open jdk debug options

[Neo Jia]

On Tue, Oct 7, 2008 at 10:13 PM, Cong Wang <jameswang99 at yahoo.com> wrote:
> OK. So, Neo, the option for -ggdb3 is for sun cc or gcc?

gcc, you just need to modify the hotspot makefile to include it there.

> Thank you all for your response so far.
> Regards
> James Wang
>
> On Wed, Oct 8, 2008 at 1:08 PM, Neo Jia <neojia at gmail.com> wrote:
>> On Tue, Oct 7, 2008 at 10:05 PM, Jon Masamitsu <Jon.Masamitsu at sun.com> wrote:
>>>
>>> When you start
>>>
>>> dbx java
>>>
>>> you are starting dbx on the java launcher.  The
>>> launcher does an exec of the VM.
>>> In the output below from dbx the "stopped in main"
>>> indicates that the exec has happened and  you've
>>> stopped in the main of the VM.  At that point
>>> dbx has forgotten about the breakpoints you've
>>> set because it thinks the breakpoints are in the
>>> launcher.
>>
>> FYI. gdb can keep follow the exec after 6.5.
>>
>> Thanks,
>> Neo
>>
>>>
>>> You need to set your LD_LIBRARY_PATH
>>> to point to the libjvm.so that you've built.
>>>
>>> Compile this program
>>>
>>> public class PrintLibraryPath {
>>>   public static void main(String[] args) {
>>>      System.out.println(System.getProperty("java.library.path"));
>>>   }
>>> }
>>>
>>> and execute it with the java you want to debug.
>>>
>>> I have /usr/jdk/jdk1.5.0_11/bin/java so
>>>
>>> -------------------
>>> /usr/jdk/jdk1.5.0_11/bin/java PrintLibraryPath
>>> /usr/jdk/instances/jdk1.5.0/jre/lib/sparc/server:/usr/jdk/instances/jdk1.5.0/jre/lib/sparc:/usr/jdk/instances/jdk1.5.0/jre/../lib/sparc:/usr/lib
>>> -------------------
>>>
>>> prints the LD_LIBRARY_PATH for /usr/jdk/jdk1.5.0_11/bin/java
>>>
>>> Set your LD_LIBRARY_PATH accordingly.
>>>
>>> Then start dbx on java and you should see something like
>>>
>>> -------------------
>>> dbx /usr/jdk/jdk1.5.0_11/bin/java
>>> For information about new features see `help changes'
>>> To remove this message, put `dbxenv suppress_startup_message 7.5' in your
>>> .dbxrcReading java
>>> Reading ld.so.1
>>> Reading libthread.so.1
>>> Reading libdl.so.1
>>> Reading libc.so.1
>>> -------------------
>>>
>>> Run with -version
>>>
>>> -------------------
>>>
>>> dbx: run -version
>>> Running: java -version
>>> (process id 6309)
>>> Reading libc_psr.so.1
>>> Reading libjvm.so
>>> Reading libsocket.so.1
>>> Reading libsched.so.1
>>> Reading libCrun.so.1
>>> Reading libm.so.1
>>> Reading libnsl.so.1
>>> Reading libm.so.2
>>> Reading libscf.so.1
>>> Reading libdoor.so.1
>>> Reading libuutil.so.1
>>> Reading libmd5.so.1
>>> Reading libmd5_psr.so.1
>>> Reading libmp.so.2
>>> Reading libhpi.so
>>> Reading libverify.so
>>> Reading libjava.so
>>> Reading libzip.so
>>> java version "1.5.0_11"
>>> Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_11-b03)
>>> Java HotSpot(TM) Server VM (build 1.5.0_11-b03, mixed mode)
>>>
>>> execution completed, exit code is 0
>>> dbx:
>>> -------------------
>>>
>>> Running with -version causes the VM to execute and all the
>>> libraries get loaded.  You should them see your
>>>
>>> /scratch/wang/java_tm_7/lib/sparc/server/libjvm.so
>>>
>>> You should be able to set your breakpoints now and run
>>> with your real java command line.
>>>
>>>
>>> Cong Wang wrote:
>>>>
>>>> Hi Jon:
>>>>    I went into the  ALT_OUTPUTDIR/bin
>>>> start dbx with :
>>>> dbx java
>>>> For information about new features see `help changes'
>>>> To remove this message, put `dbxenv suppress_startup_message 7.6' in your
>>>> .dbxrc
>>>> Reading java
>>>> Reading /usr/lib/ld.so.1
>>>> Reading /lib/libthread.so.1
>>>> Reading /scratch/wang/java_tm_7/lib/sparc/jli/libjli.so
>>>> Reading /lib/libdl.so.1
>>>> Reading /lib/libc.so.1
>>>>
>>>> then I map the src file foler into the current folder, using pathmap
>>>>
>>>> pathmap /scratch/wang/openjdk/hotspot/src/cpu/sparc/vm
>>>> /scratch/wang/java_tm_7/bin
>>>>
>>>> after the pathmap, I try to find the function using
>>>>
>>>> whereis compiler_lock_object
>>>>
>>>> there is no output.
>>>>
>>>> But I know that function is in
>>>> /scratch/wang/java_tm_7/lib/sparc/server/libjvm.so, therefore
>>>> I use the following to load the shared library:
>>>> loadobject -load /scratch/wang/java_tm_7/lib/sparc/server/libjvm.so
>>>> Reading /scratch/wang/java_tm_7/lib/sparc/server/libjvm.so
>>>> Loaded loadobject: /scratch/wang/java_tm_7/lib/sparc/server/libjvm.so
>>>>
>>>> now, when I use whereis to find compiler_lock_object, I got:
>>>>  whereis compiler_lock_object
>>>> function:
>>>>
>>>> `/scratch/wang/java_tm_7/lib/sparc/server/libjvm.so`assembler_sparc.cpp`#__1cOMacroAssemblerUcompiler_lock_object6MpnMRegisterImpl_222pnVBiasedLockingCounters__v_
>>>>     [non -g, demangles to:
>>>>
>>>> MacroAssembler::compiler_lock_object(RegisterImpl*,RegisterImpl*,RegisterImpl*,RegisterImpl*,BiasedLockingCounters*)]
>>>>
>>>> Then, I set a break point using:
>>>> stop in compiler_lock_object
>>>> dbx: warning: 'compiler_lock_object' has no debugger info -- will
>>>> trigger on first instruction
>>>> (2) stop in
>>>> MacroAssembler::compiler_lock_object(RegisterImpl*,RegisterImpl*,RegisterImpl*,RegisterImpl*,BiasedLockingCounters*)
>>>>
>>>>
>>>> So, I run my application in the debugger
>>>> using:
>>>>
>>>> run -server -Xcomp -Xbatch -Xss128k -XX:NewSize=256m -Xnoclassgc
>>>> -verbose:gc -classpath /scratch/wang/java_tm_7/bin/
>>>> SynchronizedCounter
>>>>
>>>> (process id 25142)
>>>> dbx: process 25142 about to exec("/scratch/wang/java_tm_7/bin/java")
>>>> dbx: program "/scratch/wang/java_tm_7/bin/java" just exec'ed
>>>> dbx: to go back to the original program use "debug $oprog"
>>>> t at 1 (l at 1) stopped in main at 0x00010d30
>>>> 0x00010d30: main       :        save     %sp, -128, %sp
>>>>
>>>> (dbx) cont
>>>> t at 2 (l at 2) signal SEGV (no mapping at the fault address) in (unknown)
>>>> at 0xfc063710
>>>> 0xfc063710:     ld       [%o0 + 4], %l0
>>>> Current function is jni_invoke_nonstatic (optimized)
>>>>  1084     JavaCalls::call(result, method, &java_args, CHECK);
>>>>
>>>> I will never get to my break point. But if I run this outside dbx,
>>>> everything works fine.
>>>>
>>>> SynchronizedCounter is a small multi-threaed java program I wrote to
>>>> test the jvm. It has two threads try to grab a lock and increment a
>>>> shared counter.
>>>> It works fine but I want to change how the jvm manages the lock, so I
>>>> want to stop the program when jvm creates a lock and acquires it.
>>>>
>>>> Thanks for any comment you may have in advance.
>>>>
>>>> Regards
>>>> James Wang
>>>>
>>>>
>>>> On Tue, Oct 7, 2008 at 10:03 PM, Jon Masamitsu <Jon.Masamitsu at sun.com>
>>>> wrote:
>>>>
>>>>>
>>>>> How do you start dbx on java?  And what is dbx saying
>>>>> exactly?
>>>>>
>>>>> Cong Wang wrote:
>>>>>
>>>>>>
>>>>>> Hi all:
>>>>>>  I am trying to modify some part of the hotspot runtime interpreter
>>>>>> and I would like to debug that using either dbx or gdb. I have compile
>>>>>> the file using the following options:
>>>>>>
>>>>>> ALT_BINARY_PLUGS_PATH=/scratch/wang/openjdk-binary-plugs
>>>>>> ALT_FREETYPE_LIB_PATH=/usr/local/lib
>>>>>> ALT_FREETYPE_HEADERS_PATH=/usr/local/include
>>>>>> ALT_CUPS_HEADERS_PATH=/scratch/wang/cups-1.3.8
>>>>>> ANT_HOME=/usr/sfw
>>>>>> ALT_OUTPUTDIR=/scratch/wang/java_tm_7
>>>>>> DEV_ONLY=true
>>>>>> DEBUG=true
>>>>>>
>>>>>>   I am not able to use dbx to debug java in the ALT_OUTPUTDIR/bin
>>>>>> directory. I would like to set a break point at
>>>>>> hotspot/src/cpu/sparc/vm/assembler_sparc.cpp
>>>>>> MacroAssembler::compiler_lock_object function. I have tried to use the
>>>>>> dbx pathmap command but it doesn't seem to help dbx to locate the
>>>>>> source file or the function definition.
>>>>>>  Any suggestions? Thanks in advance for any comment.
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>
>>
>>
>> --
>> I would remember that if researchers were not ambitious
>> probably today we haven't the technology we are using!
>>
>
>
>
> --
> Regards
> James Wang
>



-- 
I would remember that if researchers were not ambitious
probably today we haven't the technology we are using!