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_BARRIER_H_
18#define ART_RUNTIME_BARRIER_H_
19
20#include <memory>
21#include "base/mutex.h"
22
23namespace art {
24
25class Barrier {
26 public:
27  explicit Barrier(int count);
28  virtual ~Barrier();
29
30  // Pass through the barrier, decrements the count but does not block.
31  void Pass(Thread* self);
32
33  // Wait on the barrier, decrement the count.
34  void Wait(Thread* self);
35
36  // Set the count to a new value, if the value is 0 then everyone waiting on the condition
37  // variable is resumed.
38  void Init(Thread* self, int count);
39
40  // Increment the count by delta, wait on condition if count is non zero.
41  void Increment(Thread* self, int delta);
42
43  // Increment the count by delta, wait on condition if count is non zero, with a timeout
44  void Increment(Thread* self, int delta, uint32_t timeout_ms) LOCKS_EXCLUDED(lock_);
45
46 private:
47  void SetCountLocked(Thread* self, int count) EXCLUSIVE_LOCKS_REQUIRED(lock_);
48
49  // Counter, when this reaches 0 all people blocked on the barrier are signalled.
50  int count_ GUARDED_BY(lock_);
51
52  Mutex lock_ DEFAULT_MUTEX_ACQUIRED_AFTER;
53  ConditionVariable condition_ GUARDED_BY(lock_);
54};
55
56}  // namespace art
57#endif  // ART_RUNTIME_BARRIER_H_
58