use strict;
use warnings;
use POSIX;

if (my $pid = fork) {
        sleep 1;
        alarm 10;
        kill (POSIX::SIGUSR2, $pid);
        $SIG{CHLD} = 'IGNORE';
        while( wait() != -1 ){ print STDERR "wait\n"};
} else {
        $SIG{USR2} = sub {
                print "CHILD $$ EXIT\n";
                exit(1);
        };
        sleep 1 while (1);
}

print STDERR "DONE\n";