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@pallabpain
Created October 20, 2014 18:26
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Banker's Algorithm in C
#include<stdio.h>
#include<stdlib.h>
void print(int x[][10],int n,int m){
int i,j;
for(i=0;i<n;i++){
printf("\n");
for(j=0;j<m;j++){
printf("%d\t",x[i][j]);
}
}
}
//Resource Request algorithm
void res_request(int A[10][10],int N[10][10],int AV[10][10],int pid,int m)
{
int reqmat[1][10];
int i;
printf("\n Enter additional request :- \n");
for(i=0;i<m;i++){
printf(" Request for resource %d : ",i+1);
scanf("%d",&reqmat[0][i]);
}
for(i=0;i<m;i++)
if(reqmat[0][i] > N[pid][i]){
printf("\n Error encountered.\n");
exit(0);
}
for(i=0;i<m;i++)
if(reqmat[0][i] > AV[0][i]){
printf("\n Resources unavailable.\n");
exit(0);
}
for(i=0;i<m;i++){
AV[0][i]-=reqmat[0][i];
A[pid][i]+=reqmat[0][i];
N[pid][i]-=reqmat[0][i];
}
}
//Safety algorithm
int safety(int A[][10],int N[][10],int AV[1][10],int n,int m,int a[]){
int i,j,k,x=0;
int F[10],W[1][10];
int pflag=0,flag=0;
for(i=0;i<n;i++)
F[i]=0;
for(i=0;i<m;i++)
W[0][i]=AV[0][i];
for(k=0;k<n;k++){
for(i=0;i<n;i++){
if(F[i] == 0){
flag=0;
for(j=0;j<m;j++){
if(N[i][j] > W[0][j])
flag=1;
}
if(flag == 0 && F[i] == 0){
for(j=0;j<m;j++)
W[0][j]+=A[i][j];
F[i]=1;
pflag++;
a[x++]=i;
}
}
}
if(pflag == n)
return 1;
}
return 0;
}
//Banker's Algorithm
void accept(int A[][10],int N[][10],int M[10][10],int W[1][10],int *n,int *m){
int i,j;
printf("\n Enter total no. of processes : ");
scanf("%d",n);
printf("\n Enter total no. of resources : ");
scanf("%d",m);
for(i=0;i<*n;i++){
printf("\n Process %d\n",i+1);
for(j=0;j<*m;j++){
printf(" Allocation for resource %d : ",j+1);
scanf("%d",&A[i][j]);
printf(" Maximum for resource %d : ",j+1);
scanf("%d",&M[i][j]);
}
}
printf("\n Available resources : \n");
for(i=0;i<*m;i++){
printf(" Resource %d : ",i+1);
scanf("%d",&W[0][i]);
}
for(i=0;i<*n;i++)
for(j=0;j<*m;j++)
N[i][j]=M[i][j]-A[i][j];
printf("\n Allocation Matrix");
print(A,*n,*m);
printf("\n Maximum Requirement Matrix");
print(M,*n,*m);
printf("\n Need Matrix");
print(N,*n,*m);
}
int banker(int A[][10],int N[][10],int W[1][10],int n,int m){
int j,i,a[10];
j=safety(A,N,W,n,m,a);
if(j != 0 ){
printf("\n\n");
for(i=0;i<n;i++)
printf(" P%d ",a[i]);
printf("\n A safety sequence has been detected.\n");
return 1;
}else{
printf("\n Deadlock has occured.\n");
return 0;
}
}
int main(){
int ret;
int A[10][10];
int M[10][10];
int N[10][10];
int W[1][10];
int n,m,pid,ch;
printf("\n DEADLOCK AVOIDANCE USING BANKER'S ALGORITHM\n");
accept(A,N,M,W,&n,&m);
ret=banker(A,N,W,n,m);
if(ret !=0 ){
printf("\n Do you want make an additional request ? (1=Yes|0=No)");
scanf("%d",&ch);
if(ch == 1){
printf("\n Enter process no. : ");
scanf("%d",&pid);
res_request(A,N,W,pid-1,m);
ret=banker(A,N,W,n,m);
if(ret == 0 )
exit(0);
}
}else
exit(0);
return 0;
}
@tanmaydesai100
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tanmaydesai100 commented Mar 17, 2018

W[0][i]=AV[0][i]; // what is the use of this line in this program if in the accept method we have already inserted the values

@harshjhaa
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thanks buddy

@Om4AI
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Om4AI commented Sep 8, 2020

Thank u so much!!

@duha2001
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Can you give me 1 input for testing. Thank you very much <3

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