VM Maker: VMMaker.oscog-eem.607.mcz

 
Eliot Miranda uploaded a new version of VMMaker to project VM Maker:
http://source.squeak.org/VMMaker/VMMaker.oscog-eem.607.mcz

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

Name: VMMaker.oscog-eem.607
Author: eem
Time: 4 February 2014, 3:40:08.328 pm
UUID: 9be0d8dc-ed68-4f51-becb-f83ed96185bf
Ancestors: VMMaker.oscog-eem.606

Following forwarders in Spur markAndTrace: requires a store check.

=============== Diff against VMMaker.oscog-eem.606 ===============

Item was changed:
  ----- Method: SpurMemoryManager>>markAndTrace: (in category 'gc - global') -----
  markAndTrace: objOop
  "Mark the argument, and all objects reachable from it, and any remaining objects
  on the mark stack. Follow forwarding pointers in the scan."
  <api>
  | objToScan numStrongSlots index field |
  (self markAndShouldScan: objOop) ifFalse:
  [^self].
  "if markAndTrace: is to follow and eliminate forwarding pointers
  in its scan it cannot be handed an r-value which is forwarded."
  self assert: (self isForwarded: objOop) not.
 
  "Now scan the object, and any remaining objects on the mark stack."
  objToScan := objOop.
  "To avoid overflowing the mark stack when we encounter large objects, we
  push the obj, then its numStrongSlots, and then index the object from the stack."
  [((self isImmediate: objToScan)
   or: [numStrongSlots := self numStrongSlotsOf: objToScan ephemeronInactiveIf: #inactiveOrFailedToDeferScan:.
  numStrongSlots > self traceImmediatelySlotLimit])
  ifTrue: "scanning a large object. scan until hitting an unmarked object, then switch to it, if any."
  [(self isImmediate: objToScan)
  ifTrue:
  [index := self integerValueOf: objToScan.
  objToScan := self topOfObjStack: markStack]
  ifFalse:
  [index := numStrongSlots.
  self markAndTraceClassOf: objToScan].
  [index > 0] whileTrue:
  [index := index - 1.
  field := self fetchPointer: index ofObject: objToScan.
  (self isOopForwarded: field) ifTrue:
  [field := self followForwarded: field.
+ self storePointer: index ofObject: objToScan withValue: field].
- self storePointerUnchecked: index ofObject: objToScan withValue: field].
  (self markAndShouldScan: field) ifTrue:
  [index > 0 ifTrue:
  [(self topOfObjStack: markStack) ~= objToScan ifTrue:
  [self push: objToScan onObjStack: markStack].
  self push: (self integerObjectOf: index) onObjStack: markStack].
  objToScan := field.
  index := -1]].
  index >= 0 ifTrue: "if loop terminated without finding an unmarked referent, switch to top of stack."
  [objToScan := self popObjStack: markStack.
  objToScan = objOop ifTrue:
  [objToScan := self popObjStack: markStack]]]
  ifFalse: "scanning a small object. scan, marking, pushing unmarked referents, then switch to the top of the stack."
  [index := numStrongSlots.
  self markAndTraceClassOf: objToScan.
  [index > 0] whileTrue:
  [index := index - 1.
  field := self fetchPointer: index ofObject: objToScan.
  (self isOopForwarded: field) ifTrue:
  [field := self followForwarded: field.
+ self storePointer: index ofObject: objToScan withValue: field].
- self storePointerUnchecked: index ofObject: objToScan withValue: field].
  (self markAndShouldScan: field) ifTrue:
  [self push: field onObjStack: markStack.
  numStrongSlots := self numStrongSlotsOf: field ephemeronInactiveIf: #inactiveOrFailedToDeferScan:.
  numStrongSlots > self traceImmediatelySlotLimit ifTrue:
  [self push: (self integerObjectOf: numStrongSlots) onObjStack: markStack]]].
  objToScan := self popObjStack: markStack].
  objToScan notNil] whileTrue!