X-Git-Url: http://nsz.repo.hu/git/?p=musl;a=blobdiff_plain;f=src%2Fthread%2Fpthread_mutex_trylock.c;h=db784a73a8b9bbc5d1ea400d8f440e7421765127;hp=1e3817bbf8960fc53f36bba70c8f9c6171985e0a;hb=5e977e8b48c6862767ea0a1255233600957c05db;hpb=0b44a0315b47dd8eced9f3b7f31580cf14bbfc01 diff --git a/src/thread/pthread_mutex_trylock.c b/src/thread/pthread_mutex_trylock.c index 1e3817bb..db784a73 100644 --- a/src/thread/pthread_mutex_trylock.c +++ b/src/thread/pthread_mutex_trylock.c @@ -2,27 +2,51 @@ int pthread_mutex_trylock(pthread_mutex_t *m) { - if (m->__type == PTHREAD_MUTEX_RECURSIVE) { - pthread_t self = pthread_self(); - if (m->__owner == self) { - if ((unsigned)m->__lock >= INT_MAX) return EAGAIN; - a_inc(&m->__lock); - return 0; - } - if (a_fetch_add(&m->__lock, 1)) { - if (a_fetch_add(&m->__lock, -1)==1 && m->__waiters) - __wake(&m->__lock, 1, 0); - return EBUSY; - } - m->__owner = self; + int tid, old, own; + pthread_t self; + + if (m->_m_type == PTHREAD_MUTEX_NORMAL) + return a_cas(&m->_m_lock, 0, EBUSY) & EBUSY; + + self = pthread_self(); + tid = self->tid; + + if (m->_m_type >= 4) { + if (!self->robust_list.off) + __syscall(SYS_set_robust_list, + &self->robust_list, 3*sizeof(long)); + self->robust_list.off = (char*)&m->_m_lock-(char *)&m->_m_next; + self->robust_list.pending = &m->_m_next; + } + + old = m->_m_lock; + own = old & 0x7fffffff; + if (own == tid && (m->_m_type&3) == PTHREAD_MUTEX_RECURSIVE) { + if ((unsigned)m->_m_count >= INT_MAX) return EAGAIN; + m->_m_count++; return 0; } - if (a_xchg(&m->__lock, 1)) - if (m->__type == PTHREAD_MUTEX_ERRORCHECK - && m->__owner == pthread_self()) return EDEADLK; - else return EBUSY; - if (m->__type == PTHREAD_MUTEX_ERRORCHECK) - m->__owner = pthread_self(); + if ((own && !(own & 0x40000000)) || a_cas(&m->_m_lock, old, tid)!=old) + return EBUSY; + + if (m->_m_type < 4) return 0; + + if (m->_m_type >= 8) { + m->_m_lock = 0; + return ENOTRECOVERABLE; + } + m->_m_next = self->robust_list.head; + m->_m_prev = &self->robust_list.head; + if (self->robust_list.head) + self->robust_list.head[-1] = &m->_m_next; + self->robust_list.head = &m->_m_next; + self->robust_list.pending = 0; + if (own) { + m->_m_count = 0; + m->_m_type += 8; + return EOWNERDEAD; + } + return 0; }