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

What are two probable uses of these multiple modes, Q. Several CPUs provide...

Q. Several CPUs provide for more than two modes of operation. What are two probable uses of these multiple modes? Answer: Although most systems merely distinguish between use

What is sector sparing, What is sector sparing? Low-level formatting al...

What is sector sparing? Low-level formatting also sets aside extra sectors not visible to the operating system. The controller can be told to change each bad sector logically w

Define ufd and mfd, Define UFD and MFD. In the two-level directory stru...

Define UFD and MFD. In the two-level directory structure, every user has her own user file directory (UFD). Every UFD has a similar structure, but lists only the files of a one

What is a file, What is a file? A file is a named collection of related...

What is a file? A file is a named collection of related information that is recorded on secondary storage. A file having either programs or data. A file has particular "structu

Describe the benefits of using microkernels, Question: (a) (i) What is ...

Question: (a) (i) What is a microkernel? Describe the benefits of using microkernels. (ii) How does a microkernel-based operating system differ from a traditional operating

Define loader that executed when system is first turned on, Define a loader...

Define a loader that is executed when a system is first turned on or restarted? Bootstrap loader is executed when a system is first turned on or restarted

Explain the threadswitch function used in the netware, Explain the ThreadSw...

Explain the ThreadSwitch function used in the netware Since NetWare 3 and 4 are nonpreemptive environments, it may be necessary for the application developer to explicitly reli

Explain the advantage of assembly language, Explain the Advantage of Assemb...

Explain the Advantage of Assembly Language The advantages of assembly language program is: a)    Reduced errors  b)    Faster translation times  c)    Changes could be ma

What are the necessary conditions for deadlocks?, What are the necessary co...

What are the necessary conditions for deadlocks? 1. Mutual exclusion :  Only one process at a time is able to use the resource. 2. Hold and wait :  A process should be holdi

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