// Copyright (c) 2011 The LevelDB Authors. All rights reserved.

// Use of this source code is governed by a BSD-style license that can be

// found in the LICENSE file. See the AUTHORS file for names of contributors.

#ifndef STORAGE_LEVELDB_UTIL_MUTEXLOCK_H_

#define STORAGE_LEVELDB_UTIL_MUTEXLOCK_H_

#include "port/port.h"

#include "port/thread_annotations.h"

namespace leveldb {

// Helper class that locks a mutex on construction and unlocks the mutex when

// the destructor of the MutexLock object is invoked.

//

// Typical usage:

//

//   void MyClass::MyMethod() {

//     MutexLock l(&mu_);       // mu_ is an instance variable

//     ... some complex code, possibly with multiple return paths ...

//   }

class SCOPED_LOCKABLE MutexLock {

 public:

  explicit MutexLock(port::Mutex* mu) EXCLUSIVE_LOCK_FUNCTION(mu) : mu_(mu) {

    this->mu_->Lock();

  }

  ~MutexLock() UNLOCK_FUNCTION() { this->mu_->Unlock(); }

  MutexLock(const MutexLock&) = delete;

  MutexLock& operator=(const MutexLock&) = delete;

 private:

  port::Mutex* const mu_;

};

}  // namespace leveldb

#endif  // STORAGE_LEVELDB_UTIL_MUTEXLOCK_H_