Eliot Miranda-2 wrote: > > On Fri, Dec 18, 2009 at 6:04 PM, Martin McClure > <[email protected]>wrote: > >> Stan Shepherd wrote: >> > Pharo image: Pharo | Pharo-core >> > PharoCore1.0rc1 Latest update: #10502 >> > VM: unix - i686 - linux-gnu - Pharo0.1 of 16 May 2008 [latest update: >> > #10074] >> > >> > Steps to reproduce: >> > 1.[Object allSubInstances size inspect] timeToRun 375479 (6 minutes) >> > >> > with fix >> > [Object allSubInstances size inspect] timeToRun 22335 (22 seconds) >> > >> > Attached treats Object as a special case, and takes advantage of >> primitive >> > in SystemNavigation>>allObjectsDo: >> >> It looks like with this change, Object allSubInstances would return >> instances of classes that do not inherit from Object, for instance >> objects that inherit from ProtoObject. >> >> Perhaps the special case should go on ProtoObject? Or a test could be >> made of how many subclasses a class has, and if it's over some arbitrary >> number just iterate through all objects and test each one for isKindOf:? >> Don't know how fast that would be, maybe it's not faster. But probably >> slow is preferable to incorrect. If you just want "all objects" and >> don't care about their class then you can always use >> SystemNavigation>>allObjectsDo: rather than allSubInstances. >> > > +1. > > I don't think there's any justification for this hack. It's possible to > have another root to the hierarchy apart from ProtoObject. Further, a bit > weak, but allSubInstancesDo: has ordering properties; it will evaluate the > block with all instances of a class followed by all instances of another > and > so on; it will visit all instances of any superclass before it visits any > instances of subclasses, and that could be useful. If you want to use > allObjectsDo: use it. Of course allSubInstancesDo: is slow; it makes as > many scans of the system as there are classes (Metaclass avoids the scan > by > evaluating with soleInstance). But that's not a justification for > special-casing one use of it to a freely accessible but different > alternative. > > >> Regards, >> >> -Martin >> >> _______________________________________________ >> Pharo-project mailing list >> [email protected] >> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project >> > > _______________________________________________ > Pharo-project mailing list > [email protected] > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project >
Eliot Miranda-2 wrote: > > I don't think there's any justification for this hack. > Quite so. It was late, and I'd thought better of it by morning. However, don't feel you need to spare my feelings ;) Taking a step back, Object allSubinstances size seems to be a common proxy measure for the size/bloat/complexity of an image. (E.g. http://www.object-arts.com/docs/index.html?how_many_objects.htm ). Running it on a large production system would potentially be very slow. It could also be something a current Smalltaker would run to check out Pharo, in which case a coffee break would be warranted. So from a marketing of Pharo perspective, 6 minutes seems too long to me. Yes, an experienced user will avoid it. I have no proposal as to how to catch that case while avoiding a hack. Adding a specific allSubinstances to Object class would break inheritance chain to Behavior. In the meantime, perhaps there should be an alternative simple measure available: SystemNavigation>>allObjects "A fast way to list all current objects in the image. n.b. this will include the classes ImageSegmentRootStub MessageCatcher TestCoverage DynamicBindingsInfo, and possibly others, that do not inherit from Object. These classes probably have no instances, but it is not safe to assume this" | aCollection | aCollection := OrderedCollection new. self allObjectsDo: [:x | x == aCollection ifFalse: [aCollection add: x]]. ^ aCollection with a comment in allSubInstances "for Prototype>>allSubInstances, Object>>allSubInstances,consider using SystemNavigation>>allObjects. This is much faster. see comment there" Martin McClure wrote: > > It looks like with this change, Object allSubInstances would return > instances of classes that do not inherit from Object, for instance > objects that inherit from ProtoObject. > Yes. It doesn't currently, but it could. See comment above. Martin McClure wrote: > > Or a test could be made of how many subclasses a class has, and if it's > over some arbitrarynumber just iterate through all objects and test each > one for isKindOf:? > Don't know how fast that would be, maybe it's not faster. > Yes, I looked at that: multi single pass pass Collection 18650 29448 82 subclasses, multipass 50% faster BorderedMorph 26301 7464 206 subclasses, singlepass 3x faster GRObject 113717 6969 742 subclasses, singlepass 14x faster. Breakeven point is around 100 subclasses. Mostly allSubInstances is used in housekeeping tasks, so it's not a big issue. As it's mostly used in housekeeping, a lot of the applications would probably be fine with the unordered, one pass version. I'll do a bit of digging into whether there are any meaningful performance implications. ...Stan Behavior>>allSubInstancesDoInOnePass: attached if anyone wants to benchmark http://n2.nabble.com/file/n4192013/Behavior-allSubInstancesDoInOnePass.st Behavior-allSubInstancesDoInOnePass.st -- View this message in context: http://n2.nabble.com/Issue-1634-Object-allSubInstances-slooooow-tp4189848p4192013.html Sent from the Pharo Smalltalk mailing list archive at Nabble.com. _______________________________________________ Pharo-project mailing list [email protected] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project
