fifo.cpp

数据结构ssd5 op2

/*
 * @author:	魏	政
 * @ID:		063420
 */
#include "fifo.h"
//constructor
fifo::fifo(int seconds_per_page):simulator(seconds_per_page) {}

void fifo::simulate(string file)
{
	int time = 0;		//take count of time
	queue<event> waiting;	//define queue waiting
	loadworkload(file);		//read the file
	int size = workload.size(); //the size of load job
	double total = 0;		//total time
	int nextprinttime = workload.front().arrival_time();

	cout << "FIFO Simulation " << endl << endl;

	for(time = 0;; time++)
	{ 
		//if workload is not empty and current time equal to the job's arrival time
		while(!workload.empty() && time == workload.front().arrival_time())
		{
			waiting.push(workload.front());		//put the job into waiting queue
			cout << "      Arriving: " << workload.front().getjob() 
				<< " at " << time << " seconds" << endl;
			workload.pop();	//delete the frist job of workload
		}
		//wating is not empty then print the waiting job
		if(!waiting.empty())
		{
			//if not busy then do the waiting job
			if(time == nextprinttime)
			{
				cout<< "      Servicing: " << waiting.front().getjob()
					<< " at " << time << " seconds " << endl;
				total += time - waiting.front().arrival_time();
				nextprinttime += waiting.front().getjob().getnumpages()*seconds_per_page;
				waiting.pop();
			}
		}   
		if(workload.empty() && waiting.empty())	break;
	}

	cout << endl;
	cout << "      Total jobs: "<< size << endl;
	cout << "      Aggregate latency: " << total << " seconds" << endl;
	cout << "      Mean latency: " << total/size << " seconds" << endl;
	
}