RE: Killing caRepeater on Windows 10

[Freddie Akeroyd - UKRI STFC via Tech-talk <tech-talk@aps.anl.gov>]

Hi,

 

The PATH variable is actually number 6 in the list of places the windows CreateProcess() function will look for the caRepeater executable https://docs.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-createprocessa The first place is the directory of the calling executable, so it should normally launch the caRepeater.exe that is in the same directory as caget.exe   You can check this by right clicking on the caRepeater process in “process explorer” and looking at the Image tab.

 

So I just tried the caget test (windows 10, base 7.0.3.1, windows-x64-debug)  and I can see caRepeater in task manager; I had another epics 7 build elsewhere (windows-x64) and with this build I don’t see a caRepeater in task manager. So something strange is going on…

 

I had a brief look at osdProcess.c and noticed that the child process bases some of its STARTUPINFO on that of the parent and also doesn’t close the handles returned in the “processInfo” structure, not sure if any of this may prove relevant but if I can find some time I’ll take a deeper look

 

Regards,

 

Freddie

 

From: Tech-talk <tech-talk-bounces@aps.anl.gov> On Behalf Of Mark Rivers via Tech-talk
Sent: 14 January 2020 19:09
To: 'Johnson, Andrew N.' <anj@anl.gov>
Cc: tech-talk@aps.anl.gov
Subject: RE: Killing caRepeater on Windows 10

 

Ø  Have you tried manually running the caRepeater to see if it then shows up in Task Manager? For me it does appear in the output of tasklist

 

If caRepeater is run manually, and it is not already running, then it shows up in Task Manager.  This happens with all versions.  This is a console program that ties up the console until it is killed.

 

caRepeater always shows up in tasklist, no matter if is started manually or automatically.

 

Mark

 

 

From: Tech-talk <tech-talk-bounces@aps.anl.gov> On Behalf Of Johnson, Andrew N. via Tech-talk
Sent: Tuesday, January 14, 2020 11:54 AM
To: tech-talk@aps.anl.gov
Subject: Re: Killing caRepeater on Windows 10

 

Hi Mark,

My guess is that the Windows Tools package was registering its caRepeater.exe with the system somehow in the MSI installer, and this causes it to appear in the Task Manager — we have lost the knowledge of exactly what it did since both Ken Evans and Janet retired. The installer sources should still exist somewhere though; if someone wants to try to understand and support them I can look for them.

Have you tried manually running the caRepeater to see if it then shows up in Task Manager? For me it does appear in the output of tasklist. It's just a regular program which the CA Client library attempts to spawn when it needs it, and when run in the foreground a Control-C will stop it again.

I'm in the process of trying to see if I can get it to be started automatically as a Windows Service by the Services app, which is probably the best way to do this. I am copying a static-built version to a different directory, so it won't then get in the way of rebuilding Base.

- Andrew

On 1/14/20 11:42 AM, Mark Rivers via Tech-talk wrote:

I repeated the previous experiment, but this time I first cd’d to the EPICS Windows Tools directory.  In that case “where caRepeater” shows this:

 

C:\Program Files\EPICS Windows Tools>where caRepeater.exe

C:\Program Files\EPICS Windows Tools\caRepeater.exe

H:\epics\base\bin\windows-x64-static\caRepeater.exe

C:\Program Files\caQTDM\bin\windows-x64\caRepeater.exe

 

So it should be launching the versio of caRepeater from 2014, from this directory.

 

The result was the same.  Only if I run the version of caget from this directory does it show up in the Task Manager.  If I run any other version it does not show up.  So I conclude it is the version of caget, and not caRepeater that matters?

 

Mark

 

 

From: Mark Rivers
Sent: Tuesday, January 14, 2020 11:32 AM
To: Matt Newville <newville@cars.uchicago.edu>
Cc: Engbretson, Mark S. <engbretson@anl.gov>; tech-talk@aps.anl.gov
Subject: RE: Killing caRepeater on Windows 10

 

I just did an experiment with 4 different versions of caget.  For each experiment I did the following:

-          Kill the existing caRepeater task

-          Run caget

-          See if caRepeater.exe showed up in Task Manager Details tab.

 

The versions of caget I tested were

7.0.3.1

3.15.5

3.14.12.6

The version that comes with the most recent EPICS Windows Tools, caRepeater.exe dated 7/8/2014.

 

Of these only the EPICS Windows Tools version produced a caRepeater.exe that appeared in the Windows 10 Task Manager.  All of the others started caRepeater, but it was not visible in Task Manger.

 

Another question might be what version of caRepeater is actually run.  I assume this is the first one found in the PATH.

 

J:\epics\devel\dxp>where carepeater

H:\epics\base\bin\windows-x64-static\caRepeater.exe

C:\Program Files\caQTDM\bin\windows-x64\caRepeater.exe

 

H:\epics\base\bin\windows-x64-static is a soft link to base-7.0.3.1, so that should be the version of caRepeater it is running.

 

Mark

 

 

From: Matt Newville <newville@cars.uchicago.edu>
Sent: Tuesday, January 14, 2020 10:16 AM
To: Mark Rivers <rivers@cars.uchicago.edu>
Cc: Engbretson, Mark S. <engbretson@anl.gov>; tech-talk@aps.anl.gov
Subject: Re: Killing caRepeater on Windows 10

 

I do see caRepeater.exe appear in the Details tab of Task Manager on Windows 10 once a real CA connection is begun.

 

--Matt Newville

 

-- 

Complexity comes for free, Simplicity you have to work for.