Lamport Logical Clock to find the ordering of events in a Distributed System. In Lamport Algorithm each event has its own timestamp which depends on the occuring of events in the order the message has been sent by which event of a process to whichever event.

#include<stdio.h> #include<conio.h> int max1(int a, int b) //to find the maximum timestamp between two events { if (a>b) return a; else return b; } int main() { int i,j,k,p1[20],p2[20],e1,e2,dep[20][20]; printf("enter the events : "); scanf("%d %d",&e1,&e2); for(i=0;i<e1;i++) p1[i]=i+1; for(i=0;i<e2;i++) p2[i]=i+1; printf("enter the dependency matrix:\n"); printf("\t enter 1 if e1->e2 \n\t enter -1, if e2->e1 \n\t else enter 0 \n\n"); for(i=0;i<e2;i++) printf("\te2%d",i+1); for(i=0;i<e1;i++) { printf("\n e1%d \t",i+1); for(j=0;j<e2;j++) scanf("%d",&dep[i][j]); } for(i=0;i<e1;i++) { for(j=0;j<e2;j++) { if(dep[i][j]==1) //change the timestamp if dependency exist { p2[j]=max1(p2[j],p1[i]+1); for(k=j;k<e2;k++) p2[k+1]=p2[k]+1; } if(dep[i][j]==-1) //change the timestamp if dependency exist { p1[i]=max1(p1[i],p2[j]+1); for(k=i;k<e1;k++) p2[k+1]=p1[k]+1; } } } printf("P1 : "); //to print the outcome of Lamport Logical Clock for(i=0;i<e1;i++) { printf("%d",p1[i]); } printf("\n P2 : "); for(j=0;j<e2;j++) printf("%d",p2[j]); getch(); return 0 ; }

OUTPUT:

Tags: C program for the implementation of Lamport Logical Clock, C program for Lamport Timestamp Algorithm

thanks for the program

Really helpful, i am going to take an assignment on this. Thank you for sharing and i am going to take this as a sample and develop the code.

Check for the I/P:

4 5

0 0 1 0 0

0 0 0 0 0

0 0 -1 0 0

0 0 0 0 0

Output should be

P1:1245

P2:12356

But it’s showing wrong output!!!!

Serious Flaw in the code.