What's new in version 0.35.0

The following new features and notable changes since version 0.33.1 are included in this release:

Features and changes

Java dump files contain more information about waiting threads

For threads that are waiting for a class initialization lock, the Java dump output now shows the thread that is currently working to progress the initialization of the class. This thread is indicated by the new Initializing thread: <thread_name> string in the existing 3XMTHREADBLOCK line in the Java dump output. For example:

3XMTHREADBLOCK Waiting on: java/lang/J9VMInternals$ClassInitializationLock@0x00000000FFF5DC90 Owned by: <unowned> Initializing thread: "Class Initialization Thread 1"

For more information, see Threads.

New user2 event added for the -Xdump option

On operating systems other than Windows™, you can now use the user2 event for the -Xdump option. This event is triggered when the VM receives the SIGUSR2 signal.

There is a change in the SIGUSR2 signal behavior as well whereby, the process does not exit in response to this signal.

For more information, see -Xdump and Signal handling.

New -XX:[+|-]PerfTool option added

This option enables or disables the JIT support for the perf tool without affecting the existing Xjit options.

Since this option creates a file that is used by the Linux® system profiler, perf, it applies only to Linux.

For more information, see -XX:[+|-]PerfTool.

New options added to encrypt the JITServer exported metrics

You can use the -XX:JITServerMetricsSSLKey and -XX:JITServerMetricsSSLCert options to encrypt the custom metrics with TLS or SSL.

-XX:[+|-]JITServerLocalSyncCompiles enabled by default

The -XX:[+|-]JITServerLocalSyncCompiles option is now enabled in most cases. For more information, see -XX:[+|-]JITServerLocalSyncCompiles.