How to write a profiler?

Question

i would to know how to write a profiler? What books and / or articles recommended? Can anyone help me please?

Someone has already done something like this?

Answer 1

JVMPI spec: http://java.sun.com/j2se/1.5.0/docs/guide/jvmpi/jvmpi.html

I salute your courage and bravery

EDIT: And as noted by user Boune, JVMTI: http://java.sun.com/developer/technicalArticles/Programming/jvmti/