Linux C中多线程与volatile变量

#include <stdio.h> 
#include <stdlib.h> 
#include <pthread.h> 
 
/* volatile变量控制线程的运行与结束 */ 
static volatile int do_run_thread = 1;  
 
static pthread_t thread_tid; 
 
static void *work_thread(void *arg) 
{ 
  while (do_run_thread) { 
    printf("thread is running...\n"); 
    sleep(1); 
  } 
  printf("stop thread done!\n"); 
} 
 
static void start_thread() 
{ 
  printf("start thread...\n"); 
  pthread_create(&thread_tid, NULL, work_thread, NULL); 
} 
 
static void stop_thread() 
{ 
  printf("stop thread...\n"); 
  do_run_thread = 0; 
  pthread_join(thread_tid, NULL); /* 等待线程结束 */ 
} 
 
int main() 
{ 
  start_thread(); 
  sleep(5); 
  stop_thread(); 
 
  return 0; 
}