Prevention of a data race in a parallelised program, Operating System

Assignment Help:

Present your own fully documented and tested programming example illustrating the prevention of a data race in a parallelised program.

This is an example where total number of prime number between 2 and 10000 is being calculated. The order of memory accesses is prevented from being non-deterministic and from the code data race is avoided by making it parallelized with OpenMP directives.  The inconsistency can be seen by running the program consecutively for 3 or more times.

 

#include

#include

#include

#define MyThreads 4

#define num 10000

 

   int primeNum[num];

   int primeF[num];

 

   int is_prime(int v)

   {

    int i;

    int lim = floor(sqrt(v)) + 1;

 

    for (i = 2; i < lim; i++) {

           /* no need to check against known composites */

           if (!primeF[i])

               continue;

           if (v % i == 0) {

               primeF[v] = 0;

               return 0;

           }

       }

       return (v > 1);

   }

 

   int main(int argn, char **argv)

   {

       int i;

       int total = 0;

            printf("Enter a number greater than 2");

            scanf("%d", &num)

   #ifdef _OPEnumMP

       omp_set_dynamic(0);

       omp_set_num_threads(MyThreads);

   #endif

 

       for (i = 0; i < num; i++) {

           primeF[i] = 1;

       }

 

       #pragma omp parallel for

       for (i = 2; i < num; i++) {

           if ( is_prime(i) ) {

               primeNum[total] = i;

               total++;

           }

       }

        printf("total prime numbers that lie between 2 and %d: %d\n",

              num, total);

       return 0;

   }


Related Discussions:- Prevention of a data race in a parallelised program

Write note on process, Write note on process, process state? A process ...

Write note on process, process state? A process is in excess of the program code which is sometimes known as text section. It as well includes the current activity as represent

Explain threads in details?, What are threads? A thread - sometimes c...

What are threads? A thread - sometimes called as an implementation context or a lightweight process - is a single sequential flow of control within a program. We use threads

Is anti virus a system utility, Problem: a) Explain physically what occ...

Problem: a) Explain physically what occurs when a disk is fragmented. What is the purpose of "defragmenting" a disk? b) What is the idea behind backing up data on a secondar

How is memory management done using linked lists?, How is memory management...

How is memory management done using linked lists?   Each one node of the l list will have 4 fields as follows 1-this tells whether it s a hole or a process 2-starting ad

Explain next fit algorithm, NEXT FIT ALGORITHM Here scanning starts fro...

NEXT FIT ALGORITHM Here scanning starts from the first fit position and then it finds the next position which is large sufficient to hold the process. Thus the name next fit.

Major advantage of the layered approach to system design, Q. What is the ma...

Q. What is the major advantage of the layered approach to system design? What are the de-merits of using the layered approach? Answer: As in all cases of modular design as well

Define the term operating system, Question: a) Define the term ‘Operat...

Question: a) Define the term ‘Operating System' and identify two goals of an operating system. b) What do you understand by Symmetric multiprocessing (SMP) and Asymmetr

Paging, protection in paging

protection in paging

Operating systems structures, with the aid of diagrams describe the followi...

with the aid of diagrams describe the following OS structure monolithic,layered and client server.

What are threads?, What are threads? A thread is alike to sequential pr...

What are threads? A thread is alike to sequential programs. Single threads have a beginning, sequence and end. At any given point in time during the runtime of the thread there

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd