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POHow can I get cross-thread communication in a Perl GTK program?
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copied!<p>I have a Perl program that has a GTK2 GUI (via the <code>Gtk2</code> package). This program also opens a network socket (actually via <code>LWP</code>) in another thread, and continuously makes a request for a certain URL, waiting for an event to happen.</p> <p>If an event occurs, then its data must be processed and interpreted, and an appropriate callback function used to update the GUI. This is where my program falls down.</p> <p>Main program:</p> <pre><code># Attach to the "message received" event Foo::hook('msgRx', \&updateMsg); # ... Gtk2->main(); sub updateMsg { my ($msg) = @_; print "New message: $msg\n"; # append to a GTK TextView -- code is also used elsewhere and works fine appendMsg($msg); } </code></pre> <p>And in the module:</p> <pre><code># ... my %hooks = (); my $ev_pid = undef; sub hook($&) { my ($name, $sub) = @_; $hooks{$name} = $sub; } sub call_hook { my ($name, @args) = @_; print ">>> CALLING HOOK $name\n"; return $hooks{$name}->(@args) if (defined($hooks{$name})); } sub eventThread { while (1) { my $res = $browser->post("$baseurl/events", ['id' => $convid]); my $content = $res->content; last if ($content eq 'null'); my $events = from_json($content); foreach (@$events) { my $ev_type = shift @$_; my @ev_args = @$_; print "Event type: $ev_type\n"; print Data::Dumper->Dump([@ev_args]); handleEvent($ev_type, @ev_args); } } } sub doConnect() { # ... $ev_pid = fork; if (!defined $ev_pid) { print "ERROR forking\n"; disconnect(); return; } if (!$ev_pid) { eventThread; exit; } } </code></pre> <p>Now the console output from these is what I expect:</p> <pre>>> Starting... [["connected"]] Event type: connected >>> CALLING HOOK start [["waiting"]] Event type: waiting >>> CALLING HOOK waiting [["gotMessage", "77564"]] Event type: gotMessage $VAR1 = '77564'; >>> CALLING HOOK msgRx New message: 77564 [["idle"]] Event type: idle >>> CALLING HOOK typing [["gotMessage", "816523"]] Event type: gotMessage $VAR1 = '816523'; >>> CALLING HOOK msgRx New message: 816523 >> User ending connection null >>> CALLING HOOK end</pre> <p>However, the GUI TextView does not update. I can only presume that this is because the callback is actually happening in another thread, which has duplicates of the objects.</p> <p>Any suggestions?</p>

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