comment on

Is there an reasonable way to see what data aren't being garbage collected?

What I do is place Data::Dumper statements at critical points in the program, and watch for the variables growing....like extra hash keys.

If I really need to rethink my wanton creation and destruction of widgets, can anyone suggest some strategies for keeping a pool of widgets around and configuring them as needed?

I think you answered your own question. Hlist entries can be reconfigured, so don't delete and create new ones.

You usually do this, by separating your actual data storage, from the displaying of the data. In other words, don't use the widget to store your data, use the widget to display data stored in another hash. That way the widgets are just a "window to the screen" to display what is in some underlying data hash. They remain the same, just being reconfigured to display the new data.

Here are a few examples.

#!/usr/bin/perl
use strict;
use Tk;
use Tk::HList;

my $mw    = MainWindow->new();
my $label = $mw->Label( -width => 15 );

my $hlist = $mw->Scrolled('HList',
    -itemtype   => 'text',
    -selectmode => 'single',
)->pack;

foreach (1..1000) {
     my $text = $_.time;
     $hlist->add( $_, -text => $text );
}

my $button = $mw->Button(-text => 'Leak Test',
                         -command => \&testleak)->pack;


MainLoop;

sub testleak{
   #foreach (1..1000) { 
#        # $hlist->delete('all');  
#         $hlist->delete('entry',$_);  

 #  }  

   foreach (1..1000) {
      my $text = $_.time;
#      $hlist->add( $_, -text => $text );  
     $hlist->entryconfigure( $_, -text => $text );

   }

}
[download]

#!/usr/bin/perl
use strict;
use Tk;
use Tk::HList;

my $mw = MainWindow->new();

#create some sample data 
my %data;

foreach (0..100) {
      $data{$_}{'name'} = 'name'.$_;
      $data{$_}{'id'} =   rand(time);
      $data{$_}{'priority'} =  int rand 50;
}
#get random list of keys 
my @keys = keys %data;

################# 

my $h = $mw->Scrolled( 'HList',
                       -header => 1,
                       -columns => 3,
                       -width => 40,
                       -height => 40,
                       -takefocus => 1,
                       -background => 'steelblue',
                       -foreground =>'snow',
                       -selectmode => 'single',
                       -selectforeground => 'pink',
                       -selectbackground => 'black',
                #       -browsecmd => \&browseThis, 
                   )->pack(-side => "left", -anchor => "n");

$h->header('create', 0, -text => '   Name  ',
                        -borderwidth => 3,
                        -headerbackground => 'steelblue',
                        -relief => 'raised');

$h->header('create', 1, -text => '      ID      ',
                        -borderwidth => 3,
                        -headerbackground => 'lightsteelblue',
                        -relief => 'raised');

$h->header('create', 2, -text => '  Priority  ',
                        -borderwidth => 3,
                        -headerbackground => 'lightgreen',
                        -relief => 'raised');

foreach (@keys) {
     my $e = $h->addchild(""); #will add at end 

     $h->itemCreate ($e, 0,
           -itemtype => 'text',
           -text => $data{$_}{'name'},
            );

     $h->itemCreate($e, 1,
           -itemtype => 'text',
           -text => $data{$_}{'id'},
         );

     $h->itemCreate($e, 2,
           -itemtype => 'text',
           -text => $data{$_}{'priority'},
         );

}

my $button = $mw->Button(-text => 'exit',
                         -command => sub{exit})->pack;

my $sortid = $mw->Button(-text => 'Sort by Id',
                         -command => [\&sort_me,1] )->pack;

my $sortpriority = $mw->Button(-text => 'Sort by Priority',
                         -command => [\&sort_me,2] )->pack;


MainLoop;
######################################################### 

sub sort_me{
  my $col = shift;

  my @entries = $h->info('children');
  my @to_be_sorted =();

 foreach my $entry(@entries){
           push @to_be_sorted,
           [ $h->itemCget($entry,0,'text'),
             $h->itemCget($entry,1,'text'),
             $h->itemCget($entry,2,'text'),
           ];
           }

  my @sorted = sort{ $a->[$col] cmp $b->[$col]  || #primary sort ascii
+ 
                     $a->[1] <=> $b->[1]           #secondary sort num
+eric 
                       } @to_be_sorted;

my $entry = 0;
  foreach my $aref (@sorted){
#    print $aref->[0],' ',$aref->[1],' ',$aref->[1],"\n"; 
    $h->itemConfigure( $entry, 0, 'text' => $aref->[0] );
    $h->itemConfigure( $entry, 1, 'text' => $aref->[1] );
    $h->itemConfigure( $entry, 2, 'text' => $aref->[2] );
    $entry++;
  }

$mw->update;
}
[download]

I'm not really a human, but I play one on earth. flash japh

In reply to Re: Tk, HLists and memory leakage by zentara
in thread Tk, HLists and memory leakage by TGI

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