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<== Date ==> <== Thread ==>

Subject: Re: deadlock in pcas 3.14.12.6-rc1
From: Bruce Hill <[email protected]>
To: "Wang Xiaoqiang (PSI)" <[email protected]>, "[email protected]" <[email protected]>
Date: Wed, 7 Dec 2016 01:45:43 -0800
Hi Xiaoqiang,
Thanks, I was able to reproduce the bug using your suggestions.
I've submitted a proposed fix on launchpad.   Please let me know if you
have a chance to try it.    My version ran all day today w/o crashing.
https://code.launchpad.net/~bhill/epics-base/pcas-deadlock-fix-3.14/+merge/312638 <https://code.launchpad.net/%7Ebhill/epics-base/pcas-deadlock-fix-3.14/+merge/312638>

Cheers,
- Bruce


On 12/6/2016 1:38 AM, Wang Xiaoqiang (PSI) wrote:
Hi Bruce,

I replied you here https://github.com/paulscherrerinstitute/pcaspy/issues/29#issuecomment-265103000

I carried out the described test procedure on a SL6 64bit Linux PC. The problem appears definitely in a few seconds.

Best
Xiaoqiang

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Bruce Hill
Sent: Dienstag, 6. Dezember 2016 04:15
To: [email protected]
Subject: Re: deadlock in pcas 3.14.12.6-rc1

Hi Xiaoqiang,
Do you have a pcaspy example that I can run to reproduce this?

I'm running pcaspy 0.6.2 currently, but could also build from a github branch if available.

Thanks,
- Bruce


On 11/10/2016 08:59 AM, Wang Xiaoqiang (PSI) wrote:
Hi,

I am testing the support of dynamic array in the recent base 3.14.12.6-rc1.
Using a normal pcaspy application, which updates ~15 Hz. It repeatedly gets into a deadlock state.

The analysis has been put up here
https://github.com/paulscherrerinstitute/pcaspy/issues/29

The solution could be reversing the lock order during
casEventSys::process. But it does not seem to be easy, because the chain of calls involved.

Best
Xiaoqiang
--
Bruce Hill
Member Technical Staff
SLAC National Accelerator Lab
2575 Sand Hill Road M/S 10
Menlo Park, CA  94025



Replies:
Re: deadlock in pcas 3.14.12.6-rc1 Wang Xiaoqiang
References:
deadlock in pcas 3.14.12.6-rc1 Wang Xiaoqiang (PSI)
Re: deadlock in pcas 3.14.12.6-rc1 Bruce Hill
RE: deadlock in pcas 3.14.12.6-rc1 Wang Xiaoqiang (PSI)

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