public void Start(Func<SynchronizationContext> syncContext, int concurrentAccepts, int maxDelayMS = 0)
{
if (concurrentAccepts <= 0)
{
throw new ArgumentOutOfRangeException("concurrentAccepts", "Expected >0 concurrent accepts");
}
m_logger.Info("Listening on {0} with {1} concurrent accepts", m_listener.Prefixes.First(), concurrentAccepts);
m_listener.Start();
for (var i = 0; i < concurrentAccepts; i++)
{
var context = syncContext();
var state = new EventLoopState(maxDelayMS);
Task.Run(() => MainLoop(context, state));
if (maxDelayMS > 0 && context is EventLoopContext)
Task.Run(() => CalcDelay(context, state));
}
}
private async Task MainLoop(SynchronizationContext syncContext, EventLoopState state)
{
while (true)
{
try
{
HttpListenerContext context;
try
{
context = await m_listener.GetContextAsync();
}
catch (ObjectDisposedException)
{
return;
}
catch (HttpListenerException ex)
{
// IO error due to our request, means we're probably exiting
if (ex.NativeErrorCode == 995)
continue;
throw;
}
m_resetEvent.Wait();
syncContext.Post(async unused =>
{
var wrapper = new Context(context);
wrapper.Response.KeepAlive = m_keepAlive && wrapper.Request.KeepAlive;
await m_processor.Process(wrapper, state.Delay > state.MaxDelay);
}, null);
}
catch (Exception ex)
{
m_logger.Error("Error in accept loop: " + ex);
}
}
}
private void CalcDelay(SynchronizationContext context, EventLoopState state)
{
context.Post(async unused =>
{
var timer = Stopwatch.StartNew();
while (true)
{
// Yield back to the event loop
await Task.Yield();
// Find out how long it took for the event loop to handle our request
var elapsed = (int)timer.ElapsedMilliseconds;
state.Delay = elapsed;
await Task.Delay(Math.Max(0, 500 - elapsed));
timer.Restart();
}
}, null);
}
