commit 0c6eaa5f5ffc15919be59ebcb4665255628fb957
Author: Torvald Riegel <triegel@redhat.com>
Date: Mon Jun 8 23:47:26 2015 +0200
Add and use new glibc-internal futex API in sparc code.
This uses the futex API in the sparc-specific code. It also cleans up
EINTR handling in the sparc semaphore code in that it follows the return
code documentation of futex_wait.
@@ -21,6 +21,8 @@
#include <lowlevellock.h>
#include <pthreadP.h>
#include <sparc-nptl.h>
+#include <futex-internal.h>
+#include <libc-internal.h>
/* Wait on barrier. */
int
@@ -31,6 +33,7 @@ pthread_barrier_wait (barrier)
= (union sparc_pthread_barrier *) barrier;
int result = 0;
int private = ibarrier->s.pshared ? LLL_SHARED : LLL_PRIVATE;
+ int futex_private = ibarrier->s.pshared ? FUTEX_SHARED : FUTEX_PRIVATE;
/* Make sure we are alone. */
lll_lock (ibarrier->b.lock, private);
@@ -46,7 +49,7 @@ pthread_barrier_wait (barrier)
++ibarrier->b.curr_event;
/* Wake up everybody. */
- lll_futex_wake (&ibarrier->b.curr_event, INT_MAX, private);
+ futex_wake (&ibarrier->b.curr_event, INT_MAX, futex_private);
/* This is the thread which finished the serialization. */
result = PTHREAD_BARRIER_SERIAL_THREAD;
@@ -62,7 +65,8 @@ pthread_barrier_wait (barrier)
/* Wait for the event counter of the barrier to change. */
do
- lll_futex_wait (&ibarrier->b.curr_event, event, private);
+ ignore_value (futex_wait (&ibarrier->b.curr_event, event,
+ futex_private));
while (event == ibarrier->b.curr_event);
}
@@ -21,6 +21,8 @@
#include <lowlevellock.h>
#include <pthreadP.h>
#include <sparc-nptl.h>
+#include <futex-internal.h>
+#include <libc-internal.h>
/* Wait on barrier. */
int
@@ -31,6 +33,7 @@ pthread_barrier_wait (barrier)
= (union sparc_pthread_barrier *) barrier;
int result = 0;
int private = ibarrier->s.pshared ? LLL_SHARED : LLL_PRIVATE;
+ int futex_private = ibarrier->s.pshared ? FUTEX_SHARED : FUTEX_PRIVATE;
/* Make sure we are alone. */
lll_lock (ibarrier->b.lock, private);
@@ -46,7 +49,7 @@ pthread_barrier_wait (barrier)
++ibarrier->b.curr_event;
/* Wake up everybody. */
- lll_futex_wake (&ibarrier->b.curr_event, INT_MAX, private);
+ futex_wake (&ibarrier->b.curr_event, INT_MAX, futex_private);
/* This is the thread which finished the serialization. */
result = PTHREAD_BARRIER_SERIAL_THREAD;
@@ -62,7 +65,8 @@ pthread_barrier_wait (barrier)
/* Wait for the event counter of the barrier to change. */
do
- lll_futex_wait (&ibarrier->b.curr_event, event, private);
+ ignore_value (futex_wait (&ibarrier->b.curr_event, event,
+ futex_private));
while (event == ibarrier->b.curr_event);
}
@@ -20,23 +20,7 @@
#include <semaphore.h>
#include <shlib-compat.h>
#include "semaphoreP.h"
-#include <kernel-features.h>
-
-/* Returns FUTEX_PRIVATE if pshared is zero and private futexes are supported;
- returns FUTEX_SHARED otherwise.
- TODO Remove when cleaning up the futex API throughout glibc. */
-static __always_inline int
-futex_private_if_supported (int pshared)
-{
- if (pshared != 0)
- return LLL_SHARED;
-#ifdef __ASSUME_PRIVATE_FUTEX
- return LLL_PRIVATE;
-#else
- return THREAD_GETMEM (THREAD_SELF, header.private_futex)
- ^ FUTEX_PRIVATE_FLAG;
-#endif
-}
+#include <futex-internal.h>
int
@@ -198,7 +198,7 @@ sem_open (const char *name, int oflag, ...)
sem.newsem.nwaiters = 0;
/* This always is a shared semaphore. */
- sem.newsem.private = LLL_SHARED;
+ sem.newsem.private = FUTEX_SHARED;
/* Initialize the remaining bytes as well. */
memset ((char *) &sem.initsem + sizeof (struct new_sem), '\0',
@@ -23,34 +23,10 @@
#include <lowlevellock.h>
#include <internaltypes.h>
#include <semaphore.h>
+#include <futex-internal.h>
#include <shlib-compat.h>
-/* Wrapper for lll_futex_wake, with error checking.
- TODO Remove when cleaning up the futex API throughout glibc. */
-static __always_inline void
-futex_wake (unsigned int* futex, int processes_to_wake, int private)
-{
- int res = lll_futex_wake (futex, processes_to_wake, private);
- /* No error. Ignore the number of woken processes. */
- if (res >= 0)
- return;
- switch (res)
- {
- case -EFAULT: /* Could have happened due to memory reuse. */
- case -EINVAL: /* Could be either due to incorrect alignment (a bug in
- glibc or in the application) or due to memory being
- reused for a PI futex. We cannot distinguish between the
- two causes, and one of them is correct use, so we do not
- act in this case. */
- return;
- case -ENOSYS: /* Must have been caused by a glibc bug. */
- /* No other errors are documented at this time. */
- default:
- abort ();
- }
-}
-
/* See sem_wait for an explanation of the algorithm. */
int
@@ -17,6 +17,7 @@
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
+#include <lowlevellock.h> /* lll_futex* used by the old code. */
#include "sem_waitcommon.c"
int
@@ -19,7 +19,7 @@
#include <errno.h>
#include <sysdep.h>
-#include <lowlevellock.h>
+#include <futex-internal.h>
#include <internaltypes.h>
#include <semaphore.h>
#include <sys/time.h>
@@ -28,104 +28,6 @@
#include <shlib-compat.h>
#include <atomic.h>
-/* Wrapper for lll_futex_wait with absolute timeout and error checking.
- TODO Remove when cleaning up the futex API throughout glibc. */
-static __always_inline int
-futex_abstimed_wait (unsigned int* futex, unsigned int expected,
- const struct timespec* abstime, int private, bool cancel)
-{
- int err, oldtype;
- if (abstime == NULL)
- {
- if (cancel)
- oldtype = __pthread_enable_asynccancel ();
- err = lll_futex_wait (futex, expected, private);
- if (cancel)
- __pthread_disable_asynccancel (oldtype);
- }
- else
- {
- struct timeval tv;
- struct timespec rt;
- int sec, nsec;
-
- /* Get the current time. */
- __gettimeofday (&tv, NULL);
-
- /* Compute relative timeout. */
- sec = abstime->tv_sec - tv.tv_sec;
- nsec = abstime->tv_nsec - tv.tv_usec * 1000;
- if (nsec < 0)
- {
- nsec += 1000000000;
- --sec;
- }
-
- /* Already timed out? */
- if (sec < 0)
- return ETIMEDOUT;
-
- /* Do wait. */
- rt.tv_sec = sec;
- rt.tv_nsec = nsec;
- if (cancel)
- oldtype = __pthread_enable_asynccancel ();
- err = lll_futex_timed_wait (futex, expected, &rt, private);
- if (cancel)
- __pthread_disable_asynccancel (oldtype);
- }
- switch (err)
- {
- case 0:
- case -EAGAIN:
- case -EINTR:
- case -ETIMEDOUT:
- return -err;
-
- case -EFAULT: /* Must have been caused by a glibc or application bug. */
- case -EINVAL: /* Either due to wrong alignment or due to the timeout not
- being normalized. Must have been caused by a glibc or
- application bug. */
- case -ENOSYS: /* Must have been caused by a glibc bug. */
- /* No other errors are documented at this time. */
- default:
- abort ();
- }
-}
-
-/* Wrapper for lll_futex_wake, with error checking.
- TODO Remove when cleaning up the futex API throughout glibc. */
-static __always_inline void
-futex_wake (unsigned int* futex, int processes_to_wake, int private)
-{
- int res = lll_futex_wake (futex, processes_to_wake, private);
- /* No error. Ignore the number of woken processes. */
- if (res >= 0)
- return;
- switch (res)
- {
- case -EFAULT: /* Could have happened due to memory reuse. */
- case -EINVAL: /* Could be either due to incorrect alignment (a bug in
- glibc or in the application) or due to memory being
- reused for a PI futex. We cannot distinguish between the
- two causes, and one of them is correct use, so we do not
- act in this case. */
- return;
- case -ENOSYS: /* Must have been caused by a glibc bug. */
- /* No other errors are documented at this time. */
- default:
- abort ();
- }
-}
-
-
-/* Set this to true if you assume that, in contrast to current Linux futex
- documentation, lll_futex_wake can return -EINTR only if interrupted by a
- signal, not spuriously due to some other reason.
- TODO Discuss EINTR conditions with the Linux kernel community. For
- now, we set this to true to not change behavior of semaphores compared
- to previous glibc builds. */
-static const int sem_assume_only_signals_cause_futex_EINTR = 1;
static void
__sem_wait_32_finish (struct new_sem *sem);
@@ -149,8 +51,8 @@ do_futex_wait (struct new_sem *sem, const struct timespec *abstime)
{
int err;
- err = futex_abstimed_wait (&sem->value, SEM_NWAITERS_MASK, abstime,
- sem->private, true);
+ err = futex_abstimed_wait_cancelable (&sem->value, SEM_NWAITERS_MASK,
+ abstime, sem->private);
return err;
}
@@ -202,8 +104,7 @@ __new_sem_wait_slow (struct new_sem *sem, const struct timespec *abstime)
__sparc32_atomic_do_unlock24(&sem->pad);
err = do_futex_wait(sem, abstime);
- if (err == ETIMEDOUT ||
- (err == EINTR && sem_assume_only_signals_cause_futex_EINTR))
+ if (err == ETIMEDOUT || err == EINTR)
{
__set_errno (err);
err = -1;