[mythtv-users] mythbackend leaking file descriptors/sockets?

[Michael T. Dean]

On 08/27/2009 12:12 PM, Joel wrote:
> Michael T. Dean wrote:
>> Mixing "Internet" (Schedules Direct or XMLTV) listings and EIT on the 
>> same channel is not supported.  If you enable EIT on a channel for 
>> which you have Internet listings, the EIT will stomp all over the 
>> data, breaking duplicate matching and possibly more (including 
>> scheduling).  In the future, we may have a "safe update" approach 
>> that allows mixing them, but we don't now.
>
> Maybe we're talking about something different then.  When I select 
> SchedulesDirect as my listings grabber in mythtv-setup, an options 
> called "Perform EIT Scan" shows up.  It appears as a sub-option, only 
> visible when SchedulesDirect is selected.  If this option were somehow 
> incompatible with having SchedulesDirect selected, it's in entirely 
> the wrong place in the UI, and also completely invisible at any time 
> it might otherwise be useful, if it is at all useful.  Under what 
> context should the Perform EIT Scan option be checked if 
> SchedulesDirect is used?  If the answer is "never", then why is it there?

The "on the same channel" portion of my comment is the important 
distinction.  Note that it's quite possible that you may have a video 
source for which you wish to use Schedules Direct.  However, some, for 
example, small-time channel in the area may not provide its listings to 
TMS/Schedules Direct; therefore, you may choose to enable EIT on the 
specific channel for which you have no listings data from Schedules Direct.

The Video Sources "Perform EIT scan" setting /allows/ you to use EIT on 
the video source.  However, each channel within that source also has a 
setting, "Use on air guide," which you enable or disable to specify 
whether to use EIT for that particular channel.  (Note that it defaults 
to true, so you'll need to disable it for all channels for which you're 
using Schedules Direct to retrieve listings.)

Therefore, since many fewer users actually have video sources where they 
need to use SD/XMLTV on some channel and EIT on others, Myth is designed 
to allow easy configuration for using EIT on some or none of the 
channels (and takes more work for the "corner case" of using different 
ones on different channels within the source).  If you want to use EIT 
for all channels, simply enable the "Perform EIT Scan" setting and, 
since the channels all default to true for "Use on air guide," EIT will 
be used on all channels.  If you want to use SD/XMLTV on all channels, 
simply disable the "Perform EIT Scan" setting and, even though the 
channels default to true for "Use on air guide," EIT will not be used on 
the channel in the video source since EIT is not allowed on the video 
source.

> Also, if EIT scanning and SchedulesDirect data are incompatible, wy 
> doesn't the EIT scanner to a check to see if SchedulesDirect data 
> exists, and if so, exit?

Patches welcomed.  :)  (Though, really, the time would probably be 
better spent working on a proper fix for 
http://svn.mythtv.org/trac/ticket/1770 .  If interested, you should 
mention your proposed changes (or ask for design recommendations) on the 
-dev list as a couple of the developers already have an idea of how it 
should be implemented.)

>   The failure mode of leaking file descriptors at a rate that breaks 
> the backend in two days seems an odd choice.

That's unrelated to the mixing of EIT and SD--however, the lack of 
support for mixing means you won't lose anything (and will actually gain 
a better-working system) by disabling EIT.

Mike