Fix unlikely but possible race in `WeakValueDictionary`
It may happen that value in `valueArray` could have been already
collected by the GC but #clearDeadSlots have not yet been called.
When this happened, `#at:ifAbsentPut:` returned tombstone rather
than updating the dictionary with value from block.
This commit fixes this by checking whether `valueArray` contain
the tombstone and if so, clearing up the dead slots and restarting
the operation. HTH.
"
COPYRIGHT (c) 1996 by eXept Software AG
All Rights Reserved
This software is furnished under a license and may be used
only in accordance with the terms of that license and with the
inclusion of the above copyright notice. This software may not
be provided or otherwise made available to, or used by, any
other person. No title to or ownership of the software is
hereby transferred.
"
"{ Package: 'stx:libbasic' }"
Metaclass subclass:#PrivateMetaclass
instanceVariableNames:'owningClass'
classVariableNames:''
poolDictionaries:''
category:'Kernel-Classes'
!
!PrivateMetaclass class methodsFor:'documentation'!
copyright
"
COPYRIGHT (c) 1996 by eXept Software AG
All Rights Reserved
This software is furnished under a license and may be used
only in accordance with the terms of that license and with the
inclusion of the above copyright notice. This software may not
be provided or otherwise made available to, or used by, any
other person. No title to or ownership of the software is
hereby transferred.
"
!
documentation
"
A PrivateMetaclass is much like a regular Metaclass, but it is only visible (known)
to some owningClass (which is also true for the PrivateMetaclasses sole instance).
Its sourceCode, package and revision is forced to be the same as the owning classes'.
Therefore, privateClasses delegate some queries to their owning class.
Caution: support for private classes is an ST/X special feature.
This mechanism may not be provided by other smalltalk systems,
making your code unportable.
(However, private classes can be simulated pretty easily, using classVariables
or classInstance variables ...)
[author:]
Claus Gittinger
[see also:]
Behavior ClassDescription Class Metaclass
"
! !
!PrivateMetaclass methodsFor:'accessing'!
nameSpace
"return the nameSpace I am contained in.
For private classes, this is my owning class"
owningClass isNil ifTrue:[
^ super nameSpace
].
^ owningClass
"Created: 7.11.1996 / 13:19:18 / cg"
!
owningClass
"return my owningClass"
^ owningClass
"Created: 11.10.1996 / 16:55:43 / cg"
"Modified: 11.10.1996 / 17:35:13 / cg"
!
setOwningClass:something
"set my owningClass - this is not a public entry"
owningClass := something.
"Created: 11.10.1996 / 17:11:05 / cg"
"Modified: 11.10.1996 / 17:35:24 / cg"
!
topOwningClass
"return my outermost owningClass; that is the first non-private
class along the owner-chain."
|outerOwner|
owningClass isNil ifTrue:[^ nil].
(outerOwner := owningClass owningClass) notNil ifTrue:[
^ owningClass topOwningClass
].
^ owningClass
"Created: 3.1.1997 / 19:19:58 / cg"
"Modified: 3.1.1997 / 19:50:05 / cg"
! !
!PrivateMetaclass methodsFor:'queries'!
isBuiltInClass
^ self == PrivateMetaclass
!
package
"return my package-id"
owningClass notNil ifTrue:[
^ owningClass package
].
^ super package
"Created: 15.10.1996 / 19:45:04 / cg"
! !
!PrivateMetaclass class methodsFor:'documentation'!
version
^ '$Header: /cvs/stx/stx/libbasic/PrivateMetaclass.st,v 1.13 2004/03/05 17:53:16 cg Exp $'
!
version_SVN
^ '$Id: PrivateMetaclass.st 10761 2012-01-19 11:46:00Z vranyj1 $'
! !