Question

Write a c program to implement threads. Accept an array of 40 integers, write a thread method named sum of array elements. Divide the array into 4 equal elements and call threads to find the sum of each part. Store the sum in a variable called “arrays'. Print the sum in the main function. (10 points)

Answer 1

Answer: Hi!! Kindly finds your solution below. Let me know if any issue. Thanks.

This C program has an array with 40 integers. A thread method that divides the array into 4 parts and calculating the sum of each part. In the driver code, the main function creates 4 threads then joins all threads and the last print sum of all threads means all integers. Any confusion is there then feel free to ask me.

C-Code:

#include <stdio.h>
#include <pthread.h>
#include<stdlib.h>
  
// size of array
#define MAX_SIZE 40
  
// maximum number of threads
#define MAX_THREAD 4

int a[] = { 1, 5, 7, 10, 12, 14, 15, 18, 20, 22, 25, 27, 30, 64, 110, 2,3,11,4,9,6,34,10,17,19,21,13,
21,23,19,31,33,35,37,39,41,44,52,50,65}; //array with 40 integers
int sum[4] = { 0 };
int part = 0;
int arrays = 0;
  
void* sum_array(void* arg) //function
{
  
// divide array in 4 parts
int thread_part = part++;
  
for (int i = thread_part * (MAX_SIZE / 4); i < (thread_part + 1) * (MAX_SIZE / 4); i++)
sum[thread_part] += a[i];
}
  
// Driver Code
int main()
{
  
pthread_t threads[MAX_THREAD];
  
// Creating 4 threads
for (int i = 0; i < MAX_THREAD; i++)
pthread_create(&threads[i], NULL, sum_array, (void*)NULL);
  
// joining 4 threads i.e. waiting for all 4 threads to complete
for (int i = 0; i < MAX_THREAD; i++)
pthread_join(threads[i], NULL);
  
// calculate the sum of all 4 parts
  
for (int i = 0; i < MAX_THREAD; i++)
arrays += sum[i];
  
printf("Sum is: %d",arrays);
  
return 0;
}

Output:

pthread_join(threads[i], NULL); // calculate sum of all 4 parts for (int i = 0; i <MAX_THREAD; i++) arrays += sum[i]; 44 Sum is: 1019 ... Program finished with exit code o Press ENTER to exit console.