49 lines
1.6 KiB
C++
49 lines
1.6 KiB
C++
// timer.h
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// Data structures to emulate a hardware timer.
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//
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// A hardware timer generates a CPU interrupt every X milliseconds.
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// This means it can be used for implementing time-slicing, or for
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// having a thread go to sleep for a specific period of time.
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//
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// We emulate a hardware timer by scheduling an interrupt to occur
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// every time stats->totalTicks has increased by TimerTicks.
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//
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// In order to introduce some randomness into time-slicing, if "doRandom"
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// is set, then the interrupt comes after a random number of ticks.
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//
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// DO NOT CHANGE -- part of the machine emulation
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//
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// Copyright (c) 1992-1993 The Regents of the University of California.
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// All rights reserved. See copyright.h for copyright notice and limitation
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// of liability and disclaimer of warranty provisions.
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#ifndef TIMER_H
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#define TIMER_H
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#include "copyright.h"
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#include "utility.h"
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// The following class defines a hardware timer.
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class Timer {
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public:
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Timer(VoidFunctionPtr timerHandler, void *callArg, bool doRandom);
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// Initialize the timer, to call the interrupt
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// handler "timerHandler" every time slice.
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~Timer() {}
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// Internal routines to the timer emulation -- DO NOT call these
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void TimerExpired(); // called internally when the hardware
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// timer generates an interrupt
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int TimeOfNextInterrupt(); // figure out when the timer will generate
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// its next interrupt
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private:
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bool randomize; // set if we need to use a random timeout delay
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VoidFunctionPtr handler; // timer interrupt handler
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void *arg; // argument to pass to interrupt handler
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};
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#endif // TIMER_H
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