Alarm

This is a discussion on Alarm within the C Programming forums, part of the General Programming Boards category; plz help me out guys..i need to built a alarm in which we have to create a interrupt(or a simple ...

  1. #1
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    Alarm

    plz help me out guys..i need to built a alarm in which we have to create a interrupt(or a simple printf) after particular point of time also to take care that program in which alarm is called should not terminate before that particular point of time

  2. #2
    Deathray Engineer MacGyver's Avatar
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    Are you just supposed to have the program wait until a certain time, and then print a message? How about calling Sleep() (for Windows) or sleep() (for *nix) and then printing your message?

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    if we use sleep then the whole process will be sleeping until the particular point of time but my requirement is a timer has to run in the background without disturbing any process...

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    CSharpener vart's Avatar
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    Sleep counts time for you - so the "timer is running in the background"...
    Not whole process is sleeping - just the current thread
    And Sleep does not disturbs other processes...

    If you need the higher precision than the Sleep - you can use WaitForsingleObject on the current thread handle (in windows)

    If Sleep is not good for you - explain better what do you want to achieve...
    The first 90% of a project takes 90% of the time,
    the last 10% takes the other 90% of the time.

  5. #5
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    Code:
    Void Alarm(int time)
    {
    // code to create a interrupt
    }
    
    main()
    {
    
    //some code goes here
    
    Alarm(10);
    
    FnafterAlarm();
    
    }
    My requirement is,

    1)once the control reaches the Alarm function we have to give some i/p (time) and the alarm function have to start a timer inpendentally and the control has to come out immediately after giving i/p.

    2)if suppose the control is in FnAfterAlarm() and the timer reaches it limit then it have to create that interrupt

    3)Also program should not terminate before that interrupt by Alarm().

    b4 that i am very weak in threads....

    hope this time i am very clear abt my requirement,if it is not enough i am ready to explain better
    Last edited by kky2k; 05-29-2007 at 11:45 PM.

  6. #6
    Deathray Engineer MacGyver's Avatar
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    What O/S are you doing this for?

    Are you trying to recreate this?

    http://www.scit.wlv.ac.uk/cgi-bin/mansec?2+alarm

    If you're on Unix/Linux, you can simply fork() inside the Alarm() function and have the child sleep until the time has elapsed, and then call exit(). The parent meanwhile would return from the Alarm() function, do whatever it would like to do in other functions, and then call wait() for the child to finish. At that point the parent can terminate, too.

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    yes u r right i want to recreate that..is it possible to create that without using sleep()?

  8. #8
    CSharpener vart's Avatar
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    On windows you will need to CreateThread for this...
    The first 90% of a project takes 90% of the time,
    the last 10% takes the other 90% of the time.

  9. #9
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    hi "vart" can u explain it further...

  10. #10
    Deathray Engineer MacGyver's Avatar
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    I can't think of a better way to do it than to either fork() or create a new thread and just have the child process/thread sleep.

    Then again, maybe I just keep thinking about sleeping because I'm tired.

  11. #11
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    ok "macGyver" thanks for ur contribution...anway i am parallely googling to find the solution

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