[444] | 1 | #include "pthread_impl.h"
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| 2 |
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| 3 | int __pthread_mutex_trylock_owner(pthread_mutex_t *m)
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| 4 | {
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| 5 | int old, own;
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| 6 | int type = m->_m_type & 15;
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| 7 | pthread_t self = __pthread_self();
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| 8 | int tid = self->tid;
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| 9 |
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| 10 | old = m->_m_lock;
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| 11 | own = old & 0x7fffffff;
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| 12 | if (own == tid && (type&3) == PTHREAD_MUTEX_RECURSIVE) {
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| 13 | if ((unsigned)m->_m_count >= INT_MAX) return EAGAIN;
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| 14 | m->_m_count++;
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| 15 | return 0;
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| 16 | }
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| 17 | if (own == 0x7fffffff) return ENOTRECOVERABLE;
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| 18 |
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| 19 | if (m->_m_type & 128) {
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| 20 | if (!self->robust_list.off) {
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| 21 | self->robust_list.off = (char*)&m->_m_lock-(char *)&m->_m_next;
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| 22 | __syscall(SYS_set_robust_list, &self->robust_list, 3*sizeof(long));
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| 23 | }
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| 24 | if (m->_m_waiters) tid |= 0x80000000;
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| 25 | self->robust_list.pending = &m->_m_next;
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| 26 | }
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| 27 |
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| 28 | if ((own && (!(own & 0x40000000) || !(type & 4)))
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| 29 | || a_cas(&m->_m_lock, old, tid) != old) {
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| 30 | self->robust_list.pending = 0;
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| 31 | return EBUSY;
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| 32 | }
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| 33 |
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| 34 | volatile void *next = self->robust_list.head;
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| 35 | m->_m_next = next;
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| 36 | m->_m_prev = &self->robust_list.head;
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| 37 | if (next != &self->robust_list.head) *(volatile void *volatile *)
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| 38 | ((char *)next - sizeof(void *)) = &m->_m_next;
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| 39 | self->robust_list.head = &m->_m_next;
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| 40 | self->robust_list.pending = 0;
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| 41 |
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| 42 | if (own) {
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| 43 | m->_m_count = 0;
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| 44 | m->_m_type |= 8;
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| 45 | return EOWNERDEAD;
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| 46 | }
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| 47 |
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| 48 | return 0;
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| 49 | }
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| 50 |
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| 51 | int __pthread_mutex_trylock(pthread_mutex_t *m)
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| 52 | {
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| 53 | if ((m->_m_type&15) == PTHREAD_MUTEX_NORMAL)
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| 54 | return a_cas(&m->_m_lock, 0, EBUSY) & EBUSY;
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| 55 | return __pthread_mutex_trylock_owner(m);
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| 56 | }
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| 57 |
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| 58 | weak_alias(__pthread_mutex_trylock, pthread_mutex_trylock);
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