[Interest] Connecting signal handler to Qt application - async-handler-safety

[Giuseppe D'Angelo]

Il 15/06/20 18:12, Thiago Macieira ha scritto:
> No, you can't, because you need to block the signal using pthread_sigmask in
> all threads, otherwise the kernel may prefer delivering the signal instead of
> using the signalfd. Qt has a few background threads (like the QHostInfo thread
> pool) that you don't have access to.
> 
> signalfd is a misfeature. Don't use it.

It's very unfortunate that signalfd wants to read a pending signal, 
rather than being a "special" signal handler that overrides the 
dispositions. You may get away with installing it before spawning any 
other thread. But then again, threads+signals+libraries don't exactly 
mix well together...

-- 
Giuseppe D'Angelo | giuseppe.dangelo at kdab.com | Senior Software Engineer
KDAB (France) S.A.S., a KDAB Group company
Tel. France +33 (0)4 90 84 08 53, http://www.kdab.com
KDAB - The Qt, C++ and OpenGL Experts

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