Java tutorial
/* * @(#)MemoryMonitor.java 1.3 05/11/17 * * Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * -Redistribution of source code must retain the above copyright notice, this * list of conditions and the following disclaimer. * * -Redistribution in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * Neither the name of Sun Microsystems, Inc. or the names of contributors may * be used to endorse or promote products derived from this software without * specific prior written permission. * * This software is provided "AS IS," without a warranty of any kind. ALL * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING * ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE * OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN") * AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE * AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST * REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, * INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY * OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, * EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. * * You acknowledge that this software is not designed, licensed or intended * for use in the design, construction, operation or maintenance of any * nuclear facility. */ /* * @(#)MemoryMonitor.java 1.3 05/11/17 */ import java.awt.BorderLayout; import java.awt.Color; import java.awt.Dimension; import java.awt.Font; import java.awt.FontMetrics; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.Rectangle; import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; import java.awt.event.WindowListener; import java.awt.geom.Line2D; import java.awt.geom.Rectangle2D; import java.awt.image.BufferedImage; import java.lang.management.ManagementFactory; import java.lang.management.MemoryPoolMXBean; import java.util.Date; import javax.swing.JCheckBox; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.JTextField; import javax.swing.border.EtchedBorder; import javax.swing.border.TitledBorder; /** * Demo code which plots the memory usage by all memory pools. The memory usage * is sampled at some time interval using java.lang.management API. This demo * code is modified based java2d MemoryMonitor demo. */ public class MemoryMonitor extends JPanel { static JCheckBox dateStampCB = new JCheckBox("Output Date Stamp"); public Surface surf; JPanel controls; boolean doControls; JTextField tf; // Get memory pools. static java.util.List<MemoryPoolMXBean> mpools = ManagementFactory.getMemoryPoolMXBeans(); // Total number of memory pools. static int numPools = mpools.size(); public MemoryMonitor() { setLayout(new BorderLayout()); setBorder(new TitledBorder(new EtchedBorder(), "Memory Monitor")); add(surf = new Surface()); controls = new JPanel(); controls.setPreferredSize(new Dimension(135, 80)); Font font = new Font("serif", Font.PLAIN, 10); JLabel label = new JLabel("Sample Rate"); label.setFont(font); label.setForeground(Color.red); controls.add(label); tf = new JTextField("1000"); tf.setPreferredSize(new Dimension(45, 20)); controls.add(tf); controls.add(label = new JLabel("ms")); label.setFont(font); label.setForeground(Color.red); controls.add(dateStampCB); dateStampCB.setFont(font); addMouseListener(new MouseAdapter() { public void mouseClicked(MouseEvent e) { removeAll(); if ((doControls = !doControls)) { surf.stop(); add(controls); } else { try { surf.sleepAmount = Long.parseLong(tf.getText().trim()); } catch (Exception ex) { } surf.start(); add(surf); } validate(); repaint(); } }); } public class Surface extends JPanel implements Runnable { public Thread thread; public long sleepAmount = 1000; public int usageHistCount = 20000; private int w, h; private BufferedImage bimg; private Graphics2D big; private Font font = new Font("Times New Roman", Font.PLAIN, 11); private int columnInc; private float usedMem[][]; private int ptNum[]; private int ascent, descent; private Rectangle graphOutlineRect = new Rectangle(); private Rectangle2D mfRect = new Rectangle2D.Float(); private Rectangle2D muRect = new Rectangle2D.Float(); private Line2D graphLine = new Line2D.Float(); private Color graphColor = new Color(46, 139, 87); private Color mfColor = new Color(0, 100, 0); private String usedStr; public Surface() { setBackground(Color.black); addMouseListener(new MouseAdapter() { public void mouseClicked(MouseEvent e) { if (thread == null) start(); else stop(); } }); int i = 0; usedMem = new float[numPools][]; ptNum = new int[numPools]; } public Dimension getMinimumSize() { return getPreferredSize(); } public Dimension getMaximumSize() { return getPreferredSize(); } public Dimension getPreferredSize() { return new Dimension(135, 80); } public void paint(Graphics g) { if (big == null) { return; } big.setBackground(getBackground()); big.clearRect(0, 0, w, h); h = h / ((numPools + numPools % 2) / 2); w = w / 2; int k = 0; // index of memory pool. for (int i = 0; i < 2; i++) { for (int j = 0; j < (numPools + numPools % 2) / 2; j++) { plotMemoryUsage(w * i, h * j, w, h, k); if (++k >= numPools) { i = 3; j = (numPools + numPools % 2) / 2; break; } } } g.drawImage(bimg, 0, 0, this); } public void plotMemoryUsage(int x1, int y1, int x2, int y2, int npool) { MemoryPoolMXBean mp = mpools.get(npool); float usedMemory = mp.getUsage().getUsed(); float totalMemory = mp.getUsage().getMax(); // .. Draw allocated and used strings .. big.setColor(Color.green); // Print Max memory allocated for this memory pool. big.drawString(String.valueOf((int) totalMemory / 1024) + "K Max ", x1 + 4.0f, (float) y1 + ascent + 0.5f); big.setColor(Color.yellow); // Print the memory pool name. big.drawString(mp.getName(), x1 + x2 / 2, (float) y1 + ascent + 0.5f); // Print the memory used by this memory pool. usedStr = String.valueOf((int) usedMemory / 1024) + "K used"; big.setColor(Color.green); big.drawString(usedStr, x1 + 4, y1 + y2 - descent); // Calculate remaining size float ssH = ascent + descent; float remainingHeight = (float) (y2 - (ssH * 2) - 0.5f); float blockHeight = remainingHeight / 10; float blockWidth = 20.0f; float remainingWidth = (float) (x2 - blockWidth - 10); // .. Memory Free .. big.setColor(mfColor); int MemUsage = (int) (((totalMemory - usedMemory) / totalMemory) * 10); int i = 0; for (; i < MemUsage; i++) { mfRect.setRect(x1 + 5, (float) y1 + ssH + i * blockHeight, blockWidth, (float) blockHeight - 1); big.fill(mfRect); } // .. Memory Used .. big.setColor(Color.green); for (; i < 10; i++) { muRect.setRect(x1 + 5, (float) y1 + ssH + i * blockHeight, blockWidth, (float) blockHeight - 1); big.fill(muRect); } // .. Draw History Graph .. if (remainingWidth <= 30) remainingWidth = (float) 30; if (remainingHeight <= ssH) remainingHeight = (float) ssH; big.setColor(graphColor); int graphX = x1 + 30; int graphY = y1 + (int) ssH; int graphW = (int) remainingWidth; int graphH = (int) remainingHeight; graphOutlineRect.setRect(graphX, graphY, graphW, graphH); big.draw(graphOutlineRect); int graphRow = graphH / 10; // .. Draw row .. for (int j = graphY; j <= graphH + graphY; j += graphRow) { graphLine.setLine(graphX, j, graphX + graphW, j); big.draw(graphLine); } // .. Draw animated column movement .. int graphColumn = graphW / 15; if (columnInc == 0) { columnInc = graphColumn; } for (int j = graphX + columnInc; j < graphW + graphX; j += graphColumn) { graphLine.setLine(j, graphY, j, graphY + graphH); big.draw(graphLine); } --columnInc; // Plot memory usage by this memory pool. if (usedMem[npool] == null) { usedMem[npool] = new float[usageHistCount]; ptNum[npool] = 0; } // save memory usage history. usedMem[npool][ptNum[npool]] = usedMemory; big.setColor(Color.yellow); int w1; // width of memory usage history. if (ptNum[npool] > graphW) { w1 = graphW; } else { w1 = ptNum[npool]; } for (int j = graphX + graphW - w1, k = ptNum[npool] - w1; k < ptNum[npool]; k++, j++) { if (k != 0) { if (usedMem[npool][k] != usedMem[npool][k - 1]) { int h1 = (int) (graphY + graphH * ((totalMemory - usedMem[npool][k - 1]) / totalMemory)); int h2 = (int) (graphY + graphH * ((totalMemory - usedMem[npool][k]) / totalMemory)); big.drawLine(j - 1, h1, j, h2); } else { int h1 = (int) (graphY + graphH * ((totalMemory - usedMem[npool][k]) / totalMemory)); big.fillRect(j, h1, 1, 1); } } } if (ptNum[npool] + 2 == usedMem[npool].length) { // throw out oldest point for (int j = 1; j < ptNum[npool]; j++) { usedMem[npool][j - 1] = usedMem[npool][j]; } --ptNum[npool]; } else { ptNum[npool]++; } } public void start() { thread = new Thread(this); thread.setPriority(Thread.MIN_PRIORITY); thread.setName("MemoryMonitor"); thread.start(); } public synchronized void stop() { thread = null; notify(); } public void run() { Thread me = Thread.currentThread(); while (thread == me && !isShowing() || getSize().width == 0) { try { thread.sleep(500); } catch (InterruptedException e) { return; } } while (thread == me && isShowing()) { Dimension d = getSize(); if (d.width != w || d.height != h) { w = d.width; h = d.height; bimg = (BufferedImage) createImage(w, h); big = bimg.createGraphics(); big.setFont(font); FontMetrics fm = big.getFontMetrics(font); ascent = (int) fm.getAscent(); descent = (int) fm.getDescent(); } repaint(); try { thread.sleep(sleepAmount); } catch (InterruptedException e) { break; } if (MemoryMonitor.dateStampCB.isSelected()) { System.out.println(new Date().toString() + " " + usedStr); } } thread = null; } } // Test thread to consume memory static class Memeater extends ClassLoader implements Runnable { Object y[]; public Memeater() { } public void run() { y = new Object[10000000]; int k = 0; while (true) { if (k == 5000000) k = 0; y[k++] = new Object(); try { Thread.sleep(20); } catch (Exception x) { } // to consume perm gen storage try { // the classes are small so we load 10 at a time for (int i = 0; i < 10; i++) { loadNext(); } } catch (ClassNotFoundException x) { // ignore exception } } } Class loadNext() throws ClassNotFoundException { // public class TestNNNNNN extends java.lang.Object{ // public TestNNNNNN(); // Code: // 0: aload_0 // 1: invokespecial #1; //Method java/lang/Object."<init>":()V // 4: return // } int begin[] = { 0xca, 0xfe, 0xba, 0xbe, 0x00, 0x00, 0x00, 0x30, 0x00, 0x0a, 0x0a, 0x00, 0x03, 0x00, 0x07, 0x07, 0x00, 0x08, 0x07, 0x00, 0x09, 0x01, 0x00, 0x06, 0x3c, 0x69, 0x6e, 0x69, 0x74, 0x3e, 0x01, 0x00, 0x03, 0x28, 0x29, 0x56, 0x01, 0x00, 0x04, 0x43, 0x6f, 0x64, 0x65, 0x0c, 0x00, 0x04, 0x00, 0x05, 0x01, 0x00, 0x0a, 0x54, 0x65, 0x73, 0x74 }; int end[] = { 0x01, 0x00, 0x10, 0x6a, 0x61, 0x76, 0x61, 0x2f, 0x6c, 0x61, 0x6e, 0x67, 0x2f, 0x4f, 0x62, 0x6a, 0x65, 0x63, 0x74, 0x00, 0x21, 0x00, 0x02, 0x00, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x01, 0x00, 0x04, 0x00, 0x05, 0x00, 0x01, 0x00, 0x06, 0x00, 0x00, 0x00, 0x11, 0x00, 0x01, 0x00, 0x01, 0x00, 0x00, 0x00, 0x05, 0x2a, 0xb7, 0x00, 0x01, 0xb1, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; // TestNNNNNN String name = "Test" + Integer.toString(count++); byte value[]; try { value = name.substring(4).getBytes("UTF-8"); } catch (java.io.UnsupportedEncodingException x) { throw new Error(); } // construct class file int len = begin.length + value.length + end.length; byte b[] = new byte[len]; int i, pos = 0; for (i = 0; i < begin.length; i++) { b[pos++] = (byte) begin[i]; } for (i = 0; i < value.length; i++) { b[pos++] = value[i]; } for (i = 0; i < end.length; i++) { b[pos++] = (byte) end[i]; } return defineClass(name, b, 0, b.length); } static int count = 100000; } public static void main(String s[]) { final MemoryMonitor demo = new MemoryMonitor(); WindowListener l = new WindowAdapter() { public void windowClosing(WindowEvent e) { System.exit(0); } public void windowDeiconified(WindowEvent e) { demo.surf.start(); } public void windowIconified(WindowEvent e) { demo.surf.stop(); } }; JFrame f = new JFrame("MemoryMonitor"); f.addWindowListener(l); f.getContentPane().add("Center", demo); f.pack(); f.setSize(new Dimension(400, 500)); f.setVisible(true); demo.surf.start(); Thread thr = new Thread(new Memeater()); thr.start(); } }