12-10-2008
I've isolated the source of error a little bit more. It is because of using the third parameter of the signal handler for saving the context of the thread function. If I pass the parameter context to setcontext instead of saving it in thread_context and swapping back to scheduler_context the same error will occur.
If will post an explanation of this strange behaviour to the linux kernel mailing list. Maybe they have an answer for it. I'll post the reply then.
Last edited by XComp; 12-10-2008 at 03:26 PM..
Reason: improving language
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LEARN ABOUT LINUX
pthread_sigmask
PTHREAD_SIGMASK(3) Linux Programmer's Manual PTHREAD_SIGMASK(3)
NAME
pthread_sigmask - examine and change mask of blocked signals
SYNOPSIS
#include <signal.h>
int pthread_sigmask(int how, const sigset_t *set, sigset_t *oldset);
Compile and link with -pthread.
DESCRIPTION
The pthread_sigmask() function is just like sigprocmask(2), with the difference that its use in multithreaded programs is explicitly speci-
fied by POSIX.1-2001. Other differences are noted in this page.
For a description of the arguments and operation of this function, see sigprocmask(2).
RETURN VALUE
On success, pthread_sigmask() returns 0; on error, it returns an error number.
ERRORS
See sigprocmask(2).
CONFORMING TO
POSIX.1-2001.
NOTES
A new thread inherits a copy of its creator's signal mask.
EXAMPLE
The program below blocks some signals in the main thread, and then creates a dedicated thread to fetch those signals via sigwait(3). The
following shell session demonstrates its use:
$ ./a.out &
[1] 5423
$ kill -QUIT %1
Signal handling thread got signal 3
$ kill -USR1 %1
Signal handling thread got signal 10
$ kill -TERM %1
[1]+ Terminated ./a.out
Program source
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include <errno.h>
/* Simple error handling functions */
#define handle_error_en(en, msg)
do { errno = en; perror(msg); exit(EXIT_FAILURE); } while (0)
static void *
sig_thread(void *arg)
{
sigset_t *set = (sigset_t *) arg;
int s, sig;
for (;;) {
s = sigwait(set, &sig);
if (s != 0)
handle_error_en(s, "sigwait");
printf("Signal handling thread got signal %d
", sig);
}
}
int
main(int argc, char *argv[])
{
pthread_t thread;
sigset_t set;
int s;
/* Block SIGINT; other threads created by main() will inherit
a copy of the signal mask. */
sigemptyset(&set);
sigaddset(&set, SIGQUIT);
sigaddset(&set, SIGUSR1);
s = pthread_sigmask(SIG_BLOCK, &set, NULL);
if (s != 0)
handle_error_en(s, "pthread_sigmask");
s = pthread_create(&thread, NULL, &sig_thread, (void *) &set);
if (s != 0)
handle_error_en(s, "pthread_create");
/* Main thread carries on to create other threads and/or do
other work */
pause(); /* Dummy pause so we can test program */
}
SEE ALSO
sigaction(2), sigpending(2), sigprocmask(2) pthread_create(3), pthread_kill(3), sigsetops(3), pthreads(7), signal(7)
COLOPHON
This page is part of release 3.27 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 2009-01-25 PTHREAD_SIGMASK(3)