Question

I must execute in C using parallel Programming techniques the following serial program:

void producer_consumer(int *buffer, int size, int *vec, int n) {
   int i, j;
   long long unsigned int sum = 0;
   for(i=0;i<n;i++) {
       if(i % 2 == 0) {   // PRODUCER
           for(j=0;j<size;j++) {
               buffer[j] = vec[i] + j*vec[i+1];
           }
       }
       else {   // CONSUMER
           for(j=0;j<size;j++) {
               sum += buffer[j];
           }
       }
   }
   printf("%llu\n",sum);
}

HEADS UP:
All threads must alternate between producers and consumers among the iterations. In other words, when the iteration in the main loop is even, the thread is a producer, otherwise, a consumer.

The producer shall receive a value as an input reference, compute and store the result into a buffer in which the consumer will read in the next iteration. Consequently, the consumer shall read all computed values and sum them.

PROBLEM DESCRIPTION:
You must parallelize the above serial algorithm using OpenMP Pragmas. The program shall receive as an input 4 lines: The first one containing an integer which represents the number of threads that the program will eventually be executed. The second line contains a N integer, ALWAYS EVEN, which is the number of iteration in the main loop, it means, how many cycles of consumer-producer might occur, the third line contains an integer which is the buffer size, and the 4th line the N values used as a database for calculating the algorithm. THE VALUES MUST BE READ FROM A STANDARD INPUT (stdin) USING scanf() as following:

2 -> Number of threads
10 -> Cycles Producer + Cycles Consumer in the main loop
10 -> Buffer size
6 4 8 4 5 3 2 1 6 7 -> Values

Answer 1

Note: Given function producer consumer ) code used as it is without any changes Solution include required header files #include #include #include <stdio.h> <stdlib.h> <omp.h> // Given producerconsumer function code void producer_consumer (int *buffer, int size, int *vec, int n) long long unsigned int sum0; for (i-0; i<n;i++) [ LE (¡%2#-0) { // PRODUCER for (j=0 ; j <size; j++) buffer[vec[i j ec[i+1]; else CONSUMER for (j=0 ; j<size;J++) { sum + bufferji printf("llu\n", sum) // main method to execute the given producer_consumer function code int main () / Declare the requierd variables int nm thrds, cyls, buf size, *buffr NULL, *vectr-NULL; int lp; double stTme; printf ("Enter the value for number of threads, cycle, and buffer size: "); scanf ("%d %ded", &nrn_thras, &cyls, &buf-size); buffr= (int *) malloc (buf size * sizeof (int)); vectr (int *) malloc (buf size * sizeof (int)); if (buffr== NULL) { fprintf (stderr, "Could not allocate buffer\n") exit (1)

Copyable code:

// include required header files

#include <stdio.h>

#include <stdlib.h>

#include <omp.h>

// Given producer_consumer function code

void producer_consumer(int *buffer, int size, int *vec, int n)

{

    int i, j;

    long long unsigned int sum = 0;

    for(i=0;i<n;i++) {

        if(i % 2 == 0) {    // PRODUCER

            for(j=0;j<size;j++) {

                buffer[j] = vec[i] + j*vec[i+1];

            }

        }

        else {    // CONSUMER

            for(j=0;j<size;j++) {

                sum += buffer[j];

            }

        }

    }

    printf("%llu\n",sum);

}

// main method to execute the given producer_consumer function code

int main ()

{

     // Declare the requierd variables

    int nm_thrds, cyls, buf_size, *buffr=NULL, *vectr=NULL;

    int lp;

    double stTme;

printf("Enter the value for number of threads, cycle, and buffer size:");

    scanf("%d %d %d", &nm_thrds, &cyls, &buf_size);

    buffr = (int *) malloc (buf_size * sizeof(int));

    vectr = (int *) malloc (buf_size * sizeof(int));

    if (buffr == NULL) {

        fprintf (stderr, "Could not allocate buffer\n");

        exit (1);

    }

    for (lp = 0; lp < buf_size; lp++) {

        scanf ("%d", &vectr[lp]);

    }

    // set the number o threads specified in input

    omp_set_num_threads(nm_thrds);

    stTme = omp_get_wtime();

    producer_consumer(buffr, cyls, vectr, buf_size);

    printf("%lf\n", omp_get_wtime() - stTme);

    return 0;

}