[jboss-dev-forums] [Design of JBoss Profiler] - Re: JBoss Profiler 2 in JBoss AS 4.2.2 - Does not gather any

[justinwalsh]

ok - I think I was on a wild good chase with the manifest, although I suspect it does need some tidying up.

Looking at the source for:
org.jboss.profiler.agent.Agent.redefine(Class[] clz, boolean instrument)

This method appears to the be part involved in instrumenting classes.  I assume that without instrumentation, we cannot gather stats.  Now the confusing part:

redefine is called from the same class at three points:
addClasses()
removeClasses()
setEnabled()

each of which is called from the handler.

I don't want to add and remove classes manually each time, so I'll concern  myself with the enabled method call.

Take a look at the method:public static void setEnabled(boolean e) {
  | if (isRepository()) {
  |       List<Class> l = new ArrayList<Class>();
  |       
  |       for (Class c : instrumentation.getAllLoadedClasses()) {
  |         String className = c.getName().replace(".", "/");
  |         
  |         boolean added = false;
  |         for (int i = 0; !added && i < includeList.size(); i++) {
  |           String classes = includeList.get(i);
  |           if (className.startsWith(classes)) {
  |             l.add(c);
  |             added = true;
  |           }
  |         }
  |       }
  |       
  |       Class[] clz = new Class[l.size()];
  |       for (int i = 0; i < l.size(); i++) {
  |         clz = l.get(i);
  |       }
  |       
  |       if (enabled) {
  |         redefine(clz, true);
  |       } else {
  |         redefine(clz, false);
  |       }
  |     }
  | }

Code will never be instrumented if the repository is disabled (which is the default value)
No instrumentation = no stats.

So I do the following:
configure jboss.profiler.properties with:
core=asm (javaassist doesn't seem to work)
repository=yes

Then:
1) start the application server, and run through my test case.  I need to do this to get the classes loaded by the classloader (is there a way to circumvent this?)
2) Using the jmx-console/socket client I enable the profiler.  This causes the classes which are in the classloader to be reloaded.
3) I then run my test again.
4) stopProfiler
5) getSnapshot 1

voila

One big caveat - I had to change the logic in :
private static void redefine(Class[] clz, boolean instrument)
to handle exception on a per class basis so that if loading a class fails we don't bail out of the whole operation:

  | if (clz != null) {
  |         for (Class c : clz) {
  |         	try {
  | 	          byte[] buffer = null;
  | 	          if (instrument) {
  | 	            buffer = transformer.loadInstrumented(c.getName(), c.getClassLoader());
  | 	          } else {
  | 	            buffer = transformer.loadNonInstrumented(c.getName(), c.getClassLoader());
  | 	          }
  | 	
  | 	          if (buffer != null) {
  | 	            ClassDefinition cd = new ClassDefinition(c, buffer);
  | 	            l.add(cd);
  | 	          }
  |         	}
  |         	catch (Throwable t) {
  |         		System.err.println("Failed to load [" + c.getName() + "]: " + t.getMessage());
  |         	}
  |         }
  |       }
  | 

Has anyone else had a similar experience or can shed some light on the issues?

View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4145160#4145160

Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=4145160