private async Task AnnounceServiceStopPublishingAsync()
{
Message message = GetPublishMessage(PublishMessageType.Stop);
if (_publishing || !MulticastDNSChannel.IsJoined)
{
return;
}
await MulticastDNSChannel.SendMessageAsync(message).ConfigureAwait(false);
await TaskUtility.Delay(FirstRebroadcastInterval).ConfigureAwait(false);
if (_publishing || !MulticastDNSChannel.IsJoined)
{
return;
}
await MulticastDNSChannel.SendMessageAsync(message).ConfigureAwait(false);
await TaskUtility.Delay(SecondRebroadcastInterval).ConfigureAwait(false);
if (_publishing || !MulticastDNSChannel.IsJoined)
{
return;
}
await MulticastDNSChannel.SendMessageAsync(message).ConfigureAwait(false);
}
private async Task AnnounceServicePublishAsync()
{
if (!_publishing || !MulticastDNSChannel.IsJoined)
{
return;
}
var initialMessage = GetPublishMessage(PublishMessageType.Initial);
_currentServicePublishMessage = GetPublishMessage(PublishMessageType.Normal);
// Send initial message immediately followed by the "normal" message
await MulticastDNSChannel.SendMessageAsync(initialMessage).ConfigureAwait(false);
await SendServicePublishMessageAsync().ConfigureAwait(false);
await TaskUtility.Delay(FirstRebroadcastInterval).ConfigureAwait(false);
if (!_publishing || !MulticastDNSChannel.IsJoined)
{
return;
}
await SendServicePublishMessageAsync().ConfigureAwait(false);
await TaskUtility.Delay(SecondRebroadcastInterval).ConfigureAwait(false);
if (!_publishing || !MulticastDNSChannel.IsJoined)
{
return;
}
await SendServicePublishMessageAsync().ConfigureAwait(false);
}
public async Task <bool> ResolveAsync()
{
if (_browser == null)
{
throw new InvalidOperationException("This operation is only valid on services that were generated by a NetServiceBrowser.");
}
// Making sure that the associated NetServiceBrowser is still active ensures that the MulticastDNSChannel has not been shut down.
if (!_browser.IsRunning)
{
throw new InvalidOperationException("The associated NetServiceBrowser has been stopped.");
}
// Resolve the service
_log.Info("Resolving service '{0}'...", FullServiceInstanceName);
Message message = GetResolveMessage();
var tcs = new TaskCompletionSource <object>();
_resolveTaskCompletionSource = tcs;
// First resolution attempt
await MulticastDNSChannel.SendMessageAsync(message).ConfigureAwait(false);
Task delayTask = TaskUtility.Delay(FirstRebroadcastInterval);
await TaskUtility.WhenAny(delayTask, tcs.Task).ConfigureAwait(false);
if (tcs.Task.IsCompleted)
{
return(true);
}
// Second resolution attempt
await MulticastDNSChannel.SendMessageAsync(message).ConfigureAwait(false);
delayTask = TaskUtility.Delay(SecondRebroadcastInterval);
await TaskUtility.WhenAny(delayTask, tcs.Task).ConfigureAwait(false);
if (tcs.Task.IsCompleted)
{
return(true);
}
// Third resolution attempt
await MulticastDNSChannel.SendMessageAsync(message).ConfigureAwait(false);
delayTask = TaskUtility.Delay(ServiceResolveTimeout);
await TaskUtility.WhenAny(delayTask, tcs.Task).ConfigureAwait(false);
if (tcs.Task.IsCompleted)
{
return(true);
}
return(false);
}
private async Task SendServicePublishMessageAsync()
{
if (!_publishing || _currentServicePublishMessage == null)
{
return;
}
_log.Debug("Sending publish message for service \"{0}\"...", FullServiceInstanceName);
await MulticastDNSChannel.SendMessageAsync(_currentServicePublishMessage).ConfigureAwait(false);
_lastServicePublishBroadcast = DateTime.Now;
}
public void Stop()
{
IsRunning = false;
MulticastDNSChannel.RemoveListener(this);
_discoveredServices.Clear();
_discoveredIPs.Clear();
_currentServiceSearchMessage = null;
_log.Info("Stopped search for service type '{0}'.", _currentServiceType);
_currentServiceType = null;
}
private async Task SendServiceSearchMessageAsync()
{
if (!MulticastDNSChannel.IsJoined || _currentServiceSearchMessage == null)
{
return;
}
_log.Debug("Sending search message for '{0}'...", _currentServiceType);
await MulticastDNSChannel.SendMessageAsync(_currentServiceSearchMessage).ConfigureAwait(false);
_lastServiceBroadcast = DateTime.Now;
}
public async Task StopPublishingAsync()
{
if (!_publishing)
{
return;
}
_publishing = false;
_currentServicePublishMessage = null;
await AnnounceServiceStopPublishingAsync().ConfigureAwait(false);
MulticastDNSChannel.RemoveListener(this);
_log.Info("Stopped publishing service '{0}'.", FullServiceInstanceName);
}
public async void Publish()
{
if (_browser != null)
{
throw new InvalidOperationException("Cannot publish services that were discovered by NetServiceBrowser.");
}
_log.Info("Publishing service '{0}'...", FullServiceInstanceName);
_publishing = true;
await MulticastDNSChannel.AddListenerAsync(this).ConfigureAwait(false);
await AnnounceServicePublishAsync().ConfigureAwait(false);
StartRunLoop();
}
/// <summary>
/// Searches for services on the local network.
/// </summary>
/// <param name="type">The type of the service to search for, e.g., "_touch-able._tcp.local."</param>
public async void SearchForServices(string type)
{
_discoveredServices.Clear();
_currentServiceType = BonjourUtility.FormatLocalHostname(type);
_log.Info("Searching for service type '{0}'...", _currentServiceType);
// Create the DNS message to send
_currentServiceSearchMessage = new Message();
_currentServiceSearchMessage.Questions.Add(new Question(_currentServiceType, ResourceRecordType.PTR));
IsRunning = true;
// Listen for MDNS messages and notifications
await MulticastDNSChannel.AddListenerAsync(this).ConfigureAwait(false);
await SendServiceSearchMessageAsync().ConfigureAwait(false);
await TaskUtility.Delay(FirstRebroadcastInterval).ConfigureAwait(false);
if (!IsRunning)
{
return;
}
await SendServiceSearchMessageAsync().ConfigureAwait(false);
await TaskUtility.Delay(SecondRebroadcastInterval).ConfigureAwait(false);
if (!IsRunning)
{
return;
}
await SendServiceSearchMessageAsync().ConfigureAwait(false);
StartRunLoop();
}
