topic Re: determine if java app is 32-bit or 64-bit in Operating System - HP-UX

determine if java app is 32-bit or 64-bit

ahpuser — Sun, 05 Oct 2008 00:21:54 GMT

Hello,

I'm using HP-UX 11.11 (11i) on a HP9000 PA-RISC server.

I have done the following:

1. Downloaded the JRE v5.0.08 from: http://h20392.www2.hp.com/portal/swdepot/try.do?productNumber=JDKJRE5008

2. Installed the JRE.

3. Run a Java application like this:
/opt/java1.5/bin/java -Xmx1024m -cp bin com.examples.Test

I just need to know if this java process is a 32-bit or 64-bit process.

It's important because I have read that there are certain memory limitations for 32-bit applications in HP-UX 11.11.

Thank you very much.

Re: determine if java app is 32-bit or 64-bit

Dennis Handly — Sun, 05 Oct 2008 01:32:51 GMT

The default is 32 bit. If you want 64 bit you need to use -d64. If you have any JNIs, you would have to port them first.

Re: determine if java app is 32-bit or 64-bit

Gokul Chandola — Sun, 05 Oct 2008 12:22:01 GMT

Hi,
You are right,you have to use 64 bit process.
You have to use 64-bit process instead of 32 bit.

Regards,
Gokul Chandola

Re: determine if java app is 32-bit or 64-bit

Steven E. Protter — Sun, 05 Oct 2008 13:07:58 GMT

Shalom,

You can use the what command on the actual binary.

You can use swlist -a fileset to to analyze the java server binaries.

SEP

Re: determine if java app is 32-bit or 64-bit

ahpuser — Sun, 05 Oct 2008 17:00:55 GMT

Thanks everyone for the replies.

Dennis Handly wrote:
"The default is 32 bit. If you want 64 bit you need to use -d64. If you have any JNIs, you would have to port them first".

I'm a little confused here:
I used to think that a binary file can be either 32-bit or 64-bit (not both).
For example, some applications offers two binary executable files: one is 32-bit and the other is 64-bit.

But what about java? The java binary executable /opt/java1.5/java can produce a 32-bit process or a 64-bit process only by specifying the -d64 flag?

Gokul Chandola wrote:
"You are right,you have to use 64 bit process.
You have to use 64-bit process instead of 32 bit."

How do I use 64-bit process instead of 32-bit?
Just by using the -d64 flag?
Or I need to use another java binary executable (I'm currently using /opt/java1.5/java)?

Steven E. Protter wrote:
"You can use the what command on the actual binary.
You can use swlist -a fileset to to analyze the java server binaries."

I will try those commands as soon as I can.

Any additional information would be great. Thanks.

Re: determine if java app is 32-bit or 64-bit

Dennis Handly — Mon, 06 Oct 2008 01:27:01 GMT

You're thinking too hard, believe in the magic. :-) Just add the -d64 option.

>I used to think that a binary file can be either 32-bit or 64-bit (not both).

There is no binary file here, just instructions in memory. :-)

>some applications offers two binary executable files: one is 32-bit and the other is 64-bit.

Exactly, that's the magic. But typically applications only come one way, only shlibs may have both.

>The java binary executable /opt/java1.5/java can produce a 32-bit process or a 64-bit process only by specifying the -d64 flag?

That's just a 32 bit driver that invokes either a 32 or a 64 bit JVM.

>How do I use 64-bit process instead of 32-bit? Just by using the -d64 flag?

That's correct, read the documentation.
http://docs.hp.com/en/JAVAPROGUIDE/hotspot.html#-d64

>Any additional information would be great.

You can use tusc to see exactly how it works.

>SEP: You can use the what command on the actual binary.

Did you mean the file(1) command instead?

Re: determine if java app is 32-bit or 64-bit

ahpuser — Mon, 06 Oct 2008 18:00:28 GMT

Ok,

> That's just a 32 bit driver that invokes either a 32 or a 64 bit JVM.

That explain everything.

> You can use tusc to see exactly how it works.

I'll do that, thanx.