0f56263e62
Allows contextvars from the main thread to be accessed in the separate thread used in `asyncio.to_thread()`. See the [discussion](https://github.com/python/cpython/pull/20143#discussion_r427808225) in GH-20143 for context. Automerge-Triggered-By: @aeros
26 lines
786 B
Python
26 lines
786 B
Python
"""High-level support for working with threads in asyncio"""
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import functools
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import contextvars
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from . import events
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__all__ = "to_thread",
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async def to_thread(func, /, *args, **kwargs):
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"""Asynchronously run function *func* in a separate thread.
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Any *args and **kwargs supplied for this function are directly passed
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to *func*. Also, the current :class:`contextvars.Context` is propogated,
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allowing context variables from the main thread to be accessed in the
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separate thread.
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Return an asyncio.Future which represents the eventual result of *func*.
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"""
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loop = events.get_running_loop()
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ctx = contextvars.copy_context()
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func_call = functools.partial(ctx.run, func, *args, **kwargs)
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return await loop.run_in_executor(None, func_call)
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