[C language] detailed explanation of threads - multi threads for collaborative operation

Catalog

1、 problem

2、 problem solving

---

1、 problem

Summation problem , A child thread calculation 1 + ... + 499 Value , Another thread calculates 500 + ... + 1000 Value , The sum of the last two is added , Or get 1 + ... + 1000 Value .

2、 problem solving

#include <stdio.h>
#include <pthread.h>

int sum_1 = 0;
int sum_2 = 0;

//  Functions executed by threads 
void* myFunc_1(void* args)
{
    for(int i = 1; i < 500; i++)
    {
        sum_1 = sum_1 + i;
    }
}

//  Functions executed by threads 
void* myFunc_2(void* args)
{
    for(int i = 500; i <= 1000; i++)