typedef struct pthread_mutex_s pthread_mutex_t;
extern int pthread_mutex_init(pthread_mutex_t * mutex, const pthread_mutexattr_t *attrs);
extern int pthread_mutex_lock(pthread_mutex_t *lock);
typedef struct pthread_mutex_s pthread_mutex_t;
extern int pthread_mutex_init(pthread_mutex_t * mutex, const pthread_mutexattr_t *attrs);
extern int pthread_mutex_lock(pthread_mutex_t *lock);