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Diffstat (limited to 'nptl/sysdeps/unix/sysv/linux/lowlevellock.c')
-rw-r--r--nptl/sysdeps/unix/sysv/linux/lowlevellock.c46
1 files changed, 18 insertions, 28 deletions
diff --git a/nptl/sysdeps/unix/sysv/linux/lowlevellock.c b/nptl/sysdeps/unix/sysv/linux/lowlevellock.c
index c2cdf3a1e4..01c4f4861a 100644
--- a/nptl/sysdeps/unix/sysv/linux/lowlevellock.c
+++ b/nptl/sysdeps/unix/sysv/linux/lowlevellock.c
@@ -27,13 +27,11 @@
void
__lll_lock_wait_private (int *futex)
{
- do
- {
- int oldval = atomic_compare_and_exchange_val_acq (futex, 2, 1);
- if (oldval != 0)
- lll_futex_wait (futex, 2, LLL_PRIVATE);
- }
- while (atomic_compare_and_exchange_bool_acq (futex, 2, 0) != 0);
+ if (*futex == 2)
+ lll_futex_wait (futex, 2, LLL_PRIVATE);
+
+ while (atomic_exchange_acq (futex, 2) != 0)
+ lll_futex_wait (futex, 2, LLL_PRIVATE);
}
@@ -42,13 +40,11 @@ __lll_lock_wait_private (int *futex)
void
__lll_lock_wait (int *futex, int private)
{
- do
- {
- int oldval = atomic_compare_and_exchange_val_acq (futex, 2, 1);
- if (oldval != 0)
- lll_futex_wait (futex, 2, private);
- }
- while (atomic_compare_and_exchange_bool_acq (futex, 2, 0) != 0);
+ if (*futex == 2)
+ lll_futex_wait (futex, 2, private);
+
+ while (atomic_exchange_acq (futex, 2) != 0)
+ lll_futex_wait (futex, 2, private);
}
@@ -59,8 +55,8 @@ __lll_timedlock_wait (int *futex, const struct timespec *abstime, int private)
if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
return EINVAL;
- struct timespec rt;
- do
+ /* Try locking. */
+ while (atomic_exchange_acq (futex, 2) != 0)
{
struct timeval tv;
@@ -68,6 +64,7 @@ __lll_timedlock_wait (int *futex, const struct timespec *abstime, int private)
(void) __gettimeofday (&tv, NULL);
/* Compute relative timeout. */
+ struct timespec rt;
rt.tv_sec = abstime->tv_sec - tv.tv_sec;
rt.tv_nsec = abstime->tv_nsec - tv.tv_usec * 1000;
if (rt.tv_nsec < 0)
@@ -76,21 +73,14 @@ __lll_timedlock_wait (int *futex, const struct timespec *abstime, int private)
--rt.tv_sec;
}
- /* If timed out do not go to sleep. */
- if (__builtin_expect (rt.tv_sec >= 0, 1))
- {
- /* Wait. */
- int oldval = atomic_compare_and_exchange_val_acq (futex, 2, 1);
- if (oldval != 0)
- lll_futex_timed_wait (futex, 2, &rt, private);
- }
+ if (rt.tv_sec < 0)
+ return ETIMEDOUT;
- if (atomic_compare_and_exchange_bool_acq (futex, 2, 0) == 0)
- return 0;
+ /* Wait. */
+ lll_futex_timed_wait (futex, 2, &rt, private);
}
- while (rt.tv_sec >= 0);
- return ETIMEDOUT;
+ return 0;
}