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 deadlock, Explain Deadlock Every process in a set of processes ...

Explain Deadlock Every process in a set of processes is waiting for an event which only a process in the set can cause.

Create a gantt chart for scheduling algorithms, Question: (a) The follo...

Question: (a) The following table (table 1.0) gives the length of the CPU burst time in milliseconds of processes P 1 to P 4 . Assume the processes arrived in the order P 1 ,

Allocation techniques, Since most of the programs require a lot of memory a...

Since most of the programs require a lot of memory allocation/deallocation, we expect the memory management to be fast, to have low fragmentation, make good use of locality, and be

Briefly discuss on bankers algorithm, Briefly discuss on Bankers algorithm?...

Briefly discuss on Bankers algorithm? The resource-allocation graph algorithm is not applicable to a resource-allocation system with multiple examples  for each resource type.

Why do organisations need a structure, Problem 1: (a) The grouping of o...

Problem 1: (a) The grouping of organisational activities (usually into ‘departments' or larger ‘divisions') can be done in different ways. Outline 7 criteria which can be used

Management, what is secondary storage management

what is secondary storage management

Linux kernel components, Example 1.  The diagram illustrating the data stru...

Example 1.  The diagram illustrating the data structures of in-memory VFS objects and on-disk objects and their relationships on slide 24 of the lecture notes OSD.4. This diagram i

What do you mean by semaphore?, What do you mean by semaphore?  Semap...

What do you mean by semaphore?  Semaphore : A synchronization variable that acquires on positive integer values. Invented by the Dijkstra P (semaphore): an atomic proce

THREADS, advantage and dis advantage of threads

advantage and dis advantage of threads

How relocation bits used by relocating loader are specified, Relocation bit...

Relocation bits employed by relocating loader are specified by Relocation bits employed by relocating loader are specified by Assembler or Translator

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