[Kde-java] java threads + events + segfaults

[Benji Weber]

Greetings,

The below code produces segfaults such as

#
# An unexpected error has been detected by HotSpot Virtual Machine:
#
#  SIGSEGV (0xb) at pc=0x00002aaaaaf88849, pid=1270, tid=1078753600
#
# Java VM: Java HotSpot(TM) 64-Bit Server VM (1.5.0_06-b05 mixed mode)
# Problematic frame:
# C  [libqtjava.so.1.0.0+0x261849]  Java_org_kde_qt_QCustomEvent_finalize+0x49
#
# An error report file with more information is saved as hs_err_pid1270.log
#
# If you would like to submit a bug report, please visit:
#   http://java.sun.com/webapps/bugreport/crash.jsp
#

After clicking the segfaults button, at some point after the message
box has shown, moving/resizing the window tends to speed this up.

If one stops the Event from being garbage collected as the "won't
segfault" button does then there is no problem.

Presumably this is an issue with qtjava?

Benji
========================

import org.kde.qt.*;

public class ThreadTest extends QWidget
{
	ThreadTest()
	{
 		QVBoxLayout mainLayout = new QVBoxLayout(this,12,12,"MainLayout");
		mainLayout.setAutoAdd(true);
		QPushButton pushButton = new QPushButton("Segfaults",this,"Hello");
//this will segfault at some point after message box shown - resizing
or moving the window often triggers this
		QObject.connect( pushButton, SIGNAL( "clicked( )" ), this, SLOT(
"onClick()" ) );
		QPushButton anotherPushButton = new QPushButton("won't
segfault",this,"Hello2"); //this won't
		QObject.connect( anotherPushButton, SIGNAL( "clicked( )" ), this,
SLOT( "onClick2()" ) );
	}
	
	private void onClick()
	{
		DoSomething doSomething = new DoSomething("test","test",this);
		doSomething.start();
	}

	private void onClick2()
	{
		DoSomethingElse doSomething = new DoSomethingElse("test","test",this);
		doSomething.start();
	}


	public static void main(String[] args)
	{
		QApplication myapp = new QApplication(args);
		ThreadTest mywidget = new ThreadTest();
		mywidget.setGeometry(50, 500, 400, 400);

		myapp.setMainWidget(mywidget);
		mywidget.show();
		myapp.exec();
		return;
	}

	public void customEvent(QCustomEvent evt)
	{
		System.out.println("got custom event");
		if (evt.type() == 65432)
		{
			MessageEvent event = (MessageEvent) evt;
			System.out.println(event.getTitle());
			QMessageBox.critical(this,event.getTitle(), event.getText());
		}
	}
	
	static {
		qtjava.initialize();
	}
}

class DoSomething extends Thread
{
	private String text;
	private String title;
	private QWidget caller;

	public DoSomething(String title, String text,QWidget caller)
	{
		this.caller = caller;
		this.text = text;
		this.title = title;
	}
	public void run()
	{
		System.out.println("Thread running");
		MessageEvent event = new MessageEvent(title,text);
		QApplication.postEvent(caller,event);
		System.out.println("Thread finishing");
	}
}

class DoSomethingElse extends Thread
{
	private String text;
	private String title;
	private QWidget caller;

	public DoSomethingElse(String title, String text,QWidget caller)
	{
		this.caller = caller;
		this.text = text;
		this.title = title;
	}
	public void run()
	{
		System.out.println("Thread running");
		MessageEvent event = new MessageEvent(title,text);
		QApplication.postEvent(caller,event);
		dont.gc(event);
		System.out.println("Thread finishing");
	}
}

class dont //xxx
{
	private static java.util.ArrayList dump = new java.util.ArrayList();
	static void gc(java.lang.Object o)
	{
		dump.add(o);
	}
}

class MessageEvent extends QCustomEvent
{
	private String title;
	private String text;
	public MessageEvent(String title, String text)
	{
		super(65432);
		this.title = title;
		this.text = text;
	}
	
	public String getTitle(){return title;}
	public String getText(){return text;}
}

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