31     int ec = pthread_mutex_lock(&__m_);  in lock()  local
32     if (ec)  in lock()
33         __throw_system_error(ec, "mutex lock failed");  in lock()
45     int ec = pthread_mutex_unlock(&__m_);  in unlock()  local
46     (void)ec;  in unlock()
47     assert(ec == 0);  in unlock()
55     int ec = pthread_mutexattr_init(&attr);  in recursive_mutex()  local
56     if (ec)  in recursive_mutex()
58     ec = pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);  in recursive_mutex()
59     if (ec)  in recursive_mutex()
64     ec = pthread_mutex_init(&__m_, &attr);  in recursive_mutex()
65     if (ec)  in recursive_mutex()
70     ec = pthread_mutexattr_destroy(&attr);  in recursive_mutex()
71     if (ec)  in recursive_mutex()
78     __throw_system_error(ec, "recursive_mutex constructor failed");  in recursive_mutex()
91     int ec = pthread_mutex_lock(&__m_);  in lock()  local
92     if (ec)  in lock()
93         __throw_system_error(ec, "recursive_mutex lock failed");  in lock()