java PrintCompilation output: what's the meaning of “made not entrant” and “made zombie”

Question

When running a Java 1.6 (1.6.0_03-b05) app I\'ve added the -XX:+PrintCompilation flag. On the output for some methods, in particular some of those that I know are g

Answer 1

This is absolutely not an area of expertise for me, but I was interested and so did a bit of digging.

A couple of links you might find interesting: OpenJDK:nmethod.cpp, OpenJDK:nmethod.hpp.

A excerpt of nmethod.hpp:

// Make the nmethod non entrant. The nmethod will continue to be
// alive.  It is used when an uncommon trap happens.  Returns true
// if this thread changed the state of the nmethod or false if
// another thread performed the transition.
bool  make_not_entrant() { return make_not_entrant_or_zombie(not_entrant); }
//...

Just as a starting place.