Move WeakSet to new finalization

[guillep]

Introduce new weakset implementations based on ephemerons

[jecisc]

The code is much simpler now :)

[jecisc]

But the bootstrap does not like it: 

Looking for module  ... loaded...computing accessor depths
warning, variable nsMethodCache doesn't exist or has already been removed
...donecreating initial Objects needed by the VM
Instance of EPRemoteWeakSet did not understand #errorNoFreeSpace
EPRemoteWeakSet(Object)>>doesNotUnderstand: #errorNoFreeSpace
EPRemoteWeakSet>>scanFor:
EPRemoteWeakSet>>like:ifAbsent:
EPInternalSymbolTable>>like:ifAbsent:
[ self like: aLocalSymbol ifAbsent: aBlock ] in EPInternalSymbolTable>>at:ifAbsent: in Block: [ self like: aLocalSymbol ifAbsent: aBlock ]
EPDictionary(Dictionary)>>at:ifAbsent:
EPInternalSymbolTable>>at:ifAbsent:
EPInternalSymbolTable(EPSymbolTable)>>at:ifAbsentPut:
[
		super at: aLocalSymbol ifAbsentPut: aBlock ] in EPInternalSymbolTable>>at:ifAbsentPut: in Block: [...
EPDictionary(Dictionary)>>at:ifAbsent:
EPInternalSymbolTable>>at:ifAbsentPut:
EPObjectSpace>>fromLocalByteSymbol:
ByteSymbol>>asLiteralInObjectSpace:
PBSpurClassLoader(PBClassLoader)>>initializeClassPool:
PBSpurClassLoader(PBClassLoader)>>loadClassNamed:
PBSpurClassLoader(PBClassLoader)>>classNamed:
PBImageBuilderSpur5064bit(PBImageBuilder50)>>classNamed:
PBImageBuilderSpur5064bit(PBImageBuilder50)>>globalNamed:
EPGlobalBinding>>readWith:inNode:
EPASTInterpreter>>visitGlobalVariableNode:
EPGlobalBinding>>acceptVisitor:node:
RBVariableNode>>acceptVisitor:
EPASTInterpreter(ASTInterpreter)>>interpret:
EPASTInterpreter>>visitMessageNode:
RBMessageNode>>acceptVisitor:
EPASTInterpreter(ASTInterpreter)>>interpret:
EPASTInterpreter>>visitAssignmentNode:
RBAssignmentNode>>acceptVisitor:
EPASTInterpreter(ASTInterpreter)>>interpret:
[ :statement|
		lastResult := self interpret: statement.
		self ifSkip: [ ^ lastResult ]] in EPASTInterpreter>>visitSequenceNode: in Block: [ :statement|...

[privat]

Will this 2 bite use with random CI failures in the future?

[guillep]

Hopefully not :)
The thing is: when a single object has many ephemeron subscriptions, only one of them is triggered per GC.
That is because when one ephemeron triggers, it becomes a normal strong object and prevents triggering the other ephemerons (for that same object).

But I'm not against alternatives!! I did this to make the test pass.
Another solution that may be more robust is to GC until the size of the collection is zero.

[ ws isEmpty ] whileFalse: [ Smalltalk garbageCollect ].

This will naturally either:

• eventually be green
• or time out for the red

[guillep]

There is a dependency against Espell that assumes the internals of WeakSets to optimise the access to symbol tables.
I'll work it around for now and open an issue.

[jecisc]

The fact that it optimize the symbol table is probably the reason why my PR to replace the symbol table by a prefix tree is breaking also :)

[jecisc]

There is a new crash in espell:

Halt
EPASTInterpreter(Object)>>halt
EPASTInterpreter>>visitThisContextNode:
ThisContextVariable>>acceptVisitor:node:
RBVariableNode>>acceptVisitor:
EPASTInterpreter(ASTInterpreter)>>interpret:
EPASTInterpreter>>visitMessageNode:
RBMessageNode>>acceptVisitor:
EPASTInterpreter(ASTInterpreter)>>interpret:
EPASTInterpreter>>visitAssignmentNode:
RBAssignmentNode>>acceptVisitor:
EPASTInterpreter(ASTInterpreter)>>interpret:
[ :statement|
		lastResult := self interpret: statement.
		self ifSkip: [ ^ lastResult ]] in EPASTInterpreter>>visitSequenceNode: in Block: [ :statement|...

[guillep]

@jecisc the cause of this PR failing now is in this line: https://github.com/guillep/espell/blob/063721d51c8a7d6f0bd80ce2f182a9e256c37850/src/Espell.package/EPRemoteWeakSet.class/instance/scanFor..st#L11

The scanFor: method assumes that symbols are raw objects in a weak array.
But this new implementation introduces ephemerons inside a normal array, so there is another indirection.
We need a new release of the bootstrap for this PR to land properly.

GitHub

espell/scanFor..st at 063721d51c8a7d6f0bd80ce2f182a9e256c37850 · guillep/espell

High-level interface of a pharo runtime. Contribute to guillep/espell development by creating an account on GitHub.