X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fthread%2Fpthread_mutex_timedlock.c;h=9279fc54308ad6d8b1e1b6ada6ffb32f91c1fa15;hb=41b290ba397067a09525b6ac89b4040728349046;hp=f1c3eed74f0868561a5c3bc288ce798922b18700;hpb=047e434ef5fd5437a74f98f63c40a77a683f7f3f;p=musl

diff --git a/src/thread/pthread_mutex_timedlock.c b/src/thread/pthread_mutex_timedlock.c
index f1c3eed7..9279fc54 100644
--- a/src/thread/pthread_mutex_timedlock.c
+++ b/src/thread/pthread_mutex_timedlock.c
@@ -1,16 +1,92 @@
 #include "pthread_impl.h"
 
-int pthread_mutex_timedlock(pthread_mutex_t *m, const struct timespec *at)
+#define IS32BIT(x) !((x)+0x80000000ULL>>32)
+#define CLAMP(x) (int)(IS32BIT(x) ? (x) : 0x7fffffffU+((0ULL+(x))>>63))
+
+static int __futex4(volatile void *addr, int op, int val, const struct timespec *to)
 {
-	int r, w=0;
-	while ((r=pthread_mutex_trylock(m)) == EBUSY) {
-		if (!(r=m->_m_lock) || (r&0x40000000)) continue;
-		if (!w) a_inc(&m->_m_waiters), w++;
-		if (__timedwait(&m->_m_lock, r, CLOCK_REALTIME, at, 0) == ETIMEDOUT) {
-			if (w) a_dec(&m->_m_waiters);
-			return ETIMEDOUT;
+#ifdef SYS_futex_time64
+	time_t s = to ? to->tv_sec : 0;
+	long ns = to ? to->tv_nsec : 0;
+	int r = -ENOSYS;
+	if (SYS_futex == SYS_futex_time64 || !IS32BIT(s))
+		r = __syscall(SYS_futex_time64, addr, op, val,
+			to ? ((long long[]){s, ns}) : 0);
+	if (SYS_futex == SYS_futex_time64 || r!=-ENOSYS) return r;
+	to = to ? (void *)(long[]){CLAMP(s), ns} : 0;
+#endif
+	return __syscall(SYS_futex, addr, op, val, to);
+}
+
+static int pthread_mutex_timedlock_pi(pthread_mutex_t *restrict m, const struct timespec *restrict at)
+{
+	int type = m->_m_type;
+	int priv = (type & 128) ^ 128;
+	pthread_t self = __pthread_self();
+	int e;
+
+	if (!priv) self->robust_list.pending = &m->_m_next;
+
+	do e = -__futex4(&m->_m_lock, FUTEX_LOCK_PI|priv, 0, at);
+	while (e==EINTR);
+	if (e) self->robust_list.pending = 0;
+
+	switch (e) {
+	case 0:
+		/* Catch spurious success for non-robust mutexes. */
+		if (!(type&4) && ((m->_m_lock & 0x40000000) || m->_m_waiters)) {
+			a_store(&m->_m_waiters, -1);
+			__syscall(SYS_futex, &m->_m_lock, FUTEX_UNLOCK_PI|priv);
+			self->robust_list.pending = 0;
+			break;
 		}
+		/* Signal to trylock that we already have the lock. */
+		m->_m_count = -1;
+		return __pthread_mutex_trylock(m);
+	case ETIMEDOUT:
+		return e;
+	case EDEADLK:
+		if ((type&3) == PTHREAD_MUTEX_ERRORCHECK) return e;
+	}
+	do e = __timedwait(&(int){0}, 0, CLOCK_REALTIME, at, 1);
+	while (e != ETIMEDOUT);
+	return e;
+}
+
+int __pthread_mutex_timedlock(pthread_mutex_t *restrict m, const struct timespec *restrict at)
+{
+	if ((m->_m_type&15) == PTHREAD_MUTEX_NORMAL
+	    && !a_cas(&m->_m_lock, 0, EBUSY))
+		return 0;
+
+	int type = m->_m_type;
+	int r, t, priv = (type & 128) ^ 128;
+
+	r = __pthread_mutex_trylock(m);
+	if (r != EBUSY) return r;
+
+	if (type&8) return pthread_mutex_timedlock_pi(m, at);
+	
+	int spins = 100;
+	while (spins-- && m->_m_lock && !m->_m_waiters) a_spin();
+
+	while ((r=__pthread_mutex_trylock(m)) == EBUSY) {
+		r = m->_m_lock;
+		int own = r & 0x3fffffff;
+		if (!own && (!r || (type&4)))
+			continue;
+		if ((type&3) == PTHREAD_MUTEX_ERRORCHECK
+		    && own == __pthread_self()->tid)
+			return EDEADLK;
+
+		a_inc(&m->_m_waiters);
+		t = r | 0x80000000;
+		a_cas(&m->_m_lock, r, t);
+		r = __timedwait(&m->_m_lock, t, CLOCK_REALTIME, at, priv);
+		a_dec(&m->_m_waiters);
+		if (r && r != EINTR) break;
 	}
-	if (w) a_dec(&m->_m_waiters);
 	return r;
 }
+
+weak_alias(__pthread_mutex_timedlock, pthread_mutex_timedlock);