JDI binding for the Serviceability Agent

[Jim Holmlund]

Hello Jie Yu.  You are correct that the only way to debug without starting
the Java program in debug mode with -agentlib:.... is to use the 
SAPIDAttachingConnector,
and then you can only read information out of the VM - you can't modify 
the state.
For JDK 7, we are investigating a feature we call 'attach on demand 
debugging'
which would do just what you are asking for.

The 'SA' in SAPIDAttachingConnector stands for Serviceability Agent.
All the files under the hotspot/agent directory that you reference below
are part of the Serviceability Agent.    You can find out more about the
SA here:
   http://openjdk.java.net/groups/hotspot/docs/Serviceability.html#bsa

SA is also used by HotSpot engineers to debug HotSpot itself.  The
files you mention under the hotspot/livejvm are used for that.

HTH
- jjh


Jie Yu wrote:
> Hi,
>
> I am a student from Fudan University, China. I am working on a project that uses JPDA of JDK6. I want to debug a live java program that is not start with any debug options (e.g. -agentlib:jdwp or -Xdebug). For this reason, I can choose the SAPIDAttachingConnector. But the VirtualMachine object returned by this connector's attach() method is 'read-only', meaning that I cannot modify the state of the live java program. Is there any other options for me? I scan the source tree of openjdk, and find that in hotspot/agent/src/share/classes/sun/jvm/hotspot/livejvm, there are some related source files. What are these files for? Are they related to my problem?
>
> Best regards,
>
> Jie Yu
>
>
>