O'rtacha kutish vaqti:
Kod:
C++ da FCFS algoritmini amalga oshirish uchun kod quyida keltirilgan:
#include
using namespace std;
void findWait_Time(int processes[], int size, int burst_time[],
int wait_t[], int arrival_t[])
{
int service_time[size];
service_time[0] = arrival_t[0];
wait_t[0] = 0;
int i = 1;
// calculating waiting time
while ( i < size )
{
service_time[i] = service_time[i-1] + burst_time[i-1];
//waiting time = sum - at[i]
wait_t[i] = service_time[i] - arrival_t[i];
if (wait_t[i] < 0)
wait_t[i] = 0;
i++;
}
}
void findavg_wait_Time(int processes[], int size, int burst_t[], int arrival_t[])
{
int wt[size], tat[size];
findWait_Time(processes, size, burst_t, wt, arrival_t);
cout << "Processes " << " Burst Time " << " Arrival Time "
<< " Waiting Time \n";
int total_wt = 0, total_tat = 0;
int i = 0;
while (i < size)
{
total_wt = total_wt + wt[i];
total_tat = total_tat + tat[i];
int compl_time = tat[i] + arrival_t[i];
cout << " " << i+1 << "\t\t" << burst_t[i] << "\t\t"
<< arrival_t[i] << "\t\t" << wt[i] << "\t\t "
<< endl;
i++;
}
cout << "Average waiting time = "
<< (float)total_wt / (float)size;
}
int main()
{
int processes[] = {4, 3, 1, 5, 2};
int n = sizeof processes / sizeof processes[0];
int arrival_time[] = {0, 1, 2, 4, 5};
int burst_time[] = {3, 8, 6, 4, 2};
findavg_wait_Time(processes, n, burst_time, arrival_time);
return 0;
}
FCFS rejalashtirishni amalga oshirish
Tushuntirish:
Amalga oshirish tartibi: Dastur barcha jarayonlar uchun birinchi navbatda berilgan portlash va kelish vaqtini ishlatib, kutish vaqtini topadi va u tugagach, oʻrtacha kutish vaqtini (float)total_wt / (float) hajmi boʻyicha hisoblab chiqadi va jarayonlar boʻyicha tafsilotlarni koʻrsatadi.
23–24-qator: Agar biron-bir jarayon uchun kutish vaqti salbiy bo'lsa, bu u allaqachon navbatda turganligini anglatadi, shuning uchun protsessor ishlamay qolishidan oldin uning kutish vaqti 0, wt[i] = 0 bo'ladi.
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