Hello fellow monks,
I am writing a program built around a loop on a
IO::Select object. So far so good. Now I need to throw in a task that must be regularly executed. So I thought setting it as a
SIGALRM handler. Sounds simple:
use strict;
use warnings;
use IO::Select;
use IO::Socket;
use POSIX qw< :signal_h >;
my $port = 6681;
my $listen = IO::Socket::INET->new(
Proto => "tcp",
LocalPort => $port,
Listen => 10,
Timeout => 10,
) or die "Can't bind socket to port $port: $!";
my $select = IO::Select->new($listen);
print STDERR "listing on port $port\n";
my $alarm_handler = sub {
print STDERR "! alarm handler\n";
alarm(2);
};
my $sigset = POSIX::SigSet->new(SIGALRM);
my $sa_alarm = POSIX::SigAction->new($alarm_handler, $sigset, SA_RESTA
+RT);
sigaction(SIGALRM, $sa_alarm);
#$SIG{ALRM} = $alarm_handler;
alarm(2);
while (my @ready = $select->can_read) {
for my $fh (@ready) {
if ($fh == $listen) {
my $sock = $listen->accept;
$select->add($sock);
}
else {
# ...
}
}
}
Execpt that when running this program, it outputs:
$ perl sigalarm.pl
listing on port 6681
! alarm handler
and exits after the first
SIGALRM. What is the obvious thing I'm missing to make the
while restart (apart from nesting it in a
while(1) { .. } loop)?