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perlcrontimeoutalarm

Perl alarm() or Time::Out Without Kernel SIG

I have a script which occasionally misbehaves while communicating with a web server. The server hangs or is very slow to respond with data.

I am currently using alarm() as a hack to get the script to terminate—so as to not flood the system with threads—but this causes a cron error, which alerts the sysadmin, who really doesn't want the 200 emails this produces when the system has fallen over.

Is there an alternative method of terminating a script (or apiQuery, if need be) that won't cause a non-OK exit and the corresponding email?

Solution

  • You can throw an exception in your signal handler, and catch it elsewhere.

    my $success = eval {
    local $SIG{ALRM} = sub { die "Failure" };
    alarm 10;
    do_something_long();
    alarm 0;
    1;
};
if (!$success) {
    warn "Timeout!\n" if $verbose;
    exit 0;
}