Whole Program Tracing in JVM

Source

1. MiniTracing (the mini-tracing branch in the Javelus)
2. PHD
   • If you only want to trace locking/unlocking events, only the concurrent-lock-hooks is sufficient.

Build

Checkout the build instructions of Javelus.

Install

1. Windows
   • Replace the built jvm.dll in your local JDK or JRE installation.
2. Linux
   • Check the script hotspot in your built directory.

Run

Method Trace

To be added.

Lock Trace

We mainly trace locking and unlocking of the following locks.

1. Monitors by the synchronized keyword.
2. Locks in the package java.util.concurrent.locks.

The following options should be assigned when starting the JVM (MiniTracing).

1. Enable MiniTracing

   -XX:+EnableMiniTracing -XX:+MiniTracingGlobalLogger -XX:+MiniTracingLockAcquire -XX:+MiniTracingLockRelease -XX:+MiniTracingObjectAlloc -XX:+MiniTracingForwardPointers

2. Disable JVM optimizations

   -XX:-TieredCompilation -XX:+UseHeavyMonitors -XX:EmitSync=5 -XX:-UseCompressedOops -XX:-UseCompressedClassPointers -XX:-DoEscapeAnalysis

3. Replace the implementation of locks in the package java.util.concurrent.locks.

   For the modified implementation, check https://bitbucket.org/txgu/phd/src/master/concurrent-lock-hooks/.

   -Xbootclasspath/p:<path-to->

Feel free to contact me if you have any problem in running this easy-to-use tracer for locks in the HotSpot JVM.