Hi Volker, Happy New Year. I'd like to ask some question about hotspot of openjdk.

[xinweix at cse.unsw.edu.au]

Hi Volker,

Happy New Year.
Sorry to bother you. Thank you for your attention.

I found your email about Hotspot build instruction from the hotspot-dev maillist and your blog. I do appreciate your great help. However, I still can't quite understand the mechanism of the interpreter in hotspot. May I ask you some questions?

1) I used ddd, a graphic based client of gdb, to set up some breakpoints and stepped into the hotspot jvm. I can find how exactly the bytecode is executed, just like the following maillist:
http://markmail.org/message/lu6izmxpqzzej4lr?q=interpreter+openjdk&page=14#query:interpreter%20openjdk+page:14+mid:wvzcrnvxlqlj5oxa+state:results .Do you have some idea about that?

BTW, I successfully step into to breakpoint of StubRountes::call_stub while using another debuger: "insight". I use '-XX:+TraceBytecode -Xint' to see what is going in the Interpreter. However, it even generates a great amount of bytecodes when it is initializing and load the system class. I don't know when the interpreter runtime is initialized.


2) I tried to use some options, as '-Xint', '-XX:StopInterpreterAt=1', aiming at stopping at a specific bytecode when I can inspect the runtime datastructure. Unfortunately I failed. I don't understand why '-XX:StopInterpreterAt=1' doesn't work. The question is how to configure it correctly that I can stop where exactly I want.

3) My object is to get some information, especially about the lock and thread information when threads concurrently access a shared variant or try to lock before access using monitorenter. Can you give me some advise how and where I can start? Is it related to the InterpreterRuntime::monitorenter?

I am looking forward to hearing from you.

Regards,

Alex Xie,
University of New South Wales, Australia.
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