Program execution in AS400 - IBM AS400

This is a discussion on Program execution in AS400 - IBM AS400 ; Guys, A newbie from Mainframe into the world of AS400. Though struggled for a while, i find as400 very intresting after i learnt the option of continuing the execution of any program which faces a unmonitored exception. To put it ...

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  1. Program execution in AS400

    Guys,

    A newbie from Mainframe into the world of AS400.

    Though struggled for a while, i find as400 very intresting after i
    learnt the option of continuing the execution of any program which
    faces a unmonitored exception.

    To put it in laymen's language, when i face a abend (put it soc7 or
    decimal data error) in mainframe, the execution of program is ended in
    mainframe. whereas in as400, I could observe that, when program faces
    any exception, we are always given (whenever unmonitored) the choice
    of skipping the instruction which failed resuming after the next
    instruction.

    I am just wondering how is it possible. what is the way of program
    execution. how come the job executer can continue with execution.

    As I understand, i believe, it is the TIMI architecture which is
    enabling to execute the instructions and handle them in this format.

    Can any one help me in understanding or probably help me in directing
    to the documentation which can enlighten me

  2. Re: Program execution in AS400

    cowboy007 wrote:
    > Guys,
    >
    > A newbie from Mainframe into the world of AS400.
    >
    > Though struggled for a while, i find as400 very intresting after i
    > learnt the option of continuing the execution of any program which
    > faces a unmonitored exception.
    >
    > To put it in laymen's language, when i face a abend (put it soc7 or
    > decimal data error) in mainframe, the execution of program is ended in
    > mainframe. whereas in as400, I could observe that, when program faces
    > any exception, we are always given (whenever unmonitored) the choice
    > of skipping the instruction which failed resuming after the next
    > instruction.
    >
    > I am just wondering how is it possible. what is the way of program
    > execution. how come the job executer can continue with execution.
    >
    > As I understand, i believe, it is the TIMI architecture which is
    > enabling to execute the instructions and handle them in this format.
    >
    > Can any one help me in understanding or probably help me in directing
    > to the documentation which can enlighten me


    Extensive exception management is built into the TIMI (aka MI) and into
    the OS (OS/400, aka i5/OS and now IBM i). Some info:
    http://publib.boulder.ibm.com/infoce...rzatk/excp.htm

    Chapter 9 in the ILE Concepts book describes some concepts for ILE
    programming:
    http://publib.boulder.ibm.com/infoce...s/sc415606.pdf

    Specific languages have constructs for monitoring and handling
    exceptions. For example MONMSG in CL:
    http://publib.boulder.ibm.com/infoce...ode=int_175889
    One mechanism (of several) in C is #pragma exception_handler
    ... described in Chapt 3 here:
    http://publib.boulder.ibm.com/infoce...s/sc094816.pdf

    There is probably more info online if you search.

    --
    Karl Hanson

  3. Re: Program execution in AS400

    You need to do a LOT of reading...

    Start Here:

    http://publib.boulder.ibm.com/infoce...v5r4/index.jsp

    Notice on the right side about "manuals"...

    You can also do a lot searching in the InfoCenter..

    You might also consider a non-IBM book like this one:

    http://mcpressonline.stores.yahoo.net/5070-d.html



    cowboy007 wrote:
    > Guys,
    >
    > A newbie from Mainframe into the world of AS400.
    >
    > Though struggled for a while, i find as400 very intresting after i
    > learnt the option of continuing the execution of any program which
    > faces a unmonitored exception.
    >
    > To put it in laymen's language, when i face a abend (put it soc7 or
    > decimal data error) in mainframe, the execution of program is ended in
    > mainframe. whereas in as400, I could observe that, when program faces
    > any exception, we are always given (whenever unmonitored) the choice
    > of skipping the instruction which failed resuming after the next
    > instruction.
    >
    > I am just wondering how is it possible. what is the way of program
    > execution. how come the job executer can continue with execution.
    >
    > As I understand, i believe, it is the TIMI architecture which is
    > enabling to execute the instructions and handle them in this format.
    >
    > Can any one help me in understanding or probably help me in directing
    > to the documentation which can enlighten me


  4. Re: Program execution in AS400

    On Sep 25, 12:21*pm, cowboy007 wrote:
    > Guys,
    >
    > A newbie from Mainframe into the world of AS400.
    >
    > Though struggled for a while, i find as400 very intresting after i
    > learnt the option of continuing the execution of any program which
    > faces a unmonitored exception.
    >
    > To put it in laymen's language, when i face a abend (put it soc7 or
    > decimal data error) in mainframe, the execution of program is ended in
    > mainframe. whereas in as400, I could observe that, when program faces
    > any exception, we are always given (whenever unmonitored) the choice
    > of skipping the instruction which failed resuming after the next
    > instruction.
    >
    > I am just wondering how is it possible. what is the way of program
    > execution. how come the job executer can continue with execution.


    the system has a very robust and well structured call stack. When an
    exception message is unmonitored by the call stack invocation it was
    sent to the system does not destroy the invocation and promote the
    message down the call stack like you see in Windows or I guess Unix
    programs. Maybe you can say the difference is that when a program
    sends an *escape message back to the caller, it is the system, not the
    specific programming language which is sending and receiving the
    *escape/*exception message. So the system can decide at the OS level
    what to do when the *escape message is unmonitored for.

    -Steve



  5. Re: Program execution in AS400

    Thanks a lot Pat/Steve/Karl..

    its great to see you guys taking your time out.. let me go through the
    doc's mentioned and will come back..

    thanks again.

    On Sep 26, 2:42*am, Steve Richter wrote:
    > On Sep 25, 12:21*pm, cowboy007 wrote:
    >
    >
    >
    >
    >
    > > Guys,

    >
    > > A newbie from Mainframe into the world of AS400.

    >
    > > Though struggled for a while, i find as400 very intresting after i
    > > learnt the option of continuing the execution of any program which
    > > faces a unmonitored exception.

    >
    > > To put it in laymen's language, when i face a abend (put it soc7 or
    > > decimal data error) in mainframe, the execution of program is ended in
    > > mainframe. whereas in as400, I could observe that, when program faces
    > > any exception, we are always given (whenever unmonitored) the choice
    > > of skipping the instruction which failed resuming after the next
    > > instruction.

    >
    > > I am just wondering how is it possible. what is the way of program
    > > execution. how come the job executer can continue with execution.

    >
    > the system has a very robust and well structured call stack. When an
    > exception message is unmonitored by the call stack invocation it was
    > sent to the system does not destroy the invocation and promote the
    > message down the call stack like you see in Windows or I guess Unix
    > programs. Maybe you can say the difference is that when a program
    > sends an *escape message back to the caller, it is the system, not the
    > specific programming language which is sending and receiving the
    > *escape/*exception message. So the system can decide at the OS level
    > what to do when the *escape message is unmonitored for.
    >
    > -Steve- Hide quoted text -
    >
    > - Hide quoted text -



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