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

Example of producer consumer - semaphore, Now let's implement bounded produ...

Now let's implement bounded producer-consumer with semaphores, a Coke machine which is initially empty: semaphore sem_mutex = 1 // binary semaphore for mutual exclusion, 1==unlo

Define race condition, Define race condition. When various process acce...

Define race condition. When various process access and manipulate similar data concurrently, then the outcome of the execution depends on certain order in which the access take

Describe the differences among short-term and medium-term, Describe the dif...

Describe the differences among short-term, medium-term, and long-term scheduling.   Short-term (CPU scheduler)-selects from jobs in memory those jobs that are ready to execu

Real time operating system, PART A Question 1 Using your own words...

PART A Question 1 Using your own words, explain what a continuous random variable and a continuous probability density function are. Give examples. Question 2 Gi

Write a note on deadlocks, Write a note on deadlocks. The proper defini...

Write a note on deadlocks. The proper definition of deadlock A set of processes is deadlocked if every process in the set is waiting for an event that only a proces

Determine the task of the pass ii in a two-pass assembler, Determine the ta...

Determine the task of the Pass II In a two-pass assembler Synthesize the target program is the task of the Pass II

Define most common phase structured grammar, Which is most common phase str...

Which is most common phase structured grammar? Most common phase structured grammar is Context – Sensitive

AIMMS3.9, Do you have writers that can use the software AIMMS version 3.9?

Do you have writers that can use the software AIMMS version 3.9?

Define input - output operations, Q. Define Input - Output operations? ...

Q. Define Input - Output operations? Serial lines, Disks, tapes and other devices should be communicated with at a very low level. The user require only specify the device and

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

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