if ( my $thread = threads->new( \&do_worker ) ) {
        my $t = $thread->tid;
        lock %{ $stat{'work'} };
        $stat{'work'}{ $t } = &share( {} );
        $stat{'work'}{ $t }{'stat'} = 'idle';

##</code><code>##

    sub do_worker {
        my $t = threads->self()->tid();
#        sleep(1);
        my $c;
LOOP:    while ( !$stat{'work'}{$t}{'stat'} ne 'done' ) {

##</code><code>##

    sub do_worker {
        my $t = threads->self()->tid();
        {
            lock %{ $stat{'work'} };
            $stat{'work'}{ $t } = &share( {} );
            $stat{'work'}{ $t }{'stat'} = 'idle';
        }
        my $c;
LOOP:    while ( do{ lock %{ $stat{'work'}{$t} }; $stat{'work'}{$t}{'stat'} } ne 'done' ) {
...
    if ( my $thread = threads->new( \&do_worker ) ) {
        my $t = $thread->tid;
        trc 'dbg',  'new worker created';
        $thread->detach;
...

##</code><code>##

LOOP:    while ( $stat{'work'}{$t}{'stat'} ne 'done' ) {
            {
                lock %{ $stat{'lock'} };
                $c = $listener->accept() or next LOOP;
            }

##</code><code>##

timeout => 10,</code>. 

<P>If you remove the <c>sleep 1;
##</code><code>##

            lock %{ $stat{'work'} };
...
            $stat{'work'}{$t}{'stat'} = $s;
            $stat{'work'}{$t}{'time'} = time();
            $stat{'work'}{$t}{'work'}++ if $s eq 'idle';

##</code><code>##

            lock %{ $stat{'work'}{$t} };
...
            $stat{'work'}{$t}{'stat'} = $s;
            $stat{'work'}{$t}{'time'} = time();
            $stat{'work'}{$t}{'work'}++ if $s eq 'idle';