if($pid > 0) { #we forked successfully
	$npids++;
	if($npids>=$MAX_PROCESSES) {
		my $wait=wait();
		if($wait) { $npids--; }
	} elsif(undef $pid) { # we didn't fork successfully
		print "fork error!\n";
	}
} else { # $pid == 0, we're a kid, so what do we want to do?
	&doit($_);
	exit(0); # free this pid
}