Computer Science Tutorials

1. Explain the Dual-mode operation of an Opearting System. 2. With neat sketch, describe the services that an operaying system provides to users, processes and other system 3. Explain the difference between micro-kernel and macro-kernel. 4. What is system call? Explain the various types of system calls provided by an operating system

#include<stdio.h> int main() {    int count,j,n,time,remain,flag=0,time_quantum;   int wait_time=0,turnaround_time=0,at[10],bt[10],rt[10];   printf("Enter Total Process:\t ");   scanf("%d",&n);   remain=n;   for(count=0;count<n;count++)   {     printf("Enter Arrival Time and Burst Time for Process Process Number %d :",count+1);     scanf("%d",&at[count]);     scanf("%d",&bt[count]);     rt[count]=bt[count];   }   printf("Enter Time Quantum:\t");   scanf("%d",&time_quantum);   printf("\n\nProcess\t|Turnaround Time|Waiting Time\n\n");   for(time=0,count=0;remain!=0;)   {     if(rt[count]<=time_quantum && rt[count]>0)     {       time+=rt[count];       rt[count]=0;       flag=1;   ...

#include<stdio.h> int main() {     int bt[20],p[20],wt[20],tat[20],pr[20],i,j,n,total=0,pos,temp,avg_wt,avg_tat;     printf("Enter Total Number of Process:");     scanf("%d",&n);     printf("\nEnter Burst Time and Priority\n");     for(i=0;i<n;i++)     {         printf("\nP[%d]\n",i+1);         printf("Burst Time:");         scanf("%d",&bt[i]);         printf("Priority:");         scanf("%d",&pr[i]);         p[i]=i+1;           //contains process number     }     //sorting burst time, priority and process number in ascending order using selection sort     f...

computer system and operating system overview   click here

UNIT-I: Computer System and Operating System Overview:  Overview of computer operating systems, operating systems functions, protection and security, distributed systems, special purpose systems, operating systems structures and systems calls, operating systems generation. UNIT-II: Process Management Process concept process scheduling, operations, Inter process communication. Multi Thread programming models. Process scheduling criteria and algorithms, and their evaluation. UNIT-III: Concurrency : Process synchronization, the critical- section problem, Peterson’s Solution, synchronization Hardware, semaphores, classic problems of synchronization, monitors, Synchronization examples UNIT-IV: Memory Management: Swapping, contiguous memory allocation, paging, structure of the page table, segmentation Virtual Memory Management: virtual memory,  demand paging, page-Replacement, algorithms, Allocation of Frames, Thrashing UNIT-V: Principles o...

FCFS program in c #include<stdio.h> int main() {     int n,bt[20],wt[20],tat[20],avwt=0,avtat=0,i,j;     printf("Enter total number of processes(maximum 20):");     scanf("%d",&n);     printf("\nEnter Process Burst Time\n");     for(i=0;i<n;i++)     {         printf("P[%d]:",i+1);         scanf("%d",&bt[i]);     }     wt[0]=0;    //waiting time for first process is 0     //calculating waiting time     for(i=1;i<n;i++)     {         wt[i]=0;         for(j=0;j<i;j++)             wt[i]+=bt[j];     }     printf("\nProcess\t\tBurst Time\tWai...

SJF programming in C #include<stdio.h> void main() {     int bt[20],p[20],wt[20],tat[20],i,j,n,total=0,pos,temp;     float avg_wt,avg_tat;     printf("Enter number of process:");     scanf("%d",&n);     printf("\nEnter Burst Time:\n");     for(i=0;i<n;i++)     {         printf("p%d:",i+1);         scanf("%d",&bt[i]);         p[i]=i+1;           //contains process number     }     //sorting burst time in ascending order using selection sort     for(i=0;i<n;i++)     {         pos=i;         for(j=i+1;j<n;j++)         { ...