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

Tlb replacement algorithm, Suppose a logical address space is 1KB, and the ...

Suppose a logical address space is 1KB, and the page-size is 16 bytes. Assume no page is in the main memory for this process initially and the pure demand paging is used. Current f

Define lru page replacement algorithm, Define LRU Page Replacement Algorith...

Define LRU Page Replacement Algorithm LRU policy: LRU expands to least currently use. This policy suggests which we re- move a page whose last usage is farthest from current ti

Key piece of information stored in single page table entry, Define which is...

Define which is not a key piece of information, stored in single page table entry, supposing pure paging and virtual memory  A reference for the disk block which stores the pa

Use of c and c++, One reason to learn C and C++ is simply that so much soft...

One reason to learn C and C++ is simply that so much software is written in these languages. A related, butmore fundamental reason, is that C and C++ are relatively low-level, allo

Cpu, what is cpu

what is cpu

System service program, System Service Program system service program S...

System Service Program system service program Supports and provides the services for other program. System service program perform Varity of tasks.  They are further divided in

Define process swapping , Swapping : Whole process is moved from the swap...

Swapping : Whole process is moved from the swap machine to the main memory for execution. Process size must be equal or less than to the used main memory. It is easier to exe

What are conditions under which a deadlock situation arise, What are condit...

What are conditions under which a deadlock situation may arise? A deadlock situation can arise if the following four conditions hold simultaneously in a system: a. Mutual ex

Steps to run a program on a completely dedicated machine, Q. List the four ...

Q. List the four steps that are essential to run a program on a completely dedicated machine. Answer: a) Reserve machine time b) Manually load program into memory c)

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