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authorRich Felker <dalias@aerifal.cx>2014-08-25 20:16:26 -0400
committerRich Felker <dalias@aerifal.cx>2014-08-25 20:16:26 -0400
commit97a7512b6819014d15c679c8998caa0006d13c29 (patch)
tree0203f9cb4abd79be05dba04696903ef51e2dbc44
parent2ff714c6138da8abb50fd532503fd8d68a18811a (diff)
downloadmusl-97a7512b6819014d15c679c8998caa0006d13c29.tar.gz
spin before waiting on futex in mutex and rwlock lock operations
-rw-r--r--src/thread/pthread_mutex_timedlock.c6
-rw-r--r--src/thread/pthread_rwlock_timedrdlock.c7
-rw-r--r--src/thread/pthread_rwlock_timedwrlock.c7
3 files changed, 20 insertions, 0 deletions
diff --git a/src/thread/pthread_mutex_timedlock.c b/src/thread/pthread_mutex_timedlock.c
index 2a959d25..116a8b7b 100644
--- a/src/thread/pthread_mutex_timedlock.c
+++ b/src/thread/pthread_mutex_timedlock.c
@@ -8,6 +8,12 @@ int pthread_mutex_timedlock(pthread_mutex_t *restrict m, const struct timespec *
int r, t, priv = (m->_m_type & 128) ^ 128;
+ r = pthread_mutex_trylock(m);
+ if (r != EBUSY) return r;
+
+ int spins = 100;
+ while (spins-- && m->_m_lock) a_spin();
+
while ((r=pthread_mutex_trylock(m)) == EBUSY) {
if (!(r=m->_m_lock) || ((r&0x40000000) && (m->_m_type&4)))
continue;
diff --git a/src/thread/pthread_rwlock_timedrdlock.c b/src/thread/pthread_rwlock_timedrdlock.c
index a2b4d446..884b7a1e 100644
--- a/src/thread/pthread_rwlock_timedrdlock.c
+++ b/src/thread/pthread_rwlock_timedrdlock.c
@@ -3,6 +3,13 @@
int pthread_rwlock_timedrdlock(pthread_rwlock_t *restrict rw, const struct timespec *restrict at)
{
int r, t;
+
+ r = pthread_rwlock_tryrdlock(rw);
+ if (r != EBUSY) return r;
+
+ int spins = 100;
+ while (spins-- && rw->_rw_lock) a_spin();
+
while ((r=pthread_rwlock_tryrdlock(rw))==EBUSY) {
if (!(r=rw->_rw_lock) || (r&0x7fffffff)!=0x7fffffff) continue;
t = r | 0x80000000;
diff --git a/src/thread/pthread_rwlock_timedwrlock.c b/src/thread/pthread_rwlock_timedwrlock.c
index 63a32ecb..f02b174b 100644
--- a/src/thread/pthread_rwlock_timedwrlock.c
+++ b/src/thread/pthread_rwlock_timedwrlock.c
@@ -3,6 +3,13 @@
int pthread_rwlock_timedwrlock(pthread_rwlock_t *restrict rw, const struct timespec *restrict at)
{
int r, t;
+
+ r = pthread_rwlock_trywrlock(rw);
+ if (r != EBUSY) return r;
+
+ int spins = 100;
+ while (spins-- && rw->_rw_lock) a_spin();
+
while ((r=pthread_rwlock_trywrlock(rw))==EBUSY) {
if (!(r=rw->_rw_lock)) continue;
t = r | 0x80000000;