[Pkg] The Trunk: System-dtl.476.mcz

commits at source.squeak.org commits at source.squeak.org
Fri Mar 30 00:45:01 UTC 2012

David T. Lewis uploaded a new version of System to project The Trunk:

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

Name: System-dtl.476
Author: dtl
Time: 29 March 2012, 8:44:19.309 pm
UUID: 6cc16423-f2ef-49e2-80b5-fabaf9fb8664
Ancestors: System-edc.475

Nil out some unreferenced slots in the special objects array. Slots 32, 33 and 34 were originally used to hold instances of Float, LargePositiveInteger and Point that could be used as prototypes for fast initialization of these objects. This usage is no longer required in any current VM, so the slots in the special objects array are set to nil and marked as available for future use.

=============== Diff against System-edc.475 ===============

Item was changed:
  ----- Method: SmalltalkImage>>recreateSpecialObjectsArray (in category 'special objects') -----
  	"Smalltalk recreateSpecialObjectsArray"
  	"To external package developers:
  	If you are writing a plugin and need additional special object(s) for your own use, 
  	use addGCRoot() function and use own, separate special objects registry "
  	"The Special Objects Array is an array of objects used by the Squeak virtual machine.
  	 Its contents are critical and accesses to it by the VM are unchecked, so don't even
  	 think of playing here unless you know what you are doing."
  	| newArray |
  	newArray := Array new: 56.
  	"Nil false and true get used throughout the interpreter"
  	newArray at: 1 put: nil.
  	newArray at: 2 put: false.
  	newArray at: 3 put: true.
  	"This association holds the active process (a ProcessScheduler)"
  	newArray at: 4 put: (self associationAt: #Processor).
  	"Numerous classes below used for type checking and instantiation"
  	newArray at: 5 put: Bitmap.
  	newArray at: 6 put: SmallInteger.
  	newArray at: 7 put: ByteString.
  	newArray at: 8 put: Array.
  	newArray at: 9 put: Smalltalk.
  	newArray at: 10 put: Float.
  	newArray at: 11 put: MethodContext.
  	newArray at: 12 put: BlockContext.
  	newArray at: 13 put: Point.
  	newArray at: 14 put: LargePositiveInteger.
  	newArray at: 15 put: Display.
  	newArray at: 16 put: Message.
  	newArray at: 17 put: CompiledMethod.
  	newArray at: 18 put: (self specialObjectsArray at: 18).
  	"(low space Semaphore)"
  	newArray at: 19 put: Semaphore.
  	newArray at: 20 put: Character.
  	newArray at: 21 put: #doesNotUnderstand:.
  	newArray at: 22 put: #cannotReturn:.
  	newArray at: 23 put: nil. "This is the process signalling low space."
  	"An array of the 32 selectors that are compiled as special bytecodes,
  	 paired alternately with the number of arguments each takes."
  	newArray at: 24 put: #(	#+ 1 #- 1 #< 1 #> 1 #<= 1 #>= 1 #= 1 #~= 1
  							#* 1 #/ 1 #\\ 1 #@ 1 #bitShift: 1 #// 1 #bitAnd: 1 #bitOr: 1
  							#at: 1 #at:put: 2 #size 0 #next 0 #nextPut: 1 #atEnd 0 #== 1 #class 0
  							#blockCopy: 1 #value 0 #value: 1 #do: 1 #new 0 #new: 1 #x 0 #y 0 ).
  	"An array of the 255 Characters in ascii order.
  	 Cog inlines table into machine code at: prim so do not regenerate it."
  	newArray at: 25 put: (self specialObjectsArray at: 25).
  	newArray at: 26 put: #mustBeBoolean.
  	newArray at: 27 put: ByteArray.
  	newArray at: 28 put: Process.
  	"An array of up to 31 classes whose instances will have compact headers"
  	newArray at: 29 put: self compactClassesArray.
+ 	newArray at: 30 put: (self specialObjectsArray at: 30). "(delay Semaphore)"
+ 	newArray at: 31 put: (self specialObjectsArray at: 31). "(user interrupt Semaphore)"
+ 	"Entries 32 - 34 unreferenced. Previously these contained prototype instances to be copied for fast initialization"
+ 	newArray at: 32 put: nil. "was (Float new: 2)"
+ 	newArray at: 33 put: nil. "was (LargePositiveInteger new: 4)"
+ 	newArray at: 34 put: nil. "was Point new"
- 	newArray at: 30 put: (self specialObjectsArray at: 30).
- 	"(delay Semaphore)"
- 	newArray at: 31 put: (self specialObjectsArray at: 31).
- 	"(user interrupt Semaphore)"
- 	"Prototype instances that can be copied for fast initialization"
- 	newArray at: 32 put: (Float new: 2).
- 	newArray at: 33 put: (LargePositiveInteger new: 4).
- 	newArray at: 34 put: Point new.
  	newArray at: 35 put: #cannotInterpret:.
  	"Note: This must be fixed once we start using context prototypes (yeah, right)"
  	"(MethodContext new: CompiledMethod fullFrameSize)."
  	newArray at: 36 put: (self specialObjectsArray at: 36). "Is the prototype MethodContext (unused by the VM)"
  	newArray at: 37 put: BlockClosure.
  	"(BlockContext new: CompiledMethod fullFrameSize)."
  	newArray at: 38 put: (self specialObjectsArray at: 38). "Is the prototype BlockContext (unused by the VM)"
  	"array of objects referred to by external code"
  	newArray at: 39 put: (self specialObjectsArray at: 39).	"preserve external semaphores"
  	newArray at: 40 put: nil. "Reserved for Mutex in Cog VMs"
  	newArray at: 41 put: nil. "Reserved for a LinkedList instance for overlapped calls in CogMT"
  	"finalization Semaphore"
  	newArray at: 42 put: ((self specialObjectsArray at: 42) ifNil: [Semaphore new]).
  	newArray at: 43 put: LargeNegativeInteger.
  	"External objects for callout.
  	 Note: Written so that one can actually completely remove the FFI."
  	newArray at: 44 put: (self at: #ExternalAddress ifAbsent: []).
  	newArray at: 45 put: (self at: #ExternalStructure ifAbsent: []).
  	newArray at: 46 put: (self at: #ExternalData ifAbsent: []).
  	newArray at: 47 put: (self at: #ExternalFunction ifAbsent: []).
  	newArray at: 48 put: (self at: #ExternalLibrary ifAbsent: []).
  	newArray at: 49 put: #aboutToReturn:through:.
  	newArray at: 50 put: #run:with:in:.
  	"51 reserved for immutability message"
  	"newArray at: 51 put: #attemptToAssign:withIndex:."
  	newArray at: 52 put: #(nil "nil => generic error" #'bad receiver'
  							#'bad argument' #'bad index'
  							#'bad number of arguments'
  							#'inappropriate operation'  #'unsupported operation'
  							#'no modification' #'insufficient object memory'
  							#'insufficient C memory' #'not found' #'bad method'
  							#'internal error in named primitive machinery'
  							#'object may move').
  	"53 to 55 are for Alien"
  	newArray at: 53 put: (self at: #Alien ifAbsent: []).
  	newArray at: 54 put: #invokeCallback:stack:registers:jmpbuf:.
  	newArray at: 55 put: (self at: #UnsafeAlien ifAbsent: []).
  	"Weak reference finalization"
  	newArray at: 56 put: (self at: #WeakFinalizationList ifAbsent: []).
  	"Now replace the interpreter's reference in one atomic operation"
  	self specialObjectsArray becomeForward: newArray

More information about the Packages mailing list