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 advantages and drawback of multiple processes, Explain the Adva...

Explain the Advantages and Drawback of Multiple Processes Application architected to take advantage of multiple processes will certainly see performance gains. Functions and Fe

Explai basic concepts of demand paging, Basic concepts When a process i...

Basic concepts When a process is to be changed in, the pager guesses which pages will be used before the process is changed out again. Instead of swapping in a entire process,

Explain the proper distribution of functionality and code, Explain the Prop...

Explain the Proper Distribution of Functionality and Code It is important to note that the bandwidth of the server operating system and server processor availability is fixed.

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.

Define projected allocation state is safe - banker algorithm, A system cons...

A system consists of 10 units of resource class Ru. The resource needs of three user processes P1, P2 and P3 are like this                     Using Banker's algorithm, de

Explain about threading issues, Explain about threading issues? The for...

Explain about threading issues? The fork and exec system calls In a multithreaded program of few UNIX systems have chosen to have two versions of fork, one that duplicates e

Explain hashed page table method, Hashed page table method A general ap...

Hashed page table method A general approach for managing address spaces larger than 32 bits is to use a hashed page table with the hash values being the virtual-page number.

Write on short note dma., Write on short note DMA. Direct M emory...

Write on short note DMA. Direct M emory Access (DMA) is a technique for transferring data from  main to a device without passing it through the CPU. Computers that have

Memory management unit, When a program issues a memory load or store operat...

When a program issues a memory load or store operation, the virtual addresses (VAs) used in those operations have to be translated into "real" physical memory addresses (PAs). This

Define an imperative statement, Determine an imperative statement Imper...

Determine an imperative statement Imperative statement points out an action to be carried out during execution of assembled program

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