+ if (m->_m_type != PTHREAD_MUTEX_NORMAL) {
+ if (!m->_m_lock)
+ return EPERM;
+ self = pthread_self();
+ if ((m->_m_lock&0x1fffffff) != self->tid)
+ return EPERM;
+ if ((m->_m_type&3) == PTHREAD_MUTEX_RECURSIVE && m->_m_count)
+ return m->_m_count--, 0;
+ if (m->_m_type >= 4) {
+ robust = 1;
+ self->robust_list.pending = &m->_m_next;
+ *(void **)m->_m_prev = m->_m_next;
+ if (m->_m_next) ((void **)m->_m_next)[-1] = m->_m_prev;
+ }
+ }
+ cont = a_swap(&m->_m_lock, 0);
+ if (robust)
+ self->robust_list.pending = 0;
+ if (waiters || cont<0)
+ __wake(&m->_m_lock, 1, 0);