Apart from lots of small improvements to the code, libraries, tutorial, etc etc, and especially the typeclass based support in the library, these are major enhancements to be found in the next version.
1. Major refactoring of the build system to use a more or less entirely Felix independent build code, and to split lots of files, particularly C++ code, out of interscript so more programmers can feel comfortable working on the repository (even though the interscript format was actually better technically). 2. The garbage collector can now run automatically at any allocation, and supports functional code. This is done by a adding a conservative scan of the machine stacks of all threads. The gc is still world_stop naive mark/sweep non-copying style collector similar to Boehm collector except it is precise for non-stack memory, and doesn't need all the hacks and kludges for arbitrary C++ code. OTOH arbitrary mixing of C++ and Felix data types isn't possible (eg you cannot have an STL vector of Felix function closures, which Boehm would support). The stack scan will only work on machines with a single stack per thread. In particular, it will not work on IA64, which has two stacks (this can be fixed but I don't have an IA64). Felix collector should be considerably faster than Boehm because it scans much less memory, in particular it knows an array of float doesn't need scanning. It also supports variant length fixed size arrays much more efficiently (unused memory at the end of the array is never scanned). On small objects the 'precise' feature is unlikely to be a gain. Felix uses a Judy array to identify pointers into its heap. Boehm uses a hybrid with the front end using page tables. The Judy method is more general (it works with ANY allocator). It may also be much faster (since Judy is the result of years of tuning), however it does require 8 lookups on a 64 bit machine, so maybe not. The Boehm world-stop is much faster than Felix, since it uses signals where it can to stop threads, eg on Linux. Felix just hangs about waiting until all the threads do their next service call or allocation. The Ocaml collector allocates memory MUCH faster than Felix, since in many native code versions it just bumps a dedicated thread-local machine register. Felix uses malloc, which is thread safe, but wraps the higher level allocation calls in mutex too (doubling the mutices used). However the Ocaml collector does not support parallel programming (genuine multi-processing) whereas both Felix and Boehm do. Boehm also has the option of a parallelised mark (that is, the bit that scans for non-garbage by following roots). 3. A small improvement but Felix now builds with OpenMP support if available, for both gcc and MSVC++ based systems. Felix itself doesn't provide any support for openMP yet, and there may be considerable difficulty doing so because it primarily requires parallelising loops written in C style, and Felix NEVER generates any such loops and can't easily do so because they create stack scopes which prevent service calls by yields (particularly schannel I/O). Felix always uses gotos. However, the effect should be to support the experimental parallelised valarray and STL algorithms provided with the latest gcc installations. Note OpenMp schedules its own threads which is not compatible with Felix threading. HOWEVER Felix may support parallelisation by OpenMP for specific kinds of constructions such as matrix operations. (i.e. functional calculations should be easy to parallelise provided they don't allocate, or, the allocations disable world-stop checks, since the openMP thread aren't registered Felix threads). It may be possible work around that one in later versions of OpenMP or with hacks, where OpenMP is provide a pre-registered pool of Felix threads (however the current version of OpenMP doesn't allow for that AFAIK) -- John Skaller <skaller at users dot sf dot net> Felix, successor to C++: http://felix.sf.net ------------------------------------------------------------------------- SF.Net email is sponsored by: The Future of Linux Business White Paper from Novell. From the desktop to the data center, Linux is going mainstream. Let it simplify your IT future. http://altfarm.mediaplex.com/ad/ck/8857-50307-18918-4 _______________________________________________ Felix-language mailing list Felix-language@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/felix-language
