bpo-43356: Allow passing a signal number to interrupt_main() #24755
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Doc/library/_thread.rst
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| Simulate the effect of a :data:`signal.SIGINT` signal arriving in the main | ||
| thread. A thread can use this function to interrupt the main thread. | ||
| Simulate the effect of a signal arriving in the main thread. | ||
| A thread can use this function to interrupt the main thread. |
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Suggestion: Maybe we should add here a small sentence indicating that the signal will be processed by the main thread in the eval loop or when it calls PyErr_CheckSignals(). There may be users that get confused if the main thread is locked on some foreign mutex or running in some C code that does not check for signals.
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I tweaked the wording slightly. I'm not sure it's good idea to go into a full-length explanation of what happens under the hood, though (especially as it's a CPython implementation detail).
Misc/NEWS.d/next/Library/2021-03-04-21-51-20.bpo-43356.X7IGBM.rst
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Also introduce a new C API ``PyErr_SetInterruptEx(int signum)``.
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@pablogsal @eryksun Do you want to take another look? |
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👍 Thank you, and thanks also for the related work on bpo-43406. |
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Looks fantastic, thanks for all the improvements :) |
| @@ -224,6 +224,9 @@ PyAPI_FUNC(void) PyErr_WriteUnraisable(PyObject *); | |||
| /* In signalmodule.c */ | |||
| PyAPI_FUNC(int) PyErr_CheckSignals(void); | |||
| PyAPI_FUNC(void) PyErr_SetInterrupt(void); | |||
| #if !defined(Py_LIMITED_API) || Py_LIMITED_API+0 >= 0x030A0000 | |||
| PyAPI_FUNC(int) PyErr_SetInterruptEx(int signum); | |||
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I would prefer to exclude it from the limited C API: define it in Include/cpython/pyerrors.h.
About the name, I dislike "Ex" suffix. What about "PyErr_RaiseSignal(signum)"?
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I'd rather keep the name similar, since those functions are closely related. Also, PyErr_RaiseSignal sends the wrong message (since the signal is not raised).
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Hmm, as for excluding it from the limited C API, it doesn't seem to make sense: PyErr_SetInterrupt is in it. And I don't think it places a burden.
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If you want to add a function to the stable ABI, you must run "make regen-limited-abi" and add it to PC/python3dll.c.
And I don't think it places a burden.
Other Python implementations must implement it, it's a maintenance burden for them. _thread.interrupt_main(signum) can be called in C.
If you don't need the function, I would even suggest to remove it (make it internal/private).
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You can't call _thread.interrupt_main from a signal handler.
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Other Python implementations must implement it, it's a maintenance burden for them
It's almost zero-cost if PyErr_SetInterrupt is already implemented. PyErr_SetInterrupt is the potentially bothersome part, and it's already there.
Misc/NEWS.d/next/Library/2021-03-04-21-51-20.bpo-43356.X7IGBM.rst
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bpo-43356: Allow passing a signal number to interrupt_main() (pythonGH-24755)
Also introduce a new C API
PyErr_SetInterruptEx(int signum), and expand the C API docs a bit.https://bugs.python.org/issue43356