nnrss often hangs recent CVS Emacs

nnrss often hangs recent CVS Emacs

[Andrew A. Raines]

I switched a few days ago to Emacs 21.3.50 from 21.3.1.
Gnus seems to like the newer environment.  Things seem
much smoother and updates to the group buffer when
fetching mail and news are quicker.

nnrss, however, works intermittently.  Often when updating
a group, Emacs will hang indefinitely.  I mean _really_
hang -- if I have an external process going in the
background (like mplayer through EMMS), the track will
pause, and if I let Gnus run through its course (something
eventually times out I guess), my erc sessions get
disconnected.

I'd say about 1 out of 5 times the updates to the nnrss
groups are speedy and pleasant.  I scored my RSS groups
really low though because it's frustrating to constantly
C-g.  When I'm desperate for an update I M-g on the actual
group, which for some reason hangs less often.

I know the nnrss code is in flux right now, so if I have
to live with this issue for a while I understand; I didn't
want it to go unreported though.  Or, it could be a bug
with Emacs.  Does the newer Emacs use a different method
for fetching URLs than stable versions?

-- 
    aaraines@pobox.com (Andrew A. Raines)

Re: nnrss often hangs recent CVS Emacs

[Mark Plaksin]

"Andrew A. Raines" <aaraines@pobox.com> writes:

> I switched a few days ago to Emacs 21.3.50 from 21.3.1.
> Gnus seems to like the newer environment.  Things seem
> much smoother and updates to the group buffer when
> fetching mail and news are quicker.
>
> nnrss, however, works intermittently.  Often when updating
> a group, Emacs will hang indefinitely.  I mean _really_
> hang -- if I have an external process going in the
> background (like mplayer through EMMS), the track will
> pause, and if I let Gnus run through its course (something
> eventually times out I guess), my erc sessions get
> disconnected.

A while back I traced this problem to make-network-process.  But I'm not
sure that's the problem any more.  nnrss uses the url package which uses
make-network-process.  Unless you give it the nowait option (which the url
package doesn't), make-network-process blocks until it makes a connection
or a timeout occurs.  That seemed to explian it.

Recently I tried to reproduce the problem (by calling make-network-process
directly) and C-g always interrupted it.  So maybe the problem is gone in
the latest CVS Emacs.  I'm running on Linux; it might be a different story
on Windows.

If you happen to be using the multi-tty branch, C-g only interrupts
make-network-stream when you're in the initial Emacs window.  For some
reason it doesn't interrupt it in subsequent windows.

Re: nnrss often hangs recent CVS Emacs

[Adam Duck]

"Andrew A. Raines" <aaraines@pobox.com> writes:

> nnrss, however, works intermittently.  Often when updating
> a group, Emacs will hang indefinitely.  I mean _really_
> hang -- if I have an external process going in the
> background (like mplayer through EMMS), the track will
> pause, and if I let Gnus run through its course (something
> eventually times out I guess), my erc sessions get
> disconnected.
>
> I'd say about 1 out of 5 times the updates to the nnrss
> groups are speedy and pleasant.  I scored my RSS groups
> really low though because it's frustrating to constantly
> C-g.  When I'm desperate for an update I M-g on the actual
> group, which for some reason hangs less often.

I have a strange problem, too: whenever I make multiple rss-feeds
update and make emacs lose its focus, emacs will stay hogging all CPU
time.

Could you check for that? (because Katsumi Yamaoka can't reproduce it
but here it's reproducable every time).

bye, Adam.

Re: nnrss often hangs recent CVS Emacs

[Dan Christensen]

Adam Duck <duck@informatik.uni-frankfurt.de> writes:

> I have a strange problem, too: whenever I make multiple rss-feeds
> update and make emacs lose its focus, emacs will stay hogging all CPU
> time.

I get this too.  C-g does interrupt it, but then it goes to the next
feed and pegs the cpu again.  Let me know if I can help debug it.

Dan

-- 
Dan Christensen
jdc@uwo.ca

Re: nnrss often hangs recent CVS Emacs

[Andrew A. Raines]

Adam Duck <duck@informatik.uni-frankfurt.de> writes:

> "Andrew A. Raines" <aaraines@pobox.com> writes:
>
>> nnrss, however, works intermittently.  Often when updating a group,
>> Emacs will hang indefinitely.

[...]

> I have a strange problem, too: whenever I make multiple
> rss-feeds update and make emacs lose its focus, emacs
> will stay hogging all CPU time.
>
> Could you check for that? (because Katsumi Yamaoka can't
> reproduce it but here it's reproducable every time).

Yes, this happens to me too.  Any updating of nnrss groups
only works 10% of the time.  However, when it fails and I
hit C-g to regain control, if I immediately try an update
it will generally work.

-- 
    aaraines@pobox.com (Andrew A. Raines)

``It took me like three hours to finish the shading on
your upper lip.''
                        --Napoleon Dynamite

Re: nnrss often hangs recent CVS Emacs

[Katsumi Yamaoka]

[-- Attachment #1: Type: text/plain, Size: 865 bytes --]

>> "Andrew A. Raines" <aaraines@pobox.com> writes:
>>
>>> nnrss, however, works intermittently.  Often when updating a group,
>>> Emacs will hang indefinitely.

> Adam Duck <duck@informatik.uni-frankfurt.de> writes:

>> I have a strange problem, too: whenever I make multiple
>> rss-feeds update and make emacs lose its focus, emacs
>> will stay hogging all CPU time.

>>>>> In <87hdlpcc6r.fsf@mid.packer.its.vanderbilt.edu> Andrew A. Raines wrote:

> Yes, this happens to me too.  Any updating of nnrss groups
> only works 10% of the time.  However, when it fails and I
> hit C-g to regain control, if I immediately try an update
> it will generally work.

I found the way to reproduce the problem.  It is `g', not `M-g'.
I'm not sure but it may occur only when using the http proxy.  I
also found the way to fix it; it is to apply the following patch
to url.el.


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: Type: text/x-patch, Size: 334 bytes --]

--- url.el~	2004-11-21 22:23:54 +0000
+++ url.el	2005-01-11 06:18:59 +0000
@@ -187,7 +187,7 @@
 	;; However, raman claims that it blocks Emacs with Emacspeak
 	;; for unexplained reasons.  Put back for his benefit until
 	;; someone can understand it.
-	;; (sleep-for 0.1)
+	(sleep-for 0.1)
 	(sit-for 0.1))
       asynch-buffer)))
 

[-- Attachment #3: Type: text/plain, Size: 454 bytes --]


However, there is the unknown reason that we cannot use it in
Emacs globally.  See the comment in the url-retrieve-synchronously
function definition.

Another solution is not to use the url ELisp package.  To do
that, use the following:

(setq mm-url-use-external t)

And Gnus comes to use the wget command instead of the url ELisp
package.  Where wget is normally the default value for the
mm-url-program variable.  You can alter it to w3m, lynx, etc.

Re: nnrss often hangs recent CVS Emacs

[Adam Duck]

Katsumi Yamaoka <yamaoka@jpl.org> writes:

> I found the way to reproduce the problem.  It is `g', not `M-g'.
> I'm not sure but it may occur only when using the http proxy.  I
> also found the way to fix it; it is to apply the following patch
> to url.el.

Ah, that's very good, this fixes the bug.  Although I can't possibly
think of a _why_ this is happening -- which, sort of, explains "for
unexplained reasons"...  And you really don't see it when you mark
multiple rss-feeds and press "M-g"?  When I have only one feed to
update, I don't see it either.

But, I think I said it before: when emacs loses focus it doesn't
output this much (meaning a name of a feed stays in the minibuffer
while gnus is already updating other feeds).

> Another solution is not to use the url ELisp package.  To do
> that, use the following:
>
> (setq mm-url-use-external t)

Yes, it's faster, too.  But:

1) I don't get any output which states which feed gnus is
   updating (minor one).
2) If a feed doesn't succeed, gnus stops (bad).  Is there an option
   for this?

bye, Adam.

Re: nnrss often hangs recent CVS Emacs

[Katsumi Yamaoka]

>>>>> In <864qho9de1.fsf@oumu.localdomain> Adam Duck wrote:

> Ah, that's very good, this fixes the bug.  Although I can't possibly
> think of a _why_ this is happening -- which, sort of, explains "for
> unexplained reasons"...  And you really don't see it when you mark
> multiple rss-feeds and press "M-g"?  When I have only one feed to
> update, I don't see it either.

Hm, there's no problem when I press M-g after marking a couple
of nnrss groups.

> But, I think I said it before: when emacs loses focus it doesn't
> output this much (meaning a name of a feed stays in the minibuffer
> while gnus is already updating other feeds).

I'm inexperienced in such a phenomenon but I guess it is caused
by the timer processes (which mm-url.el uses) or the asynchronous
operations of the url ELisp package.  Unfortunately, I'm not
familiar with those any.

>> Another solution is not to use the url ELisp package.  To do
>> that, use the following:
>>
>> (setq mm-url-use-external t)

> Yes, it's faster, too.  But:

> 1) I don't get any output which states which feed gnus is
>    updating (minor one).
> 2) If a feed doesn't succeed, gnus stops (bad).  Is there an option
>    for this?

I have no idea, sorry.  Anyway, I've ticked this thread.  I'll
inform whatever I notice.

BTW, I am, so to speak, a new nnrss user and need to gain
experiences.  Now I'm trying it only in the office (behind the
proxy server), but I will have to do it in home (no proxy) as
well.

Re: nnrss often hangs recent CVS Emacs

[Andrew A. Raines]

Katsumi Yamaoka <yamaoka@jpl.org> writes:

[...]

> Another solution is not to use the url ELisp package.  To do
> that, use the following:
>
> (setq mm-url-use-external t)

Ahhhh!  This works much better (and faster)!

-- 
    aaraines@pobox.com (Andrew A. Raines)

``It took me like three hours to finish the shading on
your upper lip.''
                        --Napoleon Dynamite