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alarm.cc

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// alarm.cc
//      Routines to use a hardware timer device to provide a
//      software alarm clock.  For now, we just provide time-slicing.
//
//      Not completely implemented.
//
// Copyright (c) 1992-1996 The Regents of the University of California.
// All rights reserved.  See copyright.h for copyright notice and limitation 
// of liability and disclaimer of warranty provisions.

#include "copyright.h"
#include "alarm.h"
#include "main.h"

Alarm::Alarm(bool doRandom)
{
    timer = new Timer(doRandom, this);
}

void 
Alarm::CallBack() 
{
    Interrupt *interrupt = kernel->interrupt;
    MachineStatus status = interrupt->getStatus();
    
    if (status == IdleMode) {   
        if (!interrupt->AnyFutureInterrupts()) {
            timer->Disable();   
        }
    } else {                    
        interrupt->YieldOnReturn();
    }
}

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