System.Net.WebSockets.WebSocketBase.ReceiveAsyncCore C# (CSharp) Method

        private async Task<WebSocketReceiveResult> ReceiveAsyncCore(ArraySegment<byte> buffer,
            CancellationToken cancellationToken)
        {
            Debug.Assert(buffer != null);

            if (NetEventSource.IsEnabled)
            {
                NetEventSource.Enter(this);
            }

            WebSocketReceiveResult receiveResult;
            try
            {
                ThrowIfPendingException();
                ThrowIfDisposed();
                ThrowOnInvalidState(State, WebSocketState.Open, WebSocketState.CloseSent);

                bool ownsCancellationTokenSource = false;
                CancellationToken linkedCancellationToken = CancellationToken.None;
                try
                {
                    ownsCancellationTokenSource = _receiveOutstandingOperationHelper.TryStartOperation(cancellationToken,
                        out linkedCancellationToken);
                    if (!ownsCancellationTokenSource)
                    {
                        lock (_thisLock)
                        {
                            if (_closeAsyncStartedReceive)
                            {
                                throw new InvalidOperationException(
                                    SR.Format(SR.net_WebSockets_ReceiveAsyncDisallowedAfterCloseAsync, nameof(CloseAsync), nameof(CloseOutputAsync)));
                            }

                            throw new InvalidOperationException(
                                SR.Format(SR.net_Websockets_AlreadyOneOutstandingOperation, nameof(ReceiveAsync)));
                        }
                    }

                    EnsureReceiveOperation();
                    receiveResult = await _receiveOperation.Process(buffer, linkedCancellationToken).SuppressContextFlow();

                    if (NetEventSource.IsEnabled && receiveResult.Count > 0)
                    {
                        NetEventSource.DumpBuffer(this, buffer.Array, buffer.Offset, receiveResult.Count);
                    }
                }
                catch (Exception exception)
                {
                    bool aborted = linkedCancellationToken.IsCancellationRequested;
                    Abort();
                    ThrowIfConvertibleException(nameof(ReceiveAsync), exception, cancellationToken, aborted);
                    throw;
                }
                finally
                {
                    _receiveOutstandingOperationHelper.CompleteOperation(ownsCancellationTokenSource);
                }
            }
            finally
            {
                if (NetEventSource.IsEnabled)
                {
                    NetEventSource.Exit(this);
                }
            }

            return receiveResult;
        }