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

What are the different file operations?, What are the different file operat...

What are the different file operations? Create : - Space for the file in the file system update directory table. Write : - file name and data to be written is

Define logical address and physical address, Define logical address and phy...

Define logical address and physical address. An address formed by the CPU is referred as logical address. An address seen by the memory unit that is the single loaded into the

Explain disk scheduling algorithms-scan, SCAN o Go from the outside to...

SCAN o Go from the outside to the inside servicing requests and after that back from the outside to the inside servicing requests. o Replicate this over and over. o Diminish

Explain direct communication and indirect communication, Direct communicati...

Direct communication With direct communication each process that requires to communicate must explicitly name the recipient or sender of the communication. The send and receive

Explain how situation can be solved using active directory, Question: a...

Question: a) Windows Server 2003 has brought great enhancements the Server System as compared to the previous version. Write down short notes on the below listed enhancements.

Describe the concept of transaction atomicity, Q. Describe the concept of t...

Q. Describe the concept of transaction atomicity? Answer: A transaction is a sequence of read as well as writes operations upon some data followed by a commit operation. If the

Explain what type of group scope you will use, Question: (a) The actual...

Question: (a) The actual use and scope groups depend on the mode in which a domain is running. There are two domain modes in which you can run a Windows 2000 domain. List and d

Determine a processing that is not a part of synthesis phase, Determine a p...

Determine a processing that is not a part of Synthesis phase  Perform LC processing is not a part of Synthesis phase

Illustrate example for segmentation, EXAMPLE FOR SEGMENTATION Consider ...

EXAMPLE FOR SEGMENTATION Consider an instance as given in the table and we have five segments numbered from 0 through 4 the segment is stock in the physical memory as shown. Th

Explain schemes for defining the logical structure, What are the most commo...

What are the most common schemes for defining the logical structure of a directory? The most common schemes for explaining the logical structure of a directory Single-L

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