Re: [Caml-list] Channels not closed on gc?

[Philippe Wang <mail@philippewang.info>]

On Mon, May 21, 2012 at 1:57 PM, Gerd Stolpmann <info@gerd-stolpmann.de> wrote:
> Am 21.05.2012 13:23:36 schrieb(en) Lauri Alanko:
>
>> I only recently noticed that ocaml does not close open channels when they
>> are garbage collected. This is evidently intentional behavior, but it was
>> quite unexpected.
>>
>> To be clear, I do think it's bad style to rely on GC for releasing OS
>> resources, but that doesn't explain why GC shouldn't do this if the
>> programmer has failed to explicitly close the channel. And if the intention
>> were to _enforce_ good style, the channel finaliser would spout out an error
>> or warning upon detecting that the channel hasn't yet been closed, instead
>> of just silently leaking file handles like it does currently.
>>
>> It is of course trivial to "fix" this by attaching a simple finaliser, but
>> the fact that this is not done by default makes me suspect that there would
>> be something fishy with this approach. So, what's the rationale for the
>> current behavior?
>
>
> It's predictable.
>
> Closing a channel is not only about releasing OS resources. Imagine the
> channel is actually a pipe - closing it means to signal EOF, i.e. it's a way
> of notifying another program about an event. This should not happen behind
> one's back.
>
> Closing a regular file would in deed be harmless, but there is no generic
> way to identify such channels (in the OS).
>
> Gerd
>
>
>> Thanks,
>>
>>
>> Lauri

Wouldn't it be a good idea to provide both ways?
i.e., one that collects automatically, in addition to the current one
that doesn't.

-- 
Philippe Wang
   mail@philippewang.info