Ola Lundqvist wrote:
A java profiler is a library and/or program that show how much memory your java program allocates,I currently develop jmp (http://www.khelekore.org/jmp/) a java profiler.What exactly is a java profiler? A java debugging utility?
Java profilers are written in C/C++ and compiled to shared libraries, libjmp.so for jmp. Many profilers today have a java front end, jmp does not (it uses a gtk front end).
where it allocates it. Whats java objects are currently on the heap. It also shows where your program
spends time (how much time each method take).
It is a sort of debugging utility, but not the normal one where you run your program to breakpoints...
Screenshots of jmp can be found at: http://www.khelekore.org/jmp/screenshot.html
Most other java profilers have a java front end, jmp does not. So some java debuggers and profilersjmp is C code only.
jmp is compiled by gcc.
jmp has no binary (only libjmp.so is installed).
libjmp.so should probably go into /usr/lib/ or someplace like that.
According to this it has nothing to do with java.
will show up that in a way has nothing to do with java but are libraries that are run from inside the jvm.
They also require some java headers from the jvm to compile.
Jmp works well with the jvms from sun(1.3.x, 1.4.x), blackdown (1.3.x, most probably 1.4.x) and ibm (1.3.x).jmp needs a jvm to run (java -Xrunjmp my.fine.Program). The jvm loads the library with dlopen.
But this of course makes it java-related. Does it work with any jvm or just some specific? Actually I do not think this has to be covered by the java policy.
I havent tried any other jvm. Java profilers are coded according to the jvmpi specification.
http://java.sun.com/j2se/1.4.1/docs/guide/jvmpi/jvmpi.html
The java debugger also has a similar interface but I am not aware of any debugger that does not use any java classes.
There probably exists more interfaces that use dynamic loading to do strange stuff with the jvm....
Where to this fit in?
In the normal debian policy. We just have to make sure that the java-policy excludes this possibility. I just checked and I do not think it does.
? should that not be: ... java-policy not excludes this....
Not sure, but I noted that there is no place for tools that extend the jvm with dynamic libraries...Do you think something is needed in the policy?
What about external jits? (Just In time Compilers)? probably same thing....
/robo
