Re: Is this a deadlock ?

From:

Daniel Pitts <newsgroup.spamfilter@virtualinfinity.net>

Newsgroups:

comp.lang.java.programmer

Date:

Wed, 19 Aug 2009 09:00:55 -0700

Message-ID:

<1lVim.145072$Qg6.118691@newsfe14.iad>

Albert wrote:

Hi, sudenly, my program doesn't exit any more. Using jstack i got this
stack trace:

"AWT-Shutdown" prio=10 tid=0x08394400 nid=0xd5a in Object.wait()
[0xb4dad000..0xb4daddc0]
   java.lang.Thread.State: WAITING (on object monitor)
        at java.lang.Object.wait(Native Method)
        - waiting on <0x60065140> (a java.lang.Object)
        at java.lang.Object.wait(Object.java:485)
        at sun.awt.AWTAutoShutdown.run(AWTAutoShutdown.java:259)
        - locked <0x60065140> (a java.lang.Object)
        at java.lang.Thread.run(Thread.java:619)

I see that the thread lock an object and then wait for it. Is this a
deadlock ?

Deadlock requires at least two threads. A deadlock is formed when there
is a cycle in the graph of threads waiting on other threads.

You have only shown one thread, so this is not a deadlock. Also, it is
the AWT-Shutdown thread, which is probably waiting on the EDT thread to
finish. It would probably be Okay for that thread to block forever.

--
Daniel Pitts' Tech Blog: <http://virtualinfinity.net/wordpress/>