Scheduler

scheduler.c

//
//  scheduler.c
//  
//
//  Created by Chris Neitzer on 2/9/12.
//  Copyright (c) 2012 All rights reserved.
//

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

#define MAX_PROCESSES 3

// Structure for my processes
typedef struct {
	int id;
	int priority;
	int burstTime;
	int waitTime;
	int runningTime;
	char *myProcessName;
} myProcess;

// Declare three processes
myProcess *p;

// Global variables
int processIndex = 0;
int mySignal = 0;
int currentProcess;
int totalRunningTime = 0;

// Declare functions
void addProcess(int index, int priority, int burstTime, char *name);
int getCurrentProcess(myProcess *theProcess);
void processProcess(myProcess *theProcess);

// Iterators
int i = 0;
int j = 0;

// Main Program
int main() {
	
	// Allocate memory for process structs
	p = malloc(sizeof(myProcess) * MAX_PROCESSES);
	
	/*
	 * mySignal indicates that a new process has been added to the queue
	 */
	
	do {
		if ( i == 0 )
		{
			addProcess(processIndex, 1, 30, "Process One\0");
			printf("%s added!\n", p[0].myProcessName);

			mySignal = 1;
		} else if ( i == 5 )
		{
			addProcess(processIndex, 2, 40, "Process Two\0");
			printf("%s added!\n", p[1].myProcessName);

			mySignal = 1;
		} else if ( i == 10 )
		{
			addProcess(processIndex, 3, 20, "Process Three\0");
			printf("%s added!\n", p[2].myProcessName);

			mySignal = 1;
		} else {
			;
		}
		if (mySignal == 1)
		{
			currentProcess = getCurrentProcess(p);
		}
		printf("Current Process: %s\n", p[currentProcess].myProcessName);
		processProcess(p[currentProcess]);
		i++;
	} while (i < totalRunningTime);
	
	return 0;
}

void addProcess(int index, int priority, int burstTime, char *name)
{
	p[index].id = index;
	p[index].priority = priority;
	p[index].burstTime = burstTime;
	p[index].waitTime = 0;
	p[index].runningTime = 0;
	p[index].myProcessName = name;

	totalRunningTime += p[index].burstTime; /* Everytime a process is added, the total running time is increased by the burst time. */

	processIndex++;
}

int getCurrentProcess(myProcess *theProcess)
{
	int highestPriorityProcess = 0;
	int highestPriorityProcessId = 0;
	int k;
	for (k = 0; k < MAX_PROCESSES; ++k)
	{
		if (theProcess[k].priority > highestPriorityProcess)
		{
			highestPriorityProcess = theProcess[k].priority;
			highestPriorityProcessId = theProcess[k].id;
		}
	}

	mySignal = 0;
	return highestPriorityProcessId;
}

void processProcess(myProcess *theProcess)
{
	/*struct timespec tim, tim2;
	tim.tv_sec = 0;
	tim.tv_nsec = 1000000;
	
	if (&theProcess.burstTime != &theProcess.runningTime)
	{
		theProcess.runningTime++;
		nanosleep(&tim, &tim2);*/
		printf("%s is running: %d\n",theProcess.myProcessName, theProcess.runningTime);
	/*} else {
		printf("%s has ended.\n", theProcess.myProcessName);
	}*/
}