Running the heapTracker example
Hi there
I am trying to run the heapTracker example that is in the demo/jvmti directory, and I am having problems with it. When I try to run it with what it says in the readme file (java -Xbootclasspath/a:heapTracker.jar), I get the following error message:
ERROR: JNI: Cannot find heapTracker with FindClass
It seems like a small problem, but it is making me go crazy! Has anyone else ever encountered this before?
Cheers
Sajid
Which version is this? You should just need to put -agentlib:heapTracker on the command line and it will add heapTracker.jar to the boot class path itself. Also, the class name is HeapTracker and it's interesting that your version is looking for "heapTracker".
Hi
Thank you for your reply, I tried your suggestion, and it gave the following:
D:\My Documents\ >java -agentlib:HeapTracker MyClass
ERROR: JNI: Cannot find HeapTracker with FindClass
The version of java I am using is as follows:
D:\My Documents\ >java -version
java version "1.5.0_08"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_08-b03)
Java HotSpot(TM) Client VM (build 1.5.0_08-b03, mixed mode, sharing)
I tried adding heapTracker.jar to the classpath myself, but it did not make any difference.
Thank you for your time
Sajid
Worked for me with 5.0u8:java -Xbootclasspath/a:heapTracker.jar -agentpath:lib\heapTracker.dll ...
Hi
Yeah, I managed to get it to work?I move the jar file into the same directory as the dll抯卻eems a bit strange, but it worked.
A problem I am going to try and make some changes to the heaptracker, but I can not get it to compile, the errors I have listed below. It looks like I am missing a library or something, but I am not sure which. Has anyone else ever encountered a problem like this?
error LNK2019: unresolved external symbol _fatal_error referenced in function _checkJvmtiErrorheapTracker.obj
error LNK2019: unresolved external symbol _java_crw_demo@76 referenced in function _cbClassFileLoadHook@40heapTracker.obj
error LNK2019: unresolved external symbol _java_crw_demo_classname@12 referenced in function _cbClassFileLoadHook@40heapTracker.obj
error LNK2019: unresolved external symbol _stdout_message referenced in function _parse_agent_optionsheapTracker.obj
error LNK2019: unresolved external symbol _get_token referenced in function _parse_agent_optionsheapTracker.obj
Any help would be very much appreciated.
Thank You
Sajid
You seem to be missing the java_crw_demo when you are linking. There is a sample make file in the directory if that helps.
Hi, thanks for the advice, I tried it out, and it did improve the situation.
It now gives me 3 errors (down from 5), I have found that the unresolved references come from agent_util.h:
heapTracker.obj : error LNK2019: unresolved external symbol fatal_error referenc
ed in function checkJvmtiError
heapTracker.obj : error LNK2019: unresolved external symbol stdout_message refer
enced in function parse_agent_options
heapTracker.obj : error LNK2019: unresolved external symbol get_token referenced
in function parse_agent_options
heapTracker.dll : fatal error LNK1120: 3 unresolved externals
make: *** [heapTracker.dll] Error 1120
I am trying to link it to the agent_util.obj, but this is causing problems. I use the following command to make the obj file:
cl -I"c:\Program Files\java\jdk1.5.0_08\include" -I"c:\Program Files\java\jdk1.5.0_08\include\win32" -I"C:\Program Files\Microsoft Visual Studio 8\VC\include" /Foagent_util.obj /c agent_util.c
Then, when I try to make the heapTracker, it gave the following message:
agent_util.obj : fatal error LNK1112: module machine type 'X86' conflicts with t
arget machine type 'x64'
make: *** [heapTracker.dll] Error 1112
That is a very strange looking message, I tried looking for help but could not find anything.
I am doing something wrong when I try to create the agent_util.obj?
Hi, the compilation and running of unaltered code is quite simple - just cross check with the below -
if your java files are in directory 1/* ( 1/something.java , 1/something.c) then the directory in which it is located in must also have agent_util directory.
ie,
ls parent/ gives
drw-rw agent_util
drw-rw 1
...
now, this agent_util has a .c and .h file.
From 1, using the make file and having lib_java_crw.o , you should be able to compile it without problems. What I suggest is to just change the makefile a bit to fit your compiler and OS. The agent_util.o will be generated wit this. If you dont want to do this, just refer to options and flags to do the same.
with regards
Vaishak Belle
