C program for bankers algorithm


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This is a C program for Banker’s algorithm for finding out the safe sequence. Bankers algorithm is used to schedule processes according to the resources they need. It is very helpful in Deadlock Handling. Bankers algorithm produce a safe sequence as a output if all the resources can be executed and return error if no safe sequence of the processes available.

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C Program

#include<stdio.h>
#include<conio.h>
void main() {
	int k=0,output[10],d=0,t=0,ins[5],i,avail[5],allocated[10][5],need[10][5],MAX[10][5],pno,P[10],j,rz, count=0;
	clrscr();
	printf("\n Enter the number of resources : ");
	scanf("%d", &rz);
	printf("\n enter the max instances of each resources\n");
	for (i=0;i<rz;i++) {
		avail[i]=0;
		printf("%c= ",(i+97));
		scanf("%d",&ins[i]);
	}
	printf("\n Enter the number of processes : ");
	scanf("%d", &pno);
	printf("\n Enter the allocation matrix \n     ");
	for (i=0;i<rz;i++)
	printf(" %c",(i+97));
	printf("\n");
	for (i=0;i <pno;i++) {
		P[i]=i;
		printf("P[%d]  ",P[i]);
		for (j=0;j<rz;j++) {
			scanf("%d",&allocated[i][j]);
			avail[j]+=allocated[i][j];
		}
	}
	printf("\nEnter the MAX matrix \n     ");
	for (i=0;i<rz;i++) {
		printf(" %c",(i+97));
		avail[i]=ins[i]-avail[i];
	}
	printf("\n");
	for (i=0;i <pno;i++) {
		printf("P[%d]  ",i);
		for (j=0;j<rz;j++)
		 scanf("%d", &MAX[i][j]);
	}
	printf("\n");
	A: d=-1;
	for (i=0;i <pno;i++) {
		count=0;
		t=P[i];
		for (j=0;j<rz;j++) {
			need[t][j] = MAX[t][j]-allocated[t][j];
			if(need[t][j]<=avail[j])
			 count++;
		}
		if(count==rz) {
			output[k++]=P[i];
			for (j=0;j<rz;j++)
			avail[j]+=allocated[t][j];
		} else
		 P[++d]=P[i];
	}
	if(d!=-1) {
		pno=d+1;
		goto A;
	}
	printf("\t <");
	for (i=0;i<k;i++)
	printf(" P[%d] ",output[i]);
	printf(">");
	getch();
}





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