This is a bug on Solaris under JDK 1.1.8 only.

If a visible non-modal Dialog is made modal via Dialog.setModal(true), the AWT EventQueue thread hangs (see thread dump below). If a Dialog is visible, calling Dialog.setModal(boolean) should have no effect.


//---------------------------ModalTest.java-----------------------------
// (1) Run the test case, and a Frame comes up.
// (2) Click on the "test" button and a Dialog, initially non-modal, pops up.
// (3) Click on the "test" button again, making the Dialog modal. The
// AWT is now hung.

import java.awt.*;
import java.awt.event.*;

public class ModalTest extends Frame implements ActionListener
{
    boolean modal = false;
    TestDialog testDialog;

    public static void main(String argv[])
    {
        ModalTest Test = new ModalTest();
    }

    public ModalTest()
    {
        setSize (200,200);
        addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent evt) {
                System.exit(0);
            }
        });
        Button button = new Button("test");
        button.addActionListener(this);
        button.setSize(10,5);
        add(button);
        setVisible(true);
        testDialog = new TestDialog(this);
    }

    public void actionPerformed(ActionEvent e)
    {
        testDialog.setModal(modal);
        System.out.println("modal setting is now = " + modal);
        modal = !modal;
        testDialog.setVisible(true);
    }

    public class TestDialog extends Dialog implements ActionListener
    {
        protected Button okButton;

        public TestDialog(Frame parent)
        {
            super(parent);

            okButton = new Button("OK");
            okButton.addActionListener(this);
            add(okButton);

            setLocation(400,400);
            setSize(100,100);
        }

        public void actionPerformed(ActionEvent e)
        {
            setVisible(false);
        }
    }
}




^\SIGQUIT 3* quit

Full thread dump:
    "Screen Updater" (TID:0xee306de8, sys_thread_t:0xef0c1db8, state:CW) prio=4
        java.lang.Object.wait(Object.java)
        sun.awt.ScreenUpdater.nextEntry(ScreenUpdater.java:70)
        sun.awt.ScreenUpdater.run(ScreenUpdater.java:90)
    "AWT-Motif" (TID:0xee305288, sys_thread_t:0xef0f1db8, state:CW) prio=5
        java.lang.Thread.run(Thread.java)
    "AWT-Input" (TID:0xee304fe8, sys_thread_t:0xef121db8, state:CW) prio=5
    "AWT-EventQueue-0" (TID:0xee305000, sys_thread_t:0xef151db8, state:CW) prio=5
        sun.awt.motif.MDialogPeer.toFront(MDialogPeer.java:111)
        java.awt.Window.toFront(Window.java:204)
        java.awt.Dialog.show(Dialog.java:202)
        java.awt.Component.show(Component.java:511)
        java.awt.Component.setVisible(Component.java:473)
        ModalTest.actionPerformed(ModalTest.java:46)
        java.awt.Button.processActionEvent(Button.java:256)
        java.awt.Button.processEvent(Button.java:229)
        java.awt.Component.dispatchEventImpl(Component.java:1812)
        java.awt.Component.dispatchEvent(Component.java:1744)
        java.awt.EventDispatchThread.run(EventDispatchThread.java:79)
    "Finalizer thread" (TID:0xee300210, sys_thread_t:0xef341db8, state:CW) prio=1
    "Async Garbage Collector" (TID:0xee300258, sys_thread_t:0xef371db8, state:CW) prio=1
    "Idle thread" (TID:0xee3002a0, sys_thread_t:0xef471db8, state:R) prio=0 *current thread*
    "Clock" (TID:0xee300088, sys_thread_t:0xef561db8, state:CW) prio=12
    "main" (TID:0xee3000b0, sys_thread_t:0x43908, state:CW) prio=5
Monitor Cache Dump:
    sun.awt.ScreenUpdater@EE306DE8/EE35ADB8: <unowned>
        Waiting to be notified:
            "Screen Updater" (0xef0c1db8)
    sun.awt.motif.MToolkit@EE305088/EE353A80: <unowned>
        Waiting to be notified:
            "AWT-EventQueue-0" (0xef151db8)
            "AWT-Motif" (0xef0f1db8)
    <unknown key> (0xef371db8): <unowned>
        Waiting to be notified:
            "Async Garbage Collector" (0xef371db8)
Registered Monitor Dump:
    Thread queue lock: <unowned>
        Waiting to be notified:
            "main" (0x43908)
    Name and type hash table lock: <unowned>
    String intern lock: <unowned>
    JNI pinning lock: <unowned>
    JNI global reference lock: <unowned>
    BinClass lock: <unowned>
    Class loading lock: <unowned>
    Java stack lock: <unowned>
    Code rewrite lock: <unowned>
    Heap lock: <unowned>
    Has finalization queue lock: <unowned>
    Finalize me queue lock: <unowned>
        Waiting to be notified:
            "Finalizer thread" (0xef341db8)
    Dynamic loading lock: <unowned>
    Monitor IO lock: <unowned>
    Child death monitor: <unowned>
    Event monitor: <unowned>
    I/O monitor: <unowned>
        Waiting to be notified:
            "AWT-Input" (0xef121db8)
    Alarm monitor: <unowned>
        Waiting to be notified:
            "Clock" (0xef561db8)
    Sbrk lock: <unowned>
    Monitor registry: owner "Idle thread" (0xef471db8, 1 entry)
Thread Alarm Q:
    sys_thread_t 0xef121db8 [Timeout in 118 ms]
    sys_thread_t 0xef371db8 [Timeout in 729 ms]