Operating-System-Lab/Priority_Scheduling.cpp at master · ShabbirMahmood/Operating-System-Lab · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
/* Shabbir Mahmood  ID: 14015439 Part-3 Even Operating System Lab SJF Algorithm Date: 11-02-2017*/
#include<bits/stdc++.h>
using namespace std;

int no_of_process;
double sum_waiting_time    = 0;
double sum_turnaround_time = 0;

typedef struct
{
    int process_id;
    int burst_time;
    int waiting_time;
    int turnaround_time;
    int priority;
} Process;
bool compare(Process lhs, Process rhs) { return lhs.priority < rhs.priority; }//Sorting Function

void gantt_chart(Process process[],int no_of_process)
{
     cout<<"..........Gantt Chart.........."<<endl;
     cout<<" ";                       // Top Line
    for( int i=1; i<=no_of_process; i++)
    {
        for(int j=1; j<=process[i].burst_time; j++)
        {
            cout<<"-";
        }
        cout<<" ";
    }
    cout<<"\n|";

    for( int i=1; i<=no_of_process; i++)
    {
        for(int j=1; j<=(process[i].burst_time/2); j++)
        {
            cout<<" ";
        }
        cout<<process[i].process_id;
        if( process[i].burst_time%2==0) // Checking Odd or Even Burst time
        {
           for(int j=1; j<=(process[i].burst_time/2)-1; j++)
            {
                cout<<" ";
            }
        }
        else
        {
            for(int j=1; j<=(process[i].burst_time/2); j++)
            {
                cout<<" ";
            }
        }
        cout<<"|";
    }
    cout<<endl;
    cout<<" ";               // Bottom line
    for( int i=1; i<=no_of_process; i++)
    {
        for(int j=1; j<=process[i].burst_time; j++)
        {
            cout<<"-";
        }
        cout<<" ";
    }
    cout<<endl;
    cout<<"0";
    for( int i=1; i<=no_of_process; i++)
    {
        for(int j=1; j<=process[i].burst_time; j++)
        {
            cout<<" ";
        }
        if(process[i].turnaround_time > 9) printf("\b");//************* Consume One Space Bar
        cout<<process[i].turnaround_time;
    }
    cout<<endl;


}

void calculate(Process process[],int no_of_process)
{
    process[0].waiting_time = 0;
    process[0].burst_time   = 0;
    double sum = 0;
    for( int i=1; i<=no_of_process; i++)
    {
        sum  = sum + process[i-1].burst_time;
        process[i].waiting_time = sum;
    }

    process[0].turnaround_time = 0;
    sum = 0;
    for( int i=1; i<=no_of_process; i++)
    {
        process[i].turnaround_time = process[i].waiting_time   + process[i].burst_time;
    }
    cout<<"Assuming all the processes arrives at time 0"<<endl;
    cout<<" ----------------------------------------------------------"<<endl;
    cout<<"| Process ID | Burst Time | Waiting Time | Turnaround Time |"<<endl;
    cout<<" ---------------------------------------------------------- "<<endl;
    for( int i=1; i<=no_of_process; i++)
    {
        printf("|    %3d     |     %3d    |      %3d     |      %3d        |\n"
           , process[i].process_id, process[i].burst_time,process[i].waiting_time,process[i].turnaround_time);
    }
    cout<<" ---------------------------------------------------------- "<<endl;
    for( int i=1; i<=no_of_process; i++)
    {
        sum_waiting_time = sum_waiting_time + process[i].waiting_time;
    }
     for( int i=1; i<=no_of_process; i++)
    {
        sum_turnaround_time = sum_turnaround_time + process[i].turnaround_time;
    }

    cout<<"Average Waiting Time  : "<<(sum_waiting_time/no_of_process)<<endl;
    cout<<"Average Turnround Time: "<<(sum_turnaround_time/no_of_process)<<endl;
}

int main()
{
    Process process[100];
    cout<<"Enter the total number of process: ";
    cin>>no_of_process;
     cout<<"Enter the Burst Time & Priority of each individual process:"<<endl;;

    for(int i=1; i<=no_of_process; i++)
    {
        cout<<"P"<<i<<" : ";
        cin>>process[i].burst_time;
        cout<<"P"<<i<<" Priority: ";

        cin>>process[i].priority;
        process[i].process_id = i;
    }

    sort(process+1, process+(no_of_process+1), compare);

    calculate(process,no_of_process);
    gantt_chart(process,no_of_process);


    return 0;
}
/*
5
10 3
1 1
2 4
1 5
5 2

*/