Status

Current Release

The latest release is version 0.3. As of this release, everything should work as advertised on the supported platforms. Please post to the discussion group if you have any problems.

Download Avian 0.3

Recent changes:

• Add optional support for optimizing tail calls such that the caller's stack frame is replaced with the callee's. This convention ensures proper tail recursion, suitable for languages such as Scheme.
• Add optional support for first-class, reentrant continuations. See the API documentation for details.
• Add support for native 64-bit Windows and OS X builds.
• Support building with the Microsoft Visual C++ compiler on Windows.
• Add support for scalar SSE instructions to the JIT compiler, making floating point code up to five times faster on machines which support SSE2.
• Support intrinsics in the JIT compiler, which convert performance-sensitive calls to methods such as Math.sqrt into optimized, inline code.
• Use atomic operations instead of mutexes where appropriate in the VM. This avoids expensive system calls due to mutex contention and is especially valuable for multithreaded programs which make heavy use of the JNI.
• Support runtime-visible annotations.
• Support both blocking and non-blocking NIO sockets.
• Add preliminary support for building with GNU Classpath. This feature is still under development.

Future Releases

The next major release will be 1.0. This is the remaining criterium for that release:

• Adapt Avian to support a more complete class library, such as GNU Classpath or IcedTea. This will give us a much larger body of software to test against.

Post-1.0 Ideas

• Rework memory allocation in garbage collector to improve performance in low memory situations (see here for details)
• Experiment with optimizations and extensions to better support languages other than Java
  • First-class functions
  • invokedynamic
• Support additional architectures such as ARM, Sparc, and MIPS

Non-goals

Avian is not a complete Java implementation, nor is it intended to be. Thus, less-used Java features will only be added if they are easily maintainable and do not add significant overhead to applications which don't use them.

In particular, Avian does no bytecode verification in the VM and no security checks in the class library. Applications which run untrusted bytecode must therefore do their own verification and sanitation.