[PATCH] Add and use new glibc-internal futex API in sparc code.

[Torvald Riegel <triegel at redhat dot com>]

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.

This applies on top of the patch with the new glibc-internal futex API:
https://sourceware.org/ml/libc-alpha/2015-06/msg00284.html

Not tested at all, but this is supposed to mirror the changes applied to
the generic code.

Dave, OK to commit provided the generic patch is committed?

2015-06-08  Torvald Riegel  <triegel@redhat.com>

	* sysdeps/sparc/nptl/pthread_barrier_wait.c (pthread_barrier_wait):
	Use futex wrappers with error checking.
	* sysdeps/sparc/sparc32/pthread_barrier_wait.c (pthread_barrier_wait):
	Likewise.
	* sysdeps/sparc/sparc32/sem_init.c (futex_private_if_supported): Remove.
	* sysdeps/sparc/sparc32/sem_post.c (futex_wake): Likewise.
	* sysdeps/sparc/sparc32/sem_open.c (sem_open): Use FUTEX_SHARED.
	* sysdeps/sparc/sparc32/sem_waitcommon.c (futex_abstimed_wait): Remove.
	(futex_wake): Likewise.
	(sem_assume_only_signals_cause_futex_EINTR): Likewise.
	(do_futex_wait): Use futex wrappers with error checking.
	(__new_sem_wait_slow): Update EINTR handling.
	* sysdeps/sparc/sparc32/sem_wait.c: Include lowlevellock.h.

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.

diff --git a/sysdeps/sparc/nptl/pthread_barrier_wait.c b/sysdeps/sparc/nptl/pthread_barrier_wait.c
index b0437a1..c46a2ff 100644
--- a/sysdeps/sparc/nptl/pthread_barrier_wait.c
+++ b/sysdeps/sparc/nptl/pthread_barrier_wait.c
@@ -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);
     }
 
diff --git a/sysdeps/sparc/sparc32/pthread_barrier_wait.c b/sysdeps/sparc/sparc32/pthread_barrier_wait.c
index afab203..048bc40 100644
--- a/sysdeps/sparc/sparc32/pthread_barrier_wait.c
+++ b/sysdeps/sparc/sparc32/pthread_barrier_wait.c
@@ -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);
     }
 
diff --git a/sysdeps/sparc/sparc32/sem_init.c b/sysdeps/sparc/sparc32/sem_init.c
index 7c46cee..9b02df2 100644
--- a/sysdeps/sparc/sparc32/sem_init.c
+++ b/sysdeps/sparc/sparc32/sem_init.c
@@ -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
diff --git a/sysdeps/sparc/sparc32/sem_open.c b/sysdeps/sparc/sparc32/sem_open.c
index af9233c..8c4889b 100644
--- a/sysdeps/sparc/sparc32/sem_open.c
+++ b/sysdeps/sparc/sparc32/sem_open.c
@@ -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',
diff --git a/sysdeps/sparc/sparc32/sem_post.c b/sysdeps/sparc/sparc32/sem_post.c
index c9f85a0..fd1a2fe 100644
--- a/sysdeps/sparc/sparc32/sem_post.c
+++ b/sysdeps/sparc/sparc32/sem_post.c
@@ -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
diff --git a/sysdeps/sparc/sparc32/sem_wait.c b/sysdeps/sparc/sparc32/sem_wait.c
index c1fd10c..fce7ed4 100644
--- a/sysdeps/sparc/sparc32/sem_wait.c
+++ b/sysdeps/sparc/sparc32/sem_wait.c
@@ -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
diff --git a/sysdeps/sparc/sparc32/sem_waitcommon.c b/sysdeps/sparc/sparc32/sem_waitcommon.c
index 9c1c6a5..9e43d45 100644
--- a/sysdeps/sparc/sparc32/sem_waitcommon.c
+++ b/sysdeps/sparc/sparc32/sem_waitcommon.c
@@ -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;