C# EndPoint.Create方法代码示例

		internal int ReceiveFrom_nochecks_exc (byte [] buf, int offset, int size, SocketFlags flags, ref EndPoint remote_end, bool throwOnError, out int error)
		{
			SocketAddress sockaddr = remote_end.Serialize();

			int cnt = ReceiveFrom_internal (safe_handle, buf, offset, size, flags, ref sockaddr, out error);

			SocketError err = (SocketError) error;
			if (err != 0) {
				if (err != SocketError.WouldBlock && err != SocketError.InProgress) {
					is_connected = false;
				} else if (err == SocketError.WouldBlock && is_blocking) { // This might happen when ReceiveTimeout is set
					if (throwOnError)	
						throw new SocketException ((int) SocketError.TimedOut, TIMEOUT_EXCEPTION_MSG);
					error = (int) SocketError.TimedOut;
					return 0;
				}

				if (throwOnError)
					throw new SocketException (error);

				return 0;
			}

			is_connected = true;
			is_bound = true;

			/* If sockaddr is null then we're a connection oriented protocol and should ignore the
			 * remote_end parameter (see MSDN documentation for Socket.ReceiveFrom(...) ) */
			if (sockaddr != null) {
				/* Stupidly, EndPoint.Create() is an instance method */
				remote_end = remote_end.Create (sockaddr);
			}

			seed_endpoint = remote_end;

			return cnt;
		}

        // Routine Description:
        // 
        //    BeginReceiveFrom - Async implimentation of RecvFrom call,
        // 
        //    Called when we want to start an async receive.
        //    We kick off the receive, and if it completes synchronously we'll
        //    call the callback. Otherwise we'll return an IASyncResult, which
        //    the caller can use to wait on or retrieve the final status, as needed.
        // 
        //    Uses Winsock 2 overlapped I/O.
        // 
        // Arguments:
        // 
        //    ReadBuffer - status line that we wish to parse
        //    Index - Offset into ReadBuffer to begin reading from
        //    Request - Size of Buffer to recv
        //    Flags - Additonal Flags that may be passed to the underlying winsock call
        //    remoteEP - EndPoint that are to receive from
        //    Callback - Delegate function that holds callback, called on completeion of I/O
        //    State - State used to track callback, set by caller, not required
        // 
        // Return Value:
        // 
        //    IAsyncResult - Async result used to retreive result
        internal IAsyncResult BeginReceiveFrom(byte[] buffer, int offset, int size, SocketFlags socketFlags, ref EndPoint remoteEP, AsyncCallback callback, object state)
        {
            if (s_loggingEnabled)
            {
                Logging.Enter(Logging.Sockets, this, "BeginReceiveFrom", "");
            }

            if (CleanedUp)
            {
                throw new ObjectDisposedException(this.GetType().FullName);
            }

            // Validate input parameters.
            if (buffer == null)
            {
                throw new ArgumentNullException("buffer");
            }
            if (remoteEP == null)
            {
                throw new ArgumentNullException("remoteEP");
            }
            if (!CanTryAddressFamily(remoteEP.AddressFamily))
            {
                throw new ArgumentException(SR.Format(SR.net_InvalidEndPointAddressFamily, remoteEP.AddressFamily, _addressFamily), "remoteEP");
            }
            if (offset < 0 || offset > buffer.Length)
            {
                throw new ArgumentOutOfRangeException("offset");
            }
            if (size < 0 || size > buffer.Length - offset)
            {
                throw new ArgumentOutOfRangeException("size");
            }
            if (_rightEndPoint == null)
            {
                throw new InvalidOperationException(SR.net_sockets_mustbind);
            }

            // We don't do a CAS demand here because the contents of remoteEP aren't used by
            // WSARecvFrom; all that matters is that we generate a unique-to-this-call SocketAddress
            // with the right address family
            Internals.SocketAddress socketAddress = SnapshotAndSerialize(ref remoteEP);

            // Set up the result and set it to collect the context.
            OverlappedAsyncResult asyncResult = new OverlappedAsyncResult(this, state, callback);
            asyncResult.StartPostingAsyncOp(false);

            // Start the ReceiveFrom.
            DoBeginReceiveFrom(buffer, offset, size, socketFlags, remoteEP, socketAddress, asyncResult);

            // Capture the context, maybe call the callback, and return.
            asyncResult.FinishPostingAsyncOp(ref Caches.ReceiveClosureCache);

            if (asyncResult.CompletedSynchronously && !asyncResult.SocketAddressOriginal.Equals(asyncResult.SocketAddress))
            {
                try
                {
                    remoteEP = remoteEP.Create(asyncResult.SocketAddress);
                }
                catch
                {
                }
            }


            if (s_loggingEnabled)
            {
                Logging.Exit(Logging.Sockets, this, "BeginReceiveFrom", asyncResult);
            }
            return asyncResult;
        }

        // Routine Description:
        // 
        //    EndReceiveFrom -  Called when I/O is done or the user wants to wait. If
        //              the I/O isn't done, we'll wait for it to complete, and then we'll return
        //              the bytes of I/O done.
        // 
        // Arguments:
        // 
        //    AsyncResult - the AsyncResult Returned fron BeginReceiveFrom call
        // 
        // Return Value:
        // 
        //    int - Number of bytes transferred
        internal int EndReceiveFrom(IAsyncResult asyncResult, ref EndPoint endPoint)
        {
            if (s_loggingEnabled)
            {
                Logging.Enter(Logging.Sockets, this, "EndReceiveFrom", asyncResult);
            }
            if (CleanedUp)
            {
                throw new ObjectDisposedException(this.GetType().FullName);
            }

            // Validate input parameters.
            if (endPoint == null)
            {
                throw new ArgumentNullException("endPoint");
            }
            if (!CanTryAddressFamily(endPoint.AddressFamily))
            {
                throw new ArgumentException(SR.Format(SR.net_InvalidEndPointAddressFamily, endPoint.AddressFamily, _addressFamily), "endPoint");
            }
            if (asyncResult == null)
            {
                throw new ArgumentNullException("asyncResult");
            }

            OverlappedAsyncResult castedAsyncResult = asyncResult as OverlappedAsyncResult;
            if (castedAsyncResult == null || castedAsyncResult.AsyncObject != this)
            {
                throw new ArgumentException(SR.net_io_invalidasyncresult, "asyncResult");
            }
            if (castedAsyncResult.EndCalled)
            {
                throw new InvalidOperationException(SR.Format(SR.net_io_invalidendcall, "EndReceiveFrom"));
            }

            Internals.SocketAddress socketAddressOriginal = SnapshotAndSerialize(ref endPoint);

            int bytesTransferred = (int)castedAsyncResult.InternalWaitForCompletion();
            castedAsyncResult.EndCalled = true;

            // Update socket address size.
            castedAsyncResult.SocketAddress.InternalSize = castedAsyncResult.GetSocketAddressSize();

            if (!socketAddressOriginal.Equals(castedAsyncResult.SocketAddress))
            {
                try
                {
                    endPoint = endPoint.Create(castedAsyncResult.SocketAddress);
                }
                catch
                {
                }
            }

            if (s_perfCountersEnabled)
            {
                if (bytesTransferred > 0)
                {
                    SocketPerfCounter.Instance.Increment(SocketPerfCounterName.SocketBytesReceived, bytesTransferred);
                    if (Transport == TransportType.Udp)
                    {
                        SocketPerfCounter.Instance.Increment(SocketPerfCounterName.SocketDatagramsReceived);
                    }
                }
            }

            GlobalLog.Print("Socket#" + Logging.HashString(this) + "::EndReceiveFrom() bytesTransferred:" + bytesTransferred.ToString());

            // Throw an appropriate SocketException if the native call failed asynchronously.
            if ((SocketError)castedAsyncResult.ErrorCode != SocketError.Success)
            {
                // Update the internal state of this socket according to the error before throwing.
                SocketException socketException = new SocketException(castedAsyncResult.ErrorCode);
                UpdateStatusAfterSocketError(socketException);
                if (s_loggingEnabled)
                {
                    Logging.Exception(Logging.Sockets, this, "EndReceiveFrom", socketException);
                }
                throw socketException;
            }
            if (s_loggingEnabled)
            {
                Logging.Exit(Logging.Sockets, this, "EndReceiveFrom", bytesTransferred);
            }
            return bytesTransferred;
        }

        /*++

        Routine Description:

           EndReceiveFrom -  Called when I/O is done or the user wants to wait. If
                     the I/O isn't done, we'll wait for it to complete, and then we'll return
                     the bytes of I/O done.

        Arguments:

           AsyncResult - the AsyncResult Returned fron BeginReceiveFrom call

        Return Value:

           int - Number of bytes transferred

        --*/

        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public int EndReceiveFrom(IAsyncResult asyncResult, ref EndPoint endPoint) {
            if(s_LoggingEnabled)Logging.Enter(Logging.Sockets, this, "EndReceiveFrom", asyncResult);
            if (CleanedUp) {
                throw new ObjectDisposedException(this.GetType().FullName);
            }
            //
            // parameter validation
            //
            if (endPoint==null) {
                throw new ArgumentNullException("endPoint");
            }
            if (!CanTryAddressFamily(endPoint.AddressFamily)) {
                throw new ArgumentException(SR.GetString(SR.net_InvalidEndPointAddressFamily, 
                    endPoint.AddressFamily, addressFamily), "endPoint");
            }
            if (asyncResult==null) {
                throw new ArgumentNullException("asyncResult");
            }
            OverlappedAsyncResult castedAsyncResult = asyncResult as OverlappedAsyncResult;
            if (castedAsyncResult==null || castedAsyncResult.AsyncObject!=this) {
                throw new ArgumentException(SR.GetString(SR.net_io_invalidasyncresult), "asyncResult");
            }
            if (castedAsyncResult.EndCalled) {
                throw new InvalidOperationException(SR.GetString(SR.net_io_invalidendcall, "EndReceiveFrom"));
            }

            SocketAddress socketAddressOriginal = SnapshotAndSerialize(ref endPoint);

            int bytesTransferred = (int)castedAsyncResult.InternalWaitForCompletion();
            castedAsyncResult.EndCalled = true;
            castedAsyncResult.ExtractCache(ref Caches.ReceiveOverlappedCache);

            // Update socket address size
            castedAsyncResult.SocketAddress.SetSize(castedAsyncResult.GetSocketAddressSizePtr());

            if (!socketAddressOriginal.Equals(castedAsyncResult.SocketAddress)) {
                try {
                    endPoint = endPoint.Create(castedAsyncResult.SocketAddress);
                }
                catch {
                }
            }

#if !FEATURE_PAL // perfcounter
            if (s_PerfCountersEnabled)
            {
                if (bytesTransferred>0) {
                    NetworkingPerfCounters.Instance.Increment(NetworkingPerfCounterName.SocketBytesReceived, bytesTransferred);
                    if (Transport==TransportType.Udp) {
                        NetworkingPerfCounters.Instance.Increment(NetworkingPerfCounterName.SocketDatagramsReceived);
                    }
                }
            }
#endif //!FEATURE_PAL

            GlobalLog.Print("Socket#" + ValidationHelper.HashString(this) + "::EndReceiveFrom() bytesTransferred:" + bytesTransferred.ToString());

            //
            // if the asynchronous native call failed asynchronously
            // we'll throw a SocketException
            //
            if ((SocketError)castedAsyncResult.ErrorCode!=SocketError.Success) {
                //
                // update our internal state after this socket error and throw
                //
                SocketException socketException = new SocketException(castedAsyncResult.ErrorCode);
                UpdateStatusAfterSocketError(socketException);
                if(s_LoggingEnabled)Logging.Exception(Logging.Sockets, this, "EndReceiveFrom", socketException);
                throw socketException;
            }
            if(s_LoggingEnabled)Logging.Exit(Logging.Sockets, this, "EndReceiveFrom", bytesTransferred);
            return bytesTransferred;
        }

//.........这里部分代码省略.........
            }
            if (size < 0 || size > buffer.Length - offset)
            {
                throw new ArgumentOutOfRangeException("size");
            }
            if (_rightEndPoint == null)
            {
                throw new InvalidOperationException(SR.net_sockets_mustbind);
            }


            // Set up the result and set it to collect the context.
            ReceiveMessageOverlappedAsyncResult asyncResult = new ReceiveMessageOverlappedAsyncResult(this, state, callback);
            asyncResult.StartPostingAsyncOp(false);

            // Start the ReceiveFrom.
            EndPoint oldEndPoint = _rightEndPoint;

            // We don't do a CAS demand here because the contents of remoteEP aren't used by
            // WSARecvMsg; all that matters is that we generate a unique-to-this-call SocketAddress
            // with the right address family
            Internals.SocketAddress socketAddress = SnapshotAndSerialize(ref remoteEP);

            // Guarantee to call CheckAsyncCallOverlappedResult if we call SetUnamangedStructures with a cache in order to
            // avoid a Socket leak in case of error.
            SocketError errorCode = SocketError.SocketError;
            try
            {
                // Save a copy of the original EndPoint in the asyncResult.
                asyncResult.SocketAddressOriginal = IPEndPointExtensions.Serialize(remoteEP);

                SetReceivingPacketInformation();

                if (_rightEndPoint == null)
                {
                    _rightEndPoint = remoteEP;
                }

                errorCode = SocketPal.ReceiveMessageFromAsync(this, _handle, buffer, offset, size, socketFlags, socketAddress, asyncResult);

                if (errorCode != SocketError.Success)
                {
                    // WSARecvMsg() will never return WSAEMSGSIZE directly, since a completion is queued in this case.  We wouldn't be able
                    // to handle this easily because of assumptions OverlappedAsyncResult makes about whether there would be a completion
                    // or not depending on the error code.  If WSAEMSGSIZE would have been normally returned, it returns WSA_IO_PENDING instead.
                    // That same map is implemented here just in case.
                    if (errorCode == SocketError.MessageSize)
                    {
                        GlobalLog.Assert("Socket#" + Logging.HashString(this) + "::BeginReceiveMessageFrom()|Returned WSAEMSGSIZE!");
                        errorCode = SocketError.IOPending;
                    }
                }

                GlobalLog.Print("Socket#" + Logging.HashString(this) + "::BeginReceiveMessageFrom() Interop.Winsock.WSARecvMsg returns:" + errorCode.ToString() + " size:" + size.ToString() + " returning AsyncResult:" + Logging.HashString(asyncResult));
            }
            catch (ObjectDisposedException)
            {
                _rightEndPoint = oldEndPoint;
                throw;
            }
            finally
            {
                errorCode = asyncResult.CheckAsyncCallOverlappedResult(errorCode);
            }

            // Throw an appropriate SocketException if the native call fails synchronously.
            if (errorCode != SocketError.Success)
            {
                // Update the internal state of this socket according to the error before throwing.
                _rightEndPoint = oldEndPoint;
                SocketException socketException = new SocketException((int)errorCode);
                UpdateStatusAfterSocketError(socketException);
                if (s_loggingEnabled)
                {
                    Logging.Exception(Logging.Sockets, this, "BeginReceiveMessageFrom", socketException);
                }
                throw socketException;
            }

            // Capture the context, maybe call the callback, and return.
            asyncResult.FinishPostingAsyncOp(ref Caches.ReceiveClosureCache);

            if (asyncResult.CompletedSynchronously && !asyncResult.SocketAddressOriginal.Equals(asyncResult.SocketAddress))
            {
                try
                {
                    remoteEP = remoteEP.Create(asyncResult.SocketAddress);
                }
                catch
                {
                }
            }

            GlobalLog.Print("Socket#" + Logging.HashString(this) + "::BeginReceiveMessageFrom() size:" + size.ToString() + " returning AsyncResult:" + Logging.HashString(asyncResult));
            if (s_loggingEnabled)
            {
                Logging.Exit(Logging.Sockets, this, "BeginReceiveMessageFrom", asyncResult);
            }
            return asyncResult;
        }

		internal int ReceiveFrom_nochecks_exc (byte [] buf, int offset, int size, SocketFlags flags,
						   ref EndPoint remote_end, bool throwOnError, out int error)
		{
			SocketAddress sockaddr = remote_end.Serialize();
			int cnt = RecvFrom_internal (socket, buf, offset, size, flags, ref sockaddr, out error);
			SocketError err = (SocketError) error;
			if (err != 0) {
				if (err != SocketError.WouldBlock && err != SocketError.InProgress)
					connected = false;
				else if (err == SocketError.WouldBlock && blocking) { // This might happen when ReceiveTimeout is set
					if (throwOnError)	
						throw new SocketException ((int) SocketError.TimedOut, "Operation timed out");
					error = (int) SocketError.TimedOut;
					return 0;
				}

				if (throwOnError)
					throw new SocketException (error);
				return 0;
			}

			connected = true;

#if NET_2_0
			isbound = true;
#endif

			// If sockaddr is null then we're a connection
			// oriented protocol and should ignore the
			// remote_end parameter (see MSDN
			// documentation for Socket.ReceiveFrom(...) )
			
			if ( sockaddr != null ) {
				// Stupidly, EndPoint.Create() is an
				// instance method
				remote_end = remote_end.Create (sockaddr);
			}
			
			seed_endpoint = remote_end;
			
			return cnt;
		}

//.........这里部分代码省略.........
                throw new InvalidOperationException(SR.GetString(SR.net_sockets_mustbind));
            }


            // Set up the result and set it to collect the context.
            ReceiveMessageOverlappedAsyncResult asyncResult = new ReceiveMessageOverlappedAsyncResult(this, state, callback);
            asyncResult.StartPostingAsyncOp(false);

            // Start the ReceiveFrom.
            EndPoint oldEndPoint = m_RightEndPoint;

            // We don't do a CAS demand here because the contents of remoteEP aren't used by
            // WSARecvMsg; all that matters is that we generate a unique-to-this-call SocketAddress
            // with the right address family
            SocketAddress socketAddress = SnapshotAndSerialize(ref remoteEP);

            // Guarantee to call CheckAsyncCallOverlappedResult if we call SetUnamangedStructures with a cache in order to
            // avoid a Socket leak in case of error.
            SocketError errorCode = SocketError.SocketError;
            try
            {
                asyncResult.SetUnmanagedStructures(buffer, offset, size, socketAddress, socketFlags, ref Caches.ReceiveOverlappedCache);

                // save a copy of the original EndPoint in the asyncResult
                asyncResult.SocketAddressOriginal = remoteEP.Serialize();

                int bytesTransfered;

                SetReceivingPacketInformation();

                if (m_RightEndPoint == null)
                {
                    m_RightEndPoint = remoteEP;
                }

                errorCode = (SocketError) WSARecvMsg(
                    m_Handle,
                    Marshal.UnsafeAddrOfPinnedArrayElement(asyncResult.m_MessageBuffer,0),
                    out bytesTransfered,
                    asyncResult.OverlappedHandle,
                    IntPtr.Zero);

                if (errorCode!=SocketError.Success) {
                    errorCode = (SocketError)Marshal.GetLastWin32Error();

                    // I have guarantees from Brad Williamson that WSARecvMsg() will never return WSAEMSGSIZE directly, since a completion
                    // is queued in this case.  We wouldn't be able to handle this easily because of assumptions OverlappedAsyncResult
                    // makes about whether there would be a completion or not depending on the error code.  If WSAEMSGSIZE would have been
                    // normally returned, it returns WSA_IO_PENDING instead.  That same map is implemented here just in case.
                    if (errorCode == SocketError.MessageSize)
                    {
                        GlobalLog.Assert("Socket#" + ValidationHelper.HashString(this) + "::BeginReceiveMessageFrom()|Returned WSAEMSGSIZE!");
                        errorCode = SocketError.IOPending;
                    }
                }

                GlobalLog.Print("Socket#" + ValidationHelper.HashString(this) + "::BeginReceiveMessageFrom() UnsafeNclNativeMethods.OSSOCK.WSARecvMsg returns:" + errorCode.ToString() + " size:" + size.ToString() + " returning AsyncResult:" + ValidationHelper.HashString(asyncResult));
            }
            catch (ObjectDisposedException)
            {
                m_RightEndPoint = oldEndPoint;
                throw;
            }
            finally
            {
                errorCode = asyncResult.CheckAsyncCallOverlappedResult(errorCode);
            }

            //
            // if the asynchronous native call fails synchronously
            // we'll throw a SocketException
            //
            if (errorCode!=SocketError.Success)
            {
                //
                // update our internal state after this socket error and throw
                //
                m_RightEndPoint = oldEndPoint;
                asyncResult.ExtractCache(ref Caches.ReceiveOverlappedCache);
                SocketException socketException = new SocketException(errorCode);
                UpdateStatusAfterSocketError(socketException);
                if (s_LoggingEnabled) Logging.Exception(Logging.Sockets, this, "BeginReceiveMessageFrom", socketException);
                throw socketException;
            }

            // Capture the context, maybe call the callback, and return.
            asyncResult.FinishPostingAsyncOp(ref Caches.ReceiveClosureCache);

            if (asyncResult.CompletedSynchronously && !asyncResult.SocketAddressOriginal.Equals(asyncResult.SocketAddress)) {
                try {
                    remoteEP = remoteEP.Create(asyncResult.SocketAddress);
                }
                catch {
                }
            }

            GlobalLog.Print("Socket#" + ValidationHelper.HashString(this) + "::BeginReceiveMessageFrom() size:" + size.ToString() + " returning AsyncResult:" + ValidationHelper.HashString(asyncResult));
            if(s_LoggingEnabled)Logging.Exit(Logging.Sockets, this, "BeginReceiveMessageFrom", asyncResult);
            return asyncResult;
        }

        /*++

        Routine Description:

           EndReceiveFrom -  Called when I/O is done or the user wants to wait. If
                     the I/O isn't done, we'll wait for it to complete, and then we'll return
                     the bytes of I/O done.

        Arguments:

           AsyncResult - the AsyncResult Returned fron BeginReceiveFrom call

        Return Value:

           int - Number of bytes transferred

        --*/

        /// <include file='doc\Socket.uex' path='docs/doc[@for="Socket.EndReceiveFrom"]/*' />
        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public int EndReceiveFrom(IAsyncResult asyncResult, ref EndPoint endPoint) {
            if (CleanedUp) {
                throw new ObjectDisposedException(this.GetType().FullName);
            }
            //
            // parameter validation
            //
            if (endPoint==null) {
                throw new ArgumentNullException("endPoint");
            }
            if (asyncResult==null) {
                throw new ArgumentNullException("asyncResult");
            }
            OverlappedAsyncResult castedAsyncResult = asyncResult as OverlappedAsyncResult;
            if (castedAsyncResult==null || castedAsyncResult.AsyncObject!=this) {
                throw new ArgumentException(SR.GetString(SR.net_io_invalidasyncresult));
            }
            if (castedAsyncResult.EndCalled) {
                throw new InvalidOperationException(SR.GetString(SR.net_io_invalidendcall, "EndReceiveFrom"));
            }

            int bytesTransferred = (int)castedAsyncResult.InternalWaitForCompletion();
            castedAsyncResult.EndCalled = true;

            // pick up the saved copy of the original EndPoint from the asyncResult
            if (!castedAsyncResult.m_SocketAddressOriginal.Equals(castedAsyncResult.m_SocketAddress)) {
                try {
                    endPoint = endPoint.Create(castedAsyncResult.m_SocketAddress);
                }
                catch {
                }
            }


            GlobalLog.Print("Socket#" + ValidationHelper.HashString(this) + "::EndReceiveFrom() bytesTransferred:" + bytesTransferred.ToString());

            //
            // if the asynchronous native call failed asynchronously
            // we'll throw a SocketException
            //
            if (castedAsyncResult.ErrorCode!=SocketErrors.Success) {
                //
                // update our internal state after this socket error and throw
                //
                UpdateStatusAfterSocketError();
                throw new SocketException(castedAsyncResult.ErrorCode);
            }

            return bytesTransferred;
        }

        public int ReceiveFrom(byte[] buffer, int offset, int size, SocketFlags socketFlags, ref EndPoint remoteEP)
        {
            if (m_Handle == -1)
            {
                throw new ObjectDisposedException();
            }

            byte[] address = remoteEP.Serialize().m_Buffer;
            int len = 0;

            len = NativeSocket.recvfrom(this, buffer, offset, size, (int)socketFlags, m_recvTimeout, ref address);

            SocketAddress socketAddress = new SocketAddress(address);
            remoteEP = remoteEP.Create(socketAddress);

            return len;
        }

 /// <summary>
 /// Begins to asynchronously receive the specified number of bytes of data into the specified location of the data buffer, using the specified <see cref="T:System.Net.Sockets.SocketFlags"/>, and stores the endpoint and packet information..
 /// </summary>
 /// 
 /// <returns>
 /// An <see cref="T:System.IAsyncResult"/> that references the asynchronous read.
 /// </returns>
 /// <param name="buffer">An array of type <see cref="T:System.Byte"/> that is the storage location for the received data. </param><param name="offset">The zero-based position in the <paramref name="buffer"/> parameter at which to store the data.</param><param name="size">The number of bytes to receive. </param><param name="socketFlags">A bitwise combination of the <see cref="T:System.Net.Sockets.SocketFlags"/> values.</param><param name="remoteEP">An <see cref="T:System.Net.EndPoint"/> that represents the source of the data.</param><param name="callback">The <see cref="T:System.AsyncCallback"/> delegate.</param><param name="state">An object that contains state information for this request.</param><exception cref="T:System.ArgumentNullException"><paramref name="buffer"/> is null.-or- <paramref name="remoteEP"/> is null. </exception><exception cref="T:System.Net.Sockets.SocketException">An error occurred when attempting to access the socket. See the Remarks section for more information. </exception><exception cref="T:System.ArgumentOutOfRangeException"><paramref name="offset"/> is less than 0.-or- <paramref name="offset"/> is greater than the length of <paramref name="buffer"/>.-or- <paramref name="size"/> is less than 0.-or- <paramref name="size"/> is greater than the length of <paramref name="buffer"/> minus the value of the <paramref name="offset"/> parameter. </exception><exception cref="T:System.ObjectDisposedException">The <see cref="T:System.Net.Sockets.Socket"/> has been closed. </exception><exception cref="T:System.NotSupportedException">The operating system is Windows 2000 or earlier, and this method requires Windows XP.</exception>
 public IAsyncResult BeginReceiveMessageFrom(byte[] buffer, int offset, int size, SocketFlags socketFlags, ref EndPoint remoteEP, AsyncCallback callback, object state)
 {
     if (Socket.s_LoggingEnabled)
     Logging.Enter(Logging.Sockets, (object) this, "BeginReceiveMessageFrom", "");
       if (this.CleanedUp)
     throw new ObjectDisposedException(this.GetType().FullName);
       if (buffer == null)
     throw new ArgumentNullException("buffer");
       if (remoteEP == null)
     throw new ArgumentNullException("remoteEP");
       if (!this.CanTryAddressFamily(remoteEP.AddressFamily))
       {
     throw new ArgumentException(SR.GetString("net_InvalidEndPointAddressFamily", (object) remoteEP.AddressFamily, (object) this.addressFamily), "remoteEP");
       }
       else
       {
     if (offset < 0 || offset > buffer.Length)
       throw new ArgumentOutOfRangeException("offset");
     if (size < 0 || size > buffer.Length - offset)
       throw new ArgumentOutOfRangeException("size");
     if (this.m_RightEndPoint == null)
       throw new InvalidOperationException(SR.GetString("net_sockets_mustbind"));
     ReceiveMessageOverlappedAsyncResult overlappedAsyncResult = new ReceiveMessageOverlappedAsyncResult(this, state, callback);
     overlappedAsyncResult.StartPostingAsyncOp(false);
     EndPoint endPoint = this.m_RightEndPoint;
     SocketAddress socketAddress = this.SnapshotAndSerialize(ref remoteEP);
     SocketError socketError = SocketError.SocketError;
     try
     {
       overlappedAsyncResult.SetUnmanagedStructures(buffer, offset, size, socketAddress, socketFlags, ref this.Caches.ReceiveOverlappedCache);
       overlappedAsyncResult.SocketAddressOriginal = remoteEP.Serialize();
       this.SetReceivingPacketInformation();
       if (this.m_RightEndPoint == null)
     this.m_RightEndPoint = remoteEP;
       int bytesTransferred;
       socketError = this.WSARecvMsg(this.m_Handle, Marshal.UnsafeAddrOfPinnedArrayElement((Array) overlappedAsyncResult.m_MessageBuffer, 0), out bytesTransferred, overlappedAsyncResult.OverlappedHandle, IntPtr.Zero);
       if (socketError != SocketError.Success)
       {
     socketError = (SocketError) Marshal.GetLastWin32Error();
     if (socketError == SocketError.MessageSize)
       socketError = SocketError.IOPending;
       }
     }
     catch (ObjectDisposedException ex)
     {
       this.m_RightEndPoint = endPoint;
       throw;
     }
     finally
     {
       socketError = overlappedAsyncResult.CheckAsyncCallOverlappedResult(socketError);
     }
     if (socketError != SocketError.Success)
     {
       this.m_RightEndPoint = endPoint;
       overlappedAsyncResult.ExtractCache(ref this.Caches.ReceiveOverlappedCache);
       SocketException socketException = new SocketException(socketError);
       this.UpdateStatusAfterSocketError(socketException);
       if (Socket.s_LoggingEnabled)
     Logging.Exception(Logging.Sockets, (object) this, "BeginReceiveMessageFrom", (Exception) socketException);
       throw socketException;
     }
     else
     {
       overlappedAsyncResult.FinishPostingAsyncOp(ref this.Caches.ReceiveClosureCache);
       if (overlappedAsyncResult.CompletedSynchronously)
       {
     if (!overlappedAsyncResult.SocketAddressOriginal.Equals((object) overlappedAsyncResult.SocketAddress))
     {
       try
       {
         remoteEP = remoteEP.Create(overlappedAsyncResult.SocketAddress);
       }
       catch
       {
       }
     }
       }
       if (Socket.s_LoggingEnabled)
     Logging.Exit(Logging.Sockets, (object) this, "BeginReceiveMessageFrom", (object) overlappedAsyncResult);
       return (IAsyncResult) overlappedAsyncResult;
     }
       }
 }

 /// <summary>
 /// Ends a pending asynchronous read from a specific endpoint. This method also reveals more information about the packet than <see cref="M:System.Net.Sockets.Socket.EndReceiveFrom(System.IAsyncResult,[email protected])"/>.
 /// </summary>
 /// 
 /// <returns>
 /// If successful, the number of bytes received. If unsuccessful, returns 0.
 /// </returns>
 /// <param name="asyncResult">An <see cref="T:System.IAsyncResult"/> that stores state information and any user defined data for this asynchronous operation.</param><param name="socketFlags">A bitwise combination of the <see cref="T:System.Net.Sockets.SocketFlags"/> values for the received packet.</param><param name="endPoint">The source <see cref="T:System.Net.EndPoint"/>.</param><param name="ipPacketInformation">The <see cref="T:System.Net.IPAddress"/> and interface of the received packet.</param><exception cref="T:System.ArgumentNullException"><paramref name="asyncResult"/> is null-or- <paramref name="endPoint"/> is null. </exception><exception cref="T:System.ArgumentException"><paramref name="asyncResult"/> was not returned by a call to the <see cref="M:System.Net.Sockets.Socket.BeginReceiveMessageFrom(System.Byte[],System.Int32,System.Int32,System.Net.Sockets.SocketFlags,[email protected],System.AsyncCallback,System.Object)"/> method. </exception><exception cref="T:System.InvalidOperationException"><see cref="M:System.Net.Sockets.Socket.EndReceiveMessageFrom(System.IAsyncResult,[email protected],[email protected],[email protected])"/> was previously called for the asynchronous read. </exception><exception cref="T:System.Net.Sockets.SocketException">An error occurred when attempting to access the socket. See the Remarks section for more information. </exception><exception cref="T:System.ObjectDisposedException">The <see cref="T:System.Net.Sockets.Socket"/> has been closed. </exception>
 public int EndReceiveMessageFrom(IAsyncResult asyncResult, ref SocketFlags socketFlags, ref EndPoint endPoint, out IPPacketInformation ipPacketInformation)
 {
     if (Socket.s_LoggingEnabled)
     Logging.Enter(Logging.Sockets, (object) this, "EndReceiveMessageFrom", (object) asyncResult);
       if (this.CleanedUp)
     throw new ObjectDisposedException(this.GetType().FullName);
       if (endPoint == null)
     throw new ArgumentNullException("endPoint");
       if (!this.CanTryAddressFamily(endPoint.AddressFamily))
       {
     throw new ArgumentException(SR.GetString("net_InvalidEndPointAddressFamily", (object) endPoint.AddressFamily, (object) this.addressFamily), "endPoint");
       }
       else
       {
     if (asyncResult == null)
       throw new ArgumentNullException("asyncResult");
     ReceiveMessageOverlappedAsyncResult overlappedAsyncResult = asyncResult as ReceiveMessageOverlappedAsyncResult;
     if (overlappedAsyncResult == null || overlappedAsyncResult.AsyncObject != this)
       throw new ArgumentException(SR.GetString("net_io_invalidasyncresult"), "asyncResult");
     if (overlappedAsyncResult.EndCalled)
     {
       throw new InvalidOperationException(SR.GetString("net_io_invalidendcall", new object[1]
       {
     (object) "EndReceiveMessageFrom"
       }));
     }
     else
     {
       SocketAddress socketAddress = this.SnapshotAndSerialize(ref endPoint);
       int num = (int) overlappedAsyncResult.InternalWaitForCompletion();
       overlappedAsyncResult.EndCalled = true;
       overlappedAsyncResult.ExtractCache(ref this.Caches.ReceiveOverlappedCache);
       overlappedAsyncResult.SocketAddress.SetSize(overlappedAsyncResult.GetSocketAddressSizePtr());
       if (!socketAddress.Equals((object) overlappedAsyncResult.SocketAddress))
       {
     try
     {
       endPoint = endPoint.Create(overlappedAsyncResult.SocketAddress);
     }
     catch
     {
     }
       }
       if (Socket.s_PerfCountersEnabled && num > 0)
       {
     NetworkingPerfCounters.Instance.Increment(NetworkingPerfCounterName.SocketBytesReceived, (long) num);
     if (this.Transport == TransportType.Udp)
       NetworkingPerfCounters.Instance.Increment(NetworkingPerfCounterName.SocketDatagramsReceived);
       }
       if (overlappedAsyncResult.ErrorCode != 0 && overlappedAsyncResult.ErrorCode != 10040)
       {
     SocketException socketException = new SocketException(overlappedAsyncResult.ErrorCode);
     this.UpdateStatusAfterSocketError(socketException);
     if (Socket.s_LoggingEnabled)
       Logging.Exception(Logging.Sockets, (object) this, "EndReceiveMessageFrom", (Exception) socketException);
     throw socketException;
       }
       else
       {
     socketFlags = overlappedAsyncResult.m_flags;
     ipPacketInformation = overlappedAsyncResult.m_IPPacketInformation;
     if (Socket.s_LoggingEnabled)
       Logging.Exit(Logging.Sockets, (object) this, "EndReceiveMessageFrom", (object) num);
     return num;
       }
     }
       }
 }

 public IAsyncResult BeginReceiveFrom(byte[] buffer, int offset, int size, SocketFlags socketFlags, ref EndPoint remoteEP, AsyncCallback callback, object state)
 {
     if (Socket.s_LoggingEnabled)
     Logging.Enter(Logging.Sockets, (object) this, "BeginReceiveFrom", "");
       if (this.CleanedUp)
     throw new ObjectDisposedException(this.GetType().FullName);
       if (buffer == null)
     throw new ArgumentNullException("buffer");
       if (remoteEP == null)
     throw new ArgumentNullException("remoteEP");
       if (!this.CanTryAddressFamily(remoteEP.AddressFamily))
       {
     throw new ArgumentException(SR.GetString("net_InvalidEndPointAddressFamily", (object) remoteEP.AddressFamily, (object) this.addressFamily), "remoteEP");
       }
       else
       {
     if (offset < 0 || offset > buffer.Length)
       throw new ArgumentOutOfRangeException("offset");
     if (size < 0 || size > buffer.Length - offset)
       throw new ArgumentOutOfRangeException("size");
     if (this.m_RightEndPoint == null)
       throw new InvalidOperationException(SR.GetString("net_sockets_mustbind"));
     SocketAddress socketAddress = this.SnapshotAndSerialize(ref remoteEP);
     OverlappedAsyncResult asyncResult = new OverlappedAsyncResult(this, state, callback);
     asyncResult.StartPostingAsyncOp(false);
     this.DoBeginReceiveFrom(buffer, offset, size, socketFlags, remoteEP, socketAddress, asyncResult);
     asyncResult.FinishPostingAsyncOp(ref this.Caches.ReceiveClosureCache);
     if (asyncResult.CompletedSynchronously)
     {
       if (!asyncResult.SocketAddressOriginal.Equals((object) asyncResult.SocketAddress))
       {
     try
     {
       remoteEP = remoteEP.Create(asyncResult.SocketAddress);
     }
     catch
     {
     }
       }
     }
     if (Socket.s_LoggingEnabled)
       Logging.Exit(Logging.Sockets, (object) this, "BeginReceiveFrom", (object) asyncResult);
     return (IAsyncResult) asyncResult;
       }
 }

        public int EndReceiveMessageFrom(IAsyncResult asyncResult, ref SocketFlags socketFlags, ref EndPoint endPoint, out IPPacketInformation ipPacketInformation)
        {
            if (NetEventSource.IsEnabled) NetEventSource.Enter(this, asyncResult);

            if (CleanedUp)
            {
                throw new ObjectDisposedException(this.GetType().FullName);
            }
            if (endPoint == null)
            {
                throw new ArgumentNullException(nameof(endPoint));
            }
            if (!CanTryAddressFamily(endPoint.AddressFamily))
            {
                throw new ArgumentException(SR.Format(SR.net_InvalidEndPointAddressFamily, endPoint.AddressFamily, _addressFamily), nameof(endPoint));
            }
            if (asyncResult == null)
            {
                throw new ArgumentNullException(nameof(asyncResult));
            }

            ReceiveMessageOverlappedAsyncResult castedAsyncResult = asyncResult as ReceiveMessageOverlappedAsyncResult;
            if (castedAsyncResult == null || castedAsyncResult.AsyncObject != this)
            {
                throw new ArgumentException(SR.net_io_invalidasyncresult, nameof(asyncResult));
            }
            if (castedAsyncResult.EndCalled)
            {
                throw new InvalidOperationException(SR.Format(SR.net_io_invalidendcall, "EndReceiveMessageFrom"));
            }

            Internals.SocketAddress socketAddressOriginal = SnapshotAndSerialize(ref endPoint);

            int bytesTransferred = castedAsyncResult.InternalWaitForCompletionInt32Result();
            castedAsyncResult.EndCalled = true;

            // Update socket address size.
            castedAsyncResult.SocketAddress.InternalSize = castedAsyncResult.GetSocketAddressSize();

            if (!socketAddressOriginal.Equals(castedAsyncResult.SocketAddress))
            {
                try
                {
                    endPoint = endPoint.Create(castedAsyncResult.SocketAddress);
                }
                catch
                {
                }
            }

            if (s_perfCountersEnabled)
            {
                if (bytesTransferred > 0)
                {
                    SocketPerfCounter.Instance.Increment(SocketPerfCounterName.SocketBytesReceived, bytesTransferred);
                    if (Transport == TransportType.Udp)
                    {
                        SocketPerfCounter.Instance.Increment(SocketPerfCounterName.SocketDatagramsReceived);
                    }
                }
            }

            if (NetEventSource.IsEnabled) NetEventSource.Info(this, $"bytesTransferred:{bytesTransferred}");

            // Throw an appropriate SocketException if the native call failed asynchronously.
            if ((SocketError)castedAsyncResult.ErrorCode != SocketError.Success && (SocketError)castedAsyncResult.ErrorCode != SocketError.MessageSize)
            {
                // Update the internal state of this socket according to the error before throwing.
                SocketException socketException = new SocketException(castedAsyncResult.ErrorCode);
                UpdateStatusAfterSocketError(socketException);
                if (NetEventSource.IsEnabled) NetEventSource.Error(this, socketException);
                throw socketException;
            }

            socketFlags = castedAsyncResult.SocketFlags;
            ipPacketInformation = castedAsyncResult.IPPacketInformation;

            if (NetEventSource.IsEnabled) NetEventSource.Exit(this, bytesTransferred);
            return bytesTransferred;
        }

		internal int ReceiveFrom (byte [] buffer, int offset, int size, SocketFlags socketFlags, ref EndPoint remoteEP, out SocketError errorCode)
		{
			SocketAddress sockaddr = remoteEP.Serialize();

			int nativeError;
			int cnt = ReceiveFrom_internal (m_Handle, buffer, offset, size, socketFlags, ref sockaddr, out nativeError, is_blocking);

			errorCode = (SocketError) nativeError;
			if (errorCode != SocketError.Success) {
				if (errorCode != SocketError.WouldBlock && errorCode != SocketError.InProgress) {
					is_connected = false;
				} else if (errorCode == SocketError.WouldBlock && is_blocking) { // This might happen when ReceiveTimeout is set
					errorCode = SocketError.TimedOut;
				}

				return 0;
			}

			is_connected = true;
			is_bound = true;

			/* If sockaddr is null then we're a connection oriented protocol and should ignore the
			 * remoteEP parameter (see MSDN documentation for Socket.ReceiveFrom(...) ) */
			if (sockaddr != null) {
				/* Stupidly, EndPoint.Create() is an instance method */
				remoteEP = remoteEP.Create (sockaddr);
			}

			seed_endpoint = remoteEP;

			return cnt;
		}

        public int EndReceiveMessageFrom(IAsyncResult asyncResult, ref SocketFlags socketFlags, ref EndPoint endPoint, out IPPacketInformation ipPacketInformation)
        {
            if(Logging.On)Logging.Enter(Logging.Sockets, this, "EndReceiveMessageFrom", asyncResult);
            if (CleanedUp) {
                throw new ObjectDisposedException(this.GetType().FullName);
            }
            if (endPoint==null) {
                throw new ArgumentNullException("endPoint");
            }
            if (asyncResult==null) {
                throw new ArgumentNullException("asyncResult");
            }
            ReceiveMessageOverlappedAsyncResult castedAsyncResult = asyncResult as ReceiveMessageOverlappedAsyncResult;
            if (castedAsyncResult==null || castedAsyncResult.AsyncObject!=this) {
                throw new ArgumentException(SR.GetString(SR.net_io_invalidasyncresult), "asyncResult");
            }
            if (castedAsyncResult.EndCalled) {
                throw new InvalidOperationException(SR.GetString(SR.net_io_invalidendcall, "EndReceiveMessageFrom"));
            }

            int bytesTransferred = (int)castedAsyncResult.InternalWaitForCompletion();
            castedAsyncResult.EndCalled = true;
            castedAsyncResult.ExtractCache(ref Caches.ReceiveOverlappedCache);

            // Update socket address size
            castedAsyncResult.SocketAddress.SetSize(castedAsyncResult.GetSocketAddressSizePtr());

            // pick up the saved copy of the original EndPoint from the asyncResult
            SocketAddress socketAddressOriginal = endPoint.Serialize();

            if (!socketAddressOriginal.Equals(castedAsyncResult.SocketAddress)) {
                try {
                    endPoint = endPoint.Create(castedAsyncResult.SocketAddress);
                }
                catch {
                }
            }

            GlobalLog.Print("Socket#" + ValidationHelper.HashString(this) + "::EndReceiveMessageFrom() bytesTransferred:" + bytesTransferred.ToString());

            //
            // if the asynchronous native call failed asynchronously
            // we'll throw a SocketException
            //
            if ((SocketError)castedAsyncResult.ErrorCode!=SocketError.Success && (SocketError)castedAsyncResult.ErrorCode != SocketError.MessageSize) {
                //
                // update our internal state after this socket error and throw
                //
                SocketException socketException = new SocketException(castedAsyncResult.ErrorCode);
                UpdateStatusAfterSocketError(socketException);
                if(Logging.On)Logging.Exception(Logging.Sockets, this, "EndReceiveMessageFrom", socketException);
                throw socketException;
            }

            socketFlags = castedAsyncResult.m_flags;
            ipPacketInformation = castedAsyncResult.m_IPPacketInformation;

            if(Logging.On)Logging.Exit(Logging.Sockets, this, "EndReceiveMessageFrom", bytesTransferred);
            return bytesTransferred;
        }