Microsoft.AspNetCore.WebSockets.Protocol.CommonWebSocket.SendKeepAliveAsync C# (CSharp) Method

        private async void SendKeepAliveAsync()
        {
            // Check concurrent writes, pings & pongs, or closes
            if (!_writeLock.Wait(0))
            {
                // Sending real data is better than a ping, discard it.
                return;
            }
            try
            {
                if (State == WebSocketState.CloseSent || State >= WebSocketState.Closed)
                {
                    _keepAliveTimer.Dispose();
                    return;
                }

                int mask = GetNextMask();
                FrameHeader frameHeader = new FrameHeader(true, Constants.OpCodes.PingFrame, _maskOutput, mask, PingBuffer.Length);
                ArraySegment<byte> headerSegment = frameHeader.Buffer;

                // TODO: CancelationToken / timeout?
                if (_maskOutput && mask != 0)
                {
                    byte[] maskedFrame = Utilities.MergeAndMask(mask, headerSegment, new ArraySegment<byte>(PingBuffer));
                    await _stream.WriteAsync(maskedFrame, 0, maskedFrame.Length);
                }
                else
                {
                    await _stream.WriteAsync(headerSegment.Array, headerSegment.Offset, headerSegment.Count);
                    await _stream.WriteAsync(PingBuffer, 0, PingBuffer.Length);
                }
            }
            catch (Exception)
            {
                // TODO: Log exception, this is a background thread.

                // Shut down, we must be in a faulted state;
                Abort();
            }
            finally
            {
                _writeLock.Release();
            }
        }

        private static void SendKeepAlive(object state)
        {
            CommonWebSocket websocket = (CommonWebSocket)state;

            websocket.SendKeepAliveAsync();
        }