Pointers in Slate.

[Michael Walter]

I guess you could have some "File openFor: block" style fun.

Cheers,
Michael


On Wed, 10 Nov 2004 15:58:40 -0500, Todd Fleming <todd at flemingcnc.com> wrote:
> Brian Rice wrote:
> 
> > About finalizers, yes. Resources should be pushed into a collection
> > whose elements are then re-initialized (mostly opened) on the next
> > startup, as well as of course being closed on shutting down.
> 
> 
> I was thinking about it a little differently. An open file does no good
> if it isn't being used by something. The closest way I know if to model
> "use" is that something is pointing to it. So, if nothing is pointing at
> an open file object, it would be nice if the GC eventually closes the file.
> 
> Example: a read stream is opened on a file. The read stream is given to
> something that uses read streams, but doesn't know that it needs to
> close the stream when it's done. Instead it just "forgets" the stream
> and the GC eventually calls a finallizer which closes the file.
> 
> There are some problems with this. Some OS's (Linux) limit how many file
> descriptors a process may have open. When the limit is reached, you
> could trigger a full GC and try again. Unfortunately, Linux also has a
> limit on how many file descriptors are open across the entire system, so
> this would mean the process doesn't play well with others. Other OS's
> (Windows) don't have an open-file limit (other than memory of course),
> but keep locks on the file until it is closed. You can use non-exclusive
> locks in Windows, but most applications use exclusive locks, so they
> would be prevented from opening a file that is still hanging around in
> Slate unused.
> 
> There are probably other external resources which don't have these
> problems and would benifit from not having to manually free them.
> 
> Todd
> 
>