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

   1 #include "pthread_impl.h"
   2
   3 void __vm_lock_impl(int);
   4 void __vm_unlock_impl(void);
   5
   6 int pthread_mutex_unlock(pthread_mutex_t *m)
   7 {
   8         pthread_t self;
   9         int waiters = m->_m_waiters;
  10         int cont;
  11         int type = m->_m_type & 15;
  12         int priv = (m->_m_type & 128) ^ 128;
  13
  14         if (type != PTHREAD_MUTEX_NORMAL) {
  15                 self = __pthread_self();
  16                 if ((m->_m_lock&0x7fffffff) != self->tid)
  17                         return EPERM;
  18                 if ((type&3) == PTHREAD_MUTEX_RECURSIVE && m->_m_count)
  19                         return m->_m_count--, 0;
  20                 if (!priv) {
  21                         self->robust_list.pending = &m->_m_next;
  22                         __vm_lock_impl(+1);
  23                 }
  24                 *(void **)m->_m_prev = m->_m_next;
  25                 if (m->_m_next) ((void **)m->_m_next)[-1] = m->_m_prev;
  26         }
  27         cont = a_swap(&m->_m_lock, (type & 8) ? 0x40000000 : 0);
  28         if (type != PTHREAD_MUTEX_NORMAL && !priv) {
  29                 self->robust_list.pending = 0;
  30                 __vm_unlock_impl();
  31         }
  32         if (waiters || cont<0)
  33                 __wake(&m->_m_lock, 1, priv);
  34         return 0;
  35 }