Mitigated Serial Monitor resource exhaustion

app/src/processing/app/Serial.java

@@ -25,9 +25,7 @@
 package processing.app;
 //import processing.core.*;
 
-import processing.app.debug.MessageConsumer;
 import static processing.app.I18n._;
-
 import gnu.io.*;
 
 import java.io.*;
@@ -55,15 +53,13 @@ public class Serial implements SerialPortEventListener {
 
   // read buffer and streams 
 
-  InputStream input;
+  InputStreamReader input;
   OutputStream output;
 
   byte buffer[] = new byte[32768];
   int bufferIndex;
   int bufferLast;
 
-  MessageConsumer consumer;
-
   public Serial(boolean monitor) throws SerialException {
     this(Preferences.get("serial.port"),
       Preferences.getInteger("serial.debug_rate"),
@@ -158,7 +154,7 @@ public Serial(String iname, int irate,
           if (portId.getName().equals(iname)) {
             //System.out.println("looking for "+iname);
             port = (SerialPort)portId.open("serial madness", 2000);
-            input = port.getInputStream();
+            input = new InputStreamReader(port.getInputStream());
             output = port.getOutputStream();
             port.setSerialPortParams(rate, databits, stopbits, parity);
             port.addEventListener(this);
@@ -237,62 +233,41 @@ public void dispose() {
     port = null;
   }
 
+  char serialBuffer[] = new char[4096];
 
-  public void addListener(MessageConsumer consumer) {
-    this.consumer = consumer;
-  }
-
-
   synchronized public void serialEvent(SerialPortEvent serialEvent) {
-    //System.out.println("serial port event"); // " + serialEvent);
-    //System.out.flush();
-    //System.out.println("into");
-    //System.out.flush();
-    //System.err.println("type " + serialEvent.getEventType());
-    //System.err.println("ahoooyey");
-    //System.err.println("ahoooyeysdfsdfsdf");
     if (serialEvent.getEventType() == SerialPortEvent.DATA_AVAILABLE) {
-      //System.out.println("data available");
-      //System.err.flush();
       try {
-        while (input.available() > 0) {
-        //if (input.available() > 0) {
-          //serial = input.read();
-          //serialEvent();
-          //buffer[bufferCount++] = (byte) serial;
+        while (input.ready()) {
           synchronized (buffer) {
             if (bufferLast == buffer.length) {
               byte temp[] = new byte[bufferLast << 1];
               System.arraycopy(buffer, 0, temp, 0, bufferLast);
               buffer = temp;
             }
-            //buffer[bufferLast++] = (byte) input.read();
-            if(monitor == true)
-              System.out.print((char) input.read());
-            if (this.consumer != null)
-              this.consumer.message("" + (char) input.read());
-
-            /*
-            System.err.println(input.available() + " " + 
-                               ((char) buffer[bufferLast-1]));
-            */            //}
+            int n = input.read(serialBuffer);
+            message(serialBuffer, n);
           }
         }
-        //System.out.println("no more");
-
       } catch (IOException e) {
         errorMessage("serialEvent", e);
-        //e.printStackTrace();
-        //System.out.println("angry");
       }
       catch (Exception e) {
       }
     }
-    //System.out.println("out of");
-    //System.err.println("out of event " + serialEvent.getEventType());
   }
 
 
+  /**
+   * This method is intended to be redefined by users of Serial class
+   * 
+   * @param buff
+   * @param n
+   */
+  protected void message(char buff[], int n) {
+    // Empty
+  }
+
   /**
    * Returns the number of bytes that have been read from serial
    * and are waiting to be dealt with by the user.

app/src/processing/app/SerialMonitor.java

@@ -18,28 +18,30 @@
 
 package processing.app;
 
-import processing.app.debug.MessageConsumer;
+import processing.app.debug.TextAreaFIFO;
 import processing.core.*;
 import static processing.app.I18n._;
 
 import java.awt.*;
 import java.awt.event.*;
+
 import javax.swing.*;
 import javax.swing.border.*;
-import javax.swing.event.*;
 import javax.swing.text.*;
 
-public class SerialMonitor extends JFrame implements MessageConsumer {
+public class SerialMonitor extends JFrame implements ActionListener {
   private Serial serial;
   private String port;
-  private JTextArea textArea;
+  private TextAreaFIFO textArea;
   private JScrollPane scrollPane;
   private JTextField textField;
   private JButton sendButton;
   private JCheckBox autoscrollBox;
   private JComboBox lineEndings;
   private JComboBox serialRates;
   private int serialRate;
+  private javax.swing.Timer updateTimer;
+  private StringBuffer updateBuffer;
 
   public SerialMonitor(String port) {
     super(port);
@@ -67,7 +69,9 @@ public void actionPerformed(ActionEvent e) {
     Font editorFont = Preferences.getFont("editor.font");
     Font font = new Font(consoleFont.getName(), consoleFont.getStyle(), editorFont.getSize());
 
-    textArea = new JTextArea(16, 40);
+    textArea = new TextAreaFIFO(8000000);
+    textArea.setRows(16);
+    textArea.setColumns(40);
     textArea.setEditable(false);    
     textArea.setFont(font);
 
@@ -171,6 +175,9 @@ public void actionPerformed(ActionEvent event) {
         }
       }
     }
+
+    updateBuffer = new StringBuffer(1048576);
+    updateTimer = new javax.swing.Timer(33, this);  // redraw serial monitor at 30 Hz
   }
 
   protected void setPlacement(int[] location) {
@@ -203,9 +210,13 @@ private void send(String s) {
 
   public void openSerialPort() throws SerialException {
     if (serial != null) return;
-
-    serial = new Serial(port, serialRate);
-    serial.addListener(this);
+    serial = new Serial(port, serialRate) {
+      @Override
+      protected void message(char buff[], int n) {
+        addToUpdateBuffer(buff, n);
+      }
+    };
+    updateTimer.start();
   }
 
   public void closeSerialPort() {
@@ -219,13 +230,27 @@ public void closeSerialPort() {
     }
   }
 
-  public void message(final String s) {
-    SwingUtilities.invokeLater(new Runnable() {
-      public void run() {
-        textArea.append(s);
-        if (autoscrollBox.isSelected()) {
-        	textArea.setCaretPosition(textArea.getDocument().getLength());
-        }
-      }});
+  private synchronized void addToUpdateBuffer(char buff[], int n) {
+    updateBuffer.append(buff, 0, n);
   }
+
+  private synchronized String consumeUpdateBuffer() {
+    String s = updateBuffer.toString();
+    updateBuffer.setLength(0);
+    return s;
+  }
+
+  public void actionPerformed(ActionEvent e) {
+    final String s = consumeUpdateBuffer();
+    if (s.length() > 0) {
+      //System.out.println("gui append " + s.length());
+      if (autoscrollBox.isSelected()) {
+        textArea.appendTrim(s);
+        textArea.setCaretPosition(textArea.getDocument().getLength());
+      } else {
+        textArea.appendNoTrim(s);
+      }
+    }
+  }
+
 }

app/src/processing/app/debug/TextAreaFIFO.java

@@ -0,0 +1,92 @@
+/*
+  Copyright (c) 2014 Paul Stoffregen <[email protected]>
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software Foundation,
+  Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+  $Id$
+*/
+
+// adapted from https://community.oracle.com/thread/1479784
+
+package processing.app.debug;
+
+import javax.swing.JTextArea;
+import javax.swing.SwingUtilities;
+import javax.swing.event.DocumentEvent;
+import javax.swing.event.DocumentListener;
+import javax.swing.text.BadLocationException;
+
+public class TextAreaFIFO extends JTextArea implements DocumentListener {
+  private int maxChars;
+  private int trimMaxChars;
+
+  private int updateCount; // limit how often we trim the document
+
+  private boolean doTrim;
+
+  public TextAreaFIFO(int max) {
+    maxChars = max;
+    trimMaxChars = max / 2;
+    updateCount = 0;
+    doTrim = true;
+    getDocument().addDocumentListener(this);
+  }
+
+  public void insertUpdate(DocumentEvent e) {
+    if (++updateCount > 150 && doTrim) {
+      updateCount = 0;
+      SwingUtilities.invokeLater(new Runnable() {
+        public void run() {
+          trimDocument();
+        }
+      });
+    }
+  }
+
+  public void removeUpdate(DocumentEvent e) {
+  }
+
+  public void changedUpdate(DocumentEvent e) {
+  }
+
+  public void trimDocument() {
+    int len = 0;
+    len = getDocument().getLength();
+    if (len > trimMaxChars) {
+      int n = len - trimMaxChars;
+      //System.out.println("trimDocument: remove " + n + " chars");
+      try {
+        getDocument().remove(0, n);
+      } catch (BadLocationException ble) {
+      }
+    }
+  }
+
+  public void appendNoTrim(String s) {
+    int free = maxChars - getDocument().getLength();
+    if (free <= 0)
+      return;
+    if (s.length() > free)
+      append(s.substring(0, free));
+    else
+      append(s);
+    doTrim = false;
+  }
+
+  public void appendTrim(String str) {
+    append(str);
+    doTrim = true;
+  }
+}

build/shared/revisions.txt

@@ -13,6 +13,9 @@ ARDUINO 1.0.7
 * Fixed missing NOT_AN_INTERRUPT constant in digitalPinToInterrupt() macro
 * Fixed performance regression in HardwareSerial::available() introduced with https://github.com/arduino/Arduino/pull/2057
 
+[ide]
+* Mitigated Serial Monitor resource exhaustion when the connected device sends a lot of data (Paul Stoffregen)
+
 ARDUINO 1.0.6 - 2014.09.16
 
 [core]