Jul 10
27
HPROF profiler
Writes class profiling information to a file or a socket, in ASCII or binary.
· Heap allocation profiling.
· Heap dump.
· CPU usage - for threads, methods.
· Monitor contention profiling.
To invoke the HPROF tool: java -agentlib:hprof ToBeProfiledClass
To print the complete list of options: java -agentlib:hprof=help
jdb
Launch a simple interactive command-line debugger.
· Display Java objects and primitive values.
· List currently running threads.
· Dump the current thread stack.
· Set breakpoints.
· Step through execution.
· Examine exceptions.
jhat
Parse a binary heap dump, launch a web browser, and present standard queries.
· Execute standard queries, for example, classes, objects, class instances, reference chains from object rootset, reachable objects, and more.
· Turn on or off object allocation tracking.
· Turn on or off object reference tracking.
· Specify objects to exclude from “reachable objects” query.
· Pass flags to the Java VM on which jhat is running.
· Develop custom queries with buit-in Object Query Language.
· Compare objects in two dumps.
jinfo
Only the following subset of the functions for the jinfo tool are available on Windows:
· Dynamically set, unset, or change the value of certain Java VM flags for a process.
jmap
Only the following subset of the functions for the jmap tool are available on Windows:
· Dump the Java heap (all objects or only live objects) of a process in binary format to a file.
· Print a histogram (all objects or only live objects) of a process.
jstack
Only the following subset of the functions for the jstack tool are available on Windows:
· Print stack traces of threads for a process
· Print information about concurrent locks for a process
