System.Net.WebSockets.WebSocketBuffer.PinSendBuffer C# (CSharp) Method

        internal void PinSendBuffer(ArraySegment<byte> payload, out bool bufferHasBeenPinned)
        {
            bufferHasBeenPinned = false;
            WebSocketValidate.ValidateBuffer(payload.Array, payload.Offset, payload.Count);
            int previousState = Interlocked.Exchange(ref _sendBufferState, SendBufferState.SendPayloadSpecified);

            if (previousState != SendBufferState.None)
            {
                Debug.Assert(false, "'m_SendBufferState' MUST BE 'None' at this point.");
                // Indicates a violation in the API contract that could indicate 
                // memory corruption because the pinned sendbuffer is shared between managed and native code
                throw new AccessViolationException();
            }
            _pinnedSendBuffer = payload;
            _pinnedSendBufferHandle = GCHandle.Alloc(_pinnedSendBuffer.Array, GCHandleType.Pinned);
            bufferHasBeenPinned = true;
            _pinnedSendBufferStartAddress =
                Marshal.UnsafeAddrOfPinnedArrayElement(_pinnedSendBuffer.Array, _pinnedSendBuffer.Offset).ToInt64();
            _pinnedSendBufferEndAddress = _pinnedSendBufferStartAddress + _pinnedSendBuffer.Count;
        }