[Python-Dev] Removing PID check from signal handler (original) (raw)

Ivan Pozdeev vano at mail.mipt.ru
Fri Apr 12 14:15:59 EDT 2019

On 12.04.2019 21:05, Steve Dower wrote:

On 12Apr.2019 0919, Jeroen Demeyer wrote:

The signal handler (that receives signals from the OS) in Python starts with a check

if (getpid() == mainpid) Looking at the comments, the intent was to do a check for the main thread but this is checking the process id. So this condition is basically always true. Therefore, I suggest to remove it in https://bugs.python.org/issue36601 If you have any objections or comments, I suggest to post them to that bpo. To add a little more context, the check was added about 25 years ago as a "hack" for some reason that we can't figure out anymore. So if you are a historian of ancient operating systems and know of one that might have raised signal handlers in a different process from the one where it was registered, we'd love to hear from you.

According to https://www.linuxquestions.org/questions/programming-9/the-return-value-of-getpid-called-from-main-thread-and-new-thread-r-identical-624399/ , threads used to have different PIDs in the 2.4 Linux kernel.

Cheers, Steve

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-- Regards, Ivan

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