On Aug 3, 2011, at 8:45 AM, Pat Maddox wrote:

On Aug 2, 2011, at 11:40 PM, Sean P. DeNigris wrote:

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Pat Maddox-3 wrote:

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become: swaps the two objects entirely, becomeForward: "replaces" references with the argument.

Got it, thanks. The system tests (duh) for these are really clear.

it's generally better to use becomeForward: unless you have a really good reason to use become: and it's generally better to use anything other than becomeForward: if you can. It's what dubya would call "the nukular opshin"

And you need to take care: #become can be very slow. It can (if not both objects are in the newspace of the GC) require to scan the *whole* memory. This is slow and performance degrades the more memory you use. The "fast bulk become" that is sometimes listed as a major innovation of the squeak vm is only related to becomming multiple objects: you can become a group of objects and traverse the memory only once. But as it does scan the whole memory. The sad thing is that a fast become would be really nice for many things... e.g. if you want to do highly dynamic stuff with proxies. Making objects remote, swap them, or have proxies for objects-not-yet there (futures)... But in practice #become is far too slow for these. We should change that. Marcus -- Marcus Denker -- http://marcusdenker.de