How to trace the hotspot bytecode interpreter

[Colin(Du Li)]

Hi, Gary,

Thank you very much for your explanation!

I still have two questions.
1. If I wanna add a read barrier to bytecode interpreter, which will trap
all the object access in bytecode, where should I put this read barrier?
2. What is the bytecodeInterpreter.cpp used for? It seems to have a lot of
bytecode interpreter thing as follows:
      CASE(_aload):
          SET_STACK_OBJECT(LOCALS_OBJECT(pc[1]), 0);
          UPDATE_PC_AND_TOS_AND_CONTINUE(2, 1);

Thanks again!

Colin

Gary Benson wrote:
> 
> For x86 you need the template interpreter.  The code that executes
> bytecodes exists as fragments of assembly language, generated by code
> in hotspot/src/cpu/x86/vm/templateInterpreter_x86_32.cpp or
> hotspot/src/cpu/x86/vm/templateInterpreter_x86_64.cpp.
> 
> Cheers,
> Gary
> 
> Colin(Du Li) wrote:
>> Hi Gary,
>> 
>> I use x86. You mean bytecodeInterpreter is useless?
>> Then where is the bytecode interpreter codes in Hotspot?
>> e.g. where is the instruction, such as "getField", been interpreted
>> and executed?
>> 
>> Thanks a lot!
>> 
>> Colin
>> 
>> Gary Benson wrote:
>> > Hi Colin,
>> > 
>> > What platform are you using?  If you are on x86, x86_64 or sparc (and
>> > you haven't messed with the build to enable the C++ interpreter) then
>> > nothing in bytecodeInterpreter.cpp is ever used.
>> > 
>> > Cheers,
>> > Gary
>> > 
>> > Colin(Du Li) wrote:
>> > > I know the byte interpreter implementation is mainly in
>> > > bytecodeInterpreter.cpp, but it doesn't allow me set break point in
>> > > this file. I wanna trace the bytecode interpreter. Where can I put
>> > > break pointer?  Where is the entrance to bytecodeInterpreter.cpp,
>> > > that is, in Hotpot, which classes will call the methods in
>> > > bytecodeInterpreter.cpp?
>> > > Thanks.
> 
> -- 
> http://gbenson.net/
> 
> 

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