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

Subject: system analysis (2000 word), Overview: In this assignment, you are...

Overview: In this assignment, you are going to perform a system analysis and design of a membership and facility management system of a gymnasium of given case study Task: You are

Define field that contain segment index or an internal index, The field tha...

The field that consists of a segment index or an internal index is known as Target datum is field that consists of a segment index or an internal index.

Memory management, what is hashed page tables & explain of there work & fig...

what is hashed page tables & explain of there work & figure

Write a short note about schedulers, Write a short note about schedulers. ...

Write a short note about schedulers. Processes migrate between the various scheduling queues throughout its life time. The operating system should select for scheduling purpose

Control the access of the three global variables, Give a brief introduction...

Give a brief introduction about the operation of your program and show that you understand the idea behind threads and mutual exclusion variable. Why do we need to use mutual exclu

Do ratio analysis of financial statements, Do ratio analysis by comparing t...

Do ratio analysis by comparing the four companies financial statements, analysis and interpretation on the four-basic group : (Refer to attachment A) Liquidity ratio Asset

Fibonacci sequence, #questionThe Fibonacci sequence is the series of number...

#questionThe Fibonacci sequence is the series of numbers 0,1,1,2,3,5,8,… Formally, it can be expressed as: fib0 = 0 fib1 = 1 fibn = fib n-1 + fib n-2 Write a C program u

What is directory, What is Directory? The device directory or simply ca...

What is Directory? The device directory or simply called as directory records information-such as name, location, size, and type  for all files on that certain partition. The d

Describe why sstf scheduling tends to favour middle cylinder, Q. Describe w...

Q. Describe why SSTF scheduling tends to favour middle cylinders over the innermost and outermost cylinders. Answer: The middle of the disk is the location having the smalles

What problems arise if the directory is a general graph, What problems aris...

What problems arise if the directory structure is a general graph? Searching for a particular file may result in searching the similar directory many times. Deletion of the fil

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