Re^2: Using Tk::ProgressBar

[Courage]

using threads for GUI for Tk is very wrong. Achieve nothing, and will render program unstable.
Yet, threads in perl are unusable.

[zentara]

Threads and Tk,are NOT wrong, but they have to be done with alot of care. You cannot mix Tk code across threads, and all threads must be created before any Tk code is invoked in the main thread. See Tk-with-worker-threads or this simple example:

#!/usr/bin/perl
use strict;
use threads qw[ async ];
use threads::shared;

our $WORKMAX ||= 1_000;

#by BrowserUk 

## A shared var to communicate progess between work thread and TK 
my $progress : shared = 0;

sub work {
    for my $item ( 0 .. $WORKMAX ) {
        { lock $progress; $progress = ( $item / $WORKMAX ) * 100; }
        select undef, undef, undef, 0.001;    ## do stuff that takes t
+ime 
    }
}

threads->new( \&work )->detach;

## For lowest memory consumption require (not use) 
## Tk::* after you've started the work thread. 
require Tk::ProgressBar;

my $mw = MainWindow->new;
my $pb = $mw->ProgressBar()->pack();

my $repeat;
$repeat = $mw->repeat(
    100 => sub {
        print $progress;
        $repeat->cancel if $progress == 100;
        $pb->value($progress);
    }
);

$mw->MainLoop;