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/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef ART_RUNTIME_BASE_SCOPED_FLOCK_H_
#define ART_RUNTIME_BASE_SCOPED_FLOCK_H_
#include <memory>
#include <string>
#include "base/macros.h"
#include "os.h"
namespace art {
class ScopedFlock {
public:
ScopedFlock();
// Attempts to acquire an exclusive file lock (see flock(2)) on the file
// at filename, and blocks until it can do so.
//
// Returns true if the lock could be acquired, or false if an error
// occurred. It is an error if the file does not exist, or if its inode
// changed (usually due to a new file being created at the same path)
// between attempts to lock it.
bool Init(const char* filename, std::string* error_msg);
// Attempt to acquire an exclusive file lock (see flock(2)) on 'file'.
// Returns true if the lock could be acquired or false if an error
// occured.
bool Init(File* file, std::string* error_msg);
// Returns the (locked) file associated with this instance.
File* GetFile();
// Returns whether a file is held.
bool HasFile();
~ScopedFlock();
private:
std::unique_ptr<File> file_;
DISALLOW_COPY_AND_ASSIGN(ScopedFlock);
};
} // namespace art
#endif // ART_RUNTIME_BASE_SCOPED_FLOCK_H_