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

Mention the various features that characteristics deadlock, Mention the var...

Mention the various features that characteristics the deadlock condition .  The four circumstances that give rise to deadlock condition are: 1) Mutual exclusion : As a minim

Designing issues in a network-scalability, Scalability Scalability is t...

Scalability Scalability is the ability of the system to adapt to increased service load. A scalable system will respond more gracefully to increased load than a non scalable on

Describe the possible rmi invocation semantics, Question: (a) Explain t...

Question: (a) Explain the similarities and differences between two different threads running in the same process and two independent processes. When would you want to use two t

Write a short note about the different states of a process, Write a short n...

Write a short note about the different STATES of a process. As a process implement it changes state. The state of a process is described in part by the current activity of that

What are the various categories of software, What are the various categorie...

What are the various categories of software?  System software Application  software Engineering/Scientific software Embedded software  Web Applications Artificial I

What is busy waiting, What is busy waiting? The repeated implementation...

What is busy waiting? The repeated implementation of a loop of code while waiting for an event to happen is known as busy-waiting. The CPU is not engaged in any actual producti

Bind a real-time thread to an lwp, Q. Suppose an operating system maps user...

Q. Suppose an operating system maps user-level threads to the kernel utilizing the many-to-many model where the mapping is done through the use of LWPs. In addition the system allo

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

unix script command and echo command, Objectives 1.    Login to UNIX ...

Objectives 1.    Login to UNIX system and logout 2.    Learn features of the vi editor and to use online help (main pages).  Gain experience using them to create a document

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