Project Release Information
This release includes a number of enhancements and bugfixes. Highlights include a new framework for unit testing, fixes for building Jikes RVM using recent Java 6 and Java 7 host JVMs, source code cleanup, and a number of bugfixes.
This release adds a number of enhancements and bugfixes contributed by the Jikes RVM community.
This release has switched to using native threading. The default mature space collector has changed from Mark-Sweep to Immix. There are significant improvements over the performance of 3.0.1, with speedups of 10% and 21% on average for DaCapo and SPEC benchmarks respectively on an Intel C2Q. Highlights include a 29% improvement in jbb and a 32%
improvement in Jython.
This release is fully free software. It used to depend upon the proprietary (Sun) VM during the build process, but does not depend upon it any more.
This release mostly uses the GNU Classpath class libraries. JMTk (Java Memory management Tool kit) is introduced. There is support for gathering and exploiting dynamic branch probabilities for conditional and multi-way branches. Packages have been introduced in the Jikes RVM source code. A bytecode verifier was contributed. Support for the Intel cycle counter was contributed. Support for PowerPC hardware performance counters on AIX 5 has been added.
Jikes RVM (Research Virtual Machine) provides a flexible open testbed to prototype virtual machine technologies and experiment with a large variety of design alternatives. Jikes RVM runs on many platforms and advances the state-of-the-art of virtual machine technologies for dynamic compilation, adaptive optimization, garbage collection, thread scheduling, and synchronization. It is self-hosted, i.e. its Java code runs on itself without requiring a second virtual machine. Most other virtual machines for the Java platform are written in native code (typically C or C++). A Java implementation provides ease of portability and a seamless integration of virtual machine and application resources such as objects, threads, and operating-system interfaces.