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Full Discussion: Nanosleep in signal call
Top Forums Programming Nanosleep in signal call Post 302963454 by jim mcnamara on Wednesday 30th of December 2015 06:33:56 PM
Old 12-30-2015
I believe rand() is not async safe as well - you cannot have interruptible calls in your signal handler. Well make that should not have. It uses global variables which is another problem. Plus you are doing a lot in your signal handler, so also consider blocking SIGUSR1 as the first step in your handler. Multiple signals can mess up your code otherwise - especially the rand() call. New applications should use the POSIX signal API (sigaction(2), sigprocmask(2), etc.) which is what you did and that is good.

Next:
Code:
signal_name = "SIGUSR1";

could SEGFAULT, but in any case it is undefined behavior: const *signal_name;

Last edited by jim mcnamara; 12-30-2015 at 07:39 PM..
 

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SIGSUSPEND(2)						     Linux Programmer's Manual						     SIGSUSPEND(2)

NAME
sigsuspend - wait for a signal SYNOPSIS
#include <signal.h> int sigsuspend(const sigset_t *mask); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): sigsuspend(): _POSIX_C_SOURCE >= 1 || _XOPEN_SOURCE || _POSIX_SOURCE DESCRIPTION
sigsuspend() temporarily replaces the signal mask of the calling process with the mask given by mask and then suspends the process until delivery of a signal whose action is to invoke a signal handler or to terminate a process. If the signal terminates the process, then sigsuspend() does not return. If the signal is caught, then sigsuspend() returns after the sig- nal handler returns, and the signal mask is restored to the state before the call to sigsuspend(). It is not possible to block SIGKILL or SIGSTOP; specifying these signals in mask, has no effect on the process's signal mask. RETURN VALUE
sigsuspend() always returns -1, normally with the error EINTR. ERRORS
EFAULT mask points to memory which is not a valid part of the process address space. EINTR The call was interrupted by a signal. CONFORMING TO
POSIX.1-2001. NOTES
Normally, sigsuspend() is used in conjunction with sigprocmask(2) in order to prevent delivery of a signal during the execution of a criti- cal code section. The caller first blocks the signals with sigprocmask(2). When the critical code has completed, the caller then waits for the signals by calling sigsuspend() with the signal mask that was returned by sigprocmask(2) (in the oldset argument). See sigsetops(3) for details on manipulating signal sets. SEE ALSO
kill(2), pause(2), sigaction(2), signal(2), sigprocmask(2), sigwaitinfo(2), sigsetops(3), sigwait(3), signal(7) COLOPHON
This page is part of release 3.44 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/. Linux 2008-08-29 SIGSUSPEND(2)
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