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How to reinvoke an ocean script

ExcaIibur

I am recently encountering a challenge that an ocean script leaks memory over time. If nothing is done to deal with it, the script will eventually crash.

I want to make the script more robust in the sense that when it detects memory usage over certain boundary, it will stop the script, release the memory and start the script again.

What I have in mind is to use combination of bash and ocean. The bash script will be in an outer loop to control the execution of the ocean script. 

What I am not sure about is how the outter loop communicates with the ocean script, maybe the most stupid idea is to let the ocean script write to some intermediate file and the bash script to constantly monitor the content of that file. So, I am looking for input regarding how the outter loop can catch this 'break' in the inner loop of ocean script.

Below is the pseudo code i have in mind:

#!/bin/bash

ocean; enter ocean environment

load("ocean.ocn")

if memoryAllocated() > [some threshold]

then tell ocean.ocn to stop

exit; exit ocean environment to free leaked memory

;detect this event has occurred

ocean ; enter ocean environment again

load("ocean.ocn") ; repeat the process

  • Andrew Beckett

    In general there shouldn't be a memory leak with OCEAN, unless you are reading lots of waveform data and keeping it in variables. That said, there have been some recent improvements (in IC618/ICADVM181 ISR5) to further improve the memory usage so that when ViVA and ADE sessions are closed, we do a better job of releasing waveform-related memory. You may need to call ocnCloseSession() in your script to force that.

    However, coming back to your request, you can do this by communicating via the exit status of the OCEAN script, using the optional argument to the exit() function. For example, with this OCEAN script (I called it "bashything.ocn" even though it's not doing anything OCEAN related - this is just to illustrate it:

    printf("Hello World\n")
    exit(23)

    Then your bash script:

    #!/bin/bash

    ocean -restore bashything.ocn
    echo "STATUS IS " $?

    The script is then using $? to retrieve the exit status from the previous command. This will print the output info from ocean, and then "STATUS IS 23" afterwards...

    You can then adapt this idea to suit your needs.

    Regards,

    Andrew.

  • ExcaIibur
    in reply to Andrew Beckett

    If I want to keep this control script in ocean format as well, do you know what is the equivalent syntax to catch the exit status of a ocean script or function

  • Andrew Beckett
    in reply to ExcaIibur

    If you're using a SKILL program (OCEAN is just SKILL) to launch ocean, then you could do:

    cid=ipcBeginProcess("unset CDS_MPS_SESSION; ocean -restore bashything.ocn")
    ipcWait(cid)
    printf("EXIT STATUS IS %L\n" ipcGetExitStatus(cid))

    This blocks until the code is finished (you can't call ipcGetExitStatus until it's finished of course). Or you could use the asynchronous approach:

    procedure(MyPrintStuff(cid data)
      printf("%s" data)
    )

    procedure(MyExitHandler(cid status)
      printf("EXITED WITH STATUS: %L\n" status)
    )

    cid=ipcBeginProcess("unset CDS_MPS_SESSION; ocean -restore bashything.ocn" "" 'MyPrintStuff 'MyPrintStuff 'MyExitHandler)

    Regards,

    Andrew.

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