ports.)
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* Instead of single large package, number of subpackages are provided
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(each installable separately).
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Specific differences:
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* For millisecond scheduling, ``loop.call_later_ms()`` and
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``uasyncio.sleep_ms()`` are provided.
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* As there's no monotonic time, ``loop.call_at()`` is not provided.
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Instead, there's ``loop.call_at_()`` which is considered an internal
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function and has slightly different signature.
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* ``call_*`` funcions don't return Handle and callbacks scheduled by
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them aren't cancellable. If they need to be cancellable, they should
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accept an object as an argument, and a "cancel" flag should be set
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in the object, for a callback to test.
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* ``Future`` object is not available.
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* ``ensure_future()`` and ``Task()`` perform just scheduling operations
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and return a native coroutine, not Future/Task objects.
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* Some other functions are not (yet) implemented.
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