I'm not sure I understand your code, but why not just arrange for $taxis->taxis to immediately return if another instance is already running? 

my $RUNNING = 0;
$mw->repeat( 50 => sub { $taxis->taxis(\$RUNNING) unless $RUNNING} ];
MainLoop;

package taxis;
sub taxis
{
   my ($self, $r_running, @whatever, ) = @_;
   $mw->update;   
   $$r_running = 1;
   # do other stuff that takes a while
   $$r_running = 0;
   return;
}

[download]
Of course, this must be modified if $taxis->taxis is recursive. 
sub taxis
{
   my ($self, $r_running, @whatever, ) = @_;
   $mw->update;   
   $$r_running = 1;
   # other stuff
   my $null = 0;
   $self->taxis(\$null, $whatever); 
   $$r_running = 0;
   return;
}

[download]
....I think.....

--Bob Niederman, http://bob-n.com

All code given here is UNTESTED unless otherwise stated.

In reply to Re: Deep recursion in Tk repeat by bobn
in thread Deep recursion in Tk repeat by polypompholyx

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