Programmering i Ruby

Den Pragmatiske Programmerers Veiledning
Forrige < Innhold ^
Neste >
modulen ObjectSpace

Indeks:

_id2ref define_finalizer each_object garbage_collect undefine_finalizer

The ObjectSpace module contains a number of routines that interact with the garbage collection facility and allow you to traverse all living objects with an iterator.

ObjectSpace also provides support for object finalizers, procs that will be called when a specific object is about to be destroyed by garbage collection. 

include ObjectSpace


a = "A"
b = "B"
c = "C"


define_finalizer(a, proc {|id| puts "Finalizer one on #{id}" })
define_finalizer(a, proc {|id| puts "Finalizer two on #{id}" })
define_finalizer(b, proc {|id| puts "Finalizer three on #{id}" })
produces: 
Finalizer three on 537763324
Finalizer one on 537763474
Finalizer two on 537763474

klassemetoder
_id2ref ObjectSpace._id2ref( anId ) -> anObject

Converts an object id to a reference to the object. May not be called on an object id passed as a parameter to a finalizer.

s = "I am a string" » "I am a string"
r = ObjectSpace._id2ref(s.id) » "I am a string"
r == s » true

define_finalizer ObjectSpace.define_finalizer( anObject, aProc=proc() )

Adds aProc as a finalizer, to be called when anObject is about to be destroyed.

each_object ObjectSpace.each_object( [ aClassOrMod ] ) {| anObj | block } -> aFixnum

Calls the block once for each living, nonimmediate object in this Ruby process. If aClassOrMod is specified, calls the block for only those classes or modules that match (or are a subclass of) aClassOrMod. Returns the number of objects found. 

a = 102.7
b = 95
ObjectSpace.each_object(Numeric) {|x| p x }
print "Total count: ", ObjectSpace.each_object {} ,"\n"
produces: 
102.7
2.718281828
3.141592654
Total count: 372

garbage_collect ObjectSpace.garbage_collect -> nil

Initiates garbage collection (see module GC on page 410).

undefine_finalizer ObjectSpace.undefine_finalizer( anObject )

Removes all finalizers for anObject.

Forrige < Innhold ^
Neste >

Extracted from the book "Programming Ruby - The Pragmatic Programmer's Guide".
Translation to norwegian by Norway Ruby User Group.
Copyright for the english original authored by David Thomas and Andrew Hunt:
Copyright © 2001 Addison Wesley Longman, Inc.
This material may be distributed only subject to the terms and conditions set forth in the Open Publication License, v1.0 or later (the latest version is presently available at
http://www.opencontent.org/openpub/).

(Please note that the license for the original has changed from the above. The above is the license of the original version that was used as a foundation for the translation efforts.)

Copyright for the norwegian translation:
Copyright © 2002 Norway Ruby User Group.
This material may be distributed only subject to the terms and conditions set forth in the Open Publication License, v1.0 or later (the latest version is presently available at
http://www.opencontent.org/openpub/).
Distribution of substantively modified versions of this document is prohibited without the explicit permission of the copyright holder.
Distribution of the work or derivative of the work in any standard (paper) book form is prohibited unless prior permission is obtained from the copyright holder.