Re^3: Wx subs and threads

That makes sense but I'm a little confused as how I can start/stop my thread if it's created prior to my GUI. I've attached my (hack at this) below. Thanks for any help!

use threads;
use threads::shared;
use Wx;
use Thread::Queue;
use strict;


# Maximum working threads
my $MAX_THREADS = 1;

# Flag to inform all threads that application is terminating
my $TERM :shared = 0;

# Prevents double detach attempts
my $DETACHING :shared;


package MyApp;

use base 'Wx::App';

sub OnInit {
    my $self = shift;
       
    my $frame = MyFrame->new();

    $frame->Show(1);
    $self->SetTopWindow($frame);
    return 1;
}

package MyFrame;

use base 'Wx::Frame';
use Wx qw(wxTE_MULTILINE wxVERTICAL wxID_DEFAULT);
use Wx::Event qw(EVT_COMMAND EVT_CLOSE EVT_BUTTON);

my $done_event : shared = Wx::NewEventType;

sub new {
    my $class = shift;
    my $self = $class->SUPER::new(undef, -1, "The title");

    $self->{text} = Wx::TextCtrl->new($self, -1, "", [-1,-1], [180, 10
+0], wxTE_MULTILINE);
    $self->{button_start} = Wx::Button->new($self, -1, "&Start Test");
    $self->{button_stop}  = Wx::Button->new($self, -1, "&Stop Test");
    
    my $sizer = Wx::BoxSizer->new(wxVERTICAL);
    $sizer->Add($self->{text});
    $sizer->Add($self->{button_start});
    $sizer->Add($self->{button_stop});
    $self->SetSizer($sizer);

    $self->{text}->AppendText("test\n");

    EVT_BUTTON($self,$self->{button_start}, \&DeployTestThread ); 
    EVT_BUTTON($self,$self->{button_stop}, \&StopTestThread ); 
    
    return $self;
}

sub DeployTestThread {

    # Manage the thread pool until signalled to terminate
    while (! $TERM) {

        # Keep max threads running
        for (my $needed = $MAX_THREADS - threads->list();
             $needed && ! $TERM;
             $needed--) {

            # Create New thread
            my $thread = threads->create('ExecuteTest');
        }
    }

    # Detach and kill any remaining threads
    foreach my $thr (threads->list()) {
        lock($DETACHING);
        $thr->detach() if ! $thr->is_detached();
    print "Killing " . $thr->tid() . "\n";
        $thr->kill('KILL');
    }

    print("Done\n");
}
sub StopTestThread {

    $TERM = 1;
}


sub ExecuteTest {
    my($handler, $queue) = @_;
    use LWP::Simple;
    
    # For Testing purposes
    for (1..10) {
        my @sites = qw(
            http://www.google.com/
            http://www.microsoft.com/
            http://www.yahoo.com/
            http://www.cpan.org/
            http://www.perl.org/
        );

        for(0 .. $#sites) {
            my $page = get($sites[$_]);
            my ($title1) = $page =~ /<title[^>]*>\s*(.+?)<\/title[^>]*
+>/gsi;
            my $title : shared = $title1;

            print "$title\n";

            my $thread_event = Wx::PlThreadEvent->new(-1, $done_event,
+ $title);
            Wx::PostEvent($handler, $thread_event);
        }
    }
} 

package main;
MyApp->new->MainLoop;
[download]

Comment on Re^3: Wx subs and threads Download Code

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Re^4: Wx subs and threads by zentara (Cardinal) on Jun 28, 2008 at 13:22 UTC
I'm not experienced with the ins and outs out Wx, but look at Reusable threads demo for the basic CLI use. Then in your Wx gui, replace the while loops in the main thread, with Wx timers, etc. But I can see from your example that you are starting the thread from a Wx button callback: `EVT_BUTTON($self,$self->{button_start}, \&DeployTestThread );` [download] The general rule is to start the thread BEFORE any Wx gui code is invoked. So you may try something like `# Prevents double detach attempts my $DETACHING :shared; #start your thread here before Wx DeployTestThread(); package MyApp;` [download] then your button callback will just set the shared variable `EVT_BUTTON($self,$self->{button_start}, sub{ $TERM = 0 } );` [download] That's the idea, of course you need to setup $TERM properly. But that is the general idea of how to start the thread before the gui code, then use the gui to change a shared variable, which controls thread state. For what it's worth, Perl/Gtk2 has a thread safety mechanism, and you can do what you are trying to do in Gtk2. Also, when Wx builds itself, it will use Gtk2 or Xlib as it's base objects. So if your Wx was built on Gtk2, you may be able to invoke the Glib thread safety mechanism in Wx. You will need to search the docs, or ask someone more knowledgable than me about Wx. I'm not really a human, but I play one on earth CandyGram for Mongo	[reply] [d/l] [select]

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Re^4: Wx subs and threads
by zentara (Cardinal) on Jun 28, 2008 at 13:22 UTC

Reusable threads demo

But I can see from your example that you are starting the thread from a Wx button callback:

EVT_BUTTON($self,$self->{button_start}, \&DeployTestThread );
[download]

# Prevents double detach attempts
my $DETACHING :shared;

#start your thread here before Wx
DeployTestThread(); 

package MyApp;
[download]

EVT_BUTTON($self,$self->{button_start}, sub{  $TERM = 0  } );
[download]

For what it's worth, Perl/Gtk2 has a thread safety mechanism, and you can do what you are trying to do in Gtk2. Also, when Wx builds itself, it will use Gtk2 or Xlib as it's base objects. So if your Wx was built on Gtk2, you may be able to invoke the Glib thread safety mechanism in Wx. You will need to search the docs, or ask someone more knowledgable than me about Wx.

I'm not really a human, but I play one on earth CandyGram for Mongo

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