Daemonize() issues on Debian
- by djTeller
Hi,
I'm currently writing a multi-process client and a multi-treaded server for some project i have.
The server is a Daemon.
In order to accomplish that, i'm using the following daemonize() code:
static void daemonize(void)
{
pid_t pid, sid;
/* already a daemon */
if ( getppid() == 1 ) return;
/* Fork off the parent process */
pid = fork();
if (pid < 0) {
exit(EXIT_FAILURE);
}
/* If we got a good PID, then we can exit the parent process. */
if (pid > 0) {
exit(EXIT_SUCCESS);
}
/* At this point we are executing as the child process */
/* Change the file mode mask */
umask(0);
/* Create a new SID for the child process */
sid = setsid();
if (sid < 0) {
exit(EXIT_FAILURE);
}
/* Change the current working directory. This prevents the current
directory from being locked; hence not being able to remove it. */
if ((chdir("/")) < 0) {
exit(EXIT_FAILURE);
}
/* Redirect standard files to /dev/null */
freopen( "/dev/null", "r", stdin);
freopen( "/dev/null", "w", stdout);
freopen( "/dev/null", "w", stderr);
}
int main( int argc, char *argv[] ) {
daemonize();
/* Now we are a daemon -- do the work for which we were paid */
return 0;
}
I have a strange side effect when testing the server on Debian (Ubuntu).
The accept() function always fail to accept connections, the pid returned is -1
I have no idea what causing this, since in RedHat & CentOS it works well.
When i remove the call to daemonize(), everything works well on Debian, when i add it back, same accept() error reproduce.
I've been monitring the /proc//fd, everything looks good.
Something in the daemonize() and the Debian release just doesn't seem to work.
(Debian GNU/Linux 5.0, Linux 2.6.26-2-286 #1 SMP)
Any idea what causing this?
Thank you
