IBM JVM & heap size

[yangyuexiang <ya...@comp.nus.edu.sg>]

Hello,

I have two threads A and B, both of them are instance of the same class.
When I start both of A and B, after a while, the JVM hang.
(A and B have no shared memory, only local variables ).

But when I run two JVMs, and each starts one thread, then no problems.

Why? Is it related to the JVM heap size? But the JVM never throws any memory
exceptions.
I have 128 main memory.
I used -Xmx96m or -Xmx64m , the results are the same.

Any suggestions?

Thanks

yangyuexiang

Re: IBM JVM & heap size

[William Brogden <wb...@bga.com>]

This really sounds like a deadlock problem due to both
Threads trying for the same object - check your
synchronized methods.


yangyuexiang wrote:
> 
> Hello,
> 
> I have two threads A and B, both of them are instance of the same class.
> When I start both of A and B, after a while, the JVM hang.
> (A and B have no shared memory, only local variables ).
> 
> But when I run two JVMs, and each starts one thread, then no problems.
> 
> Why? Is it related to the JVM heap size? But the JVM never throws any memory
> exceptions.
> I have 128 main memory.
> I used -Xmx96m or -Xmx64m , the results are the same.
> 
> Any suggestions?
> 
> Thanks
> 
> yangyuexiang

-- 
WBB - wbrogden@bga.com  Chief Scientist, LANWrights, Inc.
Java Programmer Certification information and mock exam
at  http://www.lanw.com/java/javacert/

JVM & heap size and an irrecoverable stack overflow has occurred!

[yangyuexiang <ya...@comp.nus.edu.sg>]

Hi, Everyone,

When I add shutDownHook to the Runtime,
the system print out "an irrecoverable stack overflow has occurred".
My program run under SUN JVM(current version).

What's mean?

Thanks
yangyuexiang