#!/usr/bin/perl

use warnings FATAL => qw( all );
use strict;

$|=1;

print "setting main handler\n";
$SIG{ALRM} = sub { print "SIGARLM: main handler\n" };
print "set main handler\n";

sub f {
        print "sub f start\n";
        local $SIG{ALRM} = sub { print "SIGALRM: sub handler\n" }; # line 9
        print "sub f end\n";
}



if (fork) {
        # parent
        f while 1;
} else {
        # child
        sleep 7;
        print "child starting\n";
        sleep 5 while kill ALRM => getppid;
}