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arangodb/lib/Basics/ReadUnlocker.h

140 lines
5.2 KiB
C++

////////////////////////////////////////////////////////////////////////////////
/// @brief read unlocker
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2014 ArangoDB GmbH, Cologne, Germany
/// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
///
/// 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.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Frank Celler
/// @author Achim Brandt
/// @author Copyright 2014, ArangoDB GmbH, Cologne, Germany
/// @author Copyright 2010-2013, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////
#ifndef ARANGODB_BASICS_READ_UNLOCKER_H
#define ARANGODB_BASICS_READ_UNLOCKER_H 1
#include "Basics/Common.h"
#include "Basics/ReadWriteLock.h"
// -----------------------------------------------------------------------------
// --SECTION-- public macros
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief construct unlocker with file and line information
///
/// Ones needs to use macros twice to get a unique variable based on the line
/// number.
////////////////////////////////////////////////////////////////////////////////
#define READ_UNLOCKER_VAR_A(a) _read_unlock_variable ## a
#define READ_UNLOCKER_VAR_B(a) READ_UNLOCKER_VAR_A(a)
#define READ_UNLOCKER(b) \
triagens::basics::ReadUnlocker READ_UNLOCKER_VAR_B(__LINE__)(&b, __FILE__, __LINE__)
// -----------------------------------------------------------------------------
// --SECTION-- class ReadLocker
// -----------------------------------------------------------------------------
namespace triagens {
namespace basics {
////////////////////////////////////////////////////////////////////////////////
/// @brief read unlocker
///
/// A ReadUnlocker unlocks a read-write lock during its lifetime and reaquires
/// the read-lock again when it is destroyed.
////////////////////////////////////////////////////////////////////////////////
class ReadUnlocker {
ReadUnlocker (ReadUnlocker const&);
ReadUnlocker& operator= (ReadUnlocker const&);
// -----------------------------------------------------------------------------
// --SECTION-- constructors and destructors
// -----------------------------------------------------------------------------
public:
////////////////////////////////////////////////////////////////////////////////
/// @brief unlocks the lock
///
/// The constructors unlocks the lock, the destructors aquires a read-lock.
////////////////////////////////////////////////////////////////////////////////
explicit
ReadUnlocker (ReadWriteLock* readWriteLock);
////////////////////////////////////////////////////////////////////////////////
/// @brief unlocks the lock
///
/// The constructors unlocks the lock, the destructors aquires a read-lock.
////////////////////////////////////////////////////////////////////////////////
ReadUnlocker (ReadWriteLock* readWriteLock, char const* file, int line);
////////////////////////////////////////////////////////////////////////////////
/// @brief aquires the read-lock
////////////////////////////////////////////////////////////////////////////////
~ReadUnlocker ();
// -----------------------------------------------------------------------------
// --SECTION-- private variables
// -----------------------------------------------------------------------------
private:
////////////////////////////////////////////////////////////////////////////////
/// @brief the read-write lock
////////////////////////////////////////////////////////////////////////////////
ReadWriteLock* _readWriteLock;
////////////////////////////////////////////////////////////////////////////////
/// @brief file
////////////////////////////////////////////////////////////////////////////////
char const* _file;
////////////////////////////////////////////////////////////////////////////////
/// @brief line number
////////////////////////////////////////////////////////////////////////////////
int _line;
};
}
}
#endif
// -----------------------------------------------------------------------------
// --SECTION-- END-OF-FILE
// -----------------------------------------------------------------------------
// Local Variables:
// mode: outline-minor
// outline-regexp: "/// @brief\\|/// {@inheritDoc}\\|/// @page\\|// --SECTION--\\|/// @\\}"
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