Luca's meaningless thoughts  

I've just published the git repository of my D GC implementation: CDGC. The name stands for Concurrent D Garbage Collector but right now you may call it Configurable D Garbage Collector, as there is no concurrency at all yet, but the GC is configurable via environment variables :)

It's based on the Tango (0.99.9) basic GC, there are only few changes at the moment, probably the bigger ones are:

• Runtime configurability using environment variables.
• Logging of malloc()s and collections to easily get stats about time and space consumed by the GC (option malloc_stats_file [str] and collect_stats_file [str]).
• Precise heap scanning based on the patches published in bug 3463 (option conservative [bool]).
• Runtime configurable debug features (option mem_stomp [bool] and sentinel [bool]).
• Other non user-visible cleanups.

The configuration is done via the D_GC_OPTS environment variable, and the format is:

D_GC_OPTS=opt1=value:opt2=value:bool_opt:opt3=value

Where opt1, opt2, opt3 and bool_opt are option names and value is their respective values. Boolean options can omit the value (which means true) or use a value of 0 or 1 to express false and true respectively. String options have no limitations, except they can't have the : char in their values and they have a maximum value length (255 at this moment).

At the moment is a little slower than the Tango basic GC, because the precise scanning is done very naively and a lot of calls to findPool() are done. This will change in the future.

There is a lot of work to be done (cleanup, optimization and the concurrent part :), but I'm making it public because maybe someone could want to adapt some of the ideas or follow the development.