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 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

Memory Management Problems, Sir i want formulas in Memory management starti...

Sir i want formulas in Memory management starting from paging till the demang paging in a easy manner for solving problems in competitive exams

System protection, what is the need-to-know principle? why is it important ...

what is the need-to-know principle? why is it important for a protection system to adhere to this principle?

Define thrashing, Define thrashing. Thrashing is the accident of high p...

Define thrashing. Thrashing is the accident of high page traffic and low CPU utilization. It is observed that the cause of thrashing is an under-commitment of memory to program

Describe the purpose of the checkpoint mechanism, Describe the purpose of t...

Describe the purpose of the checkpoint mechanism. How habitually must checkpoints be performed? Explain how the frequency of checkpoints affects: System performance while no

What are the disadvantages of linked allocation, What are the disadvantages...

What are the disadvantages of linked allocation? The drawbacks are a. Used only for sequential access of files. b. Direct access is not supported c. Memory space neede

What is an i/o subsystem?, What is an I/O subsystem? The control of dev...

What is an I/O subsystem? The control of devices connected to the computer is a main issue while designing operating systems. Since I/O devices differ widely in their function

Making the transition to client - server programming, Making the Transition...

Making the Transition to Client - Server Programming Making the transition to client - server programming is a significant effort. Client - server applications must be designed

What is the drawbacks of contiguous allocation of disk space, What are the ...

What are the drawbacks of contiguous allocation of disk space? The disadvantages are a. Suffers from internal fragmentation b. Suffers from external fragmentation c. F

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