Experimental Physics and
Industrial Control System

Mark Rivers <[email protected]> · Mon, 30 Nov 2015 12:15:28 +0000

I also thought this might be the same problem that Tomas is referring to, but it is not, it is a different problem.

Mark

________________________________________
From: [email protected] [[email protected]] on behalf of Mazanec Tomáš [[email protected]]
Sent: Monday, November 30, 2015 4:01 AM
To: [email protected]; [email protected]; [email protected]
Subject: RE: Stream Device: infinite loop when remote closes connection

Hi Ambroz

I see a resemblance to my disconnect/reconnect problems (http://www.aps.anl.gov/epics/tech-talk/2014/msg00605.php) regarding AsynDriverInterface.cc writeHandler().
If I recall correctly, the patches were applied to synApps SVN/GIT.

Cheers,
Tomas

________________________________________
Od: [email protected] [[email protected]] za uživatele [email protected] [[email protected]]
Odesláno: 25. listopadu 2015 20:07
Komu: [email protected]; [email protected]
Předmět: Stream Device: infinite loop when remote closes connection

Hello all, Dirk,

I've found a bug in StreamDevice asynDriver code. In my case, whenever the remote TCP host closes connection, a thread in EPICS will enter an infinite loop, the connection failure will never be reported, and reconnection will never be attempted. I've tracked it down to this code in AsynDriverInterface.cc:

// now, we can write (called by asynManager)
void AsynDriverInterface::
writeHandler()
{
...
    } while (status != asynTimeout);
...

I observed that the read returns asynError and this loop continues forever. I was able to fix it by changing this line to:

    } while (status != asynTimeout && status != asynError);

Now it appears to be working correctly, the connection error is reported and reconnection works.

Best regards,
Ambroz Bizjak

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System