1 /*
2  * Copyright (C) 2017 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 CHRE_UTIL_CONDITIONAL_LOCK_GUARD_H_
18 #define CHRE_UTIL_CONDITIONAL_LOCK_GUARD_H_
19 
20 #include "chre/util/non_copyable.h"
21 
22 namespace chre {
23 
24 /**
25  * A version of LockGuard that only acquires the lock if a boolean constructor
26  * argument evaluates to true.
27  */
28 template <typename MutexType>
29 class ConditionalLockGuard : public NonCopyable {
30  public:
31   /**
32    * Acquires a lock on the mutex if shouldLock is true, otherwise does nothing
33    */
34   ConditionalLockGuard(MutexType &mutex, bool shouldLock);
35 
36   /**
37    * Releases the lock if it was acquired in the constructor
38    */
39   ~ConditionalLockGuard();
40 
41  private:
42   MutexType &mMutex;
43   bool mShouldLock;
44 };
45 
46 }  // namespace chre
47 
48 #include "chre/util/conditional_lock_guard_impl.h"
49 
50 #endif  // CHRE_UTIL_CONDITIONAL_LOCK_GUARD_H_
51