Re: Strange Linux behaviour with blocking syscalls and stop signals+SIGCONT

From: Manfred Spraul
Date: Thu Jul 06 2006 - 15:01:51 EST


Ulrich Drepper wrote:

Manfred Spraul wrote:


1) I would go further and try ERESTARTSYS: ERESTARTSYS means that the
kernel signal handler honors SA_RESTART
2) At least for the futex functions, it won't be as easy as replacing
EINTR wiht ERESTARTSYS: the futex functions receive a timeout a the
parameter, with the duration of the wait call as a parameter. You must
use ERESTART_RESTARTBLOCK.



Whoa, not so fast. At least the futex syscall but be interruptible by
signals. It is crucial to return EINTR.



Yes, of course.
ERESTARTSYS means honor SA_RESTART.
EINTR means return from the syscall, even if SA_RESTART is set in the signal handler.

Is it necessary that the futex syscall ignores SA_RESTART?

--
Manfred


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