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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 "Group.h"
#include "Multicaster.h"
#include "QueueContext.h"
#include "hash.h"
#include "qpid/cluster/types.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, Group& g, size_t maxTicks_)
: consumers(0), consuming(true), ticks(0),
queue(q), mcast(g.getMulticaster()), hash(hashof(q.getName())),
maxTicks(maxTicks_)
{
q.setClusterContext(boost::intrusive_ptr<QueueContext>(this));
q.stopConsumers(); // Stop queue initially.
g.getTicker().add(this);
}
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)
{
// 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)) {
bool start = false;
{
sys::Mutex::ScopedLock l(lock);
start = !consuming;
consuming = true;
ticks = 0;
}
if (start) queue.startConsumers();
}
}
// 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);
consumers = n;
}
if (n == 1) mcast.mcast(
framing::ClusterQueueSubscribeBody(framing::ProtocolVersion(), queue.getName()));
}
// Called in broker threads when a consumer is cancelled
void QueueContext::cancel(size_t n) {
bool stop = false;
{
sys::Mutex::ScopedLock l(lock);
consumers = n;
stop = (n == 0 && consuming);
}
if (stop) queue.stopConsumers();
}
// Called in Ticker thread.
void QueueContext::tick() {
bool stop = false;
{
sys::Mutex::ScopedLock l(lock);
stop = (consuming && ++ticks >= maxTicks);
}
// When all threads have stopped, queue will call stopped()
if (stop) 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() {
bool resubscribe = false;
{
sys::Mutex::ScopedLock l(lock);
assert(consuming);
consuming = false;
resubscribe = consumers;
}
if (resubscribe)
mcast.mcast(framing::ClusterQueueResubscribeBody(
framing::ProtocolVersion(), queue.getName()));
else
mcast.mcast(framing::ClusterQueueUnsubscribeBody(
framing::ProtocolVersion(), queue.getName()));
}
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::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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