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path: root/src/thread/pthread_mutex_timedlock.c
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Diffstat (limited to 'src/thread/pthread_mutex_timedlock.c')
-rw-r--r--src/thread/pthread_mutex_timedlock.c37
1 files changed, 37 insertions, 0 deletions
diff --git a/src/thread/pthread_mutex_timedlock.c b/src/thread/pthread_mutex_timedlock.c
index 0f171c00..6b893627 100644
--- a/src/thread/pthread_mutex_timedlock.c
+++ b/src/thread/pthread_mutex_timedlock.c
@@ -1,5 +1,40 @@
#include "pthread_impl.h"
+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 = -__syscall(SYS_futex, &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
@@ -11,6 +46,8 @@ int __pthread_mutex_timedlock(pthread_mutex_t *restrict m, const struct timespec
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();