Deadlock_test2.cc

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


pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;

void* doit(void* arg)
{
	printf("pid = %d begin doit ...\n",static_cast<int>(getpid()));
	pthread_mutex_lock(&mutex);
	struct timespec ts = {2, 0};
	nanosleep(&ts, NULL);
	pthread_mutex_unlock(&mutex);
	printf("pid = %d end doit ...\n",static_cast<int>(getpid()));

	return NULL;
}

void prepare(void)
{
	pthread_mutex_unlock(&mutex);
}

void parent(void)
{
	pthread_mutex_lock(&mutex);
}

int main(void)
{
	pthread_atfork(prepare, parent, NULL);
	printf("pid = %d Entering main ...\n", static_cast<int>(getpid()));
	pthread_t tid;
	pthread_create(&tid, NULL, doit, NULL);
	struct timespec ts = {1, 0};
	nanosleep(&ts, NULL);
	if (fork() == 0)
	{
		doit(NULL);
	}
	pthread_join(tid, NULL);
	printf("pid = %d Exiting main ...\n",static_cast<int>(getpid()));

	return 0;
}