Ex;no:7 Implement Bankers Algorithm for Dead Lock Avoidance
#include<stdio.h>
#include<process.h>
#include<conio.h>
void main()
{
int allocation[10][5],max[10][5],need[10][5],available[3],flag[10],sq[10];
int n,r,i,j,k,count,count1=0;
clrscr();
printf("\n Input the number of processes running ( <10 )..");
scanf("%d",&n);
for(i=0;i<10;i++)
flag[i]=0;
printf("\n Input the number of resources ( <5 )..");
scanf("%d",&r);
printf("\n Input the allocation matrix for the processes in row major order..\n");
for(i=0;i<n;i++)
{
printf("\n Process %d\n",i);
for(j=0;j<r;j++)
{
printf("\n Resource %d\n",j);
scanf("%d",&allocation[i][j]);
}
}
printf("\n Input the no. of resources that a process can maximum have..\n");
for(i=0;i<n;i++)
{
printf("\n Process %d\n",i);
for(j=0;j<r;j++)
{
printf("\n Resource %d\n",j);
scanf("%d",&max[i][j]);
}
}
printf("\n Input the no. of available instances of each resource..\n");
for(i=0;i<r;i++)
{
printf("\n Resource %d : ",i);
scanf("%d",&available[i]);
}
printf("\n The need matrix is as follows : \n");
for(i=0;i<n;i++)
{
for(j=0;j<r;j++)
{
need[i][j]= max[i][j]-allocation[i][j];
printf("\t %d",need[i][j]);
}
printf("\n");
}
do{
for(k=0;k<n;k++)
{
for(i=0;i<n;i++)
{
if(flag[i]==0)
{
count=0;
for(j=0;j<r;j++)
{
if(available[j]>=need[i][j])
count++;
}
if(count==r)
{
count1++;
flag[i]=1;
sq[count1-1]=i;
for(j=0;j<r;j++)
{
available[j]=available[j]+allocation[i][j];
}
break;
}
}
}
}
if(count1!=n)
{
printf("\n---------------IT'S AN UNSAFE STATE---------------");
break;
}
}while(count1!=n);
if(count1==n)
{
printf("\n *******************IT'S A SAFE STATE*******************");
printf("\n The safe sequence is....\n");
for(i=0;i<n;i++)
printf("\t P%d",sq[i]);
printf("\n");
printf("\n The available matrix is now : ");
for(i=0;i<r;i++)
printf("\t %d",available[i]);
}
getch();
}
output
Enter the no of processes : 5
Enter the no of resources : 3
Enter the Max Matrix for each process :
For process 1 : 7
5
3
For process 2 : 3
2
2
For process 3 : 7
0
2
For process 4 : 2
2
2
For process 5 : 4
3
3
Enter the allocation for each process :
For process 1 : 0
1
0
For process 2 : 2
0
0
For process 3 : 3
0
2
For process 4 : 2
1
1
For process 5 : 0
0
2
Enter the Available Resources : 3
3
2
Max matrix: Allocation matrix:
753 010
322 200
702 302
222 211
433 002
Process 2 runs to completion!
Max matrix: Allocation matrix:
753 010
000 000
702 302
222 211
433 002
Process 3 runs to completion!
Max matrix: Allocation matrix:
753 010
000 000
000 000
222 211
433 002
Process 4 runs to completion!
Max matrix: Allocation matrix:
753 010
000 000
000 000
000 000
433 002
Process 1 runs to completion!
Max matrix: Allocation matrix:
000 000
000 000
000 000
000 000
433 002
Process 5 runs to completion!
The system is in a safe state!!
Safe Sequence : < 2 3 4 1 5 >
Ex.no:8Implement an Algorithm for Dead Lock Detection
#include <stdio.h>
#include <conio.h>
void main()
{
int found,flag,l,p[4][5],tp,tr,c[4][5],i,j,k=1,m[5],r[5],a[5],temp[5],sum=0;
clrscr();
printf("Enter total no of processes");
scanf("%d",&tp);
printf("Enter total no of resources");
scanf("%d",&tr);
printf("Enter claim (Max. Need) matrix\n");
for(i=1;i<=tp;i++)
{
printf("process %d:\n",i);
for(j=1;j<=tr;j++)
scanf("%d",&c[i][j]);
}
printf("Enter allocation matrix\n");
for(i=1;i<=tp;i++)
{
printf("process %d:\n",i);
for(j=1;j<=tr;j++)
scanf("%d",&p[i][j]);
}
printf("Enter resource vector (Total resources):\n");
for(i=1;i<=tr;i++)
{
scanf("%d",&r[i]);
}
printf("Enter availability vector (available resources):\n");
for(i=1;i<=tr;i++)
{
scanf("%d",&a[i]);
temp[i]=a[i];
}
for(i=1;i<=tp;i++)
{
sum=0;
for(j=1;j<=tr;j++)
{
sum+=p[i][j];
}
if(sum==0)
{
m[k]=i;
k++;
}
}
for(i=1;i<=tp;i++)
{
for(l=1;l<k;l++)
if(i!=m[l])
{
flag=1;
for(j=1;j<=tr;j++)
if(c[i][j]<temp[j])
{
flag=0;
break;
}
}
if(flag==1)
{
m[k]=i;
k++;
for(j=1;j<=tr;j++)
temp[j]+=p[i][j];
}
}
printf("deadlock causing processes are:");
for(j=1;j<=tp;j++)
{
found=0;
for(i=1;i<k;i++)
{
if(j==m[i])
found=1;
}
if(found==0)
printf("%d\t",j);
}
getch();
}
Output-
Enter total no. of processes : 4
Enter total no. of resources : 5
Enter claim (Max. Need) matrix :
01001
00101
00001
10101
Enter allocation matrix :
10110
11000
00010
00000
Enter resource vector (Total resources) :
21121
Enter availability vector (available resources) :
00001
deadlock causing processes are : 2 3
