[Newbies] Do I need to close a FileStream?

Kyle Hamilton aerowolf at gmail.com
Sun Mar 25 20:55:36 UTC 2007


I think that some sort of diagnostic code printed out whenever an
object's finalization routine must change the internal state of the
object such that the criteria for finalization can be met would be a
good thing.

i.e., if a FileStream is holding a file open, the finalization code
should check to see that the file is closed.  If it is not, it should
warn about changing that state during the finalization.

Any finalization-related diagnostics should be treated the same way
that other languages call "leaks", and quashed, regardless.

-Kyle H

On 3/25/07, Bert Freudenberg <bert at freudenbergs.de> wrote:
>
> On Mar 24, 2007, at 17:41 , Tim Johnson wrote:
>
> >
> > On Mar 24, 2007, at 3:45 AM, Kyle Hamilton wrote:
> >
> >> The underlying OS has only a certain number of file handles that it
> >> can maintain open at a time.  On UNIX-like systems, there is also
> >> possibly a maximum number of files per process.  If this limit is
> >> hit,
> >> then no additional files can be opened, and on any attempt to do
> >> so an
> >> error is returned.
> >
> > For some reason I was confused and thought that Squeak's garbage
> > collector would somehow make me immune from this.  Like when the
> > file was no longer being used, it would be closed and purged.
>
> Actually it is indeed. We use finalization for this [*]. However, you
> cannot know _when_ an object actually will be finalized, so you may
> be eating up handles nontheless.
>
> > Now I know otherwise :)
>
> It's good practice not to rely on finalization, but treat it as a
> safety net.
>
> - Bert -
>
> [*] See for example
> http://www.mail-archive.com/beginners@lists.squeakfoundation.org/
> msg01719.html
> or
> http://www.google.com/search?q=squeak+finalization
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>


-- 

-Kyle H


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