unistd.h stdio.h main argc argv sleep(1); while printf(""); pid_t fork(void); void e
xit(int status);void _exit(int status); pid_t wait(int *status); #include <sys/wait.h
> #include <pthread.h> int pthread_create(pthread_t *thread, const pthread_attr_t *att
r, void *(*routine)(void *), void *arg);void pthread_exit(void *retval); pthread_t pthr
ead_self(void); pthread_create(pthread_t *thread, const pthread_attr_t *attr, void *(*rou
tine)(void *), void *arg); int pthread_join(pthread_t thread, void **retval);int pthre
ad_mutex_init(pthread_mutex_t *mutex, const pthread_mutexattr_t * attr);int pthread_mu
tex_destroy(pthread_mutex_t *mutex) int pthread_mutex_lock(pthread_mutex_t *mutex);int p
thread_mutex_unlock(pthread_mutex_t *mutex);int pthread_cond_wait(pthread_cond_t *restrict
cond, pthread_mutex_t *restrict mutex);int pthread_cond_timedwait(pthread_cond_t *restri
ct cond,​ pthread_mutex_t *restrict mutex, const struct timespec *restrict abstime);int pt
hread_cond_signal(pthread_cond_t *cond);int pthread_cond_broadcast(pthread_cond_t *cond);