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Diffstat (limited to 'src/mongo/db/global_timestamp.cpp')
-rw-r--r-- | src/mongo/db/global_timestamp.cpp | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/src/mongo/db/global_timestamp.cpp b/src/mongo/db/global_timestamp.cpp new file mode 100644 index 00000000000..f6cf646ba7e --- /dev/null +++ b/src/mongo/db/global_timestamp.cpp @@ -0,0 +1,82 @@ +/** + * Copyright (C) 2014 MongoDB, Inc. + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU Affero General Public License, version 3, + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + * As a special exception, the copyright holders give permission to link the + * code of portions of this program with the OpenSSL library under certain + * conditions as described in each individual source file and distribute + * linked combinations including the program with the OpenSSL library. You + * must comply with the GNU Affero General Public License in all respects for + * all of the code used other than as permitted herein. If you modify file(s) + * with this exception, you may extend this exception to your version of the + * file(s), but you are not obligated to do so. If you do not wish to do so, + * delete this exception statement from your version. If you delete this + * exception statement from all source files in the program, then also delete + * it in the license file. + */ + +#define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kDefault + +#include <boost/thread.hpp> + +#include "mongo/db/global_timestamp.h" +#include "mongo/util/concurrency/mutex.h" +#include "mongo/util/log.h" + +namespace { + mongo::mutex globalTimestampMutex; + mongo::Timestamp globalTimestamp(0, 0); + + bool skewed(const mongo::Timestamp& val) { + if (val.getInc() & 0x80000000) { + mongo::warning() << "clock skew detected prev: " << val.getSecs() + << " now: " << (unsigned) time(0) << std::endl; + return true; + } + + return false; + } +} + +namespace mongo { + void setGlobalTimestamp(const Timestamp& newTime) { + boost::lock_guard<boost::mutex> lk(globalTimestampMutex); + globalTimestamp = newTime; + } + + Timestamp getLastSetTimestamp() { + boost::lock_guard<boost::mutex> lk(globalTimestampMutex); + return globalTimestamp; + } + + Timestamp getNextGlobalTimestamp() { + boost::lock_guard<boost::mutex> lk(globalTimestampMutex); + + const unsigned now = (unsigned) time(0); + const unsigned globalSecs = globalTimestamp.getSecs(); + if ( globalSecs == now ) { + globalTimestamp = Timestamp(globalSecs, globalTimestamp.getInc() + 1); + } + else if ( now < globalSecs ) { + globalTimestamp = Timestamp(globalSecs, globalTimestamp.getInc() + 1); + // separate function to keep out of the hot code path + fassert(17449, !skewed(globalTimestamp)); + } + else { + globalTimestamp = Timestamp(now, 1); + } + + return globalTimestamp; + } +} |