"

 COPYRIGHT (c) 1996-2011 by Claus Gittinger

 New code and modifications done at SWING Research Group [1]:

 COPYRIGHT (c) 2010-2011 by Jan Vrany, Jan Kurs and Marcel Hlopko

                            SWING Research Group, Czech Technical University in Prague

 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.

 [1] Code written at SWING Research Group contains a signature

     of one of the above copright owners. For exact set of such code,

     see the differences between this version and version stx:libjava

     as of 1.9.2010

"

"{ Package: 'stx:libjava' }"

Object subclass:#JavaFinalizationRegistry

	instanceVariableNames:'activeReferees'

	classVariableNames:''

	poolDictionaries:''

	category:'Languages-Java-Support'

!

!JavaFinalizationRegistry class methodsFor:'documentation'!

copyright

"

 COPYRIGHT (c) 1996-2011 by Claus Gittinger

 New code and modifications done at SWING Research Group [1]:

 COPYRIGHT (c) 2010-2011 by Jan Vrany, Jan Kurs and Marcel Hlopko

                            SWING Research Group, Czech Technical University in Prague

 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.

 [1] Code written at SWING Research Group contains a signature

     of one of the above copright owners. For exact set of such code,

     see the differences between this version and version stx:libjava

     as of 1.9.2010

"

!

documentation

"

    A tricky class that implements Java-style finalization.

    Future versions may involve some C / VM optimization,

    if this algorithm prooves usefull

    [author:]

        Jan Vrany <jan.vrany@fit.cvut.cz>

    [instance variables:]

    [class variables:]

    [see also:]

"

! !

!JavaFinalizationRegistry class methodsFor:'instance creation'!

new

    "return an initialized instance"

    ^ self basicNew initialize.

! !

!JavaFinalizationRegistry methodsFor:'initialization'!

initialize

    "Invoked when a new instance is created."

    "/ please change as required (and remove this comment)

    activeReferees := Array new: 200.

    "/ super initialize.   -- commented since inherited method does nothing

    "Modified (comment): / 24-07-2012 / 02:05:14 / Jan Vrany <jan.vrany@fit.cvut.cz>"

! !

!JavaFinalizationRegistry methodsFor:'private'!

collectionCycle

    | referees references living wasBlocked firstPendingReference lastPendingReference|

    referees := (activeReferees collect:[:e|e notNil]) asArray.

    references := Array new: referees size.

    living := Array new: referees size.

    firstPendingReference := nil.

    ObjectMemory allObjectsIncludingContextsDo:[:o|

        | index |

        (index := self references: o anyOf: referees) ~~ 0 ifTrue:[

            o class name == #'java/lang/ref/Finalizer' ifTrue:[

                self assert: (o instVarNamed: #next) isNil.

                references at: index put: o                

            ] ifFalse:[

                living at: index put: o.

            ]

        ].

    ].

    wasBlocked := OperatingSystem blockInterrupts.

    living withIndexDo:[:each :index|

        each notNil ifTrue:[

            | ref |

            ref := references at: index.    

            references at: index put: nil.

            firstPendingReference isNil ifTrue:[

                firstPendingReference := lastPendingReference := ref

            ] ifFalse:[

                lastPendingReference instVarNamed: #'next' put: ref.

                lastPendingReference := ref.

            ].

            lastPendingReference instVarNamed: #'next' put: lastPendingReference.

        ].

    ].

    firstPendingReference notNil ifTrue:[

        (Java classForName: 'java.lang.ref.Reference') 

            instVarNamed: #pending put: firstPendingReference

        ].

    wasBlocked ifFalse:[ OperatingSystem unblockInterrupts.]

    "Created: / 24-07-2012 / 01:30:07 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

firstFreeIndex

    activeReferees withIndexDo:[:value :index|

        value isNil ifTrue:[

            ^index

        ].

    ].

    self grow.

    "Created: / 24-07-2012 / 01:19:57 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

grow

    self shouldImplement.

    "Created: / 24-07-2012 / 01:20:09 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

references: object anyOf: collection

    "If object references any object in a collection, return

     index of value which it references, zero otherwise"

    "This is naturaly a candidate for optimization, look

     at Object>>referencesAny:"

    collection withIndexDo:[:each :eachi|

        (object references: each) ifTrue:[^eachi].

    ].

    ^0

    "Created: / 24-07-2012 / 01:49:50 / Jan Vrany <jan.vrany@fit.cvut.cz>"

! !

!JavaFinalizationRegistry methodsFor:'registering objects'!

register: object

    "Register an object for being finalized"

    | index finalizedClass |

    index := self firstFreeIndex.

    activeReferees at: index put: object.

    ((finalizedClass := Java classForName:'java.lang.ref.Finalizer') methodDictionary at: #'register(Ljava/lang/Object;)V')

        valueWithReceiver: finalizedClass arguments: (Array with: object)

    "Created: / 24-07-2012 / 01:14:26 / Jan Vrany <jan.vrany@fit.cvut.cz>"

! !

!JavaFinalizationRegistry class methodsFor:'documentation'!

version_SVN

    ^ '$Id::                                                                                                                        $'

! !