[mythtv-users] ExternalRecorder - Errno 11

[Marc Rawji]

Hi Everyone,

I've been working on an external recorder for a while. It works most of the
time, but recently i've been getting new errors.

First, the sequence of calls for a successful play look like this:
StartStreaming
StopStreaming
StartStreaming

There's only a few milliseconds between the StopStreaming and the 2nd
StartStreaming, so my code allows for it and that seems to work just
fine... The StopStreaming in the logs below is probably a red herring.

My problem below is that I am getting a "Resource temporarily unavailable
(11)" when mythtv is trying to read from the stdin (the stdout of my
program with the video stream)

This seems to happen from this call:
https://github.com/MythTV/mythtv/blob/master/mythtv/libs/libmythtv/recorders/ExternalStreamHandler.cpp#L125

The STDIN stream is configured to be non blocking, so the errno 11 isn't
unexpected:
https://github.com/MythTV/mythtv/blob/master/mythtv/libs/libmythtv/recorders/ExternalStreamHandler.cpp#L343

I am not sure what to change to keep this from happening.... it fails about
50% of the time, which is annoying.

I am looking for advice on a fix, or how to troubleshoot. I am running 0.29
on Ubuntu 16.04.

Thanks!
Marc

Trimmed logs from mythbackend:
Nov 21 21:23:30  mythbackend: mythbackend[1286]: I TVRecEvent
recorders/ExternalStreamHandler.cpp:1077 (ProcessCommand)
ExternalRec(/home/recorder1/record.sh): ProcessCommand('Version?') =
'OK:1.0'
Nov 21 21:23:30 mythbackend: mythbackend[1286]: W TVRecEvent
recorders/ExternalStreamHandler.cpp:1066 (ProcessCommand)
ExternalRec(/home/recorder1/record.sh): External Recorder did not respond
to 'StopStreaming'
Nov 21 21:23:30  mythbackend: mythbackend[1286]: I TVRecEvent
recorders/ExternalStreamHandler.cpp:1077 (ProcessCommand)
ExternalRec(/home/recorder1/record.sh): ProcessCommand('StopStreaming') =
'OK:Stopped'
Nov 21 21:23:30  mythbackend: mythbackend[1286]: E TVRecEvent
recorders/ExternalStreamHandler.cpp:130 (Read) Failed to read from External
Recorder: #012#011#011#011eno: Resource temporarily unavailable (11)
Nov 21 21:23:30 everest mythbackend: mythbackend[1286]: E TVRecEvent
recorders/ExternalStreamHandler.cpp:151 (GetStatus) ExternIO::GetStatus:
already in error state: 'Failed to read from External Recorder:
#012#011#011#011eno: Resource temporarily unavailable (11)'
Nov 21 21:23:30 mythbackend: mythbackend[1286]: I TVRecEvent
recorders/ExternalStreamHandler.cpp:1014 (StopStreaming)
ExternalRec(/home/recorder1/record.sh): Streaming stopped
Nov 21 21:23:30  mythbackend: mythbackend[1286]: E ExternSH
recorders/ExternalStreamHandler.cpp:625 (run)
ExternalRec(/home/recorder1/record.sh): Failed to read from External
Recorder: Failed to read from External Recorder: #012#011#011#011eno:
Resource temporarily unavailable (11)
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