/// <summary>
/// Adds a subscription back into the queue because it has more notifications to publish.
/// </summary>
public void PublishCompleted(Subscription subscription, bool moreNotifications)
{
lock (m_lock)
{
for (int ii = 0; ii < m_queuedSubscriptions.Count; ii++)
{
if (Object.ReferenceEquals(m_queuedSubscriptions[ii].Subscription, subscription))
{
m_queuedSubscriptions[ii].Publishing = false;
if (moreNotifications)
{
AssignSubscriptionToRequest(m_queuedSubscriptions[ii]);
}
else
{
m_queuedSubscriptions[ii].ReadyToPublish = false;
m_queuedSubscriptions[ii].Timestamp = DateTime.UtcNow;
}
break;
}
}
}
}
/// <summary>
/// Adds a subscription from the publish queue.
/// </summary>
public void Add(Subscription subscription)
{
if (subscription == null) throw new ArgumentNullException("subscription");
lock (m_lock)
{
QueuedSubscription queuedSubscription = new QueuedSubscription();
queuedSubscription.Priority = subscription.Priority;
queuedSubscription.ReadyToPublish = false;
queuedSubscription.Timestamp = DateTime.UtcNow;
queuedSubscription.Subscription = subscription;
m_queuedSubscriptions.Add(queuedSubscription);
// TraceState("SUBSCRIPTION QUEUED");
}
}
/// <summary>
/// Removes a subscription from the publish queue.
/// </summary>
public void Remove(Subscription subscription)
{
if (subscription == null) throw new ArgumentNullException("subscription");
lock (m_lock)
{
// remove the subscription from the queue.
for (int ii = 0; ii < m_queuedSubscriptions.Count; ii++)
{
if (Object.ReferenceEquals(m_queuedSubscriptions[ii].Subscription, subscription))
{
m_queuedSubscriptions.RemoveAt(ii);
break;
}
}
// remove any outstanding publishes.
if (m_queuedSubscriptions.Count == 0)
{
while (m_queuedRequests.Count > 0)
{
QueuedRequest request = m_queuedRequests.First.Value;
request.Error = StatusCodes.BadNoSubscription;
request.Set();
m_queuedRequests.RemoveFirst();
}
}
// TraceState("SUBSCRIPTION REMOVED");
}
}
/// <summary>
/// Clears the queues because the session is closing.
/// </summary>
/// <returns>The list of subscriptions in the queue.</returns>
public IList<Subscription> Close()
{
lock (m_lock)
{
// TraceState("SESSION CLOSED");
// wake up any waiting publish requests.
m_publishEvent.Set();
while (m_queuedRequests.Count > 0)
{
QueuedRequest request = m_queuedRequests.First.Value;
m_queuedRequests.RemoveFirst();
request.Error = StatusCodes.BadSessionClosed;
request.Set();
}
// tell the subscriptions that the session is closed.
Subscription[] subscriptions = new Subscription[m_queuedSubscriptions.Count];
for (int ii = 0; ii < m_queuedSubscriptions.Count; ii++)
{
subscriptions[ii] = m_queuedSubscriptions[ii].Subscription;
subscriptions[ii].SessionClosed();
}
// clear the queue.
m_queuedSubscriptions.Clear();
return subscriptions;
}
}
/// <summary>
/// Called when a subscription expires.
/// </summary>
/// <param name="subscription">The subscription.</param>
internal void SubscriptionExpired(Subscription subscription)
{
lock (m_statusMessages)
{
StatusMessage message = new StatusMessage();
message.SubscriptionId = subscription.Id;
message.Message = subscription.PublishTimeout();
Queue<StatusMessage> queue = null;
if (subscription.SessionId != null && m_statusMessages.TryGetValue(subscription.SessionId, out queue))
{
queue.Enqueue(message);
}
}
}
/// <summary>
/// Raises an event related to a subscription.
/// </summary>
protected virtual void RaiseSubscriptionEvent(Subscription subscription, bool deleted)
{
SubscriptionEventHandler handler = null;
lock (m_eventLock)
{
handler = m_SubscriptionCreated;
if (deleted)
{
handler = m_SubscriptionDeleted;
}
}
if (handler != null)
{
try
{
handler(subscription, deleted);
}
catch (Exception e)
{
Utils.Trace(e, "Subscription event handler raised an exception.");
}
}
}
/// <summary>
/// Creates a new instance of a subscription.
/// </summary>
protected virtual Subscription CreateSubscription(
OperationContext context,
uint subscriptionId,
double publishingInterval,
uint lifetimeCount,
uint keepAliveCount,
uint maxNotificationsPerPublish,
byte priority,
bool publishingEnabled)
{
Subscription subscription = new Subscription(
m_server,
context.Session,
subscriptionId,
publishingInterval,
lifetimeCount,
keepAliveCount,
maxNotificationsPerPublish,
priority,
publishingEnabled,
m_maxMessageCount);
return subscription;
}
/// <summary>
/// Periodically checks if the sessions have timed out.
/// </summary>
private void PublishSubscriptions(object data)
{
try
{
Utils.Trace("Server: Publish Subscriptions Thread Started.");
int sleepCycle = Convert.ToInt32(data, CultureInfo.InvariantCulture);
int timeToWait = sleepCycle;
do
{
DateTime start = DateTime.UtcNow;
SessionPublishQueue[] queues = null;
Subscription[] abandonedSubscriptions = null;
lock (m_lock)
{
// collect active session queues.
queues = new SessionPublishQueue[m_publishQueues.Count];
m_publishQueues.Values.CopyTo(queues, 0);
// collect abandoned subscriptions.
if (m_abandonedSubscriptions != null && m_abandonedSubscriptions.Count > 0)
{
abandonedSubscriptions = new Subscription[m_abandonedSubscriptions.Count];
for (int ii = 0; ii < abandonedSubscriptions.Length; ii++)
{
abandonedSubscriptions[ii] = m_abandonedSubscriptions[ii];
}
}
}
// check the publish timer for each subscription.
for (int ii = 0; ii < queues.Length; ii++)
{
queues[ii].PublishTimerExpired();
}
// check the publish timer for each abandoned subscription.
if (abandonedSubscriptions != null)
{
List<Subscription> subscriptionsToDelete = new List<Subscription>();
for (int ii = 0; ii < abandonedSubscriptions.Length; ii++)
{
Subscription subscription = abandonedSubscriptions[ii];
if (subscription.PublishTimerExpired() != PublishingState.Expired)
{
continue;
}
if (subscriptionsToDelete == null)
{
subscriptionsToDelete = new List<Subscription>();
}
subscriptionsToDelete.Add(subscription);
SubscriptionExpired(subscription);
Utils.Trace("Server: Abandoned Subscription '{0}' Delete Scheduled.", subscription.Id);
}
// schedule cleanup on a background thread.
if (subscriptionsToDelete.Count > 0)
{
lock (m_lock)
{
for (int ii = 0; ii < subscriptionsToDelete.Count; ii++)
{
m_abandonedSubscriptions.Remove(subscriptionsToDelete[ii]);
}
}
CleanupSubscriptions(m_server, subscriptionsToDelete);
}
}
if (m_shutdownEvent.WaitOne(timeToWait))
{
Utils.Trace("Server: Publish Subscriptions Thread Exited Normally.");
break;
}
int delay = (int)(DateTime.UtcNow - start).TotalMilliseconds;
timeToWait = sleepCycle;
}
while (true);
}
catch (Exception e)
{
Utils.Trace(e, "Server: Publish Subscriptions Thread Exited Unexpectedly");
}
}
