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authorBernhard Reutner-Fischer <rep.dot.nop@gmail.com>2015-03-26 23:12:38 +0100
committerBernhard Reutner-Fischer <rep.dot.nop@gmail.com>2015-03-27 00:08:46 +0100
commitcc8d7d062e2db0a1ed3973e6af38cd1938ba74d7 (patch)
tree9e2db5741cbcb01a246821cc4fc9dc4df8e263b4 /include/atomic.h
parent560f416794403be952e850756d7e8b23e8fa92ac (diff)
include: update atomic.h from glibc
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>
Diffstat (limited to 'include/atomic.h')
-rw-r--r--include/atomic.h235
1 files changed, 231 insertions, 4 deletions
diff --git a/include/atomic.h b/include/atomic.h
index 307704cba..3680d8714 100644
--- a/include/atomic.h
+++ b/include/atomic.h
@@ -1,5 +1,5 @@
/* Internal macros for atomic operations for GNU C Library.
- Copyright (C) 2002-2006, 2009 Free Software Foundation, Inc.
+ Copyright (C) 2002-2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
@@ -32,7 +32,7 @@
the multi-thread case. The interfaces have the prefix
"catomic_".
- - support functions like barriers. They also have the preifx
+ - support functions like barriers. They also have the prefix
"atomic_".
Architectures must provide a few lowlevel macros (the compare
@@ -198,8 +198,12 @@
/* Add VALUE to *MEM and return the old value of *MEM. */
-#ifndef atomic_exchange_and_add
-# define atomic_exchange_and_add(mem, value) \
+#ifndef atomic_exchange_and_add_acq
+# ifdef atomic_exchange_and_add
+# define atomic_exchange_and_add_acq(mem, value) \
+ atomic_exchange_and_add (mem, value)
+# else
+# define atomic_exchange_and_add_acq(mem, value) \
({ __typeof (*(mem)) __atg6_oldval; \
__typeof (mem) __atg6_memp = (mem); \
__typeof (*(mem)) __atg6_value = (value); \
@@ -213,8 +217,18 @@
__atg6_oldval), 0)); \
\
__atg6_oldval; })
+# endif
#endif
+#ifndef atomic_exchange_and_add_rel
+# define atomic_exchange_and_add_rel(mem, value) \
+ atomic_exchange_and_add_acq(mem, value)
+#endif
+
+#ifndef atomic_exchange_and_add
+# define atomic_exchange_and_add(mem, value) \
+ atomic_exchange_and_add_acq(mem, value)
+#endif
#ifndef catomic_exchange_and_add
# define catomic_exchange_and_add(mem, value) \
@@ -528,6 +542,219 @@
({ __typeof (x) __x; __asm__ ("" : "=r" (__x) : "0" (x)); __x; })
#endif
+/* This is equal to 1 iff the architecture supports 64b atomic operations. */
+#define __HAVE_64B_ATOMICS 0 /* TODO: not yet used - Add these to arch bits! */
+#ifndef __HAVE_64B_ATOMICS
+#error Unable to determine if 64-bit atomics are present.
+#endif
+
+/* The following functions are a subset of the atomic operations provided by
+ C11. Usually, a function named atomic_OP_MO(args) is equivalent to C11's
+ atomic_OP_explicit(args, memory_order_MO); exceptions noted below. */
+
+/* Each arch can request to use compiler built-ins for C11 atomics. If it
+ does, all atomics will be based on these. */
+#if 0 /* not yet used USE_ATOMIC_COMPILER_BUILTINS */
+
+/* We require 32b atomic operations; some archs also support 64b atomic
+ operations. */
+void __atomic_link_error (void);
+# if __HAVE_64B_ATOMICS == 1
+# define __atomic_check_size(mem) \
+ if ((sizeof (*mem) != 4) && (sizeof (*mem) != 8)) \
+ __atomic_link_error ();
+# else
+# define __atomic_check_size(mem) \
+ if (sizeof (*mem) != 4) \
+ __atomic_link_error ();
+# endif
+
+# define atomic_thread_fence_acquire() \
+ __atomic_thread_fence (__ATOMIC_ACQUIRE)
+# define atomic_thread_fence_release() \
+ __atomic_thread_fence (__ATOMIC_RELEASE)
+# define atomic_thread_fence_seq_cst() \
+ __atomic_thread_fence (__ATOMIC_SEQ_CST)
+
+# define atomic_load_relaxed(mem) \
+ ({ __atomic_check_size((mem)); __atomic_load_n ((mem), __ATOMIC_RELAXED); })
+# define atomic_load_acquire(mem) \
+ ({ __atomic_check_size((mem)); __atomic_load_n ((mem), __ATOMIC_ACQUIRE); })
+
+# define atomic_store_relaxed(mem, val) \
+ do { \
+ __atomic_check_size((mem)); \
+ __atomic_store_n ((mem), (val), __ATOMIC_RELAXED); \
+ } while (0)
+# define atomic_store_release(mem, val) \
+ do { \
+ __atomic_check_size((mem)); \
+ __atomic_store_n ((mem), (val), __ATOMIC_RELEASE); \
+ } while (0)
+
+/* On failure, this CAS has memory_order_relaxed semantics. */
+# define atomic_compare_exchange_weak_relaxed(mem, expected, desired) \
+ ({ __atomic_check_size((mem)); \
+ __atomic_compare_exchange_n ((mem), (expected), (desired), 1, \
+ __ATOMIC_RELAXED, __ATOMIC_RELAXED); })
+# define atomic_compare_exchange_weak_acquire(mem, expected, desired) \
+ ({ __atomic_check_size((mem)); \
+ __atomic_compare_exchange_n ((mem), (expected), (desired), 1, \
+ __ATOMIC_ACQUIRE, __ATOMIC_RELAXED); })
+# define atomic_compare_exchange_weak_release(mem, expected, desired) \
+ ({ __atomic_check_size((mem)); \
+ __atomic_compare_exchange_n ((mem), (expected), (desired), 1, \
+ __ATOMIC_RELEASE, __ATOMIC_RELAXED); })
+
+# define atomic_exchange_acquire(mem, desired) \
+ ({ __atomic_check_size((mem)); \
+ __atomic_exchange_n ((mem), (desired), __ATOMIC_ACQUIRE); })
+# define atomic_exchange_release(mem, desired) \
+ ({ __atomic_check_size((mem)); \
+ __atomic_exchange_n ((mem), (desired), __ATOMIC_RELEASE); })
+
+# define atomic_fetch_add_relaxed(mem, operand) \
+ ({ __atomic_check_size((mem)); \
+ __atomic_fetch_add ((mem), (operand), __ATOMIC_RELAXED); })
+# define atomic_fetch_add_acquire(mem, operand) \
+ ({ __atomic_check_size((mem)); \
+ __atomic_fetch_add ((mem), (operand), __ATOMIC_ACQUIRE); })
+# define atomic_fetch_add_release(mem, operand) \
+ ({ __atomic_check_size((mem)); \
+ __atomic_fetch_add ((mem), (operand), __ATOMIC_RELEASE); })
+# define atomic_fetch_add_acq_rel(mem, operand) \
+ ({ __atomic_check_size((mem)); \
+ __atomic_fetch_add ((mem), (operand), __ATOMIC_ACQ_REL); })
+
+# define atomic_fetch_and_acquire(mem, operand) \
+ ({ __atomic_check_size((mem)); \
+ __atomic_fetch_and ((mem), (operand), __ATOMIC_ACQUIRE); })
+
+# define atomic_fetch_or_relaxed(mem, operand) \
+ ({ __atomic_check_size((mem)); \
+ __atomic_fetch_or ((mem), (operand), __ATOMIC_RELAXED); })
+# define atomic_fetch_or_acquire(mem, operand) \
+ ({ __atomic_check_size((mem)); \
+ __atomic_fetch_or ((mem), (operand), __ATOMIC_ACQUIRE); })
+
+#else /* !USE_ATOMIC_COMPILER_BUILTINS */
+
+/* By default, we assume that read, write, and full barriers are equivalent
+ to acquire, release, and seq_cst barriers. Archs for which this does not
+ hold have to provide custom definitions of the fences. */
+# ifndef atomic_thread_fence_acquire
+# define atomic_thread_fence_acquire() atomic_read_barrier ()
+# endif
+# ifndef atomic_thread_fence_release
+# define atomic_thread_fence_release() atomic_write_barrier ()
+# endif
+# ifndef atomic_thread_fence_seq_cst
+# define atomic_thread_fence_seq_cst() atomic_full_barrier ()
+# endif
+
+# ifndef atomic_load_relaxed
+# define atomic_load_relaxed(mem) \
+ ({ __typeof (*(mem)) __atg100_val; \
+ __asm__ ("" : "=r" (__atg100_val) : "0" (*(mem))); \
+ __atg100_val; })
+# endif
+# ifndef atomic_load_acquire
+# define atomic_load_acquire(mem) \
+ ({ __typeof (*(mem)) __atg101_val = atomic_load_relaxed (mem); \
+ atomic_thread_fence_acquire (); \
+ __atg101_val; })
+# endif
+
+# ifndef atomic_store_relaxed
+/* XXX Use inline asm here? */
+# define atomic_store_relaxed(mem, val) do { *(mem) = (val); } while (0)
+# endif
+# ifndef atomic_store_release
+# define atomic_store_release(mem, val) \
+ do { \
+ atomic_thread_fence_release (); \
+ atomic_store_relaxed ((mem), (val)); \
+ } while (0)
+# endif
+
+/* On failure, this CAS has memory_order_relaxed semantics. */
+/* XXX This potentially has one branch more than necessary, but archs
+ currently do not define a CAS that returns both the previous value and
+ the success flag. */
+# ifndef atomic_compare_exchange_weak_acquire
+# define atomic_compare_exchange_weak_acquire(mem, expected, desired) \
+ ({ __typeof (*(expected)) __atg102_expected = *(expected); \
+ *(expected) = \
+ atomic_compare_and_exchange_val_acq ((mem), (desired), *(expected)); \
+ *(expected) == __atg102_expected; })
+# endif
+# ifndef atomic_compare_exchange_weak_relaxed
+/* XXX Fall back to CAS with acquire MO because archs do not define a weaker
+ CAS. */
+# define atomic_compare_exchange_weak_relaxed(mem, expected, desired) \
+ atomic_compare_exchange_weak_acquire ((mem), (expected), (desired))
+# endif
+# ifndef atomic_compare_exchange_weak_release
+# define atomic_compare_exchange_weak_release(mem, expected, desired) \
+ ({ __typeof (*(expected)) __atg103_expected = *(expected); \
+ *(expected) = \
+ atomic_compare_and_exchange_val_rel ((mem), (desired), *(expected)); \
+ *(expected) == __atg103_expected; })
+# endif
+
+# ifndef atomic_exchange_acquire
+# define atomic_exchange_acquire(mem, val) \
+ atomic_exchange_acq ((mem), (val))
+# endif
+# ifndef atomic_exchange_release
+# define atomic_exchange_release(mem, val) \
+ atomic_exchange_rel ((mem), (val))
+# endif
+
+# ifndef atomic_fetch_add_acquire
+# define atomic_fetch_add_acquire(mem, operand) \
+ atomic_exchange_and_add_acq ((mem), (operand))
+# endif
+# ifndef atomic_fetch_add_relaxed
+/* XXX Fall back to acquire MO because the MO semantics of
+ atomic_exchange_and_add are not documented; the generic version falls back
+ to atomic_exchange_and_add_acq if atomic_exchange_and_add is not defined,
+ and vice versa. */
+# define atomic_fetch_add_relaxed(mem, operand) \
+ atomic_fetch_add_acquire ((mem), (operand))
+# endif
+# ifndef atomic_fetch_add_release
+# define atomic_fetch_add_release(mem, operand) \
+ atomic_exchange_and_add_rel ((mem), (operand))
+# endif
+# ifndef atomic_fetch_add_acq_rel
+# define atomic_fetch_add_acq_rel(mem, operand) \
+ ({ atomic_thread_fence_release (); \
+ atomic_exchange_and_add_acq ((mem), (operand)); })
+# endif
+
+/* XXX The default for atomic_and_val has acquire semantics, but this is not
+ documented. */
+# ifndef atomic_fetch_and_acquire
+# define atomic_fetch_and_acquire(mem, operand) \
+ atomic_and_val ((mem), (operand))
+# endif
+
+/* XXX The default for atomic_or_val has acquire semantics, but this is not
+ documented. */
+# ifndef atomic_fetch_or_acquire
+# define atomic_fetch_or_acquire(mem, operand) \
+ atomic_or_val ((mem), (operand))
+# endif
+/* XXX Fall back to acquire MO because archs do not define a weaker
+ atomic_or_val. */
+# ifndef atomic_fetch_or_relaxed
+# define atomic_fetch_or_relaxed(mem, operand) \
+ atomic_fetch_or_acquire ((mem), (operand))
+# endif
+
+#endif /* !USE_ATOMIC_COMPILER_BUILTINS */
+
#ifndef atomic_delay
# define atomic_delay() do { /* nothing */ } while (0)