multiple instances on one box undesirable

Hi Andrew:

I think this is a good idea, if you can write a patch for the mythfrontend
startup script, that would be even better. It's in sh, and located at
/usr/bin/mythfrontend . We'd be glad to integrate it then.

On Mon, Mar 30, 2009 at 20:23, Andrew Roazen <email address hidden> wrote:

> Public bug reported:
>
> MythTV does not restrict the number of instances of mythfrontend which
> can run simultaneously on the same box. There is no particular reason
> why one box should run multiple instances simultaneously and this can
> inadvertently lead to symptoms like the sound disappearing and
> performance degradation.
>
> The script or binary which mythfrontend runs should first check to see
> if the process already exists and refuse to continue if it does.
>
> Version installed: 0.21.0+fixes18722-0ubuntu1
> OS Description: Ubuntu 8.10 (Release: 8.10)
>
> Because MythTV is typically installed on a desktop OS, it is possible
> for users to inadvertently trigger multiple instances; some report this
> happening because of scripts associated with remote buttons. Rather than
> fix button scripts, the process should monitor itself -- unless there's
> some reason why it would be desirable for a single box to run multiple
> instances of the frontend. Again, I'm not talking about preventing
> multiple frontends running on multiple boxes, just limiting each box to
> one instance each of the frontend.
>
> ** Affects: mythtv (Ubuntu)
> Importance: Undecided
> Status: New
>
> --
> multiple instances on one box undesirable
> https://bugs.launchpad.net/bugs/352077
> You received this bug notification because you are a member of MythTV
> Ubuntu Maintainers, which is subscribed to mythtv in ubuntu.
>

--
Mario Limonciello
<email address hidden>
Sent from: Austin Texas United States.

I think fundydan's approach linked here is what I was talking about:
http://ubuntuforums.org/showpost.php?p=6305480&postcount=11

If you still require me to write the patch myself I'll do it; I'm at work and can't do it right now.

I suspect multiple instances being accidentally triggered are what's behind the number of backend crashes I've been experiencing on and off over the last few months.

On 3/31/09 7:44 AM, "Mario Limonciello" <email address hidden> wrote:

Hi Andrew:

I think this is a good idea, if you can write a patch for the mythfrontend
startup script, that would be even better. It's in sh, and located at
/usr/bin/mythfrontend . We'd be glad to integrate it then.

On Mon, Mar 30, 2009 at 20:23, Andrew Roazen <email address hidden>
wrote:

> Public bug reported:
>
> MythTV does not restrict the number of instances of mythfrontend which
> can run simultaneously on the same box. There is no particular reason
> why one box should run multiple instances simultaneously and this can
> inadvertently lead to symptoms like the sound disappearing and
> performance degradation.
>
> The script or binary which mythfrontend runs should first check to see
> if the process already exists and refuse to continue if it does.
>
> Version installed: 0.21.0+fixes18722-0ubuntu1
> OS Description: Ubuntu 8.10 (Release: 8.10)
>
> Because MythTV is typically installed on a desktop OS, it is possible
> for users to inadvertently trigger multiple instances; some report this
> happening because of scripts associated with remote buttons. Rather than
> fix button scripts, the process should monitor itself -- unless there's
> some reason why it would be desirable for a single box to run multiple
> instances of the frontend. Again, I'm not talking about preventing
> multiple frontends running on multiple boxes, just limiting each box to
> one instance each of the frontend.
>
> ** Affects: mythtv (Ubuntu)
> Importance: Undecided
> Status: New
>
> --
> multiple instances on one box undesirable
> https://bugs.launchpad.net/bugs/352077
> You received this bug notification because you are a member of MythTV
> Ubuntu Maintainers, which is subscribed to mythtv in ubuntu.
>

--
Mario Limonciello
<email address hidden>
Sent from: Austin Texas United States.

--
multiple instances on one box undesirable
https://bugs.launchpad.net/bugs/352077
You received this bug notification because you are a direct subscriber
of the bug.

I'd prefer that existing processes don't get killed, but instead if other
processes are running, just output something saying 'not starting because
...'

If you can write the patch, that would still be better. Take your time with
it when you get a chance.

On Tue, Mar 31, 2009 at 16:50, Andrew Roazen <email address hidden> wrote:

> I think fundydan's approach linked here is what I was talking about:
> http://ubuntuforums.org/showpost.php?p=6305480&postcount=11
>
> If you still require me to write the patch myself I'll do it; I'm at
> work and can't do it right now.
>
> I suspect multiple instances being accidentally triggered are what's
> behind the number of backend crashes I've been experiencing on and off
> over the last few months.
>
> On 3/31/09 7:44 AM, "Mario Limonciello" <email address hidden> wrote:
>
> Hi Andrew:
>
> I think this is a good idea, if you can write a patch for the mythfrontend
> startup script, that would be even better. It's in sh, and located at
> /usr/bin/mythfrontend . We'd be glad to integrate it then.
>
> On Mon, Mar 30, 2009 at 20:23, Andrew Roazen <email address hidden>
> wrote:
>
> > Public bug reported:
> >
> > MythTV does not restrict the number of instances of mythfrontend which
> > can run simultaneously on the same box. There is no particular reason
> > why one box should run multiple instances simultaneously and this can
> > inadvertently lead to symptoms like the sound disappearing and
> > performance degradation.
> >
> > The script or binary which mythfrontend runs should first check to see
> > if the process already exists and refuse to continue if it does.
> >
> > Version installed: 0.21.0+fixes18722-0ubuntu1
> > OS Description: Ubuntu 8.10 (Release: 8.10)
> >
> > Because MythTV is typically installed on a desktop OS, it is possible
> > for users to inadvertently trigger multiple instances; some report this
> > happening because of scripts associated with remote buttons. Rather than
> > fix button scripts, the process should monitor itself -- unless there's
> > some reason why it would be desirable for a single box to run multiple
> > instances of the frontend. Again, I'm not talking about preventing
> > multiple frontends running on multiple boxes, just limiting each box to
> > one instance each of the frontend.
> >
> > ** Affects: mythtv (Ubuntu)
> > Importance: Undecided
> > Status: New
> >
> > --
> > multiple instances on one box undesirable
> > https://bugs.launchpad.net/bugs/352077
> > You received this bug notification because you are a member of MythTV
> > Ubuntu Maintainers, which is subscribed to mythtv in ubuntu.
> >
>
>
> --
> Mario Limonciello
> <email address hidden>
> Sent from: Austin Texas United States.
>
> --
> multiple instances on one box undesirable
> https://bugs.launchpad.net/bugs/352077
> You received this bug notification because you are a direct subscriber
> of the bug.
>
> --
> multiple instances on one box undesirable
> https://bugs.launchpad.net/bugs/352077
> You received this bug notification because you are a member of MythTV
> Ubuntu Maintainers, which is subscribed to mythtv in ubuntu.
>

--
Mario Limonciello
<email address hidden>
Sent from New York, United ...

Upstream won't make a change like this without a patch. Moving to mythbuntu where it can be tracked for the script(s).

Here is a patch for this

It depends on wmctrl

--- mythfrontend.sh.orig 2009-10-06 03:54:43.000000000 -0500
+++ mythfrontend.sh 2009-10-10 22:33:30.322126832 -0500
@@ -2,6 +2,8 @@
 # Mario Limonciello, March 2007
 # partially merged with startmythtv.sh by Michael Haas, October 2007

+pidof mythfrontend.real 2>/dev/null && wmctrl -a "MythTV Frontend" 2>/dev/null && exit
+
 #source our dialog functions
 . /usr/share/mythtv/dialog_functions.sh

Thanks for the fix!

This is a significant step in the right direction albeit still not perfect.

This fix is on the trunk bzr tree, revno 215. It will be in the next upload as well as daily builds from Oct 11 and later.

This bug was fixed in the package mythtv - 0.22.0~trunk22413-0ubuntu1

---------------
mythtv (0.22.0~trunk22413-0ubuntu1) karmic; urgency=low

  [ Gary Butters ]
  * debian/control:
    - Depends on wmctrl
  * Add support to use wmctrl to bring mythfrontend to the foreground
    if already running. (LP: #352077)

  [ Mario Limonciello ]
  * New upstream snapshot (r22413)
  * Add a bug_pattern_base to the mythbuntu crashdb.
  * Fix mythbuntu crashdb to refer to project not product.
  * Simplify the apport hook so that we can catch on any set of non
    distro packages.
  * debian/rules:
    - Make *sure* /etc/default/mythtv-backend is getting installed.
      It seems that dh_installinit didn't want to install it when we use upstart.

 -- Mario Limonciello <email address hidden> Mon, 12 Oct 2009 17:13:20 -0500

I applied the patch, and my issue was recurring. I upgraded all packages, and still it recurred. Perhaps I'm experiencing a separate issue, but my fix was a simple script and to try and change all calls from mythfrontend.real to mythfrontend.real.sh.

#!/bin/bash

MYTHPID=`pidof mythfrontend.real`

echo $MYTHPID

if [ -z "$MYTHPID" ]
then
 /usr/bin/mythfrontend.real
elif [[ "$MYTHPID" =~ " " ]]
then
 echo "multiple instances running";
 kill `pidof mythfrontend.real|awk '{print $2}'`
else
 echo "There is already an instance of Mythfrontend running.";
fi

Gary Butters patch was applied in time for the -rc.

I have a genuine need to run multiple frontend processes on my computer. This worked find under 0.21, but since upgrading to 0.22 i cannot do this. I suspect this bug fix is what is preventing me from doing it. Is there a way to override this restriction?

Following up on my previous comment, i have removed the patch from my mythfrontend.sh file, but a command line switch to override this feature for those like myself who need multiple processes would be a good idea.

At the time i submitted the bug report I think I was careful to say I couldn't think of a situation where it would be desirable to have multiple frontends running on one machine. I'm intrigued as to what you're doing with multiple frontends.

On Feb 22, 2010, at 3:00 PM, Dave Pusey wrote:

> Following up on my previous comment, i have removed the patch from my
> mythfrontend.sh file, but a command line switch to override this feature
> for those like myself who need multiple processes would be a good idea.

I use two frontends when watching the Formula 1.

I have a large one for the main feed, And a smaller one without sound at the side for the onboards feed.

This is what PiP was invented for<http://en.wikipedia.org/wiki/Picture-in-picture>. Specifically. Myth even lets you switch back and forth which video/audio is outermost (like most commercial solutions).

Perhaps a preference could be added to Myth's config screens to allow multiple frontends for edge cases like yours (and have this patch check for that preference), but it should not be on by default.

On Feb 24, 2010, at 5:48 AM, Dave Pusey wrote:

I use two frontends when watching the Formula 1.

I have a large one for the main feed, And a smaller one without sound at the side for the onboards feed.

I tried PIP, but didn't won't the other feed obscuring part of the main feed.

My suggestion would be to have a command-line switch like --allow-multiple that would bypass the check if used.

I have no problem with this.

On Feb 26, 2010, at 7:09 AM, Dave Pusey wrote:

> My suggestion would be to have a command-line switch like --allow-multiple that would bypass the check if used.