bankers.c

#include<stdio.h>

#define MAX_RESOURCES   10
#define MAX_PROCESSES   10

void main() {

//    int available[MAX_RESOURCES];
//    int max[MAX_PROCESSES][MAX_RESOURCES];
//    int allocation[MAX_PROCESSES][MAX_RESOURCES];
    	int need[MAX_PROCESSES][MAX_RESOURCES];
    	int work[MAX_RESOURCES];    
    	int finish[MAX_PROCESSES];

    	int i, j, k, l, flagOK;
	int resource_count = 3;
 	int process_count = 5;

	int allocation[5][3] = {0,1,0,2,0,0,3,0,2,2,1,1,0,0,2};
	int max[5][3] = {7,5,3,3,2,2,9,0,2,2,2,2,4,3,3};
	int available[3] = {3,3,2};
	int safeorder[6];
    
    	for (i = 0; i < resource_count; i++) work[i] = available[i];
    	for (i = 0; i < process_count; i++) finish[i] = 0;
 
   	for (i = 0; i < process_count ; i++) {
        	for (j = 0; j < resource_count; j++)
             		need[i][j] = max[i][j] - allocation[i][j];
    	}
    
    	i = 0;
	int pnumber = 0;
	int unsafe = 0;

    	safeorder[0] = -1;
    	do {

       		flagOK = i;  
        	if (finish[i] == 0) {

            		for (j = 0; j < resource_count; j++) {
                 		if (need[i][j] > work[j]) {
                    			flagOK = -1;
                    			break;
               	 		}
            		}
            
            		if (flagOK != -1) {
                		safeorder[++pnumber] = flagOK;
                		printf("\nRunning process P[%d]", flagOK);
                		for (j = 0; j <  resource_count; j++) {
			                work[j] = work[j] + allocation[flagOK][j];
                    			printf("\nNew availability of resource R[%d] = %d", j, work[j]);
                		}
				finish[i] = 1;
            		}
        	}
		i = i + 1;
		if (i > process_count) i = 0;
    	} while (safeorder[pnumber] != i);

	
    	for (i = 0; i < process_count ; i++) {
		if (finish[i] == 0) unsafe = 1;
	};

	if (unsafe == 0) {
	    	printf("\nSystem is in Safe state.");
	    	printf("\nSafe order.");
	    	for (i = 1; i <= process_count ; i++) printf(" %d", safeorder[i]);
	}
	else {
	    	printf("\nSystem is in Unsafe state.");
	}
	printf("\n");
}