东北大学数据结构实验1打印机fifo

#include "fifo.h" #include <iostream> using namespace std; fifo::fifo(int seconds_per_page):simulator(seconds_per_page){} void fifo::simulate(string file){ loadworkload(file); queue<event> waiting; queue<event> servicing; int timer = 0;//现在的时间 int service_time = workload.front().arrival_time();//打印时的时间 int sz = workload.size(); float aggregate_latency = 0; int eventNum = 0; cout<<"FIFO Simulation"<<endl; while(!workload.empty()){ for( ;eventNum < sz; timer++){ while(true){ if(!workload.empty()){ //当timer等于workload中顶端元素的wait_until时，往waiting里压入even，在屏幕上打印出这项任务到达的信息。 //判断serving是否为空，空的话压入workload顶端元素even，并打印出这项任务正在打印的信息 if(timer == workload.front().arrival_time()){ waiting.push(workload.front()); cout <<"Arriving: " <<workload.front().getjob() <<" at " << timer <<" seconds "<< endl; if(servicing.empty()){ servicing.push(workload.front()); cout <<"Servicing: " << servicing.front().getjob() << " at " << timer <<" seconds "<< endl; } workload.pop(); }else break; }else break; } if(waiting.empty()){ continue; } //判断serving是否为空，空的话，waiting弹出顶端元素。Serving压入waiting的顶端元素，并打印这项任务正在打印的信息， //并且计算aggregate_latency += service_time - waiting.front().arrival_time(); if(servicing.empty()){ waiting.pop(); servicing.push(waiting.front()); cout <<"Servicing: " << servicing.front().getjob() << " at " << timer <<" seconds "<< endl; aggregate_latency += service_time - waiting.front().arrival_time(); } //判断timer == servicing.front().getjob().getnumpages() *seconds_per_page +service_time - 1 //如果是的话，证明上一项even已经处于结束阶段，打印时间+1，并且弹出serving的顶端元素。 if(timer == servicing.front().getjob().getnumpages() * seconds_per_page + service_time - 1){ service_time = timer + 1; servicing.pop(); eventNum++; } } } cout<<endl<<"Total jobs: " << eventNum <<endl; cout<<"Aggregate latency: " <<aggregate_latency <<" seconds " <<endl; cout<<"Mean latency: "<< aggregate_latency/eventNum <<" seconds" << endl; }