Separate Linuxisms from lowlevellock.h, make a generic one

1 files changed, 137 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/lowlevellock-futex.h b/sysdeps/unix/sysv/linux/lowlevellock-futex.h
new file mode 100644
index 0000000000..343afd6ddd
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/lowlevellock-futex.h
@@ -0,0 +1,137 @@
+/* Low-level locking access to futex facilities.  Linux version.
+   Copyright (C) 2005-2014 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 <sysdep.h>
+#include <tls.h>
+#include <kernel-features.h>
+
+
+#define FUTEX_WAIT		0
+#define FUTEX_WAKE		1
+#define FUTEX_REQUEUE		3
+#define FUTEX_CMP_REQUEUE	4
+#define FUTEX_WAKE_OP		5
+#define FUTEX_OP_CLEAR_WAKE_IF_GT_ONE	((4 << 24) | 1)
+#define FUTEX_LOCK_PI		6
+#define FUTEX_UNLOCK_PI		7
+#define FUTEX_TRYLOCK_PI	8
+#define FUTEX_WAIT_BITSET	9
+#define FUTEX_WAKE_BITSET	10
+#define FUTEX_WAIT_REQUEUE_PI   11
+#define FUTEX_CMP_REQUEUE_PI    12
+#define FUTEX_PRIVATE_FLAG	128
+#define FUTEX_CLOCK_REALTIME	256
+
+#define FUTEX_BITSET_MATCH_ANY	0xffffffff
+
+/* Values for 'private' parameter of locking macros.  Yes, the
+   definition seems to be backwards.  But it is not.  The bit will be
+   reversed before passing to the system call.  */
+#define LLL_PRIVATE	0
+#define LLL_SHARED	FUTEX_PRIVATE_FLAG
+
+
+#if !defined NOT_IN_libc || defined IS_IN_rtld
+/* In libc.so or ld.so all futexes are private.  */
+# ifdef __ASSUME_PRIVATE_FUTEX
+#  define __lll_private_flag(fl, private) \
+  ((fl) | FUTEX_PRIVATE_FLAG)
+# else
+#  define __lll_private_flag(fl, private) \
+  ((fl) | THREAD_GETMEM (THREAD_SELF, header.private_futex))
+# endif
+#else
+# ifdef __ASSUME_PRIVATE_FUTEX
+#  define __lll_private_flag(fl, private) \
+  (((fl) | FUTEX_PRIVATE_FLAG) ^ (private))
+# else
+#  define __lll_private_flag(fl, private) \
+  (__builtin_constant_p (private)					      \
+   ? ((private) == 0							      \
+      ? ((fl) | THREAD_GETMEM (THREAD_SELF, header.private_futex))	      \
+      : (fl))								      \
+   : ((fl) | (((private) ^ FUTEX_PRIVATE_FLAG)				      \
+	      & THREAD_GETMEM (THREAD_SELF, header.private_futex))))
+# endif
+#endif
+
+#define lll_futex_syscall(nargs, futexp, op, ...)                       \
+  ({                                                                    \
+    INTERNAL_SYSCALL_DECL (__err);                                      \
+    long int __ret = INTERNAL_SYSCALL (futex, __err, nargs, futexp, op, \
+				       __VA_ARGS__);                    \
+    (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (__ret, __err))         \
+     ? -INTERNAL_SYSCALL_ERRNO (__ret, __err) : 0);                     \
+  })
+
+#define lll_futex_wait(futexp, val, private) \
+  lll_futex_timed_wait (futexp, val, NULL, private)
+
+#define lll_futex_timed_wait(futexp, val, timeout, private)     \
+  lll_futex_syscall (4, futexp,                                 \
+		     __lll_private_flag (FUTEX_WAIT, private),  \
+		     val, timeout)
+
+#define lll_futex_timed_wait_bitset(futexp, val, timeout, clockbit, private) \
+  lll_futex_syscall (6, futexp,                                         \
+		     __lll_private_flag (FUTEX_WAIT_BITSET | (clockbit), \
+					 private),                      \
+		     val, timeout, NULL /* Unused.  */,                 \
+		     FUTEX_BITSET_MATCH_ANY)
+
+#define lll_futex_wake(futexp, nr, private)                             \
+  lll_futex_syscall (4, futexp,                                         \
+		     __lll_private_flag (FUTEX_WAKE, private), nr, 0)
+
+/* Returns non-zero if error happened, zero if success.  */
+#define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val, private) \
+  lll_futex_syscall (6, futexp,                                         \
+		     __lll_private_flag (FUTEX_CMP_REQUEUE, private),   \
+		     nr_wake, nr_move, mutex, val)
+
+/* Returns non-zero if error happened, zero if success.  */
+#define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2, private) \
+  lll_futex_syscall (6, futexp,                                         \
+		     __lll_private_flag (FUTEX_WAKE_OP, private),       \
+		     nr_wake, nr_wake2, futexp2,                        \
+		     FUTEX_OP_CLEAR_WAKE_IF_GT_ONE)
+
+/* Priority Inheritance support.  */
+#define lll_futex_wait_requeue_pi(futexp, val, mutex, private) \
+  lll_futex_timed_wait_requeue_pi (futexp, val, NULL, 0, mutex, private)
+
+#define lll_futex_timed_wait_requeue_pi(futexp, val, timeout, clockbit, \
+					mutex, private)                 \
+  lll_futex_syscall (5, futexp,                                         \
+		     __lll_private_flag (FUTEX_WAIT_REQUEUE_PI          \
+					 | (clockbit), private),        \
+		     val, timeout, mutex)
+
+
+#define lll_futex_cmp_requeue_pi(futexp, nr_wake, nr_move, mutex,       \
+				 val, private)                          \
+  lll_futex_syscall (6, futexp,                                         \
+		     __lll_private_flag (FUTEX_CMP_REQUEUE_PI,          \
+					 private),                      \
+		     nr_wake, nr_move, mutex, val)
+
+
+#endif  /* lowlevellock-futex.h */