The Trunk: Collections-ul.586.mcz

Levente Uzonyi uploaded a new version of Collections to project The Trunk:
http://source.squeak.org/trunk/Collections-ul.586.mcz

==================== Summary ====================

Name: Collections-ul.586
Author: ul
Time: 27 October 2014, 12:52:51.886 am
UUID: 4c460675-3065-4b48-aa30-52ad67e15076
Ancestors: Collections-cmm.585

Symbol table changes:
- ensure that enumerations stay consistent
- avoid read-write and write-write race conditions
- added a safe #condenseNewSymbols method, which is a replacement for former unsafe methods (#shutDown: and #compactSymbolTable). It's also automatically triggered whenever there are more than 1000 NewSymbols.
- deprecated #compactSymbolTable
- updated some comments

Note that interning many symbols is a bit slower, but thread safety is more important.

=============== Diff against Collections-cmm.585 ===============

Item was changed:
  ----- Method: Symbol class>>allSymbolTablesDo: (in category 'class initialization') -----
  allSymbolTablesDo: aBlock
+
+ | originalNewSymbols originalSymbolTable |
+ originalNewSymbols := NewSymbols.
+ originalSymbolTable := SymbolTable.
+ originalNewSymbols do: aBlock.
+ originalSymbolTable do: aBlock.!
-
- NewSymbols do: aBlock.
- SymbolTable do: aBlock.!

Item was changed:
  ----- Method: Symbol class>>allSymbolTablesDo:after: (in category 'class initialization') -----
  allSymbolTablesDo: aBlock after: aSymbol
 
+ | originalNewSymbols originalSymbolTable |
+ originalNewSymbols := NewSymbols.
+ originalSymbolTable := SymbolTable.
+ (originalNewSymbols includes: aSymbol)
- (NewSymbols includes: aSymbol)
  ifTrue: [
+ originalNewSymbols do: aBlock after: aSymbol.
+ originalSymbolTable do: aBlock after: aSymbol ]
- NewSymbols do: aBlock after: aSymbol.
- SymbolTable do: aBlock after: aSymbol ]
  ifFalse: [
+ originalSymbolTable do: aBlock after: aSymbol.
+ originalNewSymbols do: aBlock after: aSymbol ]
- SymbolTable do: aBlock after: aSymbol.
- NewSymbols do: aBlock after: aSymbol ]
  !

Item was changed:
  ----- Method: Symbol class>>allSymbols (in category 'access') -----
  allSymbols
  "Answer all interned symbols"
 
+ | originalNewSymbols originalSymbolTable |
+ originalNewSymbols := NewSymbols.
+ originalSymbolTable := SymbolTable.
  ^Array
+ new: originalNewSymbols slowSize + originalSymbolTable slowSize
- new: NewSymbols slowSize + SymbolTable slowSize
  streamContents:[ :stream |
  stream
+ nextPutAll: originalNewSymbols;
+ nextPutAll: originalSymbolTable ]
- nextPutAll: NewSymbols;
- nextPutAll: SymbolTable ]
  !

Item was changed:
  ----- Method: Symbol class>>cleanUp (in category 'class initialization') -----
  cleanUp
  "Flush caches"
 
+ self condenseNewSymbols!
- self compactSymbolTable.!

Item was changed:
  ----- Method: Symbol class>>compactSymbolTable (in category 'class initialization') -----
  compactSymbolTable
  "Reduce the size of the symbol table so that it holds all existing symbols with 25% free space."
 
+ self deprecated: 'Use #condenseNewSymbols instead'.
+ self condenseNewSymbols!
- | oldSize |
- Smalltalk garbageCollect.
- oldSize := SymbolTable capacity.
- SymbolTable compact.
- ^(oldSize - SymbolTable capacity) printString, ' slot(s) reclaimed'!

Item was added:
+ ----- Method: Symbol class>>condenseNewSymbols (in category 'private') -----
+ condenseNewSymbols
+ "Move all symbols from NewSymbols to SymbolTable, and compact SymbolTable."
+
+ | originalNewSymbols originalSymbolTable newNewSymbols newSymbolTable |
+ originalNewSymbols := NewSymbols.
+ originalSymbolTable := SymbolTable.
+ newNewSymbols := WeakSet new.
+ newSymbolTable := originalSymbolTable copy
+ addAll: originalNewSymbols;
+ compact;
+ yourself.
+ originalNewSymbols == NewSymbols ifFalse: [
+ "Some other process has modified the symbols. Try again."
+ ^self condenseNewSymbols ].
+ NewSymbols := newNewSymbols.
+ SymbolTable := newSymbolTable!

Item was changed:
  ----- Method: Symbol class>>intern: (in category 'instance creation') -----
  intern: aStringOrSymbol
 
+ | originalNewSymbols |
+ originalNewSymbols := NewSymbols.
  ^(self lookup: aStringOrSymbol) ifNil:[
+ | aClass aSymbol newNewSymbols |
- | aClass aSymbol |
  aStringOrSymbol isSymbol ifTrue:[
  aSymbol := aStringOrSymbol.
  ] ifFalse:[
  aClass := aStringOrSymbol isOctetString ifTrue:[ByteSymbol] ifFalse:[WideSymbol].
  aSymbol := aClass new: aStringOrSymbol size.
  aSymbol string: aStringOrSymbol.
  ].
+ newNewSymbols := originalNewSymbols copyWith: aSymbol.
+ originalNewSymbols == NewSymbols
+ ifTrue: [
+ NewSymbols := newNewSymbols.
+ newNewSymbols size > 1000 ifTrue: [ self condenseNewSymbols ].
+ aSymbol ]
+ ifFalse: [
+ "Some other process has modified the symbols. Try again."
+ self intern: aStringOrSymbol ] ]!
- NewSymbols add: aSymbol.
- aSymbol].!

Item was changed:
  ----- Method: Symbol class>>lookup: (in category 'instance creation') -----
  lookup: aStringOrSymbol
 
+ | originalNewSymbols originalSymbolTable |
+ originalNewSymbols := NewSymbols.
+ originalSymbolTable := SymbolTable.
+ ^(originalNewSymbols like: aStringOrSymbol) ifNil: [
+ originalSymbolTable like: aStringOrSymbol ]!
- ^(SymbolTable like: aStringOrSymbol) ifNil: [
- NewSymbols like: aStringOrSymbol
- ]!

Item was changed:
  ----- Method: Symbol class>>rehash (in category 'private') -----
+ rehash
+ "Rebuild the hash table, reclaiming unreferenced Symbols. This method will intern all symbols. You're probably looking for #condenseNewSymbols instead."
- rehash "Symbol rehash"
- "Rebuild the hash table, reclaiming unreferenced Symbols."
 
+ | originalNewSymbols originalSymbolTable newNewSymbols newSymbolTable |
+ originalNewSymbols := NewSymbols.
+ originalSymbolTable := SymbolTable.
+ newNewSymbols := WeakSet new.
+ newSymbolTable := WeakSet withAll: self allSubInstances.
+ originalNewSymbols == NewSymbols ifFalse: [
+ "Some other process has modified the symbols. Try again."
+ ^self rehash ].
+ NewSymbols := newNewSymbols.
+ SymbolTable := newSymbolTable!
- SymbolTable := WeakSet withAll: self allSubInstances.
- NewSymbols := WeakSet new.!

Item was changed:
  ----- Method: Symbol class>>shutDown: (in category 'private') -----
  shutDown: aboutToQuit
 
+ self condenseNewSymbols!
- SymbolTable addAll: NewSymbols.
- NewSymbols := WeakSet new.!