Program 11a):

AIM:  Write a program to implement Dynamic allocation of memories in Memory Variable Technique.

#include<stdio.h>

#include<conio.h>

main()

{

          int i,m,n,tot,s[20];

          clrscr();

          printf("Enter total memory size:");

          scanf("%d",&tot);

          printf("Enter no. of pages:");

          scanf("%d",&n);

          printf("Enter memory for OS:");

          scanf("%d",&m);

          for(i=0;i<n;i++)

          {

                   printf("Enter size of page%d:",i+1);

                   scanf("%d",&s[i]);

          }

          tot=tot-m;

          for(i=0;i<n;i++)

          {

                   if(tot>=s[i])

                   {

                             printf("Allocate page %d\n",i+1);

                             tot=tot-s[i];

                   }

                   else

                             printf("process p%d is blocked\n",i+1);

          }

          printf("External Fragmentation is=%d",tot);

          getch();

}

OUTPUT:

Program 11b):

AIM:  Write a program to implement Dynamic allocation of memories in Memory Fixed Technique.

#include<stdio.h>

#include<conio.h>

#include<math.h>

#define MAX 10

int main()

{

int ma,bs,ps,tmp,sbn[MAX]={0},ebn[MAX]={0},count=0,i=0,k,ifrag[MAX]={0};

char ch;

clrscr();

printf("\nEnter total memory available (in MB)");

scanf("%d",&ma);

printf("\nEnter size of each block(in MB)");

scanf("%d",&bs);

while(ma)

{

printf("\nDo u have a program(y/n)");

fflush(stdin);

scanf("%c",&ch);

if((ch!='y') && (ch!='Y'))

{

printf("\nMemory available %d MB",ma);

break;

}

printf("\nEnter the size of program(inMB)");

scanf("%d",&ps);

if(ps>ma)

{

printf("\nMemory required %d\nBUt\nMemory available:%d",ps,ma);

break;

}

count++;

if(!i)

{

sbn[i]=0;

ebn[i]=(ceil((float)ps/bs))-1;

}

else

{

sbn[i]=ebn[i-1]+1;

ebn[i]=sbn[i]+(ceil((float)ps/bs))-1;

}

tmp=((ceil((float)ps/bs)*bs));

ifrag[i]=tmp-ps;

i++;

ma-=tmp;

printf("\nMemory allocated%dMB\nMemory available%dMB",tmp,ma);

printf("\nBlocls\tnum of blocks\tInternal fragmentation(inMB)");

for(k=0;k<count;k++)

printf("\n\n%d-%d\t\t%d\t\t%d",sbn[k],ebn[k],ebn[k]-sbn[k]+1,ifrag[k]);

}

getch();

return 1;

}

OUTPUT:

Program 11c):

AIM: To implement the Memory management policy- Paging.

#include<stdio.h>

#define MAX 50

int main()

{

int page[MAX],i,n,f,ps,off,pno;

printf("\nEnter the no of pages in memory");

scanf("%d",&n);

printf("\nEnter page size");

scanf("%d",&ps);

printf("\nEnter no of frames");

scanf("%d",&f);

for(i=0;i<n;i++)

page[i]=-1;

printf("\nEnter the page table\n");

printf("(Enter frame no as -1 if that page is not present in any frame)\n\n");

printf("\npageno\tframeno\n-------\t-------");

for(i=0;i<n;i++)

{

printf("\n\n%d\t\t",i);

scanf("%d",&page[i]);

}

printf("\n\nEnter the logical address(i.e,page no & offset):");

scanf("%d%d",&pno,&off);

if(page[pno]==-1)

printf("\n\nThe required page is not available in any of frames");

else

printf("\n\nPhysical address(i.e,frame no & offset):%d,%d",page[pno],off);

return 0;

}

OUTPUT:

Program 11d):

AIM: To implement the memory management policy-segmentation.

#include <stdio.h>

#include <conio.h>

#include <math.h>

int sost;

void gstinfo();

void ptladdr();

struct segtab

{

          int sno;

          int baddr;

          int limit;

          int val[10];

}st[10];

void gstinfo()

{

          int i,j;

          printf("\n\tEnter the size of the segment table: ");

          scanf("%d",&sost);

          for(i=1;i<=sost;i++)

                   {

                   printf("\n\tEnter the information about segment: %d",i);

                   st[i].sno = i;

                   printf("\n\tEnter the base Address: ");

                   scanf("%d",&st[i].baddr);

                   printf("\n\tEnter the Limit: ");

                   scanf("%d",&st[i].limit);

                   for(j=0;j<st[i].limit;j++)

                             {

                             printf("Enter the %d address Value: ",(st[i].baddr + j));

                             scanf("%d",&st[i].val[j]);

                             }

                   }

}

void ptladdr()

{

          int i,swd,d=0,n,s,disp,paddr;

          clrscr();

          printf("\n\n\t\t\t SEGMENT TABLE \n\n");

          printf("\n\t      SEG.NO\tBASE ADDRESS\t      LIMIT \n\n");

          for(i=1;i<=sost;i++)

                   printf("\t\t%d    \t\t%d\t\t%d\n\n",st[i].sno,st[i].baddr,st[i].limit);

          printf("\n\nEnter the logical Address: ");

          scanf("%d",&swd);

          n=swd;

          while (n != 0)

          {

                   n=n/10;

                   d++;

          }

          s = swd/pow(10,d-1);

          disp = swd%(int)pow(10,d-1);

          if(s<=sost)

          {

                   if(disp < st[s].limit)

                   {

                             paddr = st[s].baddr + disp;

                             printf("\n\t\tLogical Address is: %d",swd);

                             printf("\n\t\tMapped Physical address is: %d",paddr);

                             printf("\n\tThe value is: %d",( st[s].val[disp] )  );

                   }

                   else

                             printf("\n\t\tLimit of segment %d is high\n\n",s);

          }

          else

                   printf("\n\t\tInvalid Segment Address \n");

          }

          void main()

          {

          char ch;

          clrscr();

          gstinfo();

          do

          {

          ptladdr();

          printf("\n\t Do U want to Continue(Y/N)");

          flushall();

          scanf("%c",&ch);

          }while (ch == 'Y' || ch == 'y' );

          getch();

          }