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I want to make a FadeTransition within a pane in my application. Also, with this FadeTransition I set the visibitilitys of some JavaFX inside the pane to false, to make them disappear. It's working fine but, when I call another method that I named waitForResponse(event) after the FadeTransition it just stops working. I don't know why.
If I comment the waitForResponse(event) the FadeTransitions start working again.
I've thought that maybe it's a problem with the Socket and the InputStreamReader inside the waitForResponse(event), but I tested taking it out and making another basic thing inside this method still not work.
I've made other tests and dicovered that FadeTransition and other visibility changes doesn't work if I put any bufferedReader, other loops ou decision structures after it.
I just want to make a loading screen that prevent user to click anywhere until it's finished.
This is the code:
public class LoadingScreenController implements Initializable {
// Socket que vai ser utilizado nos vários métodos para conversar com o servidor
private Socket cliente;
// PrintWriter que vai ser utilizado pelos vários métodos e vai passar o
// argumento para o switch case
private PrintWriter pr;
private InputStreamReader in;
private BufferedReader bf;
private String option;
private String response;
#FXML
private Button refreshButton;
#FXML
private ImageView loadingGif;
#FXML
private Label txtLabel;
#FXML
private AnchorPane rootPane;
public String getOption() {
return option;
}
public void setOption(String option) {
this.option = option;
}
#Override
public void initialize(URL url, ResourceBundle rb) {
}
#FXML
private void makeFadeInTransition() {
FadeTransition fadeTransition = new FadeTransition(Duration.seconds(1), loadingGif);
fadeTransition.setFromValue(0.0);
fadeTransition.setToValue(1.0);
fadeTransition.play();
}
#FXML
private void onRefreshButtonAction(ActionEvent event) {
if (option == null) {
throw new IllegalStateException("Entity was null");
}
refreshButton.setVisible(false);
refreshButton.setDisable(true);
txtLabel.setVisible(false);
makeFadeInTransition();
sendOptionToServer(event);
}
#FXML
private void sendOptionToServer(ActionEvent event) {
try {
cliente = new Socket("localhost", 3322);
pr = new PrintWriter(cliente.getOutputStream());
in = new InputStreamReader(cliente.getInputStream());
bf = new BufferedReader(in);
pr.println(option);
pr.flush();
waitForReponse(event, bf);
} catch (IOException e) {
e.printStackTrace();
}
}
private void waitForReponse(ActionEvent event, BufferedReader bf) throws IOException {
response = bf.readLine();
switch (response) {
case "a":
Utils.currentStage(event).close();
break;
}
}
}
Your sendOptionToServer(...) method, and in particular your waitForResponse(...) method, contains blocking calls that block execution until they are complete (i.e. until you receive a response from the server). Since you're running these on the FX Application Thread, you prevent that thread from doing its normal work until those calls complete. This means it won't update the UI or process any user events until you have received and processed the response from the server.
You should place the calls to blocking methods in a background thread to allow the FX Application Thread to proceed in the meantime. The javafx.concurrent API makes this reasonably easy to do; here a Task should suffice.
Here's a version that uses a Task. I also used a "try with resources" to ensure everything that needs to be closed is correctly closed.
#FXML
private void sendOptionToServer(ActionEvent event) {
Task<String> serverCommunicationTask = new Task<>() {
#Override
protected String call() throws Exception {
try (
Socket cliente = new Socket("localhost", 3322);
PrintWriter pr = new PrintWriter(cliente.getOutputStream());
BufferedReader bf = new BufferedReader(new InputStreamReader(cliente.getInputStream()));
) {
pr.println(option);
pr.flush();
return bf.readLine();
}
}
};
serverCommunicationTask.setOnSucceeded(event -> {
if ("a".equals(serverCommunicationTask.getValue())) {
rootPane.getScene().getWindow().hide();
}
});
serverCommunicationTask.setOnFailed(event -> {
event.getException().printStackTrace();
// handle exception...
});
Thread thread = new Thread(serverCommunicationTask);
thread.setDaemon(true);
thread.start();
}
We needed a Windows Service that supported TCP communications with a number of clients. So I based it on the MSDN Async Example The thing with the Microsoft example is that the client sends one message to the server, the server then resends the message then closes. Great!
So having blindly deployed this to our prod and customer site we got reports that it had crashed. Looking at Prod we noticed that after 1 day, the memory usage grew to just under 1GB before throwing an OutOfMemoryException. Lots of testing here!
This happened with 1 client connected. It sends an XML based message that is quite large ~1200 bytes every second. Yes, every second.
The service then does some processing and sends a return XML message back to the client.
I've pulled the TCP Client/Server communications into a simple set of Console applications to replicate the issue - mainly to eliminate other managed/unmanaged resources. Now I've been looking at this for a number of days now and have pulled all of my hair and teeth out.
In my example I am focusing on the following classes:
B2BSocketManager (Server Listener, Sender, Receiver)
NOTE I have changed the code to return the whoopsy readonly byte array - not the sent message. I've also removed the new AsyncCallback(delegate) from the BeginReceive/BeginSend calls.
namespace Acme.OPC.Service.Net.Sockets
{
using Acme.OPC.Service.Logging;
using System;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
public class B2BSocketManager : ISocketSender
{
private ManualResetEvent allDone = new ManualResetEvent(false);
private IPEndPoint _localEndPoint;
private readonly byte[] whoopsy = new byte[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
public B2BSocketManager(IPAddress address, int port)
{
_localEndPoint = new IPEndPoint(address, port);
}
public void StartListening()
{
StartListeningAsync();
}
private async Task StartListeningAsync()
{
await System.Threading.Tasks.Task.Factory.StartNew(() => ListenForConnections());
}
public void ListenForConnections()
{
Socket listener = new Socket(_localEndPoint.Address.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
Log.Instance.Info("B2BSocketManager Listening on " + _localEndPoint.Address.ToString() + ":" + _localEndPoint.Port.ToString());
try
{
listener.Bind(_localEndPoint);
listener.Listen(100);
while (true)
{
allDone.Reset();
Log.Instance.Info("B2BSocketManager Waiting for a connection...");
listener.BeginAccept(new AsyncCallback(ConnectCallback), listener);
allDone.WaitOne();
}
}
catch (Exception e)
{
Log.Instance.Info(e.ToString());
}
}
public void ConnectCallback(IAsyncResult ar)
{
allDone.Set();
Socket listener = (Socket)ar.AsyncState;
Socket handler = listener.EndAccept(ar);
handler.DontFragment = false;
handler.ReceiveBufferSize = ClientSocket.BufferSize;
Log.Instance.Info("B2BSocketManager Client has connected on " + handler.RemoteEndPoint.ToString());
ClientSocket state = new ClientSocket();
state.workSocket = handler;
handler.BeginReceive(state.buffer, 0, ClientSocket.BufferSize, 0, new AsyncCallback(ReadCallback), state); // SocketFlags.None
}
public void ReadCallback(IAsyncResult ar)
{
String message = String.Empty;
ClientSocket state = (ClientSocket)ar.AsyncState;
Socket handler = state.workSocket;
int bytesRead = handler.EndReceive(ar);
if (bytesRead > 0)
{
Console.WriteLine("Received " + bytesRead + " at " + DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"));
message = Encoding.ASCII.GetString(state.buffer, 0, bytesRead);
if (!string.IsNullOrEmpty(message))
{
Send(handler, message);
}
handler.BeginReceive(state.buffer, 0, ClientSocket.BufferSize, 0, ReadCallback, state);
}
}
public void Send(Socket socket, string data)
{
// just hard coding the whoopse readonly byte array
socket.BeginSend(whoopsy, 0, whoopsy.Length, 0, SendCallback, socket);
}
private void SendCallback(IAsyncResult ar)
{
Socket state = (Socket)ar.AsyncState;
try
{
int bytesSent = state.EndSend(ar);
}
catch (Exception e)
{
Log.Instance.ErrorException("", e);
}
}
}
}
ClientSender (Client Sender)
The client sends an xml string to the server every 250 milliseconds. I wanted to see how this would perform. The xml is slightly smaller than what we send on our live system and is just created using a formatted string.
namespace TestHarness
{
using System;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
class ClientSender
{
private static ManualResetEvent connectDone = new ManualResetEvent(false);
private static ManualResetEvent receiveDone = new ManualResetEvent(false);
private static ManualResetEvent sendDone = new ManualResetEvent(false);
private static void StartSpamming(Socket client)
{
while(true)
{
string message = #"<request type=""da"">{0}{1}</request>" + Environment.NewLine;
Send(client, string.Format(message, "Be someone" + DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"), String.Concat(Enumerable.Repeat("<test>Oooooooops</test>", 50))));
Thread.Sleep(250);
}
}
public static void Connect(EndPoint remoteEP)
{
Socket listener = new Socket(remoteEP.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
listener.BeginConnect(remoteEP, new AsyncCallback(ConnectCallback), listener);
connectDone.WaitOne();
}
private static void ConnectCallback(IAsyncResult ar)
{
try
{
// Retrieve the socket from the state object.
Socket client = (Socket)ar.AsyncState;
// Complete the connection.
client.EndConnect(ar);
Console.WriteLine("Socket connected to {0}", client.RemoteEndPoint.ToString());
// Signal that the connection has been made.
connectDone.Set();
System.Threading.Tasks.Task.Factory.StartNew(() => StartSpamming(client));
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
private static void Send(Socket client, String data)
{
byte[] byteData = Encoding.ASCII.GetBytes(data);
client.BeginSend(byteData, 0, byteData.Length, SocketFlags.None, new AsyncCallback(SendCallback), client);
}
private static void SendCallback(IAsyncResult ar)
{
try
{
Socket client = (Socket)ar.AsyncState;
int bytesSent = client.EndSend(ar);
Console.WriteLine("Sent {0} bytes to server " + DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"), bytesSent);
sendDone.Set();
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
private static void Receive(Socket client)
{
try
{
StateObject state = new StateObject();
state.workSocket = client;
client.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ReceiveCallback), state);
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
private static void ReceiveCallback(IAsyncResult ar)
{
try
{
StateObject state = (StateObject)ar.AsyncState;
Socket client = state.workSocket;
int bytesRead = client.EndReceive(ar);
if (bytesRead > 0)
{
state.sb.Append(Encoding.ASCII.GetString(state.buffer, 0, bytesRead));
client.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ReceiveCallback), state);
}
else
{
if (state.sb.Length > 1)
{
string response = state.sb.ToString();
}
receiveDone.Set();
}
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
}
}
State Class
All I wanted was a read buffer to strip the message out of and try and load into XML. But this has been removed from this cut down version to see the issues with just the sockets.
using System;
using System.Linq;
using System.Net.Sockets;
namespace Acme.OPC.Service.Net.Sockets
{
public class ClientSocket
{
public Socket workSocket = null;
public const int BufferSize = 4096;
public readonly byte[] buffer = new byte[BufferSize];
}
}
I've shared my code here:
Explore One Drive Share
I've been profiling things using my Telerik JustTrace Profiler. I just start the server app then start the client app. This is on my Windows 7 64-bit VS2013 development environment.
Run 1
I see Memory Usage is around 250KB with the Working Set at around 20MB. The time seems to tick along nicely, then all of a sudden the memory usage will step up after around 12 minutes. Though things vary.
It would also appear that after the ~16:45:55 (Snapshot) when I Force GC, the memory starts going up each time I press it as opposed to leaving it running and upping automatically which might be an issue with Telerik.
Run 2
Then if I am creating the array of bytes within the Send with (which is more of what the service does - sends an appropriate response string to the client):
public void Send(Socket socket, string data)
{
byte[] byteData = Encoding.ASCII.GetBytes(data);
socket.BeginSend(byteData, 0, byteData.Length, 0, SendCallback, socket);
}
We can see the memory going up more:
Which brings me to what is being retained in memory. I see a log of System.Threading.OverlappedData and I have noticed ExecutionContexts in there. The OverlappedData has a reference to a byte array this time.
With Roots Paths to GC
I am running the profiling overnight so will hopefully get to add more info to this in the morning. Hopefully somebody can point me in the right direction before that - if I'm doing something wrong and I am too blind/silly to see it.
And here are the results of running overnight:
I have a problem with a code. It's (supposed to be) an email-client with options to read messages and send them - the problem is, that it does not download the messages and is not able to send them - I assume that the problem lies in the connectiong.
The program includes following classes
EmailClient: The main class for the e-mail client application
ConnectDialog: This class displays a dialog for entering e-mail server connection settings.
MessagesTableModel: This class manages the e-mail table's data.
MessageDialog: This class displays the dialog used for creating messages.
Here's the main class, the most interesting are methods named sendMessage() and connect():
import java.awt.*;
import java.awt.event.*;
import java.net.*;
import java.util.*;
import javax.mail.*;
import javax.mail.internet.*;
import javax.swing.*;
import javax.swing.event.*;
// The E-mail Client.
public class EmailClient extends JFrame {
// Message table's data model.
private MessagesTableModel tableModel;
// Table listing messages.
private JTable table;
// This the text area for displaying messages.
private JTextArea messageTextArea;
/* This is the split panel that holds the messages
table and the message view panel. */
private JSplitPane splitPane;
// These are the buttons for managing the selected message.
private JButton replyButton, forwardButton, deleteButton;
// Currently selected message in table.
private Message selectedMessage;
// Flag for whether or not a message is being deleted.
private boolean deleting;
// This is the JavaMail session.
private Session session;
// Constructor for E-mail Client.
public EmailClient() {
// Set application title.
setTitle("E-mail Client");
// Set window size.
setSize(640, 480);
// Handle window closing events.
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
actionExit();
}
});
// Setup file menu.
JMenuBar menuBar = new JMenuBar();
JMenu fileMenu = new JMenu("File");
fileMenu.setMnemonic(KeyEvent.VK_F);
JMenuItem fileExitMenuItem = new JMenuItem("Exit",
KeyEvent.VK_X);
fileExitMenuItem.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
actionExit();
}
});
fileMenu.add(fileExitMenuItem);
menuBar.add(fileMenu);
setJMenuBar(menuBar);
// Setup buttons panel.
JPanel buttonPanel = new JPanel();
JButton newButton = new JButton("New Message");
newButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
actionNew();
}
});
buttonPanel.add(newButton);
// Setup messages table.
tableModel = new MessagesTableModel();
table = new JTable(tableModel);
table.getSelectionModel().addListSelectionListener(new
ListSelectionListener() {
public void valueChanged(ListSelectionEvent e) {
tableSelectionChanged();
}
});
// Allow only one row at a time to be selected.
table.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
// Setup E-mails panel.
JPanel emailsPanel = new JPanel();
emailsPanel.setBorder(
BorderFactory.createTitledBorder("E-mails"));
messageTextArea = new JTextArea();
messageTextArea.setEditable(false);
splitPane = new JSplitPane(JSplitPane.VERTICAL_SPLIT,
new JScrollPane(table), new JScrollPane(messageTextArea));
emailsPanel.setLayout(new BorderLayout());
emailsPanel.add(splitPane, BorderLayout.CENTER);
// Setup buttons panel 2.
JPanel buttonPanel2 = new JPanel();
replyButton = new JButton("Reply");
replyButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
actionReply();
}
});
replyButton.setEnabled(false);
buttonPanel2.add(replyButton);
forwardButton = new JButton("Forward");
forwardButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
actionForward();
}
});
forwardButton.setEnabled(false);
buttonPanel2.add(forwardButton);
deleteButton = new JButton("Delete");
deleteButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
actionDelete();
}
});
deleteButton.setEnabled(false);
buttonPanel2.add(deleteButton);
// Add panels to display.
getContentPane().setLayout(new BorderLayout());
getContentPane().add(buttonPanel, BorderLayout.NORTH);
getContentPane().add(emailsPanel, BorderLayout.CENTER);
getContentPane().add(buttonPanel2, BorderLayout.SOUTH);
}
// Exit this program.
private void actionExit() {
System.exit(0);
}
// Create a new message.
private void actionNew() {
sendMessage(MessageDialog.NEW, null);
}
// Called when table row selection changes.
private void tableSelectionChanged() {
/* If not in the middle of deleting a message, set
the selected message and display it. */
if (!deleting) {
selectedMessage =
tableModel.getMessage(table.getSelectedRow());
showSelectedMessage();
updateButtons();
}
}
// Reply to a message.
private void actionReply() {
sendMessage(MessageDialog.REPLY, selectedMessage);
}
// Forward a message.
private void actionForward() {
sendMessage(MessageDialog.FORWARD, selectedMessage);
}
// Delete the selected message.
private void actionDelete() {
deleting = true;
try {
// Delete message from server.
selectedMessage.setFlag(Flags.Flag.DELETED, true);
Folder folder = selectedMessage.getFolder();
folder.close(true);
folder.open(Folder.READ_WRITE);
} catch (Exception e) {
showError("Unable to delete message.", false);
}
// Delete message from table.
tableModel.deleteMessage(table.getSelectedRow());
// Update GUI.
messageTextArea.setText("");
deleting = false;
selectedMessage = null;
updateButtons();
}
// Send the specified message.
private void sendMessage(int type, Message message) {
// Display message dialog to get message values.
MessageDialog dialog;
try {
dialog = new MessageDialog(this, type, message);
if (!dialog.display()) {
// Return if dialog was cancelled.
return;
}
} catch (Exception e) {
showError("Unable to send message.", false);
return;
}
try {
// Create a new message with values from dialog.
Message newMessage = new MimeMessage(session);
newMessage.setFrom(new InternetAddress(dialog.getFrom()));
newMessage.setRecipient(Message.RecipientType.TO,
new InternetAddress(dialog.getTo()));
newMessage.setSubject(dialog.getSubject());
newMessage.setSentDate(new Date());
newMessage.setText(dialog.getContent());
// Send new message.
Transport.send(newMessage);
} catch (Exception e) {
showError("Unable to send message.", false);
}
}
// Show the selected message in the content panel.
private void showSelectedMessage() {
// Show hour glass cursor while message is loaded.
setCursor(Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR));
try {
messageTextArea.setText(
getMessageContent(selectedMessage));
messageTextArea.setCaretPosition(0);
} catch (Exception e) {
showError("Unabled to load message.", false);
} finally {
// Return to default cursor.
setCursor(Cursor.getDefaultCursor());
}
}
/* Update each button's state based off of whether or not
there is a message currently selected in the table. */
private void updateButtons() {
if (selectedMessage != null) {
replyButton.setEnabled(true);
forwardButton.setEnabled(true);
deleteButton.setEnabled(true);
} else {
replyButton.setEnabled(false);
forwardButton.setEnabled(false);
deleteButton.setEnabled(false);
}
}
// Show the application window on the screen.
public void show() {
super.show();
// Update the split panel to be divided 50/50.
splitPane.setDividerLocation(.5);
}
// Connect to e-mail server.
public void connect() {
// Display connect dialog.
ConnectDialog dialog = new ConnectDialog(this);
dialog.show();
// Build connection URL from connect dialog settings.
StringBuffer connectionUrl = new StringBuffer();
connectionUrl.append(dialog.getType() + "://");
connectionUrl.append(dialog.getUsername() + ":");
connectionUrl.append(dialog.getPassword() + "#");
connectionUrl.append(dialog.getServer() + "/");
/* Display dialog stating that messages are
currently being downloaded from server. */
final DownloadingDialog downloadingDialog =
new DownloadingDialog(this);
SwingUtilities.invokeLater(new Runnable() {
public void run() {
downloadingDialog.show();
}
});
// Establish JavaMail session and connect to server.
Store store = null;
try {
// Initialize JavaMail session with SMTP server.
Properties props = new Properties();
props.put("mail.smtp.host", dialog.getSmtpServer());
session = Session.getDefaultInstance(props, null);
// Connect to e-mail server.
URLName urln = new URLName(connectionUrl.toString());
store = session.getStore(urln);
store.connect();
} catch (Exception e) {
// Close the downloading dialog.
downloadingDialog.dispose();
// Show error dialog.
showError("Unable to connect.", true);
}
// Download message headers from server.
try {
// Open main "INBOX" folder.
Folder folder = store.getFolder("INBOX");
folder.open(Folder.READ_WRITE);
// Get folder's list of messages.
Message[] messages = folder.getMessages();
// Retrieve message headers for each message in folder.
FetchProfile profile = new FetchProfile();
profile.add(FetchProfile.Item.ENVELOPE);
folder.fetch(messages, profile);
// Put messages in table.
tableModel.setMessages(messages);
} catch (Exception e) {
// Close the downloading dialog.
downloadingDialog.dispose();
// Show error dialog.
showError("Unable to download messages.", true);
}
// Close the downloading dialog.
downloadingDialog.dispose();
}
// Show error dialog and exit afterwards if necessary.
private void showError(String message, boolean exit) {
JOptionPane.showMessageDialog(this, message, "Error",
JOptionPane.ERROR_MESSAGE);
if (exit)
System.exit(0);
}
// Get a message's content.
public static String getMessageContent(Message message)
throws Exception {
Object content = message.getContent();
if (content instanceof Multipart) {
StringBuffer messageContent = new StringBuffer();
Multipart multipart = (Multipart) content;
for (int i = 0; i < multipart.getCount(); i++) {
Part part = (Part) multipart.getBodyPart(i);
if (part.isMimeType("text/plain")) {
messageContent.append(part.getContent().toString());
}
}
return messageContent.toString();
} else {
return content.toString();
}
}
// Run the E-mail Client.
public static void main(String[] args) {
EmailClient client = new EmailClient();
client.show();
// Display connect dialog.
client.connect();
}
}
Adding printStackTrace() to exceptions gives the following message:
javax.mail.NoSuchProviderException: No provider for NORMAL
at javax.mail.Session.getProvider(Session.java:464)
at javax.mail.Session.getStore(Session.java:539)
at EmailClient.connect(EmailClient.java:296)
at EmailClient.main(EmailClient.java:365)
I'm grateful for all the help I can get!
I am attempting to utilize MSDN's Asynchronous Client Socket code sample to connect and control some home equipment. As I understand, the sample code's ReceiveCallback method uses an instance of the EventWaitHandle ManualResetEvent and the method receiveDone.WaitOne() to hold processing of the current thread until the thread receives a signal that all of the socket's data has been transmitted from the remote device. After all of the socket's data has been transmitted (the socket's data is empty and bytesRead = 0), the Waithandle is removed and the application continues processing.
Unfortunately, by stepping-through the execution of the code, it appears that after the last time that the client returns data from the remote device, ReceiveCallback never returns to see if the data-queue is empty (i.e. bytesRead = 0), and thus never enters the "else" condition in ReceiveCallback where the state of the ManualResetEvent would have been reset and the application would have continued to process. Thus, since it never enters the "else" condition, ManualResetEvent is never reset and the application freezes.
Although I can remove the "receiveDone.WaitOne()" method from the code - permitting execution without waiting for the ManualResetEvent's notification that all of the data has been received; this returns a data-string from the equipment that is typically incomplete.
Am I using this code sample incorrectly? Has anyone seen this before or had any experience on how to work-around this issue?
7/14/2012 - UPDATE: After further testing of the MSDN's Asynchronous Client Socket Example, it became clear that ReceiveCallback actually re-polls the port and the "bytesRead = 0" condition is satisfied only when the socket is released (i.e. client.Shutdown(SocketShutdown.Both); client.Close(); ). If I understand this correctly, this means that the connection has to be closed to get past the receiveDone.WaitOne() method. If the connection is closed to satisfy the WaitOne() Waithandle, it totally defeats the purpose of the application in that I had been hoping to leave the connection open so that the application could listen for equipment updates, which happen continually.
7/16/2012 - UPDATE: I have written to Microsoft Tech Support who have responded that "We're doing research on this issue. It might take some time before we get back to you." As such, it seems that it doesn't appear that this challenge can be resolved at this time through massaging this code.
Without the availability of the Asynchronous Client Socket example code as a foundation for writing asynchronous communication procedures, may I ask if anyone can please suggest a replacement routine that is more reliable? There are three pieces of equipment, each with it's own ip-address and port number. Thus, it would be ideal if a class could be utilized, where an instance could be created for each device. Additionally, the port must remain open to receive spontaneous updates continually sent by the equipment. Lastly, the updates do not have a end character or defined length signalling that the transmission of the message is complete, thus the routine must continually poll the port for available data. Any advice or suggestions would be greatly appreciated.
7/18/2012 - WORKAROUND: After spending a considerable amount of time attempting to get the MSDN's Asynchronous Client Socket code sample working, it became clear that I would have to look elsewhere to get the device responses continuously recognized by the program. In the hope to save someone else the brain-damage, I have included the work-around that I used which seems to work well to this point. If anyone has any suggestions, please don't hesitate to add to this question!
//
// ORIGINAL CODE ATTEMPT
//
public static Socket LutronClient;
public static String LutronResponse = String.Empty;
private const int LutronPort = 4999;
private const string LutronIP = "192.168.1.71";
private static ManualResetEvent LutronConnectDone = new ManualResetEvent(false);
private static ManualResetEvent LutronSendDone = new ManualResetEvent(false);
private static ManualResetEvent LutronReceiveDone = new ManualResetEvent(false);
private static void StartLutronClient()
{
try
{
var lutronIPAddress = IPAddress.Parse(LutronIP);
var lutronRemoteEP = new IPEndPoint(lutronIPAddress, LutronPort);
LutronClient = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
LutronClient.BeginConnect(lutronRemoteEP, LutronConnectCallback, LutronClient);
LutronConnectDone.WaitOne();
LutronSend(LutronClient, "sdl,14,100,0,S2\x0d");
LutronSendDone.WaitOne();
LutronReceive(LutronClient);
LutronReceiveDone.WaitOne(new TimeSpan(5000));
MessageBox.Show("Response received from Lutron: " + LutronResponse);
txtBoxLutron.Text = LutronResponse;
LutronClient.Shutdown(SocketShutdown.Both);
LutronClient.Close();
}
catch (Exception e) { MessageBox.Show(e.ToString()); }
}
private static void LutronConnectCallback(IAsyncResult lutronAr)
{
try
{
var lutronClient = (Socket)lutronAr.AsyncState;
lutronClient.EndConnect(lutronAr);
LutronConnectDone.Set();
}
catch (Exception e) { MessageBox.Show(e.ToString()); }
}
private static void LutronReceive(Socket lutronClient)
{
try
{
var lutronState = new LutronStateObject { LutronWorkSocket = lutronClient };
lutronClient.BeginReceive(lutronState.LutronBuffer, 0, LutronStateObject.BufferSize, 0, new AsyncCallback(LutronReceiveCallback), lutronState);
}
catch (Exception e) { MessageBox.Show(e.ToString()); }
}
private static void LutronReceiveCallback(IAsyncResult lutronAR)
{
try
{
var lutronState = (LutronStateObject)lutronAR.AsyncState;
var lutronClient = lutronState.LutronWorkSocket;
var bytesRead = lutronClient.EndReceive(lutronAR);
if (bytesRead > 0)
{
lutronState.LutronStringBuilder.AppendLine(Encoding.ASCII.GetString(lutronState.LutronBuffer, 0, bytesRead));
lutronClient.BeginReceive(lutronState.LutronBuffer, 0, LutronStateObject.BufferSize, 0, new AsyncCallback(LutronReceiveCallback), lutronState);
}
else
{
if (lutronState.LutronStringBuilder.Length > 0) { LutronResponse = lutronState.LutronStringBuilder.ToString(); }
LutronReceiveDone.Set();
}
}
catch (Exception e) { MessageBox.Show(e.ToString()); }
}
public static void LutronSend(Socket client, String data)
{
var byteData = Encoding.ASCII.GetBytes(data);
client.BeginSend(byteData, 0, byteData.Length, 0, LutronSendCallback, client);
}
private static void LutronSendCallback(IAsyncResult ar)
{
try
{
var client = (Socket)ar.AsyncState;
var bytesSent = client.EndSend(ar);
LutronSendDone.Set();
}
catch (Exception e) { MessageBox.Show(e.ToString()); }
}
public class LutronStateObject
{
public Socket LutronWorkSocket;
public const int BufferSize = 256;
public byte[] LutronBuffer = new byte[BufferSize];
public StringBuilder LutronStringBuilder = new StringBuilder();
}
}
This is the work-around I used:
//
// WORK-AROUND
//
using System;
using System.Windows.Forms;
namespace _GlobalCacheInterface
{
public partial class GlobalCacheDataScreen : Form
{
//Interface objects
private static GC_Interface _lutronInterface;
private const int LutronPort = 4999;
private const string LutronIP = "192.168.1.71";
delegate void ThreadSafeLutronCallback(string text);
private static GC_Interface _elanInterface;
private const int ElanPort = 4998;
private const string ElanIP = "192.168.1.70";
delegate void ThreadSafeElanCallback(string text);
private static GC_Interface _tuneSuiteInterface;
private const int TuneSuitePort = 5000;
private const string TuneSuiteIP = "192.168.1.70";
delegate void ThreadSafeTuneSuiteCallback(string text);
public GlobalCacheDataScreen()
{
InitializeComponent();
_lutronInterface = new GC_Interface(LutronIP, LutronPort);
_elanInterface = new GC_Interface(ElanIP, ElanPort);
_tuneSuiteInterface = new GC_Interface(TuneSuiteIP, TuneSuitePort);
// Create event handlers to notify application of available updated information.
_lutronInterface.DataAvailable += (s, e) => ThreadSafeTxtBoxLutron(_lutronInterface._returnString);
_elanInterface.DataAvailable += (s, e) => ThreadSafeTxtBoxElan(_elanInterface._returnString);
_tuneSuiteInterface.DataAvailable += (s, e) => ThreadSafeTxtBoxTuneSuite(_tuneSuiteInterface._returnString);
_lutronInterface.Connected += (s, e) => UpdateUI();
_elanInterface.Connected += (s, e) => UpdateUI();
_tuneSuiteInterface.Connected += (s, e) => UpdateUI();
UpdateUI();
}
private void UpdateUI()
{
_buttonConnectToLutron.Enabled = !_lutronInterface._isConnected;
_buttonConnectToElan.Enabled = !_elanInterface._isConnected;
_buttonConnectToTuneSuite.Enabled = !_tuneSuiteInterface._isConnected;
_buttonDisconnectFromLutron.Enabled = _lutronInterface._isConnected;
_buttonDisconnectFromElan.Enabled = _elanInterface._isConnected;
_buttonDisconnectFromTuneSuite.Enabled = _tuneSuiteInterface._isConnected;
string connectLutronStatus = _lutronInterface._isConnected ? "Connected" : "Not Connected";
string connectElanStatus = _elanInterface._isConnected ? "Connected" : "Not Connected";
string connectTuneSuiteStatus = _tuneSuiteInterface._isConnected ? "Connected" : "Not Connected";
_textBoxLutronConnectStatus.Text = connectLutronStatus;
_textBoxElanConnectStatus.Text = connectElanStatus;
_textBoxTuneSuiteConnectStatus.Text = connectTuneSuiteStatus;
}
private void ThreadSafeTxtBoxLutron(string message) { if (_lutronRichTextRxMessage.InvokeRequired) { var d = new ThreadSafeLutronCallback(ThreadSafeTxtBoxLutron); _lutronRichTextRxMessage.Invoke(d, new object[] { message }); } else { _lutronRichTextRxMessage.Text = message; } }
private void ThreadSafeTxtBoxElan(string message) { if (_elanRichTextRxMessage.InvokeRequired) { var d = new ThreadSafeElanCallback(ThreadSafeTxtBoxElan); _elanRichTextRxMessage.Invoke(d, new object[] { message }); } else { _elanRichTextRxMessage.Text = message; if (message.EndsWith("\r")) { MessageBoxEx.Show(message, "Message from Lutron Elan", 1000); } } }
private void ThreadSafeTxtBoxTuneSuite(string message) { if (_tuneSuiteRichTextRxMessage.InvokeRequired) { var d = new ThreadSafeTuneSuiteCallback(ThreadSafeTxtBoxTuneSuite); _tuneSuiteRichTextRxMessage.Invoke(d, new object[] { message }); } else { _tuneSuiteRichTextRxMessage.Text = message; if (message.EndsWith("\r")) { MessageBoxEx.Show(message, "Message from TuneSuite", 1000); } } }
private void _buttonConnectToLutron_Click(object sender, EventArgs e) { _lutronInterface.Connect(); }
private void _buttonDisconnectFromLutron_Click(object sender, EventArgs e) { _lutronInterface.Disconnect(); }
private void _buttonConnectToElan_Click(object sender, EventArgs e) { _elanInterface.Connect(); }
private void _buttonDisconnectFromElan_Click(object sender, EventArgs e) { _elanInterface.Disconnect(); }
private void _buttonConnectToTuneSuite_Click(object sender, EventArgs e) { _tuneSuiteInterface.Connect(); }
private void _buttonDisconnectFromTuneSuite_Click(object sender, EventArgs e) { _tuneSuiteInterface.Disconnect(); }
private void _buttonLutronSendMessage_Click(object sender, EventArgs e) { _lutronInterface.SendCommand(_lutronRichTextTxMessage.Text); }
private void _buttonElanSendMessage_Click(object sender, EventArgs e) { _elanInterface.SendCommand(_elanRichTextTxMessage.Text); }
private void _buttonTuneSuiteSendMessage_Click(object sender, EventArgs e) { _tuneSuiteInterface.SendCommand(_elanRichTextTxMessage.Text); }
private void _buttonLightOn_Click(object sender, EventArgs e) { _lutronInterface.SendCommand("sdl,14,100,0,S2"); }
private void _buttonLightOff_Click(object sender, EventArgs e) { _lutronInterface.SendCommand("sdl,14,0,0,S2"); }
private void _buttonStereoOnOff_Click(object sender, EventArgs e) { _elanInterface.SendCommand("sendir,4:3,1,40000,4,1,21,181,21,181,21,181,21,181,21,181,21,181,21,181,21,181,21,181,21,181,21,181,21,800"); }
private void _button30_Click(object sender, EventArgs e) { _tuneSuiteInterface.SendCommand("\xB8\x4D\xB5\x33\x30\x00\x30\x21\xB8"); }
private void _button31_Click(object sender, EventArgs e) { _tuneSuiteInterface.SendCommand("\xB8\x4D\xB5\x33\x31\x00\x30\x21\xB8"); }
private void _button26_Click(object sender, EventArgs e) { _tuneSuiteInterface.SendCommand("\xB8\x4D\xB5\x32\x36\x00\x30\x21\xB8"); }
}
}
and the GC_Interface class:
using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Windows.Forms;
namespace _GlobalCacheInterface
{
class GC_Interface
{
// Declare an event handler to notify when updates are available.
public event EventHandler<EventArgs> DataAvailable;
public string _returnString = "";
// Declare an event handler to notify status of connection.
public event EventHandler<EventArgs> Connected;
public bool _isConnected;
public AsyncCallback ReceiveCallback;
public Socket Client;
private string _ipAddress;
private int _port;
private bool _waitForEndCharacter;
private byte _endCharacter;
byte[] m_DataBuffer = new byte[10];
IAsyncResult m_Result;
public GC_Interface(string ipAddress, int port) { Init(ipAddress, port, false, 0); }
private void Init(string ipAddress, int port, bool waitForEndCharacter, byte endCharacter)
{
_ipAddress = ipAddress;
_port = port;
_waitForEndCharacter = waitForEndCharacter;
_endCharacter = endCharacter;
_isConnected = false;
}
public bool Connect()
{
try
{
// Create a TCP/IP socket.
Client = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
// Establish the remote endpoint for the socket.
var address = IPAddress.Parse(_ipAddress);
var remoteEP = new IPEndPoint(address, _port);
// Connect to the remote endpoint.
Client.Connect(remoteEP);
if (Client.Connected)
{
_isConnected = true;
ConnectedEventHandler();
WaitForData();
}
return true;
}
catch (SocketException se) { MessageBox.Show("\n connection failed, is the server running?\n" + se.Message ); return false; }
}
public bool SendCommand(string command)
{
try
{
// Convert the string data to byte data using ASCII encoding.
var byteData = Encoding.Default.GetBytes(command);
// Add a carraige-return to the end.
var newArray = new byte[byteData.Length + 1];
byteData.CopyTo(newArray, 0);
newArray[newArray.Length - 1] = 13;
if (Client == null) { return false; }
Client.Send(newArray);
return true;
}
catch (SocketException se) { MessageBox.Show(se.Message); return false; }
}
public void WaitForData()
{
try
{
if (ReceiveCallback == null) { ReceiveCallback = new AsyncCallback(OnDataReceived); }
var theSocPkt = new SocketPacket { thisSocket = Client };
m_Result = Client.BeginReceive(theSocPkt.DataBuffer, 0, theSocPkt.DataBuffer.Length, SocketFlags.None, ReceiveCallback, theSocPkt);
}
catch (SocketException se) { MessageBox.Show(se.Message); }
}
public class SocketPacket
{
public System.Net.Sockets.Socket thisSocket;
public byte[] DataBuffer = new byte[1];
}
public void OnDataReceived(IAsyncResult asyn)
{
try
{
SocketPacket theSockId = (SocketPacket)asyn.AsyncState;
var iRx = theSockId.thisSocket.EndReceive(asyn);
char[] Chars = new char[iRx + 1];
System.Text.Decoder d = System.Text.Encoding.UTF8.GetDecoder();
int CharLen = d.GetChars(theSockId.DataBuffer, 0, iRx, Chars, 0);
System.String szData = new System.String(Chars);
_returnString = _returnString + szData.Replace("\0", "");
// When an update is received, raise DataAvailable event
DataAvailableEventHandler();
WaitForData();
}
catch (ObjectDisposedException) { System.Diagnostics.Debugger.Log(0, "1", "\nOnDataReceived: Socket has been closed\n"); }
catch (SocketException se) { MessageBox.Show(se.Message); }
}
public bool Disconnect()
{
try
{
if (Client == null) { return false; }
Client.Close();
Client = null;
_isConnected = false;
return true;
}
catch (Exception) { return false; }
}
protected virtual void DataAvailableEventHandler()
{
var handler = DataAvailable;
if (handler != null) { handler(this, EventArgs.Empty); }
}
protected virtual void ConnectedEventHandler()
{
var handler = Connected;
if (handler != null) { handler(this, EventArgs.Empty); }
}
}
}
I had the same issue, adding an Available check to the code fixed my problem. Below is the revised code.
private static void ReceiveCallback( IAsyncResult ar ) {
try {
StateObject state = (StateObject) ar.AsyncState;
Socket client = state.workSocket;
int bytesRead = client.EndReceive(ar);
if (bytesRead > 0) {
state.sb.Append(Encoding.ASCII.GetString(state.buffer, 0, bytesRead));
// Check if there is anymore data on the socket
if (client.Available > 0) {
client.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ReceiveCallback), state);
}
}
if (bytesRead == 0 || client.Available == 0) {
if (state.sb.Length > 1) {
response = state.sb.ToString();
}
receiveDone.Set();
}
} catch (Exception e) {
Console.WriteLine(e.ToString());
}
}
Hope that helps.
I'm sidestepping the question here. I try to answer what you need, not what you ask for:
Use synchronous code. It will be easier to understand, you don't need callbacks or events. Also, for low thread counts, it is likely to perform better.
You also avoid bugs that you have in your current code. If an exception occurs your computation never completes. Synchronous code does not have that problem.
May I ask for help with the following?
I am attempting to connect and control three pieces of household electronic equipment by computer through a GlobalCache GC-100 and iTach. As you will see in the following code, I created a class ("GlobalCacheAdapter") that can communicate and control the equipment, and created an instance of the class for each piece of equipment. Although each instance seems to work well with communicating and in controlling each piece of equipment, the *feedback returned from the equipment* seems only to be visible at the defining class level's - "ReaderThreadProc" procedure. Further processing of the feedback is required for each piece of equipment and I am uncertain as to how to forward this feedback at the equipment specific instance-level. I suspect that an instance-specific EventHandler will need to be implemented; however I am not aware as to how to implement this type of instance-specific EventHandler in order to complete processing and update the appropriate controls.
Any help wold be greatly appreciated.
using System;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using System.Windows.Forms;
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
// Create three new instances of GlobalCacheAdaptor and connect.
// GC-100 (Elan) 192.168.1.70 4998
// GC-100 (TuneSuite) 192.168.1.70 5000
// GC iTach (Lighting) 192.168.1.71 4999
private GlobalCacheAdaptor elanGlobalCacheAdaptor;
private GlobalCacheAdaptor tuneSuiteGlobalCacheAdaptor;
private GlobalCacheAdaptor lutronGlobalCacheAdaptor;
public Form1()
{
InitializeComponent();
elanGlobalCacheAdaptor = new GlobalCacheAdaptor();
elanGlobalCacheAdaptor.ConnectToDevice(IPAddress.Parse("192.168.1.70"), 4998);
tuneSuiteGlobalCacheAdaptor = new GlobalCacheAdaptor();
tuneSuiteGlobalCacheAdaptor.ConnectToDevice(IPAddress.Parse("192.168.1.70"), 5000);
lutronGlobalCacheAdaptor = new GlobalCacheAdaptor();
lutronGlobalCacheAdaptor.ConnectToDevice(IPAddress.Parse("192.168.1.71"), 4999);
elanTextBox.Text = elanGlobalCacheAdaptor._line;
tuneSuiteTextBox.Text = tuneSuiteGlobalCacheAdaptor._line;
lutronTextBox.Text = lutronGlobalCacheAdaptor._line;
}
private void btnZoneOnOff_Click(object sender, EventArgs e) { elanGlobalCacheAdaptor.SendMessage("sendir,4:3,1,40000,4,1,21,181,21,181,21,181,21,181,21,181,21,181,21,181,21,181,21,181,21,181,21,181,21,800" + Environment.NewLine); }
private void btnSourceInput1_Click(object sender, EventArgs e) { elanGlobalCacheAdaptor.SendMessage("sendir,4:3,1,40000,1,1,20,179,20,179,20,179,20,179,20,179,20,179,20,179,20,278,20,179,20,179,20,179,20,780" + Environment.NewLine); }
private void btnSystemOff_Click(object sender, EventArgs e) { elanGlobalCacheAdaptor.SendMessage("sendir,4:3,1,40000,1,1,20,184,20,184,20,184,20,184,20,184,20,286,20,286,20,286,20,184,20,184,20,184,20,820" + Environment.NewLine); }
private void btnLightOff_Click(object sender, EventArgs e) { lutronGlobalCacheAdaptor.SendMessage("sdl,14,0,0,S2\x0d"); }
private void btnLightOn_Click(object sender, EventArgs e) { lutronGlobalCacheAdaptor.SendMessage("sdl,14,100,0,S2\x0d"); }
private void btnChannel31_Click(object sender, EventArgs e) { tuneSuiteGlobalCacheAdaptor.SendMessage("\xB8\x4D\xB5\x33\x31\x00\x30\x21\xB8\x0D"); }
private void btnChannel30_Click(object sender, EventArgs e) { tuneSuiteGlobalCacheAdaptor.SendMessage("\xB8\x4D\xB5\x33\x30\x00\x30\x21\xB8\x0D"); }
}
}
public class GlobalCacheAdaptor
{
public Socket _multicastListener;
public string _preferredDeviceID;
public IPAddress _deviceAddress;
public Socket _deviceSocket;
public StreamWriter _deviceWriter;
public bool _isConnected;
public int _port;
public IPAddress _address;
public string _line;
public GlobalCacheAdaptor() { }
public static readonly GlobalCacheAdaptor Instance = new GlobalCacheAdaptor();
public bool IsListening { get { return _multicastListener != null; } }
public GlobalCacheAdaptor ConnectToDevice(IPAddress address, int port)
{
if (_deviceSocket != null) _deviceSocket.Close();
try
{
_port = port;
_address = address;
_deviceSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
_deviceSocket.Connect(new IPEndPoint(address, port)); ;
_deviceAddress = address;
var stream = new NetworkStream(_deviceSocket);
var reader = new StreamReader(stream);
var writer = new StreamWriter(stream) { NewLine = "\r", AutoFlush = true };
_deviceWriter = writer;
writer.WriteLine("getdevices");
var readerThread = new Thread(ReaderThreadProc) { IsBackground = true };
readerThread.Start(reader);
_isConnected = true;
return Instance;
}
catch { DisconnectFromDevice(); MessageBox.Show("ConnectToDevice Error."); throw; }
}
public void SendMessage(string message)
{
try
{
var stream = new NetworkStream(_deviceSocket);
var reader = new StreamReader(stream);
var writer = new StreamWriter(stream) { NewLine = "\r", AutoFlush = true };
_deviceWriter = writer;
writer.WriteLine(message);
var readerThread = new Thread(ReaderThreadProc) { IsBackground = true };
readerThread.Start(reader);
}
catch { MessageBox.Show("SendMessage() Error."); }
}
public void DisconnectFromDevice()
{
if (_deviceSocket != null)
{
try { _deviceSocket.Close(); _isConnected = false; }
catch { MessageBox.Show("DisconnectFromDevice Error."); }
_deviceSocket = null;
}
_deviceWriter = null;
_deviceAddress = null;
}
**private void ReaderThreadProc(object state)**
{
var reader = (StreamReader)state;
try
{
while (true)
{
var line = reader.ReadLine();
if (line == null) break;
_line = _line + line + Environment.NewLine;
}
**// Feedback from each piece of equipment is visible here.
// Need to create EventHandler to notify the TextBoxes to update with _line**
}
catch { MessageBox.Show("ReaderThreadProc Error."); }
}
}
From my understanding of the question, you want to do something like this?
You need to know when a GlobalCacheAdapter updates and which one updated in order to update textboxes on a form. My question to you is this - do you actually need to know which updated?
If you declare in your class an event handler like this:
public class GlobalCacheAdaptor
{
public event EventHandler<EventArgs> Updated;
protected virtual void OnUpdated()
{
var handler = Updated;
if (handler != null)
{
handler(this, EventArgs.Empty);
}
}
private void Foo()
{
// When an update is received, raise Updated event
OnUpdated();
}
}
Then in your form subscribe to Updated for all three GlobalCacheHandler instances
public Form1()
{
elanGlobalCacheAdaptor.Updated += (s,e) =>
{
elanTextBox.Text = elanGlobalCacheAdaptor._line;
}
tuneSuiteGlobalCacheAdaptor.Updated += (s,e) =>
{
tuneSuiteTextBox.Text = tuneSuiteGlobalCacheAdaptor._line;
}
lutronGlobalCacheAdaptor.Updated += (s,e) =>
{
lutronTextBox.Text = lutronGlobalCacheAdaptor._line;
}
}
You should be able to update the correct text box when the appropriate cache handler raises the Updated event.
Finally you may need to handle cross-thread interactions. if so, see this article on MSDN, particularly the part "Thread-Safe Calls to a Windows Forms Control"