lib/ovs-atomic-flag-gcc4.7+.h

   1 /*
   2  * Copyright (c) 2013, 2014 Nicira, Inc.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 /* This header implements atomic_flag on Clang and on GCC 4.7 and later. */
  18 #ifndef IN_OVS_ATOMIC_H
  19 #error "This header should only be included indirectly via ovs-atomic.h."
  20 #endif
  21
  22 /* atomic_flag */
  23
  24 typedef struct {
  25     unsigned char b;
  26 } atomic_flag;
  27 #define ATOMIC_FLAG_INIT { .b = false }
  28
  29 static inline bool
  30 atomic_flag_test_and_set_explicit(volatile atomic_flag *object,
  31                                   memory_order order)
  32 {
  33     return __atomic_test_and_set(&object->b, order);
  34 }
  35
  36 static inline bool
  37 atomic_flag_test_and_set(volatile atomic_flag *object)
  38 {
  39     return atomic_flag_test_and_set_explicit(object, memory_order_seq_cst);
  40 }
  41
  42 static inline void
  43 atomic_flag_clear_explicit(volatile atomic_flag *object, memory_order order)
  44 {
  45     __atomic_clear(object, order);
  46 }
  47
  48 static inline void
  49 atomic_flag_clear(volatile atomic_flag *object)
  50 {
  51     atomic_flag_clear_explicit(object, memory_order_seq_cst);
  52 }