sub worker {
    ....
}

...

my @workers = map threads->new( \&worker, ... ), 1 .. $WORKERS;

##</code><code>##

sub worker {
    ....
}

sub proxy {
    my( $code, @args ) = @_;
    eval{ $code->( @args )   } or print $@;
}

...

my @workers = map threads->new( \&proxy, \&worker, ... ), 1 .. $WORKERS;