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

Write a short note on file organization and access, Write a short note on f...

Write a short note on file organization and access. There are three methods to access files 1Record Access 2Sequential Access 3Random Access The record access

What is process control block, What is process control block? Every pro...

What is process control block? Every process is represented in the OS by a process control block. It has many pieces of information associated with an exact process.

Write in brief on unix file structure, Write in brief on UNIX file structur...

Write in brief on UNIX file structure. UNIX considers every file to be a sequence of 8-bit bytes no interpretation of these bits is made by the operating system. This system pr

What is the sequence of a page fault causes to occur, A page fault causes t...

A page fault causes the following sequence to occur. 1. Trap (shut in) to the operating system. 2. Save the process registers and process state. 3. Verify that the interr

Locks - mutexes, Locks (also known as mutexes, short for mutual exclusion l...

Locks (also known as mutexes, short for mutual exclusion locks) provide mutual exclusion to shared data inside a critical session. They are implemented by means of two atomic routi

Explain about directory structure, Normal 0 false false fal...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

What is the concept of an atomic operation, Question: Concurrency and Sync...

Question: Concurrency and Synchronization a) Define the following terms: I. Critical section II. Mutual Exclusion III. Deadlock IV. Starvation. b) Name three methods w

Explain medium term scheduling, Medium term scheduling This is componen...

Medium term scheduling This is component of the swapping function. Usually the swapping in decision is based on the need to manage the degree of multiprogramming. At a system t

Single-level page table, Consider a computer system with a 32-bit logical a...

Consider a computer system with a 32-bit logical address and 4KB page size. The system supports up to 512MB of physical memory. How many entries are there in a conventional single-

Explain fixed partitioning, Explain fixed partitioning. Partitioning ar...

Explain fixed partitioning. Partitioning are the simpler techniques that don't involve virtual memory. Partitioning has been used in numerous variations in operating systems.

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