92 lines
2.0 KiB
C++
92 lines
2.0 KiB
C++
// distlock.h
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/* Copyright 2009 10gen Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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/**
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* distributed locking mechanism
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*/
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#include "../pch.h"
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#include "dbclient.h"
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#include "connpool.h"
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#include "redef_macros.h"
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#include "syncclusterconnection.h"
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namespace mongo {
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class DistributedLock {
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public:
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/**
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* @param takeoverMinutes how long before we steal lock in minutes
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*/
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DistributedLock( const ConnectionString& conn , const string& name , unsigned takeoverMinutes = 10 );
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int getState(){
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return _state.get();
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}
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bool isLocked(){
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return _state.get() != 0;
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}
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bool lock_try( string why , BSONObj * other = 0 );
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void unlock();
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private:
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ConnectionString _conn;
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string _name;
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unsigned _takeoverMinutes;
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string _ns;
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BSONObj _id;
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ThreadLocalValue<int> _state;
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};
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class dist_lock_try {
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public:
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dist_lock_try( DistributedLock * lock , string why )
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: _lock(lock){
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_got = _lock->lock_try( why , &_other );
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}
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~dist_lock_try(){
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if ( _got ){
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_lock->unlock();
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}
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}
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bool got() const {
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return _got;
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}
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BSONObj other() const {
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return _other;
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}
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private:
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DistributedLock * _lock;
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bool _got;
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BSONObj _other;
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};
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}
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