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

Multiprogramming, what are the main advantages of multiprogramming

what are the main advantages of multiprogramming

Prepare gantt charts and determine the average waiting time, Prepare Gantt ...

Prepare Gantt Charts and Determine the Average Waiting Time 1. Classify the interaction among the processes on the basis if degree to which they are aware of each  other's exi

Explain micro-kernel, Operating Systems 1. Explain Micro-kernel? Specif...

Operating Systems 1. Explain Micro-kernel? Specify the benefits of Micro-kernel? 2. Describe seven state process models used for OS with necessary diagram. Differentiate bet

Differences among user-level threads and kernel-level thread, Q. What are t...

Q. What are two differences among user-level threads and kernel-level threads? Under what situations is one type better than the other? Answer: (1) User-level threads are un

What are the deadlock prevention methodologies?, What are the deadlock p r...

What are the deadlock p revention methodologies? a.       Necessitate that processes request all resources before starting - if cannot be granted don't run. b.      Process

Explain clustered file organization, Clustered file organization A cl...

Clustered file organization A clustered file is also called a B-tree-clustered file is a tree-structured file in which records with adjacent index values are clustered toget

Clocks in distributed systems, Clocks in distributed systems : a. Why ar...

Clocks in distributed systems : a. Why are clocks difficult to synchronize in distributed systems? b. What features in a system assume that the clocks are (reasonably) synchr

Inter-process Communication !, My code it didn''t run properly ,i tried to ...

My code it didn''t run properly ,i tried to pass 2 parameter example : ./a.out ls -ll ,but it execute only the ls instead of the ls -ll ! plz help amd thank you ! #include #inclu

Determine what the expansion of nested macro calls follows, Determine what ...

Determine what the expansion of nested macro calls follows  The expansion of nested macro calls follows the Last in First out (LIFO) rule.

How can the deadlock be prevented-safe state, How can the deadlock be preve...

How can the deadlock be prevented-Safe State Safe state : A state is safe if the system is able to allocate resources to each process in some order and still avoid deadlock.

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