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 fixed partitioning in memory management, FIXED PARTITIONING Us...

FIXED PARTITIONING Using fixed partitioning we are able to allocate the memory Here we are dividing the memory into a few fixed partitions.Every partition may not be of the si

What is the basic approach of page replacement, What is the basic approach ...

What is the basic approach of page replacement? If no frame is free is available, find one that is not presently being used and free it. A frame can be freed by writing its con

List post-installation procedures that need to be performed, Problem: (...

Problem: (a) Based on your experience in setting up Windows 2003 Server operating system, briefly describe the twelve different steps in which the installation is conducted du

Explain three major components of page-fault service time, We are faced wit...

We are faced with three major components of the page-fault service time. 1. Service the page-fault interrupts. 2. Read in the page. 3. Restart the processes.

Describe the file system architecture, Describe the file system architectur...

Describe the file system architecture. File System Architecture contains the subsequent components:- Device Driver 1 Device Driver 2 Device Driver 3 Basic fi

Allocating new pages, Processes have valid and invalid entries on their pag...

Processes have valid and invalid entries on their page tables. The valid entries all point to some where "real" (e.g. a physical page, or some portion of disk in case of non-reside

Explain combined ult/klt approaches, COMBINED ULT/KLT APPROACHES Idea i...

COMBINED ULT/KLT APPROACHES Idea is to merge the best of both approaches Solaris is an illustration of an OS that combines both ULT and KLT  Thread creation complete i

Why we need to use a while statement when using wait method, Q. The wait()...

Q. The wait() statement in every Java program examples was part of a while loop. Describe why you would always need to use a while statement when using wait() and why you would ne

What disadvantages are there to this two-level directory, What disadvantage...

What disadvantages are there to this two-level directory? Without other provisions, two users who require cooperating with each other are hampered in reaching every other's fi

State in a deadlock-avoidance system, Question: In a deadlock, processe...

Question: In a deadlock, processes never finish executing and system resources are tied up, preventing other jobs from starting. Deadlocks can be characterised by a set of cond

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