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

Explain the various page replacement strategies, Explain the various page r...

Explain the various page replacement strategies. Page replacement-basic scheme with diagram Optimal page replacement LRU page replacement FIFO page replacement LRU

Name the evolutionary process models, Normal 0 false false ...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

What is a semaphore, Question 1: a) State the different file attribute...

Question 1: a) State the different file attributes and briefly explain the operations that can be performed on each files. b) What is a semaphore? Describe why it is impor

Define the term system software, Question: (a) Define the term system ...

Question: (a) Define the term system software and application software, giving an example for each. (b) Draw a diagram to represent the abstract view of a computer system i

What is meant by demand paging? explain, What is meant by demand paging? Ex...

What is meant by demand paging? Explain. Demand paging is a technique to implement virtual memory. In demand paging simply when a page is required it is brought into memory. As

Define a policy for data storage, Produce a referenced four page report whi...

Produce a referenced four page report which describes the possible functionality of the system; similar systems that are out there and different possible approaches to delivering t

What are the major differences between operating systems, Q. What are the m...

Q. What are the major differences between operating systems for mainframe computers and personal computers? Answer: In general operating systems for batch systems have simpler

Explaintable management techniques, Discuss in detail Table management Tech...

Discuss in detail Table management Techniques?     An Assembler employs the subsequent tables: OPTAB: Operation Code Table consists of mnemonic operation code and its machi

Advanced synchronization, Synchronization serves two purposes: 1) to ensure...

Synchronization serves two purposes: 1) to ensure safety for updates on shared data (e.g. to avoid races conditions), and 2) to coordinate and order actions taken by threads (e.g.

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