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#ifndef QPID_HA_PRIMARYTXOBSERVER_H
#define QPID_HA_PRIMARYTXOBSERVER_H
/*
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
*
*/
#include "types.h"
#include "ReplicationTest.h"
#include "LogPrefix.h"
#include "qpid/broker/SessionState.h"
#include "qpid/broker/TransactionObserver.h"
#include "qpid/log/Statement.h"
#include "qpid/types/Uuid.h"
#include "qpid/sys/unordered_map.h"
#include "qpid/sys/Monitor.h"
#include <boost/enable_shared_from_this.hpp>
#include <boost/intrusive_ptr.hpp>
namespace qpid {
namespace broker {
class Broker;
class Message;
class Consumer;
class AsyncCompletion;
}
namespace ha {
class HaBroker;
class ReplicatingSubscription;
class Primary;
/**
* Observe events in the lifecycle of a transaction.
*
* The observer is called by TxBuffer for each transactional event.
* It puts the events on a special tx-queue.
* A TxReplicator on the backup replicates the tx-queue and creates
* a TxBuffer on the backup equivalent to the one on the primary.
*
* Creates an exchange to receive prepare-ok/prepare-fail messages from backups.
*
* Monitors for tx-queue subscription cancellations.
*
* THREAD SAFE: called in user connection thread for TX events,
* and in backup connection threads for prepare-completed events
* and unsubscriptions.
*/
class PrimaryTxObserver : public broker::TransactionObserver,
public boost::enable_shared_from_this<PrimaryTxObserver>
{
public:
static boost::shared_ptr<PrimaryTxObserver> create(
Primary&, HaBroker&, const boost::intrusive_ptr<broker::TxBuffer>&);
~PrimaryTxObserver();
void enqueue(const QueuePtr&, const broker::Message&);
void dequeue(const QueuePtr& queue, QueuePosition, ReplicationId);
bool prepare();
void commit();
void rollback();
types::Uuid getId() const { return id; }
QueuePtr getTxQueue() const { return txQueue; }
std::string getExchangeName() const { return exchangeName; }
// Notify that a backup subscription has been cancelled.
void cancel(const ReplicatingSubscription&);
private:
class Exchange;
typedef qpid::sys::unordered_map<
QueuePtr, ReplicationIdSet, Hasher<QueuePtr> > QueueIdsMap;
enum State {
SENDING, ///< Sending TX messages and acks
PREPARING, ///< Prepare sent, waiting for response
ENDED ///< Commit or rollback sent, local transaction ended.
};
PrimaryTxObserver(Primary&, HaBroker&, const boost::intrusive_ptr<broker::TxBuffer>&);
void initialize();
void skip(sys::Mutex::ScopedLock&);
void checkState(State expect, const std::string& msg);
void end(sys::Mutex::ScopedLock&);
void txPrepareOkEvent(const std::string& data);
void txPrepareFailEvent(const std::string& data);
bool completed(const types::Uuid& id, sys::Mutex::ScopedLock&);
bool error(const types::Uuid& id, const std::string& msg, sys::Mutex::ScopedLock& l);
sys::Monitor lock;
State state;
LogPrefix2 logPrefix;
Primary& primary;
HaBroker& haBroker;
broker::Broker& broker;
ReplicationTest replicationTest;
// NOTE: There is an intrusive_ptr cycle between PrimaryTxObserver
// and TxBuffer. The cycle is broken in PrimaryTxObserver::end()
boost::intrusive_ptr<broker::TxBuffer> txBuffer;
types::Uuid id;
std::string exchangeName;
QueuePtr txQueue;
QueueIdsMap enqueues, dequeues;
UuidSet backups; // All backups of transaction.
UuidSet incomplete; // Incomplete backups (not yet responded to prepare)
bool empty; // True if the transaction is empty - no enqueues/dequeues.
};
}} // namespace qpid::ha
#endif /*!QPID_HA_PRIMARYTXOBSERVER_H*/
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