System.Net.Security.SslStreamInternal.StartReading C# (CSharp) Method

        private int StartReading(byte[] buffer, int offset, int count, AsyncProtocolRequest asyncRequest)
        {
            int result = 0;

            if (InternalBufferCount != 0)
            {
                NetEventSource.Fail(this, $"Previous frame was not consumed. InternalBufferCount: {InternalBufferCount}");
            }

            do
            {
                if (asyncRequest != null)
                {
                    asyncRequest.SetNextRequest(buffer, offset, count, s_resumeAsyncReadCallback);
                }

                int copyBytes = _sslState.CheckEnqueueRead(buffer, offset, count, asyncRequest);
                if (copyBytes == 0)
                {
                    // Queued but not completed!
                    return 0;
                }

                if (copyBytes != -1)
                {
                    asyncRequest?.CompleteUser(copyBytes);

                    return copyBytes;
                }
            }

            // When we read -1 bytes means we have decrypted 0 bytes or rehandshaking, need looping.
            while ((result = StartFrameHeader(buffer, offset, count, asyncRequest)) == -1);

            return result;
        }

        private static void ReadFrameCallback(AsyncProtocolRequest asyncRequest)
        {
            try
            {
                SslStreamInternal sslStream    = (SslStreamInternal)asyncRequest.AsyncObject;
                BufferAsyncResult bufferResult = (BufferAsyncResult)asyncRequest.UserAsyncResult;
                if (-1 == sslStream.ProcessFrameBody(asyncRequest.Result, bufferResult.Buffer, bufferResult.Offset, bufferResult.Count, asyncRequest))
                {
                    // in case we decrypted 0 bytes start another reading.
                    sslStream.StartReading(bufferResult.Buffer, bufferResult.Offset, bufferResult.Count, asyncRequest);
                }
            }
            catch (Exception e)
            {
                if (asyncRequest.IsUserCompleted)
                {
                    // This will throw on a worker thread.
                    throw;
                }

                asyncRequest.CompleteUserWithError(e);
            }
        }