kopia lustrzana https://github.com/peterhinch/micropython-samples
38 wiersze
974 B
Python
38 wiersze
974 B
Python
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try:
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import uasyncio as asyncio
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except ImportError:
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import asyncio
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# A Semaphore is typically used to limit the number of coros running a
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# particular piece of code at once. The number is defined in the constructor.
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class Semaphore():
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def __init__(self, value=1):
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self._count = value
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async def __aenter__(self):
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await self.acquire()
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return self
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async def __aexit__(self, *args):
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self.release()
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await asyncio.sleep(0)
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async def acquire(self):
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while self._count == 0:
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await asyncio.sleep_ms(0)
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self._count -= 1
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def release(self):
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self._count += 1
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class BoundedSemaphore(Semaphore):
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def __init__(self, value=1):
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super().__init__(value)
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self._initial_value = value
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def release(self):
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if self._count < self._initial_value:
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self._count += 1
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else:
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raise ValueError('Semaphore released more than acquired')
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