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

Subject: Re: Callback error from pyepics and python with GUI development
From: Tong Zhang via Tech-talk <tech-talk@aps.anl.gov>
To: Matt Newville <newville@cars.uchicago.edu>
Cc: "Chabot, Daron" <chabot@frib.msu.edu>, "tech-talk@aps.anl.gov" <tech-talk@aps.anl.gov>
Date: Fri, 12 Apr 2019 17:57:11 -0400
Hi Matt,

I was trying to craft a simple PyQt demo to reproduce the issue, but failed, since the craft demo just worked, any may not reflect the real issue, the real application is too complicated to present here. The reason we cannot simply work around this issue by using Python 3.6 or newer is that the Stretch OS (which is current deployed in our controls network) only provides the version of 3.5.3, and it is not easy to deploy a newer one. So looking forward the new release of pyepics. Thanks!

Tong

On 4/12/19 2:49 PM, Matt Newville wrote:
Hi Tong,

On Fri, Apr 12, 2019 at 12:23 PM Tong Zhang <zhangt@frib.msu.edu <mailto:zhangt@frib.msu.edu>> wrote:

    Hi Matt,

    Just tried this PR (https://github.com/pyepics/pyepics/pull/150), it
    solved my issue (probably threading race condition), thank Daron for
    the
    help!


It would be helpful to know what the issue you had actually was.  If we understood what the issue was, we might be able to make sure that was tested so it could not happen in the future.  At this point, I do not have the slightest idea what the issue is.  You have not provided any example code, even when explicitly asked to do so.  You say it is related to a GUI toolkit, but have not even said which toolkit that is.

The PR you point to maes many changes.  You say the problem is "probably thread race condition" and maybe that is correct, but did not give evidence supporting this claim.  You also say it is specific to Python 3.5.  Maybe that alleged race condition is actually a problem with some other library?

Again, please provide an example that shows the problem you are having.

--Matt


Replies:
Re: Callback error from pyepics and python with GUI development Jemian, Pete R. via Tech-talk
Re: Callback error from pyepics and python with GUI development Matt Newville via Tech-talk
References:
Re: Callback error from pyepics and python with GUI development Tong Zhang via Tech-talk

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