nsz Git - musl/blob - src/thread/pthread_mutex_unlock.c

   1 #include "pthread_impl.h"
   2
   3 int pthread_mutex_unlock(pthread_mutex_t *m)
   4 {
   5         pthread_t self;
   6         int waiters = m->_m_waiters;
   7         int cont;
   8         int robust = 0;
   9
  10         if (m->_m_type != PTHREAD_MUTEX_NORMAL) {
  11                 if (!m->_m_lock)
  12                         return EPERM;
  13                 self = pthread_self();
  14                 if ((m->_m_lock&0x1fffffff) != self->tid)
  15                         return EPERM;
  16                 if ((m->_m_type&3) == PTHREAD_MUTEX_RECURSIVE && m->_m_count)
  17                         return m->_m_count--, 0;
  18                 if (m->_m_type >= 4) {
  19                         robust = 1;
  20                         self->robust_list.pending = &m->_m_next;
  21                         *(void **)m->_m_prev = m->_m_next;
  22                         if (m->_m_next) ((void **)m->_m_next)[-1] = m->_m_prev;
  23                 }
  24         }
  25         cont = a_swap(&m->_m_lock, 0);
  26         if (robust)
  27                 self->robust_list.pending = 0;
  28         if (waiters || cont<0)
  29                 __wake(&m->_m_lock, 1, 0);
  30         return 0;
  31 }