Author vstinner
Recipients gvanrossum, loewis, neologix, pitrou, python-dev, vstinner, yselivanov
Date 2014-07-22.23:43:26
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Message-id <1406072607.24.0.679789058549.issue22018@psf.upfronthosting.co.za>
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I talked with Charles-Fran├žois. He doesn't like the idea of a new function because it would be harder to write portable code: which function should be used? signal.set_wakeup_fd() already works with sockets on UNIX.

Here is a new patch version 4 which tries to combine previous patchs:

- don't touch anything to existing code on UNIX. Keep the sig_atomic_t type for wakeup_fd and continue to use write() on sockets.

- on Windows, use a new "wakeup" structure to store the file descriptor or socket handle (use the  SOCKET_T type) and the last send() errors (errno and GetLastError())

- on Windows, use getsockopt(fd, SOL_SOCKET, SO_ERROR, ...) to check if fd is a socket: the function fails with WSAENOTSOCK if fd is not a socket.

- on Windows, PySignal_SetWakeupFd() only supports file descriptors. The function returns -1 if signal.set_wakeup_fd() was called with a socket handler, because the return type (int) is too small to store a socket handle (need type SOCKET_T) and we cannot change the prototype of this public API.

Reminder: the purpose of the whole patch is to be able to wakeup an event loop based on select.select() on Windows. select() only supports sockets on Windows.

Notes:

- we still need to add a dependency to the WinSock library

- the test are still skipped on Windows, I will work on a new patch to make the file descriptor or socket non-blocking and to run more wakeup fd tests on Windows

- if send() fails twice, the error is only reported once until report_wakeup_send_error() is called to consume the error. Anything, if send() failed, it will probably fail again quickly, there is no need to flood the terminal with these errors.
History
Date User Action Args
2014-07-22 23:43:27vstinnersetrecipients: + vstinner, gvanrossum, loewis, pitrou, neologix, python-dev, yselivanov
2014-07-22 23:43:27vstinnersetmessageid: <1406072607.24.0.679789058549.issue22018@psf.upfronthosting.co.za>
2014-07-22 23:43:27vstinnerlinkissue22018 messages
2014-07-22 23:43:26vstinnercreate