Branches Come Crashing In
19 Aug 2009The release wasn't barely out the door before some branches started merging into trunk. Just like I predicted, there were a few changes ripe and waiting to land as soon as the feature freeze was listed, and so they did.
First, NotFound's auto_attrs branch landed, bringing with it a change to almost every PMC type and a major simplification to the way PMC attribute structures are managed. Also, it is the first major user of the fixed-size structure allocator I developed last month, so it's a cool test of that. My hope is that once we've given it a good exercise we can start using the allocator in a variety of other places where we need small, fixed-size structure allocations and we are able to manage the lifetimes of those structures manually. This branch represents a big algorithmic improvement and with a few cleanups, improvements, and optimizations, this could usher in some other big changes in the near future.
Closely thereafter, bacek (who I swear is some sort of magical coding robot) landed his branch to cleanup the Sub PMC and remove the Parrot_Sub structure. This brought with it another huge changeset that swept most of the repo, but provided us with some major improvements to subroutine allocation and management (not to mention some much-needed code aesthetics). Very nice.
That success out of the way, I suggested he take a look at the context_pmc2 branch and see if he could work some similar magic on the Parrot_Context structure and the new Context PMC. Less then 24 hours later he had a gigantic change committed that not only cleaned up the structure but completed the conversion and got Parrot to build! There were some segfaults in miniparrot during initialization though (trying to create the first context before all the PMC types were initialized, and things like that) so it wasn't perfect, but was quite good progress. I just committed a fix to the initialization logic, and bacek claims that he'll be able to get the branch finished by the end of the day. Magical robot indeed!
I talked with Allison last night about the pmc_sans_unionval branch which I had gotten building and passing all tests (including codingstd tests) and was ready to merge in. However, by the time I got the thumbs up and was ready to merge, the above two branches had already landed and I could no longer merge that branch cleanly. Now, the branch segfaults on one particular test (t/pmc/complex.t) because of a bad pointer in a RetContinuation PMC, which I haven't been able to track down yet. As soon as I can get that last test to STFU, I'll merge that branch in as well.
I'm hearing good news about the pluggable runcores branch and the profiling stuff from chromatic and Cotto. Not to mention the long-awaited PCC refactors that Allison has been working on. With any luck we could see both these two branches landed into trunk soon, folloed by a flurry of activity from people wanting to use and improve these new toys.
Yesterday at the #parrotskech meeting, chromatic asked what the weekly development priority should be and I suggested, knowing how many branches were poised to land, that we should focus on basic, raw stability. With a few test failures being reported here and there it seems that might not have been such a bad suggestion. Plus, as I mentioned above, there are at least three branches that could plausibly land soon, which will just increase the short-term instability. Basic program stability is a very good thing to focus on (and it gives us a good excuse to write a bunch more tests for all the fun new things).
So things are moving quickly and I hope that the rest of this release cycle stays as eventful as the first two days were. I'm also looking forward to tomorrow's Rakudo release because I've heard good things about that too.
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