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/*
*
* 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 "QueueContext.h"
#include "Multicaster.h"
#include "qpid/cluster/types.h"
#include "BrokerContext.h" // for ScopedSuppressReplication
#include "hash.h"
#include "qpid/framing/ProtocolVersion.h"
#include "qpid/framing/ClusterQueueResubscribeBody.h"
#include "qpid/framing/ClusterQueueSubscribeBody.h"
#include "qpid/framing/ClusterQueueUnsubscribeBody.h"
#include "qpid/broker/Broker.h"
#include "qpid/broker/Queue.h"
#include "qpid/broker/QueuedMessage.h"
#include "qpid/log/Statement.h"
namespace qpid {
namespace cluster {
QueueContext::QueueContext(broker::Queue& q, sys::Duration consumeLock, Multicaster& m)
: timer(boost::bind(&QueueContext::timeout, this),
q.getBroker()->getTimer(),
consumeLock),
queue(q), mcast(m), consumers(0), hash(hashof(q.getName()))
{
q.setClusterContext(boost::intrusive_ptr<QueueContext>(this));
q.stopConsumers(); // Stop queue initially.
}
QueueContext::~QueueContext() {}
namespace {
bool isOwner(QueueOwnership o) { return o == SOLE_OWNER || o == SHARED_OWNER; }
}
// Called by QueueReplica in CPG deliver thread when state changes.
void QueueContext::replicaState(
QueueOwnership before, QueueOwnership after, bool selfDelivered)
{
// No lock, this function does not touch any member variables.
// Invariants for ownership:
// UNSUBSCRIBED, SUBSCRIBED <=> timer stopped, queue stopped
// SOLE_OWNER <=> timer stopped, queue started
// SHARED_OWNER <=> timer started, queue started
// Interested in state changes and my own events which lead to
// ownership.
if ((before != after || selfDelivered) && isOwner(after)) {
QPID_LOG(trace, "cluster start consumers on " << queue.getName() << ", timer "
<< (after==SHARED_OWNER? "start" : "stop"));
queue.startConsumers();
if (after == SHARED_OWNER) timer.start();
else timer.stop();
}
// If we lost ownership then the queue and timer will already have
// been stopped by timeout()
}
// FIXME aconway 2011-07-27: Dont spin the token on an empty queue.
// Called in connection threads when a consumer is added
void QueueContext::consume(size_t n) {
sys::Mutex::ScopedLock l(lock);
consumers = n;
if (n == 1) mcast.mcast(
framing::ClusterQueueSubscribeBody(framing::ProtocolVersion(), queue.getName()));
}
// Called in connection threads when a consumer is cancelled
void QueueContext::cancel(size_t n) {
sys::Mutex::ScopedLock l(lock);
consumers = n;
// When consuming threads are stopped, this->stopped will be called.
if (n == 0) {
QPID_LOG(trace, "cluster stop consumers and timer on " << queue.getName());
timer.stop();
queue.stopConsumers();
}
}
// Called in timer thread.
void QueueContext::timeout() {
// When all threads have stopped, queue will call stopped()
QPID_LOG(trace, "cluster timeout, stopping consumers on " << queue.getName());
queue.stopConsumers();
}
// Callback set up by queue.stopConsumers() called in connection or timer thread.
// Called when no threads are dispatching from the queue.
void QueueContext::stopped() {
sys::Mutex::ScopedLock l(lock);
QPID_LOG(trace, "cluster timeout, stopped consumers on " << queue.getName()
<< (consumers == 0 ? " unsubscribed" : " resubscribe"));
if (consumers == 0)
mcast.mcast(framing::ClusterQueueUnsubscribeBody(
framing::ProtocolVersion(), queue.getName()));
else // FIXME aconway 2011-09-13: check if we're owner?
mcast.mcast(framing::ClusterQueueResubscribeBody(
framing::ProtocolVersion(), queue.getName()));
}
void QueueContext::requeue(uint32_t position, bool redelivered) {
// No lock, unacked has its own lock.
broker::QueuedMessage qm;
if (unacked.get(position, qm)) {
unacked.erase(position);
if (redelivered) qm.payload->redeliver();
BrokerContext::ScopedSuppressReplication ssr;
queue.requeue(qm);
}
}
void QueueContext::acquire(const broker::QueuedMessage& qm) {
unacked.put(qm.position, qm);
}
broker::QueuedMessage QueueContext::dequeue(uint32_t position) {
return unacked.pop(position);
}
boost::intrusive_ptr<QueueContext> QueueContext::get(broker::Queue& q) {
return boost::intrusive_ptr<QueueContext>(
static_cast<QueueContext*>(q.getClusterContext().get()));
}
}} // namespace qpid::cluster
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