X-Git-Url: http://nsz.repo.hu/git/?p=musl;a=blobdiff_plain;f=src%2Fthread%2Fpthread_mutex_trylock.c;h=db784a73a8b9bbc5d1ea400d8f440e7421765127;hp=6fc604fe1e731617e2510e8ff69989bb22dce559;hb=5e977e8b48c6862767ea0a1255233600957c05db;hpb=e914f8b7ec79f622fa3b017af434642f61d45ce8 diff --git a/src/thread/pthread_mutex_trylock.c b/src/thread/pthread_mutex_trylock.c index 6fc604fe..db784a73 100644 --- a/src/thread/pthread_mutex_trylock.c +++ b/src/thread/pthread_mutex_trylock.c @@ -2,21 +2,51 @@ int pthread_mutex_trylock(pthread_mutex_t *m) { - int tid; + int tid, old, own; + pthread_t self; if (m->_m_type == PTHREAD_MUTEX_NORMAL) - return (m->_m_lock || a_swap(&m->_m_lock, 1)) ? EBUSY : 0; + return a_cas(&m->_m_lock, 0, EBUSY) & EBUSY; - tid = pthread_self()->tid; + self = pthread_self(); + tid = self->tid; - if (m->_m_owner == tid && m->_m_type == PTHREAD_MUTEX_RECURSIVE) { + 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 (m->_m_owner || a_xchg(&m->_m_lock, 1)) return EBUSY; - m->_m_owner = tid; - m->_m_count = 1; + 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; }