Linux中線程的掛起與恢復（進程暫停）

今天在網上查了一下Linux中對進程的掛起與恢復的實現，相關資料少的可憐，大部分都是粘貼復制。也沒有完整詳細的代碼。故自己整理了一下

程序流程為：主線程創建子線程（當前子線程狀態為stop停止狀態），5秒後主線程喚醒子線程，10秒後主線程掛起子線程，15秒後主線程再次喚醒子線程，20秒後主線程執行完畢等待子線程退出。

代碼如下：
#include
#include
#include
#include
#include

#define RUN 1
#define STOP 0

pthread_mutex_t mut = PTHREAD_MUTEX_INITIALIZER;
pthread_cond_t cond = PTHREAD_COND_INITIALIZER;

int status = STOP;
void * thread_function(void)
{
static int i = 0;
while (1)
{
pthread_mutex_lock(&mut);
while (!status)
{
pthread_cond_wait(&cond, &mut);
}
pthread_mutex_unlock(&mut);

printf("child pthread %d\n", i++);
if (i == 20)
break;
sleep(1);
}
}

void thread_resume()
{
if (status == STOP)
{
pthread_mutex_lock(&mut);
status = RUN;
pthread_cond_signal(&cond);
printf("pthread run!\n");
pthread_mutex_unlock(&mut);
}
else
{
printf("pthread run already\n");
}
}

void thread_pause()
{
if (status == RUN)
{
pthread_mutex_lock(&mut);
status = STOP;
printf("thread stop!\n");
pthread_mutex_unlock(&mut);
}
else
{
printf("pthread pause already\n");
}
}

int main()
{
int err;
static int i = 0;
pthread_t child_thread;

#if 0
if (pthread_mutex_init(&mut, NULL) != 0)
printf("mutex init error\n");
if (pthread_cond_init(&cond, NULL) != 0)
printf("cond init error\n");
#endif

err = pthread_create(&child_thread, NULL, (void *)thread_function, NULL);
if (err != 0 )
printf("can't create thread: %s\n", strerror(err));
while(1)
{
printf("father pthread %d\n", i++);
sleep(1);
if (i == 5)
thread_resume();
if (i == 10)
thread_pause();
if (i == 15)
thread_resume();
if (i == 20)
break;
}
if (0 == pthread_join(child_thread, NULL))
printf("child thread is over\n");
return 0;
}