private async Task StartAsyncCore()
{
if (Features.Get <IConnectionInherentKeepAliveFeature>() == null)
{
Debug.Assert(ProtocolReaderWriter != null, "Expected the ProtocolReaderWriter to be set before StartAsync is called");
_pingMessage = ProtocolReaderWriter.WriteMessage(PingMessage.Instance);
_connectionContext.Features.Get <IConnectionHeartbeatFeature>()?.OnHeartbeat(state => ((HubConnectionContext)state).KeepAliveTick(), this);
}
try
{
while (await Output.Reader.WaitToReadAsync())
{
while (Output.Reader.TryRead(out var hubMessage))
{
var buffer = ProtocolReaderWriter.WriteMessage(hubMessage);
while (await _connectionContext.Transport.Writer.WaitToWriteAsync())
{
if (_connectionContext.Transport.Writer.TryWrite(buffer))
{
Interlocked.Exchange(ref _lastSendTimestamp, Stopwatch.GetTimestamp());
break;
}
}
}
}
}
catch (Exception ex)
{
Abort(ex);
}
}
public override async Task WriteAsync(HubMessage message)
{
try
{
await _writeLock.WaitAsync();
var buffer = ProtocolReaderWriter.WriteMessage(message);
await _connection.SendAsync(buffer, CancellationToken.None);
}
finally
{
_writeLock.Release();
}
}
public virtual async Task WriteAsync(HubMessage message)
{
try
{
await _writeLock.WaitAsync();
var buffer = ProtocolReaderWriter.WriteMessage(message);
_connectionContext.Transport.Output.Write(buffer);
Interlocked.Exchange(ref _lastSendTimestamp, Stopwatch.GetTimestamp());
await _connectionContext.Transport.Output.FlushAsync(CancellationToken.None);
}
finally
{
_writeLock.Release();
}
}