Separate Linuxisms from lowlevellock.h, make a generic one

1 files changed, 86 insertions, 0 deletions

diff --git a/sysdeps/nptl/lowlevellock-futex.h b/sysdeps/nptl/lowlevellock-futex.h
new file mode 100644
index 0000000000..12f3876cd5
--- /dev/null
+++ b/sysdeps/nptl/lowlevellock-futex.h
@@ -0,0 +1,86 @@
+/* Low-level locking access to futex facilities.  Stub version.
+   Copyright (C) 2014 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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/>.  */
+
+#ifndef _LOWLEVELLOCK_FUTEX_H
+#define _LOWLEVELLOCK_FUTEX_H   1
+
+#include <errno.h>
+
+
+/* Values for 'private' parameter of locking macros.  Note pthreadP.h
+   optimizes for these exact values, though they are not required.  */
+#define LLL_PRIVATE     0
+#define LLL_SHARED      128
+
+
+/* For most of these macros, the return value is never really used.
+   Nevertheless, the protocol is that each one returns a negated errno
+   code for failure or zero for success.  (Note that the corresponding
+   Linux system calls can sometimes return positive values for success
+   cases too.  We never use those values.)  */
+
+
+/* Wait while *FUTEXP == VAL for an lll_futex_wake call on FUTEXP.  */
+#define lll_futex_wait(futexp, val, private) \
+  lll_futex_timed_wait (futexp, val, NULL, private)
+
+/* Wait until a lll_futex_wake call on FUTEXP, or TIMEOUT elapses.  */
+#define lll_futex_timed_wait(futexp, val, timeout, private)             \
+  -ENOSYS
+
+/* This macro should be defined only if FUTEX_CLOCK_REALTIME is also defined.
+   If CLOCKBIT is zero, this is identical to lll_futex_timed_wait.
+   If CLOCKBIT has FUTEX_CLOCK_REALTIME set, then it's the same but
+   TIMEOUT is counted by CLOCK_REALTIME rather than CLOCK_MONOTONIC.  */
+#define lll_futex_timed_wait_bitset(futexp, val, timeout, clockbit, private) \
+  -ENOSYS
+
+/* Wake up up to NR waiters on FUTEXP.  */
+#define lll_futex_wake(futexp, nr, private)                             \
+  -ENOSYS
+
+/* Wake up up to NR_WAKE waiters on FUTEXP.  Move up to NR_MOVE of the
+   rest from waiting on FUTEXP to waiting on MUTEX (a different futex).  */
+#define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val, private) \
+  -ENOSYS
+
+/* Wake up up to NR_WAKE waiters on FUTEXP and NR_WAKE2 on FUTEXP2.  */
+#define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2, private) \
+  -ENOSYS
+
+
+/* Like lll_futex_wait (FUTEXP, VAL, PRIVATE) but with the expectation
+   that lll_futex_cmp_requeue_pi (FUTEXP, _, _, MUTEX, _, PRIVATE) will
+   be used to do the wakeup.  Confers priority-inheritance behavior on
+   the waiter.  */
+#define lll_futex_wait_requeue_pi(futexp, val, mutex, private) \
+  lll_futex_timed_wait_requeue_pi (futexp, val, NULL, 0, mutex, private)
+
+/* Like lll_futex_wait_requeue_pi, but with a timeout.  */
+#define lll_futex_timed_wait_requeue_pi(futexp, val, timeout, clockbit, \
+                                        mutex, private)                 \
+  -ENOSYS
+
+/* Like lll_futex_requeue, but pairs with lll_futex_wait_requeue_pi
+   and inherits priority from the waiter.  */
+#define lll_futex_cmp_requeue_pi(futexp, nr_wake, nr_move, mutex,       \
+                                 val, private)                          \
+  -ENOSYS
+
+
+#endif  /* lowlevellock-futex.h */