read_processs_output on closing network servers

read_processs_output on closing network servers

[Juanma Barranquero]

Closing a datagram server hangs up Emacs (at least on Windows), on the
call to recvfrom() on read_process_output() (process.c ~ 4799).

Now, I understand the need of calling status_notify() on closing a
server process (as any other process), but I'm not sure I understand
why status_notify() must in turn call read_process_output() while
*closing* network server processes.

Could someone please explain to me why is this necessary?

-- 
                    /L/e/k/t/u

Re: read_processs_output on closing network servers

[Kim F. Storm]

Juanma Barranquero <lekktu@gmail.com> writes:

> Closing a datagram server hangs up Emacs (at least on Windows), on the
> call to recvfrom() on read_process_output() (process.c ~ 4799).

So it never returns from the recvfrom call?

Is this actually the only time you see emacs hanging there?

I would guess that if it can hang in that case, you can device other
cases (combining more processes) that would make it hang there in case
any process changes state...

>
> Now, I understand the need of calling status_notify() on closing a
> server process (as any other process), but I'm not sure I understand
> why status_notify() must in turn call read_process_output() while
> *closing* network server processes.

In what way is the network server process closed?

I agree that using delete-process should not call read_process_output
for the deleted process.  I just installed a change to avoid that.

--
Kim F. Storm <storm@cua.dk> http://www.cua.dk

Re: read_processs_output on closing network servers

[Juanma Barranquero]

On 8/15/05, Kim F. Storm <storm@cua.dk> wrote:

> So it never returns from the recvfrom call?

That's it.

> Is this actually the only time you see emacs hanging there?

Yes.

> I would guess that if it can hang in that case, you can device other
> cases (combining more processes) that would make it hang there in case
> any process changes state...

Perhaps, but I don't know of any other case. I will report any I find,
of course.

> In what way is the network server process closed?

By calling `delete-process'.

> I agree that using delete-process should not call read_process_output
> for the deleted process.  I just installed a change to avoid that.

Yeah, thanks!

Now, if you can shed some light on the other big problem with network
processes on Windows...  :-)

-- 
                    /L/e/k/t/u