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 basic concepts of segmentation, Explain the basic concepts of s...

Explain the basic concepts of segmentation. Segmentation definition User view of program Hardware used with diagram-segment table, base, limit & offset Protection and

What is the use of fork and exec system calls, What is the use of fork and ...

What is the use of fork and exec system calls? Fork is a system call by which a latest process is created. Exec is also a system call, which is used after a fork by one of the

Mutual exclusion variable, Since each thread has its own processing space t...

Since each thread has its own processing space therefore communication between threads will need to be done through a common global variable. Since multiple threads can access the

Operating system, What criteria are important in choosing a file organisati...

What criteria are important in choosing a file organisation?

Illustrate scope of consumer behaviour, Q. Illustrate Scope of Consumer beh...

Q. Illustrate Scope of Consumer behaviour ? Scope of consumer behaviour is extremely wide due to following reasons: >>Ever rising intensifying competition. >>Additional a

Write about critical regions and monitors, Write about critical regions and...

Write about critical regions and monitors. Critical region definition Monitor definition Implementation of the conditional-region construct Syntax of monitor Monito

What is meant by file management systems?, What is meant by file management...

What is meant by file management systems? File Management systems are as well referred to as simply a file system .File system is the system that an OS operating system or prog

Define file permission in unix, The permission function is used to calculat...

The permission function is used to calculate what, if any access each class or level of user has to each file on a Unix machine. The permission task is one of the data components s

Explain process termination - operating system, Process termination A p...

Process termination A process terminates when it finishes implementing its final statement and asks the operating system to delete it by using the exit system call. At that tim

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