如何开始优化我的Java代码？ – CPU为100％

我写了一个应用程序，但由于某种原因，它保持在100％的峰值。 我在一些类上运行了一个配置文件r，并且报告显示isReset（）和isRunning（）似乎被调用了很多次。 你看错了吗请告诉我。 谢谢

Class 1是唯一使用isReset（）代码的类，所以我希望这有助于你们检测错误

1级

package SKA; /* * ver 0.32 June 2009 * * Bug Fix Release: * * Fixed Array resize * Fixed Red Black Tree delete method * Fixed Red Black Tree save/read option * Update help file * */ /* * Additions: * ver 0.30 May 2009 * * Added Red Black Tree structure * Added Delete method for canvases * Added Array structure * Added ability to recolor nodes. * Added Bubble Sort Algorithm * Added Insertion Sort Algorithm * Added Shell Sort Algorithm * Added Selection Sort Algorithm * Added Quick Sort Algorithm * Added Red Black Tree Search Algorithm * Added Black Height Check Algorithm * Bug fix in canvas - could not delete canvas properly */ // Additions: /* ver 0.25 August 2004 * Added recursion in SkaExecutionPanel by adding SkaFunction * and using desktop internal panes. * * Added binary tree node annotation - text and drawn * Added subtree highlight feature to VizBinaryTreeNode using SkaRectangle * Improved node highlighting and selection scheme in VizBinaryTrees/VizDS * Added Binary tree save and read methods * Added visual subtree deletion (has bug) * * Added ability to set breaks from within algorithm * Added tooltip messages to SkaProgram/SkaFunction to show variable values * Added simple value input and output methods to SkaProgram/SkaFunction * Added SkaTriangle. * Added Font Adjustment and Color scheme options to show on overhead projectors * * Found bug in SkaGraph deleteVertex (with edges) */ /* ver 0.16 October 15, 2001 Added Graph save and read methods. Save is an instance method, while read is a class method. Added circular layout for graphs, Added fit/adjust graph layout to plate size method. Added label editing for Binary Trees and Graphs. SkaLabels (glyphs) now truncate the string displayed to the width specified in the constructor. */ /* ver 0.15 July 21, 2001 Fixed Reset function in Execution using exceptions so that Ska Algorithms can be run repeatedly without quitting the entire Ska System. This also allows trying the same program on different data structures. Problems with reset so far: 1. Reset message to user can appear much later. I think this is an I/O sequencing problem and it should go away if a message status GUI area is used. 2. Bound variable names remain afterwards, eg Graph bound to G will still show name as G after algorithm is interrupted. Fixed problem with multiple input requests in 0.14 - by adding another wait call which waits on before asking for input. Also introduced trial orderly layout of canvas and program windows , which fixes problem in 0.14 */ /* ver 0.14 July 18, 2001 Added subclasses of SkaProgram, so that multiple programs can run simultaneously. Problem - when multiple programs start, their windows overlay each other Problem - Send DS to algorithm can get confused, if an algorithm requests input while another is waiting on input or if two algorithms request input at the same time */ /* ver 0.13 Added BinaryTree - does not have node value display yet. Added arrows on edges of directed graphs */ /* ver 0.12 Added VizElementListener - separated from VizElement Element Input menu item only highlights when input for that DS is requested DS Input has been cleaned up */ /* ver 0.11 can ask user to select individual elements, eg vertices removed standard java cloning code which wasn't being used anyway */ import java.awt.BorderLayout; import java.awt.Dimension; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.KeyEvent; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; import java.io.IOException; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JMenu; import javax.swing.JMenuBar; import javax.swing.JMenuItem; import javax.swing.JOptionPane; import javax.swing.JScrollPane; import javax.swing.KeyStroke; import javax.swing.border.BevelBorder; import javax.swing.border.SoftBevelBorder; // TimerQueue public class SkaTest { public static final int WIDTH = 500; public static final int HEIGHT = 500; public static final int CANVAS_X = 100; public static final int CANVAS_Y = 100; public static final int CANVAS_FRAME_WIDTH = WIDTH+100; public static final int CANVAS_FRAME_HEIGHT = HEIGHT + 100; public static final int EXEC_WIDTH = 550; public static final int EXEC_HEIGHT = 400; static VizDSList dsList = new VizDSList(); static SkaCanvas canvas = new SkaCanvas(dsList); static JFrame canvasFrame = new JFrame("Data Structure Canvas"); static JMenuBar menuBar = new JMenuBar(); static JMenu algorithmMenu = new JMenu("Algorithm"); static JMenu dsMenu = new JMenu("Create"); static JMenu helpMenu = new JMenu ("Help"); static JLabel status = new JLabel(" "); static SkaProgram[] alg; static JFrame execFrame[]; static SkaExecutionPanel execPanel[]; public static void setupFrames(int nAlgs) { int i; for (i=0; i < nAlgs; i++) { // execFrame[i] = new JFrame("Execution Control Panel "+(i+1)); execFrame[i] = new JFrame(); execPanel[i] = new SkaExecutionPanel(execFrame[i]); } canvas.setMinimumSize(new Dimension(WIDTH, HEIGHT)); canvasFrame.setSize(CANVAS_FRAME_WIDTH, CANVAS_FRAME_WIDTH); canvasFrame.getContentPane().setLayout(new BorderLayout(10,7)); // canvasFrame.getContentPane().setPreferredSize(new Dimension(WIDTH, HEIGHT)); canvasFrame.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { System.exit(0); } }); // canvas.setMinimumSize(new Dimension(WIDTH, HEIGHT)); for (i=0; i < nAlgs; i++) { execFrame[i].setSize(EXEC_WIDTH, EXEC_HEIGHT); // execFrame[i].getContentPane().setLayout(new BorderLayout(10,7)); execFrame[i].addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { System.exit(0); } }); execPanel[i].setBorder(new SoftBevelBorder(BevelBorder.RAISED)); // execFrame[i].setContentPane(execPanel[i]); execFrame[i].getContentPane().add("Center", execPanel[i]); // execFrame[i].setLocation(CANVAS_X +CANVAS_FRAME_WIDTH, CANVAS_Y + i*EXEC_HEIGHT); execFrame[i].setLocation(CANVAS_X +CANVAS_FRAME_WIDTH + i*30, CANVAS_Y + i*50); } canvas.setBorder(new SoftBevelBorder(BevelBorder.RAISED)); canvasFrame.getContentPane().add("Center", new JScrollPane(canvas) ); // canvasFrame.getContentPane().add("Center", new JScrollPane(canvas, ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS, ScrollPaneConstants.HORIZONTAL_SCROLLBAR_ALWAYS) ); canvasFrame.getContentPane().add("South", status); canvasFrame.setLocation(CANVAS_X, CANVAS_Y); JMenu fileMenu = new JMenu("File"); JMenuItem quitItem = new JMenuItem("Quit"); //TODO Add quit listener quitItem.addActionListener(new ActionListener () { public void actionPerformed(ActionEvent arg0) { //System.exit(0); int again = JOptionPane.showConfirmDialog(null, "Are you sure you want to exit system", "Exiting", JOptionPane.YES_NO_OPTION); if (again == JOptionPane.YES_OPTION) { System.exit(0); } } } ); fileMenu.add(quitItem); menuBar.add(fileMenu); menuBar.add(algorithmMenu); // menuBar.add(dsMenu); menuBar.add(helpMenu); JMenuItem help = new JMenuItem ("Help Contents"); //help.setMnemonic(KeyEvent.VK_H); //TODO Fix this method help.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_F1, ActionEvent.CTRL_MASK)); help.addActionListener(new ActionListener() { /* @Override public void actionPerformed(ActionEvent arg0) { JOptionPane.showMessageDialog(null, "Alot of the functionality have not yet been included in this version\nCurrently working on the automation features now!", "SKA 0.2 Beta", JOptionPane.WARNING_MESSAGE); } */ public void actionPerformed(ActionEvent arg0) { try { Runtime.getRuntime().exec("hh.exe C:/ska.chm"); } catch (IOException e) { e.printStackTrace(); JOptionPane.showMessageDialog(null, "File not found", "Error", JOptionPane.ERROR_MESSAGE); } } }); JMenuItem about = new JMenuItem ("About SKA"); about.addActionListener(new ActionListener(){ public void actionPerformed(ActionEvent arg0) { JOptionPane.showMessageDialog(null, "SKA Version 0.1 Beta"); } }); helpMenu.add(help); helpMenu.add(about); canvasFrame.setJMenuBar(menuBar); } /** The create menu item */ public static void createProgram(int i) { JMenuItem algItem; switch (i) { case 0 : alg[0] = new RedBlackValidate(canvas, execPanel[0]); execFrame[0].setTitle("Validate Algorithm"); System.out.println("Validate Algorithm"); algItem = new JMenuItem("Validate Algorithm"); algorithmMenu.add(algItem); break; /* case 0 : alg[0] = new BreadthFirstSearch(canvas, execPanel[0]); execFrame[0].setTitle("BFS Graph Algorithm"); // System.out.println("BreadthFirstSearch"); algItem = new JMenuItem("BFS Graph Algorithm"); algorithmMenu.add(algItem); break; case 1: alg[1] = new LevelOrderAlgorithm(canvas, execPanel[1]); execFrame[1].setTitle("Level Order Tree Algorithm"); System.out.println("LevelOrderAlgorithm"); algItem = new JMenuItem("Level Order Tree Algorithm"); algorithmMenu.add(algItem); break; case 2: alg[2] = new BinarySearchTreeAlgRecursive(canvas, execPanel[2]); execFrame[2].setTitle("BinaryTreeSearchRec Algorithm"); System.out.println("BinaryTreeSearchRec Algorithm"); algItem = new JMenuItem("BinaryTreeSearchRec Algorithm"); algorithmMenu.add(algItem); break; case 3: alg[3] = new BinarySearchTreeAlgIterative(canvas, execPanel[3]); execFrame[3].setTitle("BinaryTreeSearchIter Algorithm"); System.out.println("BinaryTreeSearchIter Algorithm"); algItem = new JMenuItem("BinaryTreeSearchIter Algorithm"); algorithmMenu.add(algItem); break; case 4: alg[4] = new RebBlackTreeSearch (canvas, execPanel[4]); execFrame[4].setTitle("Red Black Search Algorithm"); System.out.println("Red Black Search Algorithm"); algItem = new JMenuItem("Red Black Search Algoithm Algorithm"); algorithmMenu.add(algItem); break; case 5: alg[5] = new ArrayInsertionSortAlg (canvas, execPanel[5]); execFrame[5].setTitle("Array Insertion Sort Algorithm"); System.out.println("Array Insertion Sort"); algItem = new JMenuItem("Array Insertion Sort Algorithm"); algorithmMenu.add(algItem); break; case 6: alg[6] = new ArraySelectionSortAlg (canvas, execPanel[6]); execFrame[6].setTitle("Array Selection Sort Algorithm"); System.out.println("Array SelectionSearch"); algItem = new JMenuItem("Array Selection Sort Algorithm"); algorithmMenu.add(algItem); break; */ default: break; } } public static void main(String args[]) { int i, nAlgs = 1; //nAlgs = 7; alg = new SkaProgram[nAlgs]; execPanel = new SkaExecutionPanel[nAlgs]; execFrame = new JFrame[nAlgs]; // canvas.setDebugGraphicsOptions(DebugGraphics.BUFFERED_OPTION); setupFrames(nAlgs); canvasFrame.setVisible(true); for (i=0; i < alg.length; i++) { createProgram(i); execFrame[i].setVisible(true); alg[i].start(); alg[i].displayAlgorithm(); } while (true) { for (i=0; i < alg.length; i++) if (execPanel[i].isReset()) { alg[i].terminate(); createProgram(i); alg[i].start(); execPanel[i].unreset(); } } } } // End class SkaTest 

2级

 package SKA; import java.awt.Font; import java.awt.event.ActionEvent; import java.awt.event.ItemEvent; import java.awt.event.ItemListener; import java.util.Stack; import javax.swing.AbstractAction; import javax.swing.Action; import javax.swing.JComboBox; import javax.swing.JDesktopPane; import javax.swing.JFrame; import javax.swing.JScrollPane; import javax.swing.JTextArea; import javax.swing.JToolBar; @SuppressWarnings("serial") public class SkaExecutionPanel extends JDesktopPane { public static final int EXEC_WIDTH = SkaTest.EXEC_WIDTH-100; public static final int EXEC_HEIGHT = SkaTest.EXEC_HEIGHT-50; boolean run = false, pause = true, step = false, reset = false; JToolBar toolbar = new JToolBar(); JTextArea textOutputArea = new JTextArea(); SkaProgram prog; Stack functionStack = new Stack(); SkaFunction currentFunction = null; int level = 0, in = 30; public void doCall(String[] subAlg, String subAlgName) { doCall(subAlg, subAlgName, false); // make non-icon default } public void doCall(String[] subAlg, String subAlgName, boolean iconify) { if (currentFunction != null) functionStack.push(currentFunction); currentFunction = new SkaFunction(this, subAlg, subAlgName, iconify); add(currentFunction, new Integer(1)); currentFunction.setBounds(level*in,level*in,EXEC_WIDTH, EXEC_HEIGHT); // currentFunction.setBounds(level*in,level*in,EXEC_WIDTH-(level+1)*in, EXEC_HEIGHT-(level+1)*in); currentFunction.setVisible(true); level++; } public void doReturn() { if (currentFunction == null) return; if (currentFunction.makeIconWhenDone()) { getDesktopManager().iconifyFrame(currentFunction); // currentFunction.setIcon(true); currentFunction.setIconifiable(true); } else currentFunction.setVisible(false); currentFunction = (SkaFunction) functionStack.pop(); level--; } public void displayAlgorithm(String[] a) { doCall(a, "main"); } public void displayAlgorithm(String[] a, String aname) { doCall(a, aname); } public void setControlsEnabled(boolean b) { toolbar.setEnabled(b); } class RunAction extends AbstractAction { RunAction() { super("run"); } public void actionPerformed(ActionEvent e) { run = true; pause = false; step = false; } } class StepAction extends AbstractAction { StepAction() { super("step"); } public void actionPerformed(ActionEvent e) { run = false; pause = false; step = true; } } class PauseAction extends AbstractAction { PauseAction() { super("pause"); } public void actionPerformed(ActionEvent e) { pause = true; // System.out.print("breaks"); // for (int i=0; i<breaks.length; i++) // System.out.print("[" +i+ "]=" + breaks[i].toString() + " "); // System.out.println(""); } } class ResetAction extends AbstractAction { ResetAction() { super("reset"); putValue(Action.SHORT_DESCRIPTION, "stop program and reset state to begining"); } public void actionPerformed(ActionEvent e) { run = false; pause = true; step = false; // should also restart SkaProgram reset = true; if (currentFunction != null) currentFunction.reset(); /* JInternalFrame[] frames = getAllFrames(); for (int i = 0; i < frames.length; i++) { // frames[i].dispose(); if (frames[i].isIcon()) frames[i].dispose(); } */ } } JComboBox speedControl; String speedNames[] = { "slow", "normal", "fast", "very fast" }; int speeds[] = {4000, 2000, 1000, 500} ; // milliseconds int speed = speeds[1]; private void initSpeedMenu() { speedControl = new JComboBox(speedNames); // speedControl.setMaximumRowCount(3); speedControl.addItemListener( new ItemListener() { public void itemStateChanged( ItemEvent e) { speed = speeds[speedControl.getSelectedIndex()]; } } ); speedControl.setSelectedIndex(1); speedControl.setMaximumSize(speedControl.getPreferredSize()); speedControl.setToolTipText("execution speed"); } SkaExecutionPanel(JFrame frame) { initSpeedMenu(); toolbar.add(new RunAction()); toolbar.add(new StepAction()); toolbar.add(new ResetAction()); toolbar.add(new PauseAction()); toolbar.addSeparator(); toolbar.add(speedControl); // frame.getContentPane().setLayout(new BorderLayout(10,7)); // makeTable(); frame.getContentPane().add("North", toolbar); Font f = new Font("SansSerif", Font.BOLD, 14); textOutputArea.setFont(f); frame.getContentPane().add("South", new JScrollPane(textOutputArea)); // frame.getContentPane().add(this, BorderLayout.CENTER) // frame.getContentPane().add("Center", toolbar, BorderLayout.NORTH); // setSize(300,250); // add toolbar, table, set layout, sizes } // public void setAlgorithm(SkaProgram p) { // prog = p; // sendAlgorithm(p.getPseudocode()); // } public int getSpeed() { return speed; } public boolean isRunning() { return run; } public boolean isPaused() { return pause; } public boolean isStepping() { return step; } public boolean isReset() { return reset; } public void pause() { pause = true; } public void unreset() { reset = false; } public void aboutToWait() { currentFunction.aboutToWait(); } public void doneWait() { currentFunction.doneWait(); } public void showToolTipValue(String s) { currentFunction.showToolTipValue(s); } public void showAlgLineBreak(int i) { currentFunction.showAlgLineBreak(i); } public void showAlgLine(int i) { currentFunction.showAlgLine(i); } public void displayText(String s) { textOutputArea.append(s); // +"\n" add newline? } } // End class SkaExecutionPanel 

Answer 1

问题似乎并没有出现在被大量使用的方法中，而是你打电话给他们的频率，这似乎是他们如此频繁出现的原因。 我会检查所有的电话，看看是否有任何多余的电话，然后转到第三个最耗时的方法。 在那之后，我会检查我的算法是否特别密集。 此外，检查所有方法调用并确保它们不会在没有需要的情况下运行。

我知道这不是解决问题本身，而是从给出的信息开始。

编辑：while循环是一个无限循环，导致for循环运行，其中已检查数组中的每个项目以查看它是否已重置。 您可以使用观察者模式替换它，当重置对象时，它会通知观察对象，然后执行该组步骤。 这样你就没有无限循环，你减少了.isReset（）的用法。 这是Class 1的主要方法。

编辑2：这是维基百科上观察者模式的实现示例。

Answer 2

“ 我如何开始优化我的Java代码？ ”

首先要对其进行分析 。

Answer 3

从读数中最常用的方法开始，然后转到越来越少的方法，直到找到一个带有循环结构的方法（for，while）。 检查循环结构以查看它是否做了太多工作，并查看调用此函数的函数是否经常调用它。

即（伪代码）

 dotProduct(vector a, vector b) { //create vector dot product here maths maths maths } calc(data) { for obj in data: dotproduct(obj, foo) } 

dotProduct将使用最多的CPU时间，但calc是开始的地方 – 我们可以缓存结果吗？ 我们要重新计算数据吗？ 我们是以愚蠢的方式迭代数据吗？

Answer 4

通过函数名称“isReset（）”和“isRunning（）”来判断，我猜你正在浪费CPU时间轮询条件/事件。 Java应该有一些信号量/信令系统，你可以使用它来让事件在事件发生时准确地通知等待者。

Answer 5

首先要做的事情。 你在代码中有一个警告，就像你使用了注释一样

  @SuppressWarnings（ “串行”） 

。 虽然这很好可能与您的CPU最大化无关。 先解决这个问题，你很可能会遇到问题。