X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fthread%2Fpthread_mutex_trylock.c;h=a24e7c58ac390d857bf41d305d6a2e317ab7c38f;hb=acfe6d033eafe12d61ad91f496850b1bf58c6f98;hp=232e172b6e0f5fcd1ee1b9d10df3e1694317f6e5;hpb=aa398f56fa398f2202b04e82c67f822f3233786f;p=musl

diff --git a/src/thread/pthread_mutex_trylock.c b/src/thread/pthread_mutex_trylock.c
index 232e172b..a24e7c58 100644
--- a/src/thread/pthread_mutex_trylock.c
+++ b/src/thread/pthread_mutex_trylock.c
@@ -1,53 +1,74 @@
 #include "pthread_impl.h"
 
-int pthread_mutex_trylock(pthread_mutex_t *m)
+int __pthread_mutex_trylock_owner(pthread_mutex_t *m)
 {
-	int tid;
-	int own;
-	pthread_t self;
+	int old, own;
+	int type = m->_m_type;
+	pthread_t self = __pthread_self();
+	int tid = self->tid;
 
-	if (m->_m_type == PTHREAD_MUTEX_NORMAL)
-		return (m->_m_lock || a_swap(&m->_m_lock, 1)) ? EBUSY : 0;
-
-	self = pthread_self();
-	tid = self->tid | 0x80000000;
-
-	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 & 0x3fffffff;
+	if (own == tid) {
+		if ((type&8) && m->_m_count<0) {
+			old &= 0x40000000;
+			m->_m_count = 0;
+			goto success;
+		}
+		if ((type&3) == PTHREAD_MUTEX_RECURSIVE) {
+			if ((unsigned)m->_m_count >= INT_MAX) return EAGAIN;
+			m->_m_count++;
+			return 0;
+		}
 	}
+	if (own == 0x3fffffff) return ENOTRECOVERABLE;
+	if (own || (old && !(type & 4))) return EBUSY;
 
-	if (m->_m_lock == tid && (m->_m_type&3) == PTHREAD_MUTEX_RECURSIVE) {
-		if ((unsigned)m->_m_count >= INT_MAX) return EAGAIN;
-		m->_m_count++;
-		return 0;
+	if (type & 128) {
+		if (!self->robust_list.off) {
+			self->robust_list.off = (char*)&m->_m_lock-(char *)&m->_m_next;
+			__syscall(SYS_set_robust_list, &self->robust_list, 3*sizeof(long));
+		}
+		if (m->_m_waiters) tid |= 0x80000000;
+		self->robust_list.pending = &m->_m_next;
 	}
+	tid |= old & 0x40000000;
 
-	own = m->_m_lock;
-	if ((own && !(own & 0x40000000)) || a_cas(&m->_m_lock, own, tid)!=own)
+	if (a_cas(&m->_m_lock, old, tid) != old) {
+		self->robust_list.pending = 0;
+		if ((type&12)==12 && m->_m_waiters) return ENOTRECOVERABLE;
 		return EBUSY;
+	}
 
-	m->_m_count = 1;
-
-	if (m->_m_type < 4) return 0;
-
-	if (m->_m_type >= 8) {
-		m->_m_lock = 0;
-		return ENOTRECOVERABLE;
+success:
+	if ((type&8) && m->_m_waiters) {
+		int priv = (type & 128) ^ 128;
+		__syscall(SYS_futex, &m->_m_lock, FUTEX_UNLOCK_PI|priv);
+		self->robust_list.pending = 0;
+		return (type&4) ? ENOTRECOVERABLE : EBUSY;
 	}
-	m->_m_next = self->robust_list.head;
+
+	volatile void *next = self->robust_list.head;
+	m->_m_next = next;
 	m->_m_prev = &self->robust_list.head;
-	if (self->robust_list.head)
-		self->robust_list.head[-1] = &m->_m_next;
+	if (next != &self->robust_list.head) *(volatile void *volatile *)
+		((char *)next - sizeof(void *)) = &m->_m_next;
 	self->robust_list.head = &m->_m_next;
 	self->robust_list.pending = 0;
-	if (own) {
-		m->_m_type += 8;
+
+	if (old) {
+		m->_m_count = 0;
 		return EOWNERDEAD;
 	}
 
 	return 0;
 }
+
+int __pthread_mutex_trylock(pthread_mutex_t *m)
+{
+	if ((m->_m_type&15) == PTHREAD_MUTEX_NORMAL)
+		return a_cas(&m->_m_lock, 0, EBUSY) & EBUSY;
+	return __pthread_mutex_trylock_owner(m);
+}
+
+weak_alias(__pthread_mutex_trylock, pthread_mutex_trylock);