Experimental Physics and
Industrial Control System

"bryan.tester--- via Tech-talk" <[email protected]> · Mon, 1 Apr 2019 13:08:25 +0000

Hi,

The work I've been doing on adPython is located here: https://github.com/dls-controls/adPython/tree/killable_workers.

As Tom mentioned it incorporates the change to how the GIL is acquired and released, in addition to significantly changing how the actual processing is done; the processArray function is now called in a python multiprocessing worker process, and the main thread waits on the result in a queue (as such if the main thread no longer gets locked up if processArray fails for some way).

May be worth checking out this version of adPython and seeing if this helps things?

Thanks,

Bryan

________________________________
From: Cobb, Tom (DLSLtd,RAL,LSCI)
Sent: 01 April 2019 13:41:46
To: Malu, Sandeep Kumar (-,RAL,CLF)
Cc: [email protected]; J. Lewis Muir; Tester, Bryan (DLSLtd,RAL,LSCI)
Subject: RE: ADpython issues with openCV

Hi Sandeep,

This sounds very similar to an issue that Lewis (copied) had. processArray() would be called, but as soon as it called an openCV function then it hung there. For Lewis, changing the datatype from Int8 to UInt8 fixed things. Lewis also had some suggestions to do with using GIL Ensure and Release rather than SaveThread and RestoreThread in https://github.com/dls-controls/adPython/pull/9 which Bryan (also copied) is looking at merging, but we weren’t convinced those were contributing to the problem.

To continue debugging, I suggest you try an IOC with a simDetector, then change the datatype to UInt8 or UInt16 and see if that works. You can also try putting a debug statement in to print the array you are passed to check what datatype it is. You could also try throwing away the array processArray() is passed, making your own, and passing that to the OpenCV library to see if that works.

Thanks,
Tom

From: Malu, Sandeep Kumar (-,RAL,CLF) <[email protected]>
Sent: 01 April 2019 12:06
To: Cobb, Tom (DLSLtd,RAL,LSCI) <[email protected]>
Subject: RE: ADpython issues with openCV

Hi Tom

Thank you for the help.

On putting debug before add(), it display message once. On checking data type with PV- CAM:cam1:DataType_RBV , it reads UInt8.

Is this I need to confirm? Where exactly I need to mention UInt8 for NDArray?

Many Thanks
Sandeep Malu

Sent from Workspace ONE Boxer

On 01-Apr-2019 3:37 PM, "Cobb, Tom (DLSLtd,RAL,LSCI)" <[email protected]<mailto:[email protected]>> wrote:
Hi Sandeep,

A couple of things to try:

•         Could you put a logging debug statement at the beginning of the processArray() function before calling add() to see if it gets there

•         Can you tell me what DataType the NDArray is? I know we’ve had problems with Int8 and OpenCV before, but UInt8 seems to work

Thanks,
Tom

From: [email protected]<mailto:[email protected]> <[email protected]<mailto:[email protected]>> On Behalf Of sandeep-kumar.malu--- via Tech-talk
Sent: 26 March 2019 12:16
To: [email protected]<mailto:[email protected]>
Subject: ADpython issues with openCV

Hi
I created an IOC using the build instruction http://controls.diamond.ac.uk/downloads/support/adPython/0-1/documentation/doxygen/build_instructions_example.html.
On using numpy in adPythonTemplate.py<http://controls.diamond.ac.uk/downloads/support/adPython/0-1/documentation/doxygen/adPythonTemplate_8py.html> , it works but same didn’t work with openCV (“Array processed” debug message in console). Also I am not able to run any of the openCV functions inside adPythonTemplate.py<http://controls.diamond.ac.uk/downloads/support/adPython/0-1/documentation/doxygen/adPythonTemplate_8py.html>.   My st.cmd looks something like this

# Prosilica driver
###########################
prosilicaConfig("$(PREFIX)CAM", $(CAMID), 50, 0)
dbLoadRecords("ADBase.template","P=$(PREFIX),R=cam1:,PORT=$(PREFIX)CAM,ADDR=0,TIMEOUT=1")
dbLoadRecords("NDFile.template","P=$(PREFIX),R=cam1:,PORT=$(PREFIX)CAM,ADDR=0,TIMEOUT=1")
#adPythonPlugin
################################
adPythonPluginConfigure("$(PREFIX)CONTOUR", "/home/malu/adPython_sample/adPythonTemplate.py", "Template", 16, 0, "$(PREFIX)CAM", 0, 50, 0,0,2097152)
dbLoadRecords("NDPluginBase.template","P=$(PREFIX),R=Contour1:, PORT=$(PREFIX)CONTOUR,ADDR=0,TIMEOUT=1,NDARRAY_PORT=$(PREFIX)CAM,NDARRAY_ADDR=0")
dbLoadRecords("$(ADPYTHON)/db/adPythonPlugin.template","P=$(PREFIX),R=Contour1:, PORT=$(PREFIX)CONTOUR, TIMEOUT=1,NDARRAY_PORT=$(PREFIX)CAM")

I am using following configurations
Areadetector - R3-2
ADpython – 1-4
Python-opencv-headless – 3.4.0
Opencv(build from source) – 3.4.0
Ubuntu – 18

Look forward to hear from you at an early date.

Many thanks
Sandeep Malu

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Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System