Additional stack unwind features are available starting with SDK 1.4.2. These features fall into three categories: Java stack unwind enhancements, Java heap support, and Java threads support.

These additional features are available as part of the Java stack unwind enhancements:

•View Java compiled frame inlined methods.

•View Java interpreted or compiled frame specific information.

•View Java interpreted or compiled frame arguments and local variables.

•Disassemble Java method bytecodes.

•Print out the Java unwind table.

These additional features are available as part of Java heap support:

•View Java heap parameters.

•Dump Java object.

•Print Java heap histogram.

•Find all the instances of a given Java class.

•Find all the references to a given object in the Java heap.

•Find out the object OOP (object-oriented pointer) of the given field address.

These additional features are available as part of Java threads support:

•View Java threads state information.

•View current Java thread information.

•View Java interpreted frame monitors information.

14.25.1.2 gdb Subcommands for Java VM Debugging

Commands for Examining Java Virtual Machine(JVM) internals

To view the gdb commands that support Java VM debugging, type help java at the gdb prompt.

(gdb) help java

Java and JVM debugging commands.

List of java subcommands:

java args -- Show the current or specified Java frame arguments info java bytecodes -- Disassemble the given Java method's bytecodes java heap-histogram -- Show the Java heap object histogram

java instances -- Find all the instances of the given klassOop in the Java heap java jvm-state -- Show Java virtual machine's current internal states

java locals -- Show the current or specified Java frame locals info java mutex-info -- Print out details of the static mutexes

java object -- Print out the given Java object's fields info

java oop -- Find the Java object oop of the given Java heap address

java references -- Find all the references to the given Java object in the Java heap java unwind-info -- Show the unwind info of the code where the given pc is located java unwind-table -- Print out the dynamically generated Java Unwind Table

Type help java followed by java subcommand name for full documentation. Command name abbreviations are allowed if unambiguous.

218 HP-UX Configuration-Specific Information