Add low-level coroutine suspension notifications#372
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Add low-level coroutine suspension notifications#372
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Don't we need to add an |
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@oldnewthing right, I'll add that. |
oldnewthing
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Oct 10, 2019
strings/base_coroutine_foundation.h
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| template <typename T> | ||
| struct notify_awaiter |
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Consider moving this out of impl so it can be used by user-defined promise types. (Like my simple_task<T>.)
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This is a pretty invasive hook so I'll give it some time to bake, make sure it's what we really want, and then make a helper available outside the impl namespace.
Scottj1s
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Oct 15, 2019
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The OS uses a form of activity tracking to log events that might complete asynchronously. When this is mixed with coroutines, the activity is tripped up because it does not realize that a suspension point may have switched the thread on which it is executing. This update provides a very low-level hook for use by WIL to notify the system that a coroutine is being suspended or resumed. As with the winrt_to_hresult_handler hook, this is intended for low-level interop with WIL and I don't recommend developers using this as a general purpose notification mechanism.
The "get_awaiter" implementation here is pretty convoluted, but fortunately C++23 will have more library support for coroutines including a "get_awaiter" like function that will be part of the standard library.