Tuesday, February 15, 2011

CLOS work on trunk

Over the past few days, work has been going on with respect to our CLOS implementation again. There were a few outstanding issues - some of them rather long already.

One of such longer standing issues was the performance of object instantiation. In the CLHS there's a specific section about the validity of initialization arguments (initargs) and which ones are to be considered valid. A number of improvements have been committed to trunk:
1. The check has been generalized to support all four cases of that specific section of the CLHS.
2. The checks done during object instantiation have been a performance bottleneck ever since they were implemented; as an improvement, a cache has been implemented, speeding up object instantiation significantly: the performance has been doubled (ie the same amount of time now allows creation of twice as many objects).

On a completely different subject (within CLOS), we had an issue where instantiation of an object depending on a forward referenced class caused evaluation to be aborted, without useful feedback. While fixing this issue could have been done quickly and completely unrelated to other changes, I decided to change the behaviour of some of the functions involved according to the AMOP class finalization specification.

So we have taken some small steps on the long (and hard) road toward a performant CLOS/AMOP implementation on the JVM again!

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