public async Task CloseAcceptAsync()
{
TaskCompletionSource <object> tcs = null;
lock (_gate)
{
if (_state == State.Initial)
{
_state = State.Stopped;
return;
}
else if (_state == State.AcceptClosed || _state == State.Stopping || _state == State.Stopped)
{
return;
}
else if (_state == State.ClosingAccept)
{
tcs = _stateChangeCompletion;
}
}
if (tcs != null)
{
await tcs.Task;
return;
}
try
{
await StartAsync();
}
catch
{}
bool triggerStateChange = false;
lock (_gate)
{
if (_state == State.AcceptClosed || _state == State.Stopping || _state == State.Stopped)
{
return;
}
else if (_state == State.ClosingAccept)
{
tcs = _stateChangeCompletion;
}
else if (_state == State.Started)
{
triggerStateChange = true;
tcs = _stateChangeCompletion = new TaskCompletionSource <object>();
_state = State.ClosingAccept;
}
else
{
// Cannot happen
ThrowInvalidState();
}
}
if (triggerStateChange)
{
_threadContext.CloseAccept();
}
await tcs.Task;
}