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

Major advantage of the layered approach to system design, Q. What is the ma...

Q. What is the major advantage of the layered approach to system design? What are the de-merits of using the layered approach? Answer: As in all cases of modular design as well

Which of the subsequent instructions should be privileged, Q. Which of the ...

Q. Which of the subsequent instructions should be privileged? a) Read the clock b) Clear memory c) Set value of timer d) Issue a trap instruction e) Turn off interr

Define local procedure call, Q. What kinds of services does the process man...

Q. What kinds of services does the process manager provide? Define local procedure call? Answer: The process manager offers services for creating and deleting and using proce

Explain the tlsalloc (void) - tls function call, Explain the TlsAlloc (VOID...

Explain the TlsAlloc (VOID) This function is used to allocate a TLS index.Any subsequent TLS function calls will require  the handle returned  from TlsAlloc to be passed. The i

Explain relative file organization, Relative file organization A rela...

Relative file organization A relative file is an array of fixed-length slots and the records can be inserted in the first free slot found from the beginning of the file and

How does an operating system make multiprogramming possible, How does an op...

How does an operating system make multiprogramming possible by using single processor?

Calculate the maximum file size , A UNIX file system has 1-KB blocks and 4-...

A UNIX file system has 1-KB blocks and 4-byte disk addresses. What is the maximum file size if i-nodes contains 10 direct entries, and one single, double, and triple indirect entry

Describe the state when you run an unlink operation, Describe when you run ...

Describe when you run an unlink() operation to remove a file on the ext3 file system. Be specific about what disk blocks have to be written where in what order. State your assumpti

Batch system, what is a batch system give me answer in simple words so that...

what is a batch system give me answer in simple words so that i can understand

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