1/*
2 * Copyright (C) 2012 The Android Open Source Project
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#ifndef ART_RUNTIME_ATOMIC_INTEGER_H_
18#define ART_RUNTIME_ATOMIC_INTEGER_H_
19
20#include "cutils/atomic.h"
21#include "cutils/atomic-inline.h"
22
23namespace art {
24
25class AtomicInteger {
26 public:
27  AtomicInteger() : value_(0) { }
28
29  explicit AtomicInteger(int32_t value) : value_(value) { }
30
31  // Unsafe = operator for non atomic operations on the integer.
32  void store(int32_t desired) {
33    value_ = desired;
34  }
35
36  AtomicInteger& operator=(int32_t desired) {
37    store(desired);
38    return *this;
39  }
40
41  int32_t load() const {
42    return value_;
43  }
44
45  operator int32_t() const {
46    return load();
47  }
48
49  int32_t fetch_add(const int32_t value) {
50    return android_atomic_add(value, &value_);
51  }
52
53  int32_t fetch_sub(const int32_t value) {
54    return android_atomic_add(-value, &value_);
55  }
56
57  int32_t operator++() {
58    return android_atomic_inc(&value_) + 1;
59  }
60
61  int32_t operator++(int32_t) {
62    return android_atomic_inc(&value_);
63  }
64
65  int32_t operator--() {
66    return android_atomic_dec(&value_) - 1;
67  }
68
69  int32_t operator--(int32_t) {
70    return android_atomic_dec(&value_);
71  }
72
73  bool compare_and_swap(int32_t expected_value, int32_t desired_value) {
74    return android_atomic_cas(expected_value, desired_value, &value_) == 0;
75  }
76
77 private:
78  volatile int32_t value_;
79};
80
81}  // namespace art
82
83#endif  // ART_RUNTIME_ATOMIC_INTEGER_H_
84