FULL PRODUCT VERSION :
java version "1.6.0-beta2"
Java(TM) SE Runtime Environment (build 1.6.0-beta2-b80)
Java HotSpot(TM) Client VM (build 1.6.0-beta2-b80, mixed mode, sharing)

(also seen with various earlier 1.6.0 betas.)

ADDITIONAL OS VERSION INFORMATION :
Linux bertha 2.6.12-1-686-smp #1 SMP Tue Sep 27 13:10:31 JST 2005 i686 GNU/Linux

A DESCRIPTION OF THE PROBLEM :

i've seen crashes with different applications on different architectures
(x86 and amd64) on diffeerent physical machines using -- as best i can guess
from the contexts -- different fonts. i just saw b82 closed 6402537, and wonder if this could be a duplicate of
that?

sometimes an application will hang trying to get font metrics. i've seen this with a few applications, but here's an example chunk of stack trace (from jstack(1)):

"AWT-EventQueue-0" prio=10 tid=0x080e1c00 nid=0x3d90 runnable [0xb4aad000..0xb4aaeec0]
   java.lang.Thread.State: RUNNABLE
at java.lang.Thread.isInterrupted(Native Method)
at java.lang.Thread.isInterrupted(Thread.java:889)
at java.nio.channels.spi.AbstractInterruptibleChannel.begin(AbstractInterruptibleChannel.java:153)
at sun.nio.ch.FileChannelImpl.read(FileChannelImpl.java:142)
- locked <0x50120000> (a java.lang.Object)
at sun.font.TrueTypeFont.readBlock(TrueTypeFont.java:305)
- locked <0x54f7b4a8> (a sun.font.TrueTypeFont)
at sun.font.TrueTypeFont.createScaler(Native Method)
at sun.font.TrueTypeFont.getScaler(TrueTypeFont.java:1025)
- locked <0x54f7b4a8> (a sun.font.TrueTypeFont)
at sun.font.FileFontStrike.<init>(FileFontStrike.java:98)
at sun.font.FileFont.createStrike(FileFont.java:74)
at sun.font.Font2D.getStrike(Font2D.java:331)
at sun.font.Font2D.getStrike(Font2D.java:262)
at sun.font.CompositeStrike.getStrikeForSlot(CompositeStrike.java:59)
at sun.font.CompositeStrike.getFontMetrics(CompositeStrike.java:75)
at sun.font.FontDesignMetrics.initMatrixAndMetrics(FontDesignMetrics.java:345)
at sun.font.FontDesignMetrics.<init>(FontDesignMetrics.java:336)
at sun.font.FontDesignMetrics.getMetrics(FontDesignMetrics.java:284)
at sun.swing.SwingUtilities2.getFontMetrics(SwingUtilities2.java:902)
at javax.swing.JComponent.getFontMetrics(JComponent.java:1616)
at javax.swing.plaf.synth.SynthGraphicsUtils.getPreferredSize(SynthGraphicsUtils.java:264)
at javax.swing.plaf.synth.SynthGraphicsUtils.getMinimumSize(SynthGraphicsUtils.java:176)
at javax.swing.plaf.synth.SynthLabelUI.getMinimumSize(SynthLabelUI.java:199)
at javax.swing.JComponent.getMinimumSize(JComponent.java:1731)
at javax.swing.BoxLayout.checkRequests(BoxLayout.java:436)
at javax.swing.BoxLayout.preferredLayoutSize(BoxLayout.java:254)
- locked <0x50120008> (a javax.swing.BoxLayout)
at java.awt.Container.preferredSize(Container.java:1576)
- locked <0x54f463a8> (a java.awt.Component$AWTTreeLock)
at java.awt.Container.getPreferredSize(Container.java:1561)
at javax.swing.JComponent.getPreferredSize(JComponent.java:1653)
at javax.swing.JRootPane$RootLayout.preferredLayoutSize(JRootPane.java:860)
at java.awt.Container.preferredSize(Container.java:1576)
- locked <0x54f463a8> (a java.awt.Component$AWTTreeLock)
at java.awt.Container.getPreferredSize(Container.java:1561)
at javax.swing.JComponent.getPreferredSize(JComponent.java:1653)
at java.awt.BorderLayout.preferredLayoutSize(BorderLayout.java:702)
- locked <0x54f463a8> (a java.awt.Component$AWTTreeLock)
at java.awt.Container.preferredSize(Container.java:1576)
- locked <0x54f463a8> (a java.awt.Component$AWTTreeLock)
at java.awt.Container.getPreferredSize(Container.java:1561)
at java.awt.Window.pack(Window.java:558)
at e.gui.AboutBox.makeUi(AboutBox.java:176)
at e.gui.AboutBox.show(AboutBox.java:90)
at e.gui.HelpMenu$AboutBoxAction.actionPerformed(HelpMenu.java:79)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1982)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2305)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:377)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:232)
at javax.swing.AbstractButton.doClick(AbstractButton.java:357)
at javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:1137)
at javax.swing.plaf.basic.BasicMenuItemUI$Handler.menuDragMouseReleased(BasicMenuItemUI.java:1241)
at javax.swing.JMenuItem.fireMenuDragMouseReleased(JMenuItem.java:553)
at javax.swing.JMenuItem.processMenuDragMouseEvent(JMenuItem.java:450)
at javax.swing.JMenuItem.processMouseEvent(JMenuItem.java:396)
at javax.swing.MenuSelectionManager.processMouseEvent(MenuSelectionManager.java:292)
at javax.swing.plaf.basic.BasicPopupMenuUI$MouseGrabber.eventDispatched(BasicPopupMenuUI.java:784)
at java.awt.Toolkit$SelectiveAWTEventListener.eventDispatched(Toolkit.java:2358)
at java.awt.Toolkit$ToolkitEventMulticaster.eventDispatched(Toolkit.java:2250)
at java.awt.Toolkit.notifyAWTEventListeners(Toolkit.java:2208)
at java.awt.Component.dispatchEventImpl(Component.java:4285)
at java.awt.Container.dispatchEventImpl(Container.java:2042)
at java.awt.Component.dispatchEvent(Component.java:4217)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4246)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3910)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3840)
at java.awt.Container.dispatchEventImpl(Container.java:2028)
at java.awt.Window.dispatchEventImpl(Window.java:2297)
at java.awt.Component.dispatchEvent(Component.java:4217)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
at e.debug.EventDispatchThreadHangMonitor.dispatchEvent(EventDispatchThreadHangMonitor.java:192)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:273)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:183)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:173)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:168)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:160)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:121)

strace(1) doesn't show any activity:

bertha:~$ strace -c -p 15746
Process 15746 attached - interrupt to quit
Process 15746 detached
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
------ ----------- ----------- --------- --------- ----------------
100.00 0.000000 0 total

and it looks like we're stuck:

bertha:~$ strace -p 15746
Process 15746 attached - interrupt to quit
futex(0xb7d95bf8, FUTEX_WAIT, 15747, NULL <unfinished ...>

jconsole(1) says no deadlock detected.

it usually happens when the application has already been running for a while. in this instance, the application had been running for over 4 hours.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
i don't have guaranteed steps to reproduce. i've been using Java 6 all day every day for a few weeks, and i've seen this four or five times.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
no hang
ACTUAL -
hang; quite a lot of CPU usage. attaching ltrace(1) to see what it was up to produced the following output and brought the CPU usage down to zero:

bertha:~$ ltrace -p 15746
--- SIGSTOP (Stopped (signal)) ---
--- SIGSTOP (Stopped (signal)) ---

jstack(1) now hangs, so i guess i've come to the end of my poking about here!

killing the process then dumped a lot of log output suggesting that it may have been making some very slow progress (or just giving a better idea of exactly where it's spinning):

2006-04-14T17:48:19.490-0700 Terminator: (hang #664) event dispatch thread stuck processing event for 108910 ms:
    sun.nio.ch.FileChannelImpl.position0(Native Method)
    sun.nio.ch.FileChannelImpl.position(FileChannelImpl.java:290)
    sun.font.TrueTypeFont.readBlock(TrueTypeFont.java:304)
    sun.font.TrueTypeFont.createScaler(Native Method)
    sun.font.TrueTypeFont.getScaler(TrueTypeFont.java:1025)
    sun.font.FileFontStrike.<init>(FileFontStrike.java:98)
    sun.font.FileFont.createStrike(FileFont.java:74)
    sun.font.Font2D.getStrike(Font2D.java:331)
    sun.font.Font2D.getStrike(Font2D.java:262)
    sun.font.CompositeStrike.getStrikeForSlot(CompositeStrike.java:59)
    sun.font.CompositeStrike.getFontMetrics(CompositeStrike.java:75)
.
.
.
2006-04-14T17:48:19.591-0700 Terminator: (hang #665) event dispatch thread stuck processing event for 109011 ms:
    java.lang.Thread.isInterrupted(Native Method)
    java.lang.Thread.isInterrupted(Thread.java:889)
    java.nio.channels.spi.AbstractInterruptibleChannel.begin(AbstractInterruptibleChannel.java:153)
    sun.nio.ch.FileChannelImpl.read(FileChannelImpl.java:142)
    sun.font.TrueTypeFont.readBlock(TrueTypeFont.java:305)
    sun.font.TrueTypeFont.createScaler(Native Method)
    sun.font.TrueTypeFont.getScaler(TrueTypeFont.java:1025)
    sun.font.FileFontStrike.<init>(FileFontStrike.java:98)
    sun.font.FileFont.createStrike(FileFont.java:74)
    sun.font.Font2D.getStrike(Font2D.java:331)
    sun.font.Font2D.getStrike(Font2D.java:262)
    sun.font.CompositeStrike.getStrikeForSlot(CompositeStrike.java:59)
    sun.font.CompositeStrike.getFontMetrics(CompositeStrike.java:75)
.
.
.
2006-04-14T17:48:19.692-0700 Terminator: (hang #666) event dispatch thread stuck processing event for 109112 ms:
    sun.nio.ch.FileChannelImpl.position0(Native Method)
    sun.nio.ch.FileChannelImpl.position(FileChannelImpl.java:290)
    sun.font.TrueTypeFont.readBlock(TrueTypeFont.java:304)
    sun.font.TrueTypeFont.createScaler(Native Method)
    sun.font.TrueTypeFont.getScaler(TrueTypeFont.java:1025)
    sun.font.FileFontStrike.<init>(FileFontStrike.java:98)
    sun.font.FileFont.createStrike(FileFont.java:74)
    sun.font.Font2D.getStrike(Font2D.java:331)
    sun.font.Font2D.getStrike(Font2D.java:262)
    sun.font.CompositeStrike.getStrikeForSlot(CompositeStrike.java:59)
    sun.font.CompositeStrike.getFontMetrics(CompositeStrike.java:75)
    sun.font.FontDesignMetrics.initMatrixAndMetrics(FontDesignMetrics.java:345)
    sun.font.FontDesignMetrics.<init>(FontDesignMetrics.java:336)
    sun.font.FontDesignMetrics.getMetrics(FontDesignMetrics.java:284)
    sun.swing.SwingUtilities2.getFontMetrics(SwingUtilities2.java:902)
    javax.swing.JComponent.getFontMetrics(JComponent.java:1616)
.
.
.
2006-04-14T17:48:19.995-0700 Terminator: (hang #667) event dispatch thread stuck processing event for 109415 ms:
    java.lang.Thread.isInterrupted(Native Method)
    java.lang.Thread.isInterrupted(Thread.java:889)
    java.nio.channels.spi.AbstractInterruptibleChannel.begin(AbstractInterruptibleChannel.java:153)
    sun.nio.ch.FileChannelImpl.position(FileChannelImpl.java:285)
    sun.font.TrueTypeFont.readBlock(TrueTypeFont.java:304)
    sun.font.TrueTypeFont.createScaler(Native Method)
    sun.font.TrueTypeFont.getScaler(TrueTypeFont.java:1025)
    sun.font.FileFontStrike.<init>(FileFontStrike.java:98)
    sun.font.FileFont.createStrike(FileFont.java:74)
    sun.font.Font2D.getStrike(Font2D.java:331)
    sun.font.Font2D.getStrike(Font2D.java:262)
    sun.font.CompositeStrike.getStrikeForSlot(CompositeStrike.java:59)
    sun.font.CompositeStrike.getFontMetrics(CompositeStrike.java:75)

et cetera.

REPRODUCIBILITY :
This bug can be reproduced occasionally.