nptl: Replace non cancellable pause/nanosleep with futex

To help y2038 work avoid duplicate all the logic of nanosleep on
non cancellable version, the patch replace it with a new futex
operation, lll_timedwait.  The changes are:

  - Add a expected value for __lll_clocklock_wait, so it can be used
    to wait for generic values.

  - Remove its internal atomic operation and move the logic to
    __lll_clocklock.  It makes __lll_clocklock_wait even more generic
    and __lll_clocklock slight faster on fast-path (since it won't
    require a function call anymore).

  - Add lll_timedwait, which uses __lll_clocklock_wait, to replace both
    __pause_nocancel and __nanosleep_nocancel.

It also allows remove the sparc32 __lll_clocklock_wait implementation
(since it is similar to the generic one).

Checked on x86_64-linux-gnu, sparcv9-linux-gnu, and i686-linux-gnu.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

1 files changed, 0 insertions, 42 deletions

diff --git a/sysdeps/sparc/sparc32/lowlevellock.c b/sysdeps/sparc/sparc32/lowlevellock.c
index 074ecf0636..1a0ab4d9f2 100644
--- a/sysdeps/sparc/sparc32/lowlevellock.c
+++ b/sysdeps/sparc/sparc32/lowlevellock.c
@@ -50,46 +50,4 @@ __lll_lock_wait (int *futex, int private)
     }
   while (atomic_compare_and_exchange_val_24_acq (futex, 2, 0) != 0);
 }
-
-
-int
-__lll_clocklock_wait (int *futex, clockid_t clockid,
-                      const struct timespec *abstime, int private)
-{
-  /* Reject invalid timeouts.  */
-  if (! valid_nanoseconds (abstime->tv_nsec))
-    return EINVAL;
-
-  do
-    {
-      struct timespec ts;
-      struct timespec rt;
-
-      /* Get the current time. This can only fail if clockid is not
-         valid. */
-      if (__glibc_unlikely (__clock_gettime (clockid, &ts) != 0))
-        return EINVAL;
-
-      /* Compute relative timeout.  */
-      rt.tv_sec = abstime->tv_sec - ts.tv_sec;
-      rt.tv_nsec = abstime->tv_nsec - ts.tv_nsec;
-      if (rt.tv_nsec < 0)
-	{
-	  rt.tv_nsec += 1000000000;
-	  --rt.tv_sec;
-	}
-
-      /* Already timed out?  */
-      if (rt.tv_sec < 0)
-	return ETIMEDOUT;
-
-      /* Wait.  */
-      int oldval = atomic_compare_and_exchange_val_24_acq (futex, 2, 1);
-      if (oldval != 0)
-	lll_futex_timed_wait (futex, 2, &rt, private);
-    }
-  while (atomic_compare_and_exchange_val_24_acq (futex, 2, 0) != 0);
-
-  return 0;
-}
 #endif