I have a daemonized server (Linux/Perl 5.8.8) and I would like to perform a task every few minutes. Using a SIGALRM handler seems to not work because it causes accept() to return. So I'm trying to fork off a daemon process that just sleeps and sends SIGUSR1 to my process. However, my server dies the first time the signal handler is run. Here's a simple reduced case with the same behavior:

The server: 
#!/usr/bin/perl
use IO::Socket;

#defined(my $pid=fork) or die "Can't fork: $!";
#exit if $pid;
#setsid or die "Can't start a new session: $!";

my $sock = new IO::Socket::INET (
                "Proto" => "tcp",
                "LocalPort" => 8819,
                "Reuse" => 1,
                "Listen" => 1
                        ) or die "Server croaked";

$SIG{'USR1'} = \&sigHandler;
system("./sleep.pl $$");

while($client = $sock->accept())
{
}

sub sigHandler
{
        print "SIGNAL HANDLER\n";
}

[download]
The forked process (sleep.pl): 
#!/usr/bin/perl

$ppid = $ARGV[0];
print "$ppid";

defined(my $pid=fork) or die "Can't fork: $!";
exit if $pid;
setsid or die "Can't start a new session: $!";

while(1)
{
   sleep(10);
   print "DISPATCHING SIGNAL\n";
   kill(SIGUSR1, $ppid);
}

[download]
If you know why my server is dying or you know A Much Better way to accomplish the same objective, I'd be very appreciative.

In reply to Catching a signal causes my socket server to die by jimmy5804

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