Question about Finalize & SuppressFinalize

[Barry Anderberg]

I've been doing some reading about Finalize and garbage collection.
I've learned that finalizing should be avoided because objects that
have a finalize method require 2 (possibly more) itterations of the
garbage collector to run before the memory is returned to the heap.
The first time the GC runs the Finalize method is called, then the
second time the memory is actually freed.

The problem is that most of the major classes in the .NET framework
have a Finalize method.

The System.Windows. Forms.Control and System.Windows. Forms.Form classes
BOTH have finalize methods.

Am I to understand that I should always call GC.SuppressFina lize after
creating these objects?

Otherwise from what I have read it will take two or MORE garbage
collection cycles to free the memory!!

This seems wrong. Why would MS do this? I don't think they would
which makes me think there's some part of the picture I don't get.

Help!

[Mattias Sjögren]

Re: Question about Finalize & SuppressFinaliz e

Barry,

You should also read up on the Dispose method pattern and the
IDisposable interface. Disposable classes typically call
SuppressFinaliz e when Dispose is called. You generally shouldn't call
SuppressFinaliz e for objects other than your own.

Forms are disposed when closed, and they ensure that all constrols on
the form are disposed as well.



Mattias

--
Mattias Sjögren [MVP] mattias @ mvps.org
http://www.msjogren.net/dotnet/ | http://www.dotnetinterop.com
Please reply only to the newsgroup.

[Chris Lyon [MSFT]]

RE: Question about Finalize & SuppressFinaliz e

Hi Barry

Most of the classes in the .NET Framework that have finalizers also implement the IDisposable interface, and inside the Dispose method is a call to GC.SuppressFina lize. As a
user, you should not be calling SuppressFinaliz e on Framework classes, you just need to properly use the Dispose pattern.

More infor ont he Dispose pattern:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpgenref/html/cpconfinalizedispose.asp

Hope that helps
-Chris


--------------------[color=blue]
>From: banderbe@yahoo. com (Barry Anderberg)
>Newsgroups: microsoft.publi c.dotnet.genera l
>Subject: Question about Finalize & SuppressFinaliz e
>Date: 10 May 2004 13:19:35 -0700
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>
>I've been doing some reading about Finalize and garbage collection.
>I've learned that finalizing should be avoided because objects that
>have a finalize method require 2 (possibly more) itterations of the
>garbage collector to run before the memory is returned to the heap.
>The first time the GC runs the Finalize method is called, then the
>second time the memory is actually freed.
>
>The problem is that most of the major classes in the .NET framework
>have a Finalize method.
>
>The System.Windows. Forms.Control and System.Windows. Forms.Form classes
>BOTH have finalize methods.
>
>Am I to understand that I should always call GC.SuppressFina lize after
>creating these objects?
>
>Otherwise from what I have read it will take two or MORE garbage
>collection cycles to free the memory!!
>
>This seems wrong. Why would MS do this? I don't think they would
>which makes me think there's some part of the picture I don't get.
>
>Help!
>[/color]


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