C Program to Implement Bully Election Algorithm : Election Algorithms

Bully Election Algorithm in C Programming Language

Each node has access to some permanent storage that survives node failures.
There are no transmission errors.
The communication subsystem does not fail

Algorithm :

The bully election algorithm
Process 4 holds an election
Process 5 and 6 respond, telling 4 to stop
Now 5 and 6 each hold an election
Process 6 tells 5 to stop
Process 6 wins and tells everyone

C Program for Bully Election Algorithm : Election Algorithms

#include<stdio.h>
#include<conio.h>
#include<alloc.h>
#include<stdlib.h>
struct process {
   int no;
   int priority;
   int active;
   struct process *next;
};
typedef struct process proc;
struct priority {
   int pri;
   struct priority *next;
   proc *pp;
};
typedef struct priority pri;
pri* find_priority(proc *head, pri *head1) {
   proc *p1;
   pri *p2, *p3;
   p1 = head;
   while (p1->next != head) {
      if (p1->active == 1) {
         if (head1 == NULL) {
            head1 = (pri*) malloc(sizeof(pri));
            head1->pri = p1->priority;
            head1->next = NULL;
            head1->pp = p1;
            p2 = head1;
         } else {
            p3 = (pri*) malloc(sizeof(pri));
            p3->pri = p1->priority;
            p3->pp = p1;
            p3->next = NULL;
            p2->next = p3;
            p2 = p2->next;
         }
         p1 = p1->next;
      } else
         p1 = p1->next;
   } //end while
   p3 = (pri*) malloc(sizeof(pri));
   p3->pri = p1->priority;
   p3->pp = p1;
   p3->next = NULL;
   p2->next = p3;
   p2 = p2->next;
   p3 = head1;
   return head1;
} //end find_priority()
int find_max_priority(pri *head) {
   pri *p1;
   int max = -1;
   int i = 0;
   p1 = head;
   while (p1 != NULL) {
      if (max < p1->pri && p1->pp->active == 1) {
         max = p1->pri;
         i = p1->pp->no;
      }
      p1 = p1->next;
   }
   return i;
}
void bully() {
   proc *head;
   proc *p1;
   proc *p2;
   int n, i, pr, maxpri, a, pid, max, o;
   char ch;
   head = p1 = p2 = NULL;
   printf("\nnEnter how many process: ");
   scanf("%d", &n);
   for (i = 0; i < n; i++) {
      printf("\nEnter priority of process %d: ", i + 1);
      scanf("%d", &pr);
      printf("\nIs process with id %d is active ?(0/1) :", i + 1);
      scanf("%d", &a);
	  if (head == NULL) {
         head = (proc*) malloc(sizeof(proc));
         if (head == NULL) {
            printf("\nMemory cannot be allocated");
            getch();
            exit(0);
         }
         head->no = i + 1;
         head->priority = pr;
         head->active = a;
         head->next = head;
         p1 = head;
      } else {
         p2 = (proc*) malloc(sizeof(proc));
         if (p2 == NULL) {
            printf("\nMemory cannot be allocated");
            getch();
            exit(0);
         }
         p2->no = i + 1;
         p2->priority = pr;
         p2->active = a;
         p1->next = p2;
         p2->next = head;
         p1 = p2;
      }
   } //end for
   printf("\nEnter the process id that invokes election algorithm: ");
   scanf("%d", &pid);
   p2 = head;
   while (p2->next != head) {
      if (p2->no == pid) {
         p2 = p2->next;
         break;
      }
      p2 = p2->next;
   }
   printf("\nProcess with id %d has invoked election algorithm", pid);
   printf("\t\nElection message is sent to processes");
   while (p2->next != head) {
      if (p2->no > pid)
         printf("%d", p2->no);
      p2 = p2->next;
   }
   printf("%d", p2->no);
   p2 = head;
   max = 0;
   while (1) {
      if (p2->priority > max && p2->active == 1)
         max = p2->no;
      p2 = p2->next;
      if (p2 == head)
         break;
   }
   printf("\n\tProcess with the id %d is the co-ordinator", max);
   while (1) {
      printf("\nDo you want to continue?(y/n): ");
      flushall();
      scanf("%c", &ch);
      if (ch == 'n' || ch == 'N')
         break;
      p2 = head;
      while (1) {
         printf("\nEnter the process with id %d is active or not (0/1): ",
               p2->no);
         scanf("%d", &p2->active);
         p2 = p2->next;
         if (p2 == head)
            break;
      }
      printf("\nEnter the process id that invokes election algorithm: ");
      scanf("%d", &pid);
      printf("\n\tElection message is sent to processes ");
      while (p2->next != head) {
         if (p2->no > pid)
            printf("%d", p2->no);
         p2 = p2->next;
      }
      printf("%d", p2->no);
      p2 = head;
      max = 0;
      while (1) {
         if (p2->no > max && p2->active == 1)
            max = p2->no;
         p2 = p2->next;
         if (p2 == head)
            break;
      }
      printf("\n\tProcess with id %d is the co-ordinator", max);
   }
}
void main() {
   clrscr();
   bully();
   getch();
}

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#include<stdio.h>

#include<conio.h>

#include<alloc.h>

#include<stdlib.h>

struct process {

int no;

int priority;

int active;

struct process *next;

};

typedef struct process proc;

struct priority {

int pri;

struct priority *next;

proc *pp;

};

typedef struct priority pri;

pri* find_priority(proc *head, pri *head1) {

proc *p1;

pri *p2, *p3;

p1 = head;

while (p1->next != head) {

if (p1->active == 1) {

if (head1 == NULL) {

head1 = (pri*) malloc(sizeof(pri));

head1->pri = p1->priority;

head1->next = NULL;

head1->pp = p1;

p2 = head1;

} else {

p3 = (pri*) malloc(sizeof(pri));

p3->pri = p1->priority;

p3->pp = p1;

p3->next = NULL;

p2->next = p3;

p2 = p2->next;

}

p1 = p1->next;

} else

p1 = p1->next;

} //end while

p3 = (pri*) malloc(sizeof(pri));

p3->pri = p1->priority;

p3->pp = p1;

p3->next = NULL;

p2->next = p3;

p2 = p2->next;

p3 = head1;

return head1;

} //end find_priority()

int find_max_priority(pri *head) {

pri *p1;

int max = -1;

int i = 0;

p1 = head;

while (p1 != NULL) {

if (max < p1->pri && p1->pp->active == 1) {

max = p1->pri;

i = p1->pp->no;

}

p1 = p1->next;

}

return i;

}

void bully() {

proc *head;

proc *p1;

proc *p2;

int n, i, pr, maxpri, a, pid, max, o;

char ch;

head = p1 = p2 = NULL;

printf("\nnEnter how many process: ");

scanf("%d", &n);

for (i = 0; i < n; i++) {

printf("\nEnter priority of process %d: ", i + 1);

scanf("%d", &pr);

printf("\nIs process with id %d is active ?(0/1) :", i + 1);

scanf("%d", &a);

if (head == NULL) {

head = (proc*) malloc(sizeof(proc));

if (head == NULL) {

printf("\nMemory cannot be allocated");

getch();

exit(0);

}

head->no = i + 1;

head->priority = pr;

head->active = a;

head->next = head;

p1 = head;

} else {

p2 = (proc*) malloc(sizeof(proc));

if (p2 == NULL) {

printf("\nMemory cannot be allocated");

getch();

exit(0);

}

p2->no = i + 1;

p2->priority = pr;

p2->active = a;

p1->next = p2;

p2->next = head;

p1 = p2;

}

} //end for

printf("\nEnter the process id that invokes election algorithm: ");

scanf("%d", &pid);

p2 = head;

while (p2->next != head) {

if (p2->no == pid) {

p2 = p2->next;

break;

}

p2 = p2->next;

}

printf("\nProcess with id %d has invoked election algorithm", pid);

printf("\t\nElection message is sent to processes");

while (p2->next != head) {

if (p2->no > pid)

printf("%d", p2->no);

p2 = p2->next;

}

printf("%d", p2->no);

p2 = head;

max = 0;

while (1) {

if (p2->priority > max && p2->active == 1)

max = p2->no;

p2 = p2->next;

if (p2 == head)

break;

}

printf("\n\tProcess with the id %d is the co-ordinator", max);

while (1) {

printf("\nDo you want to continue?(y/n): ");

flushall();

scanf("%c", &ch);

if (ch == 'n' || ch == 'N')

break;

p2 = head;

while (1) {

printf("\nEnter the process with id %d is active or not (0/1): ",

p2->no);

scanf("%d", &p2->active);

p2 = p2->next;

if (p2 == head)

break;

}

printf("\nEnter the process id that invokes election algorithm: ");

scanf("%d", &pid);

printf("\n\tElection message is sent to processes ");

while (p2->next != head) {

if (p2->no > pid)

printf("%d", p2->no);

p2 = p2->next;

}

printf("%d", p2->no);

p2 = head;

max = 0;

while (1) {

if (p2->no > max && p2->active == 1)

max = p2->no;

p2 = p2->next;

if (p2 == head)

break;

}

printf("\n\tProcess with id %d is the co-ordinator", max);

}

void main() {

clrscr();

bully();

getch();

}