I'm newbie in UNIX programming, I have a problem with signals. I'm writing multithread program, where threads can die at any moment. When thread dies it generates signal SIGUSR1 to main thread and then thread dies. Main thread gets a signal and waits for thread dead.
I wrote program like this:
I've got a problem: some signals were not sended/received and I've got deadlock (main thread waits for signal, but signal never comes).
Program prints:
After it program locks.
Why some signals were not received? Program should send/recive 3 SIGUSR1 and exit, but there are only 2 SIGUSR1. Why?
Last edited by DendyGamer; 12-02-2011 at 04:56 AM..
I am trying to send a SIGUSR1 to a set of process. Please tell
me how to do. I've tried the system call raise(int sig) but it just
raise a signal of to the 'current process.'
My program is about a network chat server. When a client
connects in, The main process will fork a new process... (1 Reply)
hi
I have created a application which uses SIGUSR2. It send this signal to server and waits for signal SIGUSR2 from server after server performing some operation server sends SIGUSR2 back to the application. The application then quits.
This works fine which ran from terminal , but when I... (3 Replies)
I am using the signal function, and passing it a function named quit procedure...I get the following warning....
passing arg2 of signal from incompatible pointer type...
void quit_procedure(void); //this is the way i define my prototype...
signal(SIGINT, quit_procedure);
Please guide... (5 Replies)
#include<signal.h>
void suicide();
main()
{
printf("use CTRL \\ for exiting \n");
//signal(SIGINT,SIG_DFL);
signal(SIGQUIT,suicide);
for (;;);
}
void suicide()
{ printf("hello here you r in the suicide code ");
}
i was just starting with signals .. and tried this ,, but in the... (10 Replies)
Hi,
I have a daq program that runs in an infinite loop until it receives SIGINT. A handler catches the signal and sets a flag to stop the while loop. After the loop some things have to be cleaned up.
The problem is that I want my main while loop to wait until the next full second begins, to... (2 Replies)
i wrote handler for sigsegv such that i can allocate memory for a variable to which
sigsegv generated for illlegal acces of memory.
my code is
#include <signal.h>
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
char *j;
void segv_handler(int dummy)
{
j=(char *)malloc(10);
... (4 Replies)
hi friends i have a problem in signal handling ...
let me explain my problem clearly..
i have four process ..
main process forks two child process and each child process again forks another new process respectively...
the problem is whenever i kill the child process it is reforking and the... (2 Replies)
Hi all,
Sorry about the title,at first i decided to ask a problem about the signal mechanism,however,i'm now figured it out.Sorry to forget modify the title:wall:.I had a small problem that if i use the code which is commented,the code would get a segment fault,while the above code NOT.what's... (4 Replies)
hey,
i have been facing a very fatel error with dovecot..
i am getting this error in my dovecot.log file
dovecot: Feb 13 15:21:02 Fatal: chdir(/var/mail/folders/user1) failed with uid 1001: Permission denied
dovecot: Feb 13 15:21:02 Error: child 18732 (imap) returned error 89
dovecot: Feb... (3 Replies)
Discussion started by: htshshrm2
3 Replies
LEARN ABOUT SUSE
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 3.25 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)