bug#15946: 24.3; Mac OS X, Mavericks, distnoted process

[Jan Djärv]

Hello.

This is good to know, but others said they used Emacs downloaded from 
emacsformacosx.com, which is supposed to be unpatched.  So there might be more 
than one reason for this.

        Jan D.

27 dec 2013 kl. 06:15 skrev SB <richstyles@gmail.com>:

> Hello, I've investigated this problem since I had similar symptoms
> that correlated with everyone else's reports (quit emacs.app and
> distnoted quiets down). Also, in my case when I download the vanilla
> emacs.app from the emacs for OSX site, the problem does not appear. In
> my case, under Mavericks, this problem only occurs when I use
> Emacs.app with the inline patch applied (for more native Japanese
> input).
> 
> Emacs inline patch
> http://svn.sourceforge.jp/svnroot/macemacsjp/inline_patch/trunk/emacs-inline.patch
> 
> After investigating, it seems that the purpose of distnoted is to
> serve as a daemon to facilitate interapplication communication. In the
> case of the "inline patch", to capture the moment the IME is changed
> so that Emacs can do likewise to change language input. This is done
> by adding an observer using NSDistributedNotificationCenter and there
> is also a corresponding Core Foundation method. I didn't find any used
> of NSDistributedNotificationCenter in the official release (24.3)
> source.
> 
> https://developer.apple.com/library/mac/documentation/cocoa/reference/foundation/classes/NSDistributedNotificationCenter_Class/Reference/Reference.html
> 
> The fix was to add
> "suspensionBehavior:NSNotificationSuspensionBehaviorDeliverImmediately"
> rather than the default which was
> "NSNotificationSuspensionBehaviorCoalesce". For whatever reason,
> modifying the inline patch in this manner fixed the issue for me. This
> would be consistent with the report above that "Cmd Tabbing" seems to
> trigger it (since it would activate the suspension behavior).
> 
> Others with the same problem seem to take a sledgehammer approach of
> killing distnoted with a cronjob (which I did manually as well).
> 
> This is the patch (modified by hand so it may not apply) against emacs 24.3.
> 
> https://gist.github.com/anonymous/8142555
> 
> The modified line:
> 
>  [[NSDistributedNotificationCenter defaultCenter] addObserver: NSApp
>                    selector: @selector (changeInputMethod:)
>                           name:
> @"AppleSelectedInputSourcesChangedNotification" object: nil
> suspensionBehavior:NSNotificationSuspensionBehaviorDeliverImmediately];
> 
> Suspension Behavior
> https://developer.apple.com/library/mac/documentation/cocoa/reference/foundation/classes/NSDistributedNotificationCenter_Class/Reference/Reference.html#//apple_ref/doc/c_ref/NSNotificationSuspensionBehavior
> 
> For others who do not use the patch, there may be other applications,
> since this is most likely a bug with Mavericks itself and you may want
> to log distnoted for additional hints and grep the source of your
> emacs build to see if NSDistributedNotificationCenter is being used.
> 
> Logging Distnoted
> http://www.cocoawithlove.com/2009/02/interprocess-communication-snooping.html
> 
> Hope this helps someone.
> 
> Cheers,
> 
> Sam
> 
> On Mon, Dec 9, 2013 at 7:06 PM, Jan Djärv <jan.h.d@swipnet.se> wrote:
>> Hello.
>> 
>>> 9 dec 2013 kl. 05:38 skrev Christopher Smith <cbsmith@gmail.com>:
>>> 
>>> Donald Tillman <don <at> till.com> writes:
>>>> Hi!
>>>> 
>>>> I use Emacs on Mac OS X, Mavericks, Intel MacBook Pro, downloaded from
>>>> emacsformacosx.com.
>>>> 
>>>> Running Emacs, a process named "distnoted" starts around 1% or 2% of the
>>>> CPU, and after a while, slowly works its way up to 50% to 100% of
>>>> the CPU.  Yoiks!  Actually there appear to be 3 distnoted processes,
>>>> but only one eats up the CPU.
>>>> 
>>>> Quitting Emacs brings distnoted down to under 1% within seconds.
>>> 
>>> Just wanted to bump this up, as I've now seen this bug myself. Not sure
>>> why Emacs is causing the problem. My emacs was built from macports.
>> 
>> It is no use bumping anything that isn't reproducable. More helpful would be 
>> if those that have this can do some debugging. For example dtruss on Emacs 
>> and distnoted.
>> 
>>     Jan D.
>> 
>>