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authorUlrich Drepper <drepper@redhat.com>2007-11-09 09:09:07 +0000
committerUlrich Drepper <drepper@redhat.com>2007-11-09 09:09:07 +0000
commitcbed6a607d6b42b0cb264d2bee1bd784c8504d60 (patch)
treeddbae943982b9b03fc676bf98ce597273de2c268
parent0f7e0ee507c4bfba62c9059451197e9a25a0598e (diff)
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[BZ #5240]
* sysdeps/unix/sysv/linux/lowlevellock.c (__lll_timedlock_wait): If we time out, try one last time to lock the futex to avoid losing a wakeup signal. * sysdeps/unix/sysv/linux/i386/i486/lowlevellock.S: Likewise. * sysdeps/unix/sysv/linux/x86_64/lowlevellock.S: Likewise.
-rw-r--r--nptl/ChangeLog7
-rw-r--r--nptl/sysdeps/unix/sysv/linux/i386/i486/lowlevellock.S6
-rw-r--r--nptl/sysdeps/unix/sysv/linux/lowlevellock.c23
-rw-r--r--nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.S6
4 files changed, 29 insertions, 13 deletions
diff --git a/nptl/ChangeLog b/nptl/ChangeLog
index bcec5e9..c5019e4 100644
--- a/nptl/ChangeLog
+++ b/nptl/ChangeLog
@@ -1,5 +1,12 @@
2007-11-08 Ulrich Drepper <drepper@redhat.com>
+ [BZ #5240]
+ * sysdeps/unix/sysv/linux/lowlevellock.c (__lll_timedlock_wait):
+ If we time out, try one last time to lock the futex to avoid
+ losing a wakeup signal.
+ * sysdeps/unix/sysv/linux/i386/i486/lowlevellock.S: Likewise.
+ * sysdeps/unix/sysv/linux/x86_64/lowlevellock.S: Likewise.
+
[BZ #5245]
* sysdeps/pthread/createthread.c (do_clone): Translate clone error
if necessary.
diff --git a/nptl/sysdeps/unix/sysv/linux/i386/i486/lowlevellock.S b/nptl/sysdeps/unix/sysv/linux/i386/i486/lowlevellock.S
index 745ab91..6d3943b 100644
--- a/nptl/sysdeps/unix/sysv/linux/i386/i486/lowlevellock.S
+++ b/nptl/sysdeps/unix/sysv/linux/i386/i486/lowlevellock.S
@@ -203,7 +203,7 @@ __lll_timedlock_wait:
addl $1000000000, %edx
subl $1, %ecx
4: testl %ecx, %ecx
- js 5f /* Time is already up. */
+ js 9f /* Time is already up. */
/* Store relative timeout. */
movl %ecx, (%esp)
@@ -271,6 +271,10 @@ __lll_timedlock_wait:
5: movl $ETIMEDOUT, %eax
jmp 6b
+
+9: movl $-ETIMEDOUT, %ecx
+ movl $2, %edx
+ jmp 8b
cfi_endproc
.size __lll_timedlock_wait,.-__lll_timedlock_wait
#endif
diff --git a/nptl/sysdeps/unix/sysv/linux/lowlevellock.c b/nptl/sysdeps/unix/sysv/linux/lowlevellock.c
index f0e4295..c2cdf3a 100644
--- a/nptl/sysdeps/unix/sysv/linux/lowlevellock.c
+++ b/nptl/sysdeps/unix/sysv/linux/lowlevellock.c
@@ -59,10 +59,10 @@ __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
{
struct timeval tv;
- struct timespec rt;
/* Get the current time. */
(void) __gettimeofday (&tv, NULL);
@@ -76,18 +76,21 @@ __lll_timedlock_wait (int *futex, const struct timespec *abstime, int private)
--rt.tv_sec;
}
- /* Already timed out? */
- if (rt.tv_sec < 0)
- return ETIMEDOUT;
+ /* 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);
+ }
- /* Wait. */
- int oldval = atomic_compare_and_exchange_val_acq (futex, 2, 1);
- if (oldval != 0)
- lll_futex_timed_wait (futex, 2, &rt, private);
+ if (atomic_compare_and_exchange_bool_acq (futex, 2, 0) == 0)
+ return 0;
}
- while (atomic_compare_and_exchange_bool_acq (futex, 2, 0) != 0);
+ while (rt.tv_sec >= 0);
- return 0;
+ return ETIMEDOUT;
}
diff --git a/nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.S b/nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.S
index 7065cfa..a5ad88c 100644
--- a/nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.S
+++ b/nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.S
@@ -199,14 +199,16 @@ __lll_timedlock_wait:
addq $1000000000, %rsi
decq %rdi
4: testq %rdi, %rdi
- js 5f /* Time is already up. */
+ movq $-ETIMEDOUT, %rcx
+ movl $2, %edx
+ js 8f /* Time is already up. */
/* Futex call. */
movq %rdi, (%rsp) /* Store relative timeout. */
movq %rsi, 8(%rsp)
movl $1, %eax
- movl $2, %edx
+ /* NB: $edx has been loaded early. */
LOCK
cmpxchgl %edx, (%r12)