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Postings from August 2013
Currently, global destruction is a (mostly) two phase: objects and then non-objects. In the first phase, objects are destroyed in random order, so any destructor had to take this into account. In many cases, that means that the destructor skips itself when global destruction is going on because it can't know if any object it depends on is still alive, this is rather unfortunate for a variety of reasons. But what if we did support reliable global destruction? How? By first doing a topological sort[1] of the object graph, and then destroying them root-up. There are some caveats there: it doesn't handle hard loops and fieldhashes are a bit tricky too (though I think that's fixable). And then there are objects created during global destruction… Still, I'm fairly certain the situation can be made a lot more sane than it currently is. I'm just not sure what the runtime cost of this would be. I can only imagine it being more than a mark-and-sweep garbage collection cycle, but then again it's only done once. Leon 1: https://en.wikipedia.org/wiki/Topological_sortThread Next