_PyOS_SigintEvent() is needed for interruptible waiting on main thread

Bug report

Bug description:

Moved from https://github.com/python/cpython/pull/108605#issuecomment-2521215855

In https://github.com/python/cpython/pull/108605, _PyOS_SigintEvent was removed from the public headers.

TensorStore relies on that function here: https://github.com/google/tensorstore/blob/eda046b10158e7d82fdb0f23aeecdfdeb8ac5aa3/python/tensorstore/future.cc#L105 to enable synchronously blocking on the readiness of a custom Future type while allowing Ctrl+C to interrupt when running on the main thread.

The current workaround is to manually declare the function since the symbol is still available.

I'm not aware of a usable alternative. Since signal.set_wakeup_fd only allows a single fd to be set globally, it isn't usable from a library. The best alternative would probably be to poll by waking up every few hundred milliseconds.

CPython versions tested on:

3.13

Operating systems tested on:

No response

Comece revisando CPython PR #108605 e o uso de _PyOS_SigintEvent em python/tensorstore/future.cc do TensorStore, na linha 105. Rastreie como a remoção da declaração do cabeçalho público afeta as bibliotecas de extensão e compare as alternativas disponíveis de despertar por sinal. Considera-se concluído quando for fornecida uma forma compatível para que uma biblioteca interrompa a espera síncrona na thread principal, preservando o comportamento de Ctrl+C.