mirror of
https://github.com/openvswitch/ovs
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31a3fc6e3e
This library should prove useful for the threading changes coming up. The following commit introduces one (very simple) user. Signed-off-by: Ben Pfaff <blp@nicira.com> Acked-by: Ethan Jackson <ethan@nicira.com>
266 lines
9.5 KiB
C
266 lines
9.5 KiB
C
/*
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* Copyright (c) 2013 Nicira, Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at:
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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/* This header implements atomic operation primitives on GCC 4.x. */
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#ifndef IN_OVS_ATOMIC_H
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#error "This header should only be included indirectly via ovs-atomic.h."
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#endif
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#define OVS_ATOMIC_GCC4P_IMPL 1
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#define DEFINE_LOCKLESS_ATOMIC(TYPE, NAME) typedef struct { TYPE value; } NAME
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#define ATOMIC_BOOL_LOCK_FREE 2
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DEFINE_LOCKLESS_ATOMIC(bool, atomic_bool);
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#define ATOMIC_CHAR_LOCK_FREE 2
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DEFINE_LOCKLESS_ATOMIC(char, atomic_char);
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DEFINE_LOCKLESS_ATOMIC(signed char, atomic_schar);
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DEFINE_LOCKLESS_ATOMIC(unsigned char, atomic_uchar);
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#define ATOMIC_SHORT_LOCK_FREE 2
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DEFINE_LOCKLESS_ATOMIC(short, atomic_short);
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DEFINE_LOCKLESS_ATOMIC(unsigned short, atomic_ushort);
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#define ATOMIC_INT_LOCK_FREE 2
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DEFINE_LOCKLESS_ATOMIC(int, atomic_int);
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DEFINE_LOCKLESS_ATOMIC(unsigned int, atomic_uint);
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#if ULONG_MAX <= UINTPTR_MAX
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#define ATOMIC_LONG_LOCK_FREE 2
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DEFINE_LOCKLESS_ATOMIC(long, atomic_long);
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DEFINE_LOCKLESS_ATOMIC(unsigned long, atomic_ulong);
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#elif ULONG_MAX == UINT64_MAX
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#define ATOMIC_LONG_LOCK_FREE 0
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typedef struct locked_int64 atomic_long;
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typedef struct locked_uint64 atomic_ulong;
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#else
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#error "not implemented"
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#endif
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#if ULLONG_MAX <= UINTPTR_MAX
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#define ATOMIC_LLONG_LOCK_FREE 2
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DEFINE_LOCKLESS_ATOMIC(long long, atomic_llong);
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DEFINE_LOCKLESS_ATOMIC(unsigned long long, atomic_ullong);
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#elif ULLONG_MAX == UINT64_MAX
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#define ATOMIC_LLONG_LOCK_FREE 0
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typedef struct locked_int64 atomic_llong;
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typedef struct locked_uint64 atomic_ullong;
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#else
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#error "not implemented"
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#endif
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#if SIZE_MAX <= UINTPTR_MAX
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DEFINE_LOCKLESS_ATOMIC(size_t, atomic_size_t);
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DEFINE_LOCKLESS_ATOMIC(ptrdiff_t, atomic_ptrdiff_t);
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#elif SIZE_MAX == UINT64_MAX
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typedef struct locked_uint64 atomic_size_t;
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typedef struct locked_int64 atomic_ptrdiff_t;
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#else
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#error "not implemented"
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#endif
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#if UINTMAX_MAX <= UINTPTR_MAX
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DEFINE_LOCKLESS_ATOMIC(intmax_t, atomic_intmax_t);
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DEFINE_LOCKLESS_ATOMIC(uintmax_t, atomic_uintmax_t);
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#elif UINTMAX_MAX == UINT64_MAX
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typedef struct locked_int64 atomic_intmax_t;
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typedef struct locked_uint64 atomic_uintmax_t;
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#else
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#error "not implemented"
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#endif
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#define ATOMIC_POINTER_LOCK_FREE 2
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DEFINE_LOCKLESS_ATOMIC(intptr_t, atomic_intptr_t);
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DEFINE_LOCKLESS_ATOMIC(uintptr_t, atomic_uintptr_t);
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/* Nonstandard atomic types. */
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DEFINE_LOCKLESS_ATOMIC(uint8_t, atomic_uint8_t);
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DEFINE_LOCKLESS_ATOMIC(uint16_t, atomic_uint16_t);
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DEFINE_LOCKLESS_ATOMIC(uint32_t, atomic_uint32_t);
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DEFINE_LOCKLESS_ATOMIC(int8_t, atomic_int8_t);
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DEFINE_LOCKLESS_ATOMIC(int16_t, atomic_int16_t);
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DEFINE_LOCKLESS_ATOMIC(int32_t, atomic_int32_t);
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#if UINT64_MAX <= UINTPTR_MAX
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DEFINE_LOCKLESS_ATOMIC(uint64_t, atomic_uint64_t);
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DEFINE_LOCKLESS_ATOMIC(int64_t, atomic_int64_t);
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#else
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typedef struct locked_uint64 atomic_uint64_t;
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typedef struct locked_int64 atomic_int64_t;
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#endif
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typedef enum {
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memory_order_relaxed,
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memory_order_consume,
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memory_order_acquire,
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memory_order_release,
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memory_order_acq_rel,
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memory_order_seq_cst
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} memory_order;
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/* locked_uint64. */
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#define IF_LOCKED_UINT64(OBJECT, THEN, ELSE) \
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__builtin_choose_expr( \
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__builtin_types_compatible_p(typeof(OBJECT), struct locked_uint64), \
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(THEN), (ELSE))
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#define AS_LOCKED_UINT64(OBJECT) ((struct locked_uint64 *) (OBJECT))
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#define AS_UINT64(OBJECT) ((uint64_t *) (OBJECT))
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struct locked_uint64 {
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uint64_t value;
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};
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uint64_t locked_uint64_load(const struct locked_uint64 *);
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void locked_uint64_store(struct locked_uint64 *, uint64_t);
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uint64_t locked_uint64_add(struct locked_uint64 *, uint64_t arg);
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uint64_t locked_uint64_sub(struct locked_uint64 *, uint64_t arg);
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uint64_t locked_uint64_or(struct locked_uint64 *, uint64_t arg);
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uint64_t locked_uint64_xor(struct locked_uint64 *, uint64_t arg);
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uint64_t locked_uint64_and(struct locked_uint64 *, uint64_t arg);
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#define IF_LOCKED_INT64(OBJECT, THEN, ELSE) \
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__builtin_choose_expr( \
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__builtin_types_compatible_p(typeof(OBJECT), struct locked_int64), \
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(THEN), (ELSE))
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#define AS_LOCKED_INT64(OBJECT) ((struct locked_int64 *) (OBJECT))
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#define AS_INT64(OBJECT) ((int64_t *) (OBJECT))
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struct locked_int64 {
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int64_t value;
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};
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int64_t locked_int64_load(const struct locked_int64 *);
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void locked_int64_store(struct locked_int64 *, int64_t);
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int64_t locked_int64_add(struct locked_int64 *, int64_t arg);
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int64_t locked_int64_sub(struct locked_int64 *, int64_t arg);
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int64_t locked_int64_or(struct locked_int64 *, int64_t arg);
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int64_t locked_int64_xor(struct locked_int64 *, int64_t arg);
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int64_t locked_int64_and(struct locked_int64 *, int64_t arg);
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#define ATOMIC_VAR_INIT(VALUE) { .value = (VALUE) }
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#define atomic_init(OBJECT, VALUE) ((OBJECT)->value = (VALUE), (void) 0)
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static inline void
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atomic_thread_fence(memory_order order)
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{
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if (order != memory_order_relaxed) {
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__sync_synchronize();
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}
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}
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static inline void
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atomic_thread_fence_if_seq_cst(memory_order order)
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{
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if (order == memory_order_seq_cst) {
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__sync_synchronize();
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}
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}
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static inline void
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atomic_signal_fence(memory_order order OVS_UNUSED)
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{
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if (order != memory_order_relaxed) {
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asm volatile("" : : : "memory");
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}
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}
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#define ATOMIC_SWITCH(OBJECT, LOCKLESS_CASE, \
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LOCKED_UINT64_CASE, LOCKED_INT64_CASE) \
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IF_LOCKED_UINT64(OBJECT, LOCKED_UINT64_CASE, \
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IF_LOCKED_INT64(OBJECT, LOCKED_INT64_CASE, \
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LOCKLESS_CASE))
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#define atomic_is_lock_free(OBJ) \
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((void) (OBJ)->value, \
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ATOMIC_SWITCH(OBJ, true, false, false))
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#define atomic_store(DST, SRC) \
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atomic_store_explicit(DST, SRC, memory_order_seq_cst)
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#define atomic_store_explicit(DST, SRC, ORDER) \
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(ATOMIC_SWITCH(DST, \
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(atomic_thread_fence(ORDER), \
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(DST)->value = (SRC), \
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atomic_thread_fence_if_seq_cst(ORDER)), \
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locked_uint64_store(AS_LOCKED_UINT64(DST), SRC), \
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locked_int64_store(AS_LOCKED_INT64(DST), SRC)), \
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(void) 0)
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#define atomic_read(SRC, DST) \
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atomic_read_explicit(SRC, DST, memory_order_seq_cst)
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#define atomic_read_explicit(SRC, DST, ORDER) \
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(ATOMIC_SWITCH(SRC, \
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(atomic_thread_fence_if_seq_cst(ORDER), \
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(*DST) = (SRC)->value, \
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atomic_thread_fence(ORDER)), \
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*(DST) = locked_uint64_load(AS_LOCKED_UINT64(SRC)), \
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*(DST) = locked_int64_load(AS_LOCKED_INT64(SRC))), \
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(void) 0)
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#define atomic_op__(RMW, OP, ARG, ORIG) \
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(ATOMIC_SWITCH(RMW, \
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*(ORIG) = __sync_fetch_and_##OP(&(RMW)->value, ARG), \
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*(ORIG) = locked_uint64_##OP(AS_LOCKED_UINT64(RMW), ARG), \
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*(ORIG) = locked_int64_##OP(AS_LOCKED_INT64(RMW), ARG)), \
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(void) 0)
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#define atomic_add(RMW, ARG, ORIG) atomic_op__(RMW, add, ARG, ORIG)
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#define atomic_sub(RMW, ARG, ORIG) atomic_op__(RMW, sub, ARG, ORIG)
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#define atomic_or( RMW, ARG, ORIG) atomic_op__(RMW, or, ARG, ORIG)
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#define atomic_xor(RMW, ARG, ORIG) atomic_op__(RMW, xor, ARG, ORIG)
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#define atomic_and(RMW, ARG, ORIG) atomic_op__(RMW, and, ARG, ORIG)
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#define atomic_add_explicit(RMW, OPERAND, ORIG, ORDER) \
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((void) (ORDER), atomic_add(RMW, OPERAND, ORIG))
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#define atomic_sub_explicit(RMW, OPERAND, ORIG, ORDER) \
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((void) (ORDER), atomic_sub(RMW, OPERAND, ORIG))
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#define atomic_or_explicit(RMW, OPERAND, ORIG, ORDER) \
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((void) (ORDER), atomic_or(RMW, OPERAND, ORIG))
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#define atomic_xor_explicit(RMW, OPERAND, ORIG, ORDER) \
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((void) (ORDER), atomic_xor(RMW, OPERAND, ORIG))
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#define atomic_and_explicit(RMW, OPERAND, ORIG, ORDER) \
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((void) (ORDER), atomic_and(RMW, OPERAND, ORIG))
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/* atomic_flag */
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typedef struct {
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int b;
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} atomic_flag;
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#define ATOMIC_FLAG_INIT { false }
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static inline bool
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atomic_flag_test_and_set(volatile atomic_flag *object)
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{
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return __sync_lock_test_and_set(&object->b, 1);
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}
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static inline bool
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atomic_flag_test_and_set_explicit(volatile atomic_flag *object,
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memory_order order OVS_UNUSED)
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{
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return atomic_flag_test_and_set(object);
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}
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static inline void
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atomic_flag_clear(volatile atomic_flag *object)
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{
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__sync_lock_release(&object->b);
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}
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static inline void
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atomic_flag_clear_explicit(volatile atomic_flag *object,
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memory_order order OVS_UNUSED)
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{
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atomic_flag_clear(object);
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}
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