kopia lustrzana https://github.com/espressif/esp-idf
69 wiersze
2.0 KiB
Python
69 wiersze
2.0 KiB
Python
# Copyright 2015-2021 Espressif Systems (Shanghai) CO LTD
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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import threading
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from typing import Optional
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class StoppableThread(object):
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"""
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Provide a Thread-like class which can be 'cancelled' via a subclass-provided
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cancellation method.
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Can be started and stopped multiple times.
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Isn't an instance of type Thread because Python Thread objects can only be run once
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"""
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def __init__(self):
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# type: () -> None
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self._thread = None # type: Optional[threading.Thread]
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@property
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def alive(self):
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# type: () -> bool
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"""
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Is 'alive' whenever the internal thread object exists
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"""
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return self._thread is not None
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def start(self):
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# type: () -> None
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if self._thread is None:
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self._thread = threading.Thread(target=self._run_outer)
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self._thread.start()
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def _cancel(self):
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# type: () -> None
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pass # override to provide cancellation functionality
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def run(self):
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# type: () -> None
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pass # override for the main thread behaviour
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def _run_outer(self):
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# type: () -> None
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try:
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self.run()
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finally:
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self._thread = None
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def stop(self):
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# type: () -> None
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if self._thread is not None:
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old_thread = self._thread
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self._thread = None
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self._cancel()
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old_thread.join()
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