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arangodb/lib/Basics/WriteLocker.cpp

133 lines
4.0 KiB
C++

////////////////////////////////////////////////////////////////////////////////
/// @brief Write Locker
///
/// @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
////////////////////////////////////////////////////////////////////////////////
#include "WriteLocker.h"
#ifdef TRI_SHOW_LOCK_TIME
#include "Basics/logging.h"
#endif
using namespace triagens::basics;
// -----------------------------------------------------------------------------
// --SECTION-- constructors and destructors
// -----------------------------------------------------------------------------
////////////////////////////////////////////////////////////////////////////////
/// @brief aquires a write-lock
///
/// The constructors aquires a write lock, the destructors unlocks the lock.
////////////////////////////////////////////////////////////////////////////////
#ifdef TRI_SHOW_LOCK_TIME
WriteLocker::WriteLocker (ReadWriteLock* readWriteLock, char const* file, int line)
: _readWriteLock(readWriteLock), _file(file), _line(line) {
double t = TRI_microtime();
_readWriteLock->writeLock();
_time = TRI_microtime() - t;
}
#else
WriteLocker::WriteLocker (ReadWriteLock* readWriteLock)
: _readWriteLock(readWriteLock) {
_readWriteLock->writeLock();
}
#endif
////////////////////////////////////////////////////////////////////////////////
/// @brief aquires a write-lock, with periodic sleeps while not acquired
/// sleep time is specified in nanoseconds
////////////////////////////////////////////////////////////////////////////////
#ifdef TRI_SHOW_LOCK_TIME
WriteLocker::WriteLocker (ReadWriteLock* readWriteLock,
uint64_t sleepTime,
char const* file,
int line)
: _readWriteLock(readWriteLock), _file(file), _line(line) {
double t = TRI_microtime();
while (! _readWriteLock->tryWriteLock()) {
#ifdef _WIN32
usleep((unsigned long) sleepTime);
#else
usleep((useconds_t) sleepTime);
#endif
}
_time = TRI_microtime() - t;
}
#else
WriteLocker::WriteLocker (ReadWriteLock* readWriteLock,
uint64_t sleepTime)
: _readWriteLock(readWriteLock) {
while (! _readWriteLock->tryWriteLock()) {
#ifdef _WIN32
usleep((unsigned long) sleepTime);
#else
usleep((useconds_t) sleepTime);
#endif
}
}
#endif
////////////////////////////////////////////////////////////////////////////////
/// @brief releases the write-lock
////////////////////////////////////////////////////////////////////////////////
WriteLocker::~WriteLocker () {
_readWriteLock->unlock();
#ifdef TRI_SHOW_LOCK_TIME
if (_time > TRI_SHOW_LOCK_THRESHOLD) {
LOG_WARNING("WriteLocker %s:%d took %f s", _file, _line, _time);
}
#endif
}
// -----------------------------------------------------------------------------
// --SECTION-- END-OF-FILE
// -----------------------------------------------------------------------------
// Local Variables:
// mode: outline-minor
// outline-regexp: "/// @brief\\|/// {@inheritDoc}\\|/// @page\\|// --SECTION--\\|/// @\\}"
// End: