mirror of
https://github.com/openvswitch/ovs
synced 2025-10-15 14:17:18 +00:00
4597d2a572
Standard C11 doesn't need these functions because it is able to require implementations not to need them. But we can't construct a portable implementation that does not need them in every case, so this commit adds them. These functions are only needed for atomic_flag objects that are dynamically allocated (because statically allocated objects can use ATOMIC_FLAG_INIT). So far there aren't any of those, but an upcoming commit will introduce one. Signed-off-by: Ben Pfaff <blp@nicira.com> Acked-by: Ethan Jackson <ethan@nicira.com>
159 lines
5.6 KiB
C
159 lines
5.6 KiB
C
/*
|
||
* Copyright (c) 2013 Nicira, Inc.
|
||
*
|
||
* Licensed under the Apache License, Version 2.0 (the "License");
|
||
* you may not use this file except in compliance with the License.
|
||
* You may obtain a copy of the License at:
|
||
*
|
||
* http://www.apache.org/licenses/LICENSE-2.0
|
||
*
|
||
* Unless required by applicable law or agreed to in writing, software
|
||
* distributed under the License is distributed on an "AS IS" BASIS,
|
||
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||
* See the License for the specific language governing permissions and
|
||
* limitations under the License.
|
||
*/
|
||
|
||
/* This header implements atomic operation primitives using pthreads. */
|
||
#ifndef IN_OVS_ATOMIC_H
|
||
#error "This header should only be included indirectly via ovs-atomic.h."
|
||
#endif
|
||
|
||
#define OVS_ATOMIC_PTHREADS_IMPL 1
|
||
|
||
#define DEFINE_PTHREAD_ATOMIC(TYPE, NAME) \
|
||
typedef struct { \
|
||
TYPE value; \
|
||
pthread_mutex_t mutex; \
|
||
} NAME;
|
||
|
||
#define ATOMIC_BOOL_LOCK_FREE 0
|
||
DEFINE_PTHREAD_ATOMIC(bool, atomic_bool);
|
||
|
||
#define ATOMIC_CHAR_LOCK_FREE 0
|
||
DEFINE_PTHREAD_ATOMIC(char, atomic_char);
|
||
DEFINE_PTHREAD_ATOMIC(signed char, atomic_schar);
|
||
DEFINE_PTHREAD_ATOMIC(unsigned char, atomic_uchar);
|
||
|
||
#define ATOMIC_SHORT_LOCK_FREE 0
|
||
DEFINE_PTHREAD_ATOMIC(short, atomic_short);
|
||
DEFINE_PTHREAD_ATOMIC(unsigned short, atomic_ushort);
|
||
|
||
#define ATOMIC_INT_LOCK_FREE 0
|
||
DEFINE_PTHREAD_ATOMIC(int, atomic_int);
|
||
DEFINE_PTHREAD_ATOMIC(unsigned int, atomic_uint);
|
||
|
||
#define ATOMIC_LONG_LOCK_FREE 0
|
||
DEFINE_PTHREAD_ATOMIC(long, atomic_long);
|
||
DEFINE_PTHREAD_ATOMIC(unsigned long, atomic_ulong);
|
||
|
||
#define ATOMIC_LLONG_LOCK_FREE 0
|
||
DEFINE_PTHREAD_ATOMIC(long long, atomic_llong);
|
||
DEFINE_PTHREAD_ATOMIC(unsigned long long, atomic_ullong);
|
||
|
||
DEFINE_PTHREAD_ATOMIC(size_t, atomic_size_t);
|
||
DEFINE_PTHREAD_ATOMIC(ptrdiff_t, atomic_ptrdiff_t);
|
||
|
||
DEFINE_PTHREAD_ATOMIC(intmax_t, atomic_intmax_t);
|
||
DEFINE_PTHREAD_ATOMIC(uintmax_t, atomic_uintmax_t);
|
||
|
||
#define ATOMIC_POINTER_LOCK_FREE 0
|
||
DEFINE_PTHREAD_ATOMIC(intptr_t, atomic_intptr_t);
|
||
DEFINE_PTHREAD_ATOMIC(uintptr_t, atomic_uintptr_t);
|
||
|
||
/* Nonstandard atomic types. */
|
||
DEFINE_PTHREAD_ATOMIC(uint8_t, atomic_uint8_t);
|
||
DEFINE_PTHREAD_ATOMIC(uint16_t, atomic_uint16_t);
|
||
DEFINE_PTHREAD_ATOMIC(uint32_t, atomic_uint32_t);
|
||
DEFINE_PTHREAD_ATOMIC(int8_t, atomic_int8_t);
|
||
DEFINE_PTHREAD_ATOMIC(int16_t, atomic_int16_t);
|
||
DEFINE_PTHREAD_ATOMIC(int32_t, atomic_int32_t);
|
||
DEFINE_PTHREAD_ATOMIC(uint64_t, atomic_uint64_t);
|
||
DEFINE_PTHREAD_ATOMIC(int64_t, atomic_int64_t);
|
||
|
||
typedef enum {
|
||
memory_order_relaxed,
|
||
memory_order_consume,
|
||
memory_order_acquire,
|
||
memory_order_release,
|
||
memory_order_acq_rel,
|
||
memory_order_seq_cst
|
||
} memory_order;
|
||
|
||
#define ATOMIC_VAR_INIT(VALUE) { VALUE, PTHREAD_MUTEX_INITIALIZER }
|
||
#define atomic_init(OBJECT, VALUE) \
|
||
((OBJECT)->value = (VALUE), \
|
||
pthread_mutex_init(&(OBJECT)->mutex, NULL), \
|
||
(void) 0)
|
||
|
||
static inline void
|
||
atomic_thread_fence(memory_order order OVS_UNUSED)
|
||
{
|
||
/* Nothing to do. */
|
||
}
|
||
|
||
static inline void
|
||
atomic_signal_fence(memory_order order OVS_UNUSED)
|
||
{
|
||
/* Nothing to do. */
|
||
}
|
||
|
||
#define atomic_is_lock_free(OBJ) false
|
||
|
||
#define atomic_store(DST, SRC) \
|
||
(pthread_mutex_lock(&(DST)->mutex), \
|
||
(DST)->value = (SRC), \
|
||
pthread_mutex_unlock(&(DST)->mutex), \
|
||
(void) 0)
|
||
#define atomic_store_explicit(DST, SRC, ORDER) \
|
||
((void) (ORDER), atomic_store(DST, SRC))
|
||
|
||
#define atomic_read(SRC, DST) \
|
||
(pthread_mutex_lock(CONST_CAST(pthread_mutex_t *, &(SRC)->mutex)), \
|
||
*(DST) = (SRC)->value, \
|
||
pthread_mutex_unlock(CONST_CAST(pthread_mutex_t *, &(SRC)->mutex)), \
|
||
(void) 0)
|
||
#define atomic_read_explicit(SRC, DST, ORDER) \
|
||
((void) (ORDER), atomic_read(SRC, DST))
|
||
|
||
#define atomic_op__(RMW, OPERATOR, OPERAND, ORIG) \
|
||
(pthread_mutex_lock(&(RMW)->mutex), \
|
||
*(ORIG) = (RMW)->value, \
|
||
(RMW)->value OPERATOR (OPERAND), \
|
||
pthread_mutex_unlock(&(RMW)->mutex), \
|
||
(void) 0)
|
||
|
||
#define atomic_add(RMW, OPERAND, ORIG) atomic_op__(RMW, +=, OPERAND, ORIG)
|
||
#define atomic_sub(RMW, OPERAND, ORIG) atomic_op__(RMW, -=, OPERAND, ORIG)
|
||
#define atomic_or( RMW, OPERAND, ORIG) atomic_op__(RMW, |=, OPERAND, ORIG)
|
||
#define atomic_xor(RMW, OPERAND, ORIG) atomic_op__(RMW, ^=, OPERAND, ORIG)
|
||
#define atomic_and(RMW, OPERAND, ORIG) atomic_op__(RMW, &=, OPERAND, ORIG)
|
||
|
||
#define atomic_add_explicit(RMW, OPERAND, ORIG, ORDER) \
|
||
((void) (ORDER), atomic_add(RMW, OPERAND, ORIG))
|
||
#define atomic_sub_explicit(RMW, OPERAND, ORIG, ORDER) \
|
||
((void) (ORDER), atomic_sub(RMW, OPERAND, ORIG))
|
||
#define atomic_or_explicit(RMW, OPERAND, ORIG, ORDER) \
|
||
((void) (ORDER), atomic_or(RMW, OPERAND, ORIG))
|
||
#define atomic_xor_explicit(RMW, OPERAND, ORIG, ORDER) \
|
||
((void) (ORDER), atomic_xor(RMW, OPERAND, ORIG))
|
||
#define atomic_and_explicit(RMW, OPERAND, ORIG, ORDER) \
|
||
((void) (ORDER), atomic_and(RMW, OPERAND, ORIG))
|
||
|
||
/* atomic_flag */
|
||
|
||
typedef struct {
|
||
bool b;
|
||
pthread_mutex_t mutex;
|
||
} atomic_flag;
|
||
#define ATOMIC_FLAG_INIT { false, PTHREAD_MUTEX_INITIALIZER }
|
||
|
||
void atomic_flag_init(volatile atomic_flag *);
|
||
void atomic_flag_destroy(volatile atomic_flag *);
|
||
|
||
bool atomic_flag_test_and_set(volatile atomic_flag *);
|
||
bool atomic_flag_test_and_set_explicit(volatile atomic_flag *, memory_order);
|
||
|
||
void atomic_flag_clear(volatile atomic_flag *);
|
||
void atomic_flag_clear_explicit(volatile atomic_flag *, memory_order);
|