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unify lock and owner fields of mutex structure

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this change is necessary to free up one slot in the mutex structure so
that we can use doubly-linked lists in the implementation of robust
mutexes.
This commit is contained in:
Rich Felker 2011-03-17 12:21:32 -04:00
commit b1c43161c2
4 changed files with 6 additions and 8 deletions
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5
src/thread/pthread_mutex_trylock.c
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@ -9,14 +9,13 @@ int pthread_mutex_trylock(pthread_mutex_t *m)
tid = pthread_self()->tid;
if (m->_m_owner == tid && m->_m_type == PTHREAD_MUTEX_RECURSIVE) {
if (m->_m_lock == tid && m->_m_type == PTHREAD_MUTEX_RECURSIVE) {
if ((unsigned)m->_m_count >= INT_MAX) return EAGAIN;
m->_m_count++;
return 0;
}
if (m->_m_owner || a_xchg(&m->_m_lock, 1)) return EBUSY;
m->_m_owner = tid;
if (m->_m_lock || a_cas(&m->_m_lock, 0, tid)) return EBUSY;
m->_m_count = 1;
return 0;
}