BANKERS ALGORITHM USING C

bankersalgorithm.c

@@ -0,0 +1,136 @@
+
+#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]);
+                }
+        }
+}
+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];
+        }
+}
+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;
+}
+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;
+}