>> I am working on a memory model for expandable collection in Pharo. >> Currently, OrderedCollection, Dictionary and other expandable collections >> use a internal array to store their data. My new collection library recycle >> these array instead of letting the garbage collector dispose them. I simply >> insert the arrays in an ordered collection when an array is not necessary >> anymore. And I remove one when I need one. > > Hm, is that really going to be worth the trouble?
This technique reduces the consumption of about 15% of memory. >> At the end, #add: and #remove: are performed on these polls of arrays. I >> haven’t been able to spot any problem regarding concurrency and I made no >> effort in preventing them. I have a simple global collection and each call >> site of "OrderedCollection new” can pick an element of my global collection. >> >> I have the impression that I simply need to guard the access to the global >> poll, which is basically guarding #add: #remove: and #includes: > > One of the AtomicCollections might be the right things for you? I will have a look at it. >> What is funny, is that I did not care at all about multi-threading and >> concurrency, and I have not spotted any problem so far. > > There isn’t any ‘multi-threading’ like in Java, you got a much more control > version: cooperative on the same priority, preemptive between priorities. > So, I am not surprised. And well, these operations are likely not to be > problematic when they are racy, except when the underling data structure > could get into an inconsistent state itself. The overall operations > (adding/removing/searing) are racy on the application level anyway. > > However, much more interesting would be to know what kind of benefit do you > see for such reuse? > And especially, with Spur around the corner, will it still pay off then? Or > is it an application-specific optimization? I am exploring a new design of the collection library of Pharo. Not all the (academic) ideas will be worth porting into the mainstream of Pharo. But some of them yes. Thanks for all your help guys! You’re great! Cheers, Alexandre -- _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: Alexandre Bergel http://www.bergel.eu ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;.
