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* [PATCH] Remove hppa lowlevellock.c
@ 2014-04-28 15:51 Bernie Ogden
  2014-04-28 17:02 ` Carlos O'Donell
  2014-04-29  9:14 ` Carlos O'Donell
  0 siblings, 2 replies; 5+ messages in thread
From: Bernie Ogden @ 2014-04-28 15:51 UTC (permalink / raw)
  To: libc-ports; +Cc: carlos

lowlevellock.c for hppa differs from the generic lowlevellock.c only in
insignificant ways, so can be removed. I don't have any hppa targets
to work with, so have not been able to test this patch.

The notable differences between the hppa and generic implementations are:

1) Some functions in hppa's lowlevellock.c set futex to 2 if it was 1.
The generic version always sets the futex to 2. As futex can only be
0, 1 or 2 on entry into these functions, the behaviour is equivalent.
(If the futex manages to be 0 on entry then we've just lost an
unlikely fast path out.)
2) hppa places most of the functions in this file in both libc and
libpthread. The generic implementation places only
__lll_lock_wait_private in libc. As these are internal functions I
think that, if this does cause a problem, it would show up at build
time - but I'm new to glibc so prepared to be corrected (and have not
been able to build).

I would be grateful if the maintainer could test/comment.

Regards,

Bernie

ports/ChangeLog.hppa
2014-04-24  Bernard Ogden  <bernie.ogden@linaro.org>

[BZ #15119]
* ports/sysdeps/unix/sysv/linux/hppa/nptl/lowlevellock.c: Remove file.


diff --git a/ports/sysdeps/unix/sysv/linux/hppa/nptl/lowlevellock.c
b/ports/sysdeps/unix/sysv/linux/hppa/nptl/lowlevellock.c
deleted file mode 100644
index d61c5d3..0000000
--- a/ports/sysdeps/unix/sysv/linux/hppa/nptl/lowlevellock.c
+++ /dev/null
@@ -1,127 +0,0 @@
-/* low level locking for pthread library.  Generic futex-using version.
-   Copyright (C) 2003-2014 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library.  If not, see
-   <http://www.gnu.org/licenses/>.  */
-
-#include <errno.h>
-#include <sysdep.h>
-#include <lowlevellock.h>
-#include <sys/time.h>
-
-void
-__lll_lock_wait (lll_lock_t *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_val_acq (futex, 2, 0) != 0);
-}
-
-void
-__lll_lock_wait_private (lll_lock_t *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_val_acq (futex, 2, 0) != 0);
-}
-
-int
-__lll_timedlock_wait (lll_lock_t *futex, const struct timespec
*abstime, int private)
-{
-  /* Reject invalid timeouts.  */
-  if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
-    return EINVAL;
-
-  do
-    {
-      struct timeval tv;
-      struct timespec rt;
-
-      /* Get the current time.  */
-      (void) __gettimeofday (&tv, NULL);
-
-      /* Compute relative timeout.  */
-      rt.tv_sec = abstime->tv_sec - tv.tv_sec;
-      rt.tv_nsec = abstime->tv_nsec - tv.tv_usec * 1000;
-      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_acq (futex, 2, 1);
-      if (oldval != 0)
- lll_futex_timed_wait (futex, 2, &rt, private);
-    }
-  while (atomic_compare_and_exchange_bool_acq (futex, 2, 0) != 0);
-  return 0;
-}
-
-
-/* These don't get included in libc.so  */
-#ifdef IS_IN_libpthread
-int
-__lll_timedwait_tid (int *tidp, const struct timespec *abstime)
-{
-  int tid;
-
-  if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
-    return EINVAL;
-
-  /* Repeat until thread terminated.  */
-  while ((tid = *tidp) != 0)
-    {
-      struct timeval tv;
-      struct timespec rt;
-
-      /* Get the current time.  */
-      (void) __gettimeofday (&tv, NULL);
-
-      /* Compute relative timeout.  */
-      rt.tv_sec = abstime->tv_sec - tv.tv_sec;
-      rt.tv_nsec = abstime->tv_nsec - tv.tv_usec * 1000;
-      if (rt.tv_nsec < 0)
- {
-  rt.tv_nsec += 1000000000;
-  --rt.tv_sec;
- }
-
-      /* Already timed out?  */
-      if (rt.tv_sec < 0)
- return ETIMEDOUT;
-
-      /* Wait until thread terminates.  */
-      if (lll_futex_timed_wait (tidp, tid, &rt, LLL_SHARED) == -ETIMEDOUT)
- return ETIMEDOUT;
-    }
-
-  return 0;
-}
-#endif
-

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2014-06-10  3:25 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2014-04-28 15:51 [PATCH] Remove hppa lowlevellock.c Bernie Ogden
2014-04-28 17:02 ` Carlos O'Donell
2014-04-29  9:14 ` Carlos O'Donell
2014-06-09 20:29   ` Bernard Ogden
2014-06-10  3:25     ` Carlos O'Donell

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