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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 "BrokerContext.h"
#include "EventHandler.h"
#include "Group.h"
#include "Multicaster.h"
#include "QueueContext.h"
#include "QueueHandler.h"
#include "hash.h"
#include "qpid/broker/Broker.h"
#include "qpid/broker/Queue.h"
#include "qpid/broker/QueuedMessage.h"
#include "qpid/framing/ClusterMessageAcquireBody.h"
#include "qpid/framing/ClusterMessageDequeueBody.h"
#include "qpid/framing/ClusterQueueConsumedBody.h"
#include "qpid/framing/ClusterQueueSubscribeBody.h"
#include "qpid/framing/ClusterQueueUnsubscribeBody.h"
#include "qpid/framing/ProtocolVersion.h"
#include "qpid/log/Statement.h"
namespace qpid {
namespace cluster {
using framing::SequenceSet;
const framing::ProtocolVersion pv; // shorthand
QueueContext::QueueContext(broker::Queue& q, Group& g, size_t maxTicks_)
: ownership(UNSUBSCRIBED), consumers(0), consuming(false), ticks(0),
queue(q), mcast(g.getMulticaster()), hash(hashof(q.getName())),
maxTicks(maxTicks_), group(g)
{
q.setClusterContext(std::auto_ptr<broker::Context>(this));
q.stopConsumers(); // Stop queue initially.
group.getTicker().add(this);
}
QueueContext::~QueueContext() {
// Lifecycle: must remove all references to this context before it is deleted.
// Must be sure that there can be no use of this context later.
group.getTicker().remove(this);
group.getEventHandler().getHandler<QueueHandler>()->remove(queue);
}
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)
{
sys::Mutex::ScopedLock l(lock);
// Interested in state changes which lead to ownership.
// We voluntarily give up ownership before multicasting
// the state change so we don't need to handle transitions
// that lead to non-ownership.
if (before != after && isOwner(after)) {
assert(before == ownership);
if (!consuming) queue.startConsumers();
consuming = true;
ticks = 0;
}
ownership = after;
}
// FIXME aconway 2011-07-27: Dont spin the token on an empty queue.
// Called in broker threads when a consumer is added
void QueueContext::consume(size_t n) {
sys::Mutex::ScopedLock l(lock);
if (consumers == 0 && n > 0 && ownership == UNSUBSCRIBED)
mcast.mcast(
framing::ClusterQueueSubscribeBody(pv, queue.getName()));
consumers = n;
}
// Called in broker threads when a consumer is cancelled
void QueueContext::cancel(size_t n) {
sys::Mutex::ScopedLock l(lock);
consumers = n;
if (n == 0 && consuming) queue.stopConsumers();
}
// FIXME aconway 2011-11-03: review scope of locking around sendConsumed
// Called in Ticker thread.
void QueueContext::tick() {
sys::Mutex::ScopedLock l(lock);
if (!consuming) return; // Nothing to do if we don't have the lock.
if (ownership == SHARED_OWNER && ++ticks >= maxTicks) queue.stopConsumers();
else if (ownership == SOLE_OWNER) sendConsumed(l); // Status report on consumption
}
// 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);
if (!consuming) return; // !consuming => initial stopConsumers in ctor.
sendConsumed(l);
mcast.mcast(
framing::ClusterQueueUnsubscribeBody(pv, queue.getName(), consumers));
consuming = false;
}
void QueueContext::sendConsumed(const sys::Mutex::ScopedLock&) {
if (acquired.empty() && dequeued.empty()) return; // Nothing to send
mcast.mcast(
framing::ClusterQueueConsumedBody(pv, queue.getName(), acquired,dequeued));
acquired.clear();
dequeued.clear();
}
void QueueContext::requeue(uint32_t position, bool redelivered) {
// No lock, unacked has its own lock.
broker::QueuedMessage qm = unacked.pop(position);
if (qm.queue) {
if (redelivered) qm.payload->redeliver();
BrokerContext::ScopedSuppressReplication ssr;
queue.requeue(qm);
}
}
void QueueContext::localAcquire(uint32_t position) {
QPID_LOG(trace, "cluster queue " << queue.getName() << " acquired " << position);
sys::Mutex::ScopedLock l(lock);
assert(consuming);
acquired.add(position);
}
void QueueContext::localDequeue(uint32_t position) {
QPID_LOG(trace, "cluster queue " << queue.getName() << " dequeued " << position);
// FIXME aconway 2010-10-28: for local dequeues, we should
// complete the ack that initiated the dequeue at this point.
sys::Mutex::ScopedLock l(lock);
// FIXME aconway 2011-11-03: this assertion fails for explicit accept
// because it doesn't respect the consume lock.
// assert(consuming);
dequeued.add(position);
}
void QueueContext::consumed(
const MemberId& sender,
const SequenceSet& acquired,
const SequenceSet& dequeued)
{
// No lock, doesn't touch any members.
// FIXME aconway 2011-09-15: systematic logging across cluster module.
// FIXME aconway 2011-09-23: pretty printing for identifier.
QPID_LOG(trace, "cluster: " << sender << " acquired: " << acquired
<< " dequeued: " << dequeued << " on queue: " << queue.getName());
// Note acquires from other members. My own acquires were executed in
// the connection thread
if (sender != group.getSelf()) {
// FIXME aconway 2011-09-23: avoid individual finds, scan queue once.
for (SequenceSet::iterator i = acquired.begin(); i != acquired.end(); ++i)
acquire(*i);
}
// Process deques from the queue owner.
// FIXME aconway 2011-09-23: avoid individual finds, scan queue once.
for (SequenceSet::iterator i = dequeued.begin(); i != dequeued.end(); ++i)
dequeue(*i);
}
// Remote acquire
void QueueContext::acquire(uint32_t position) {
// No lock, doesn't touch any members.
broker::QueuedMessage qm;
BrokerContext::ScopedSuppressReplication ssr;
if (!queue.acquireMessageAt(position, qm))
// FIXME aconway 2011-10-31: error handling
throw Exception(QPID_MSG("cluster: acquire: message not found: "
<< queue.getName() << "[" << position << "]"));
assert(qm.position.getValue() == position);
assert(qm.payload);
unacked.put(qm.position, qm); // unacked has its own lock.
}
void QueueContext::dequeue(uint32_t position) {
// No lock, doesn't touch any members. unacked has its own lock.
broker::QueuedMessage qm = unacked.pop(position);
BrokerContext::ScopedSuppressReplication ssr;
if (qm.queue) queue.dequeue(0, qm);
}
QueueContext* QueueContext::get(broker::Queue& q) {
return static_cast<QueueContext*>(q.getClusterContext());
}
// FIXME aconway 2011-09-23: make unacked a plain map, use lock.
}} // namespace qpid::cluster
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