Java实现进程调度算法(二) RR(时间片轮转)

rr类（主类）

只有calc()中涉及了算法，init()和printresult()都只有简单的输入输出操作。

  1 package xqy.algorithm;
  2 
  3 import java.util.*;
  4 
  5 import xqy.util.tools;
  6 import xqy.been.process;
  7 
  8 /**
  9  * @author xqy
 10  * @date 2018年12月19日19:14:49
 11  */
 12 public class rr {
 13     private int processnumber;
 14     private arraylist<process> processlist;
 15     private int timeslice;
 16     
 17     public rr() {
 18         init();
 19         calc();
 20         tools.printresult(processlist);
 21     }
 22 
 23     private void init() {
 24         scanner sc = new scanner(system.in);
 25 
 26         system.out.print("<rr> please enter the slice time:");
 27         timeslice = sc.nextint();
 28         system.out.print("<rr> please enter the process num:");
 29         processnumber = sc.nextint();
 30 
 31         processlist = new arraylist<process>();
 32         for (int i = 0; i < processnumber; i++) {
 33             processlist.add(new process());
 34         }
 35 
 36         system.out.println("<rr> please enter each process arrival time:");
 37         for (int i = 0; i < processnumber; i++) {
 38             system.out.print("    process" + (i + 1) + ":");
 39             processlist.get(i).setarrivaltime(sc.nextint());
 40         }
 41 
 42         system.out.println("<rr> please enter each process service time:");
 43         for (int i = 0; i < processnumber; i++) {
 44             system.out.print("    process" + (i + 1) + ":");
 45             int servicestime = sc.nextint();
 46             system.out.println();
 47             
 48             processlist.get(i).setservicestime(servicestime);
 49             processlist.get(i).setremainservicetime(servicestime);
 50         }
 51     }
 52 
 53     private void calc() {
 54         int timenow = 0;
 55         int processremain = processnumber;
 56         process opprocess;
 57         
 58         while (processremain != 0) {
 59             for (int i = 0; i < processnumber; i++) {
 60                 opprocess = processlist.get(i);
 61                 
 62                 if (opprocess.getremainservicetime() > 0) {                    
 63                     // first time
 64                     if (opprocess.getservicestime() == opprocess.getremainservicetime()) {
 65                         int waittime = timenow - opprocess.getarrivaltime();
 66                         
 67                         opprocess.setstarttime(timenow);
 68                         opprocess.setwaittime(waittime);                        
 69                     }
 70 
 71                     // calculating remain service time
 72                     int remainservicetime = opprocess.getremainservicetime() - timeslice;
 73                     opprocess.setremainservicetime(remainservicetime);
 74                     
 75                     // last time
 76                     if (remainservicetime <= 0) {
 77                         int completiontime = timenow + timeslice; // 进程是运行完当前时间片才结束的
 78                         int turnaroundtime = completiontime
 79                                 - opprocess.getarrivaltime();
 80                         double turnaroundtimewithweight = 1.0 * turnaroundtime
 81                                 / opprocess.getservicestime();
 82                         
 83                         opprocess.setcompletiontime(completiontime);
 84                         opprocess.setturnaroundtime(turnaroundtime);
 85                         opprocess.setturnaroundtimewithweight(
 86                                 turnaroundtimewithweight);
 87                         
 88                         processremain--;
 89                     }
 90                     
 91                     system.out.println("    #step#process" + (i + 1) + " remain service time:" + opprocess.getremainservicetime() + ((remainservicetime <= 0)?" finish":""));
 92                     timenow += timeslice;
 93                 } else {
 94                     // do noting, because this process has been completed.
 95                 }
 96                 
 97             } 
 98         }
 99     }
100     
101     public static void main(string [] args) {
102         new rr();
103     }
104 }

process类

模拟了进程，对属性进行了封装。

 1 package xqy.been;
 2 
 3 public class process {
 4     private int arrivaltime;
 5     private int servicestime;
 6     private int remainservicetime;
 7     private int starttime;
 8     private int waittime;
 9     private int completiontime;
10     
11     /**
12      * turnaroundtime = completiontime - arrivaltime
13      */
14     private int turnaroundtime;
15     
16     /**
17      * turnaroundtimewithweight = turnaroundtime / servicestime
18      */
19     private double turnaroundtimewithweight;
20     
21     public process() {
22         ;
23     }
24 
25     public int getarrivaltime() {
26         return arrivaltime;
27     }
28 
29     public void setarrivaltime(int arrivaltime) {
30         this.arrivaltime = arrivaltime;
31     }
32 
33     public int getservicestime() {
34         return servicestime;
35     }
36 
37     public void setservicestime(int servicestime) {
38         this.servicestime = servicestime;
39     }
40 
41     public int getremainservicetime() {
42         return remainservicetime;
43     }
44 
45     public void setremainservicetime(int remainservicetime) {
46         this.remainservicetime = remainservicetime;
47     }
48 
49     public int getstarttime() {
50         return starttime;
51     }
52 
53     public void setstarttime(int starttime) {
54         this.starttime = starttime;
55     }
56 
57     public int getwaittime() {
58         return waittime;
59     }
60 
61     public void setwaittime(int waittime) {
62         this.waittime = waittime;
63     }
64 
65     public int getcompletiontime() {
66         return completiontime;
67     }
68 
69     public void setcompletiontime(int completiontime) {
70         this.completiontime = completiontime;
71     }
72 
73     public int getturnaroundtime() {
74         return turnaroundtime;
75     }
76 
77     public void setturnaroundtime(int turnaroundtime) {
78         this.turnaroundtime = turnaroundtime;
79     }
80 
81     public double getturnaroundtimewithweight() {
82         return turnaroundtimewithweight;
83     }
84 
85     public void setturnaroundtimewithweight(double turnaroundtimewithweight) {
86         this.turnaroundtimewithweight = turnaroundtimewithweight;
87     }
88 
89     @override
90     public string tostring() {
91         return "process [arrivaltime=" + arrivaltime + ", servicestime="
92                 + servicestime + ", remainservicetime=" + remainservicetime
93                 + ", starttime=" + starttime + ", waittime=" + waittime
94                 + ", completiontime=" + completiontime + ", turnaroundtime="
95                 + turnaroundtime + ", turnaroundtimewithweight="
96                 + turnaroundtimewithweight + "]";
97     }
98 }

 

tools类

因为我这次作业要实现几个类似的算法，所以我把每个算法中都要用到的方法都提取出来作为单独的工具类。

也可以将这些工具方法都放入fcfs类中。

 1 package xqy.util;
 2 
 3 import java.util.arraylist;
 4 
 5 import xqy.been.process;
 6 
 7 public class tools {
 8 
 9     public static double calcaverageturnaroundtime(
10             arraylist<process> processlist) {
11         double sum = 0;
12         for (int i = 0; i < processlist.size(); i++) {
13             sum += processlist.get(i).getturnaroundtime();
14         }
15         return math.round(sum / processlist.size() * 100) / 100.0;
16     }
17 
18     public static double calcaverageturnaroundtimewithweight(
19             arraylist<process> processlist) {
20         double sum = 0;
21         for (int i = 0; i < processlist.size(); i++) {
22             sum += processlist.get(i).getturnaroundtimewithweight();
23         }
24         return math.round(sum / processlist.size() * 100) / 100.0;
25     }
26 
27     public static void printresult(arraylist<process> processlist) {
28         system.out.println("\n    #result#");
29 
30         system.out.print("\tarrive:\t\t");
31         for (int i = 0; i < processlist.size(); i++) {
32             system.out.print(processlist.get(i).getarrivaltime() + "\t");
33         }
34         system.out.println();
35 
36         system.out.print("\tservice:\t");
37         for (int i = 0; i < processlist.size(); i++) {
38             system.out.print(processlist.get(i).getservicestime() + "\t");
39         }
40         system.out.println();
41 
42         system.out.print("\tstart:\t\t");
43         for (int i = 0; i < processlist.size(); i++) {
44             system.out.print(processlist.get(i).getstarttime() + "\t");
45         }
46         system.out.println();
47 
48         system.out.print("\twait:\t\t");
49         for (int i = 0; i < processlist.size(); i++) {
50             system.out.print(processlist.get(i).getwaittime() + "\t");
51         }
52         system.out.println();
53 
54         system.out.print("\tfinish:\t\t");
55         for (int i = 0; i < processlist.size(); i++) {
56             system.out.print(processlist.get(i).getcompletiontime() + "\t");
57         }
58         system.out.println();
59 
60         system.out.print("\tturn around:\t");
61         for (int i = 0; i < processlist.size(); i++) {
62             system.out.print(processlist.get(i).getturnaroundtime() + "\t");
63         }
64         system.out.println();
65 
66         system.out.print("\tta wight:\t");
67         for (int i = 0; i < processlist.size(); i++) {
68             system.out.print(math.round(processlist.get(i)
69                     .getturnaroundtimewithweight() * 100) / 100.0 + "\t");
70         }
71         system.out.println();
72 
73         system.out.println("\taverage turn around time:"
74                 + tools.calcaverageturnaroundtime(processlist) + "\t");
75         system.out.println("\taverage turn around time with wight:"
76                 + tools.calcaverageturnaroundtimewithweight(processlist));
77         
78         system.out.println();
79     }
80 }