c多线程不加锁demo

Arce

//
// Created by gxf on 2019/12/13.
//
#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
int shareInt = 0;
void increase_num(void);
int main() {
  int ret;
  pthread_t thread1, thread2, thread3;
  ret = pthread_create(&thread1, NULL, increase_num, NULL);
  ret = pthread_create(&thread2, NULL, increase_num, NULL);
  ret = pthread_create(&thread3, NULL, increase_num, NULL);
  pthread_join(thread1, NULL);
  pthread_join(thread2, NULL);
  pthread_join(thread3, NULL);
  printf("sharedInt:%d\n", shareInt);
  return 0;
}
void increase_num(void) {
  long i, tmp;
  for (i=0; i <= 100000; i++) {
    tmp = shareInt;
    tmp = tmp + 1;
    shareInt = tmp;
  }
}