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Title: GH-96704: Add task.get_context(), use it in call_exception_handler() by gvanrossum · Pull Request #96756 · python/cpython · GitHub

Open Graph Title: GH-96704: Add task.get_context(), use it in call_exception_handler() by gvanrossum · Pull Request #96756 · python/cpython

X Title: GH-96704: Add task.get_context(), use it in call_exception_handler() by gvanrossum · Pull Request #96756 · python/cpython

Description: The point here is for call_exception_handler() to make an effort to run the exception handler in the correct task context (contextvars.Context), if it is called on behalf of a task. The easiest way seems to be to retrieve the task context from the task passed into the context dict that's being passed to call_exception_handler(). This doesn't always exist, and because Task inherits from Future, it may be stored under either a "task" key or a "future" key. So try both. We then need to retrieve the contextvars.Context from the task, for which I have added a get_context() method to the Task class (analogous to get_name()). It is possible that the task doesn't have this method (e.g. if the loop is using a 3rd party task implementation that doesn't yet support this new method). Only if get_context() exists and returns something that has a run() method do we run the exception handler using that contextvars.Context.run() method. Otherwise we use the default contextvars.Context. We only do this for an exception handler set by the user; the default exception handler should not be interested in the context. (This is because I'm lazy, there are two calls to it and I don't want to bother giving those the same treatment -- we can reconsider if you think the logger might also be interested in the contextvars.Context.) PS. It's unfortunate that call_exception_handler() has a parameter named context that is a dict, not a contextvars.Context. But nothing we can do it now (this API probably predates contextvars). Issue: gh-96704

Open Graph Description: The point here is for call_exception_handler() to make an effort to run the exception handler in the correct task context (contextvars.Context), if it is called on behalf of a task. The easiest way...

X Description: The point here is for call_exception_handler() to make an effort to run the exception handler in the correct task context (contextvars.Context), if it is called on behalf of a task. The easiest way...

Opengraph URL: https://github.com/python/cpython/pull/96756

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