How do I start optimising my Java code? - CPU is at 100%(如何开始优化我的 Java 代码?- CPU 为 100%)
本文介绍了如何开始优化我的 Java 代码?- CPU 为 100%的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我编写了一个应用程序，但由于某种原因，它一直处于 100% 的峰值.我在一些类上运行了配置文件 r，并且报告显示 isReset() 和 isRunning() 似乎被调用了很多次.你看有什么不对的，请告诉我.谢谢
i have written an application, but for some reason it keeps peaking at 100%. I ran a profile r on a few of the classes and a report show that isReset() and isRunning() seems to be called alot of times. Do you see anything wrong please inform me. thanks
Class 1 是唯一使用 isReset() 代码的类，所以我希望这可以帮助你们检测错误
Class 1 is the only class that uses the isReset() code so i hope this helps u guys in detecting the error
1 类
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,
e.g. 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, e.g. 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
Currently 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 类
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<SkaFunction> functionStack = new Stack<SkaFunction>();
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); // +"
" add newline?
}
} // End class SkaExecutionPanel
推荐答案
问题似乎不在于经常使用的方法，而是您调用它们的频率，这似乎是它们出现的原因如此频繁.我会检查所有的调用，看看是否有多余的，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不需要的情况下运行.
The problem doesn't seem to be in the methods which are being used a lot, it's how frequently you call them which appears to be why they are showing up so frequently. I'd check for all of the calls, see if any are superfluous then go to the third most time consuming method. After that, I would check my algorithms for being particularly intensive. Also, check all method calls and make sure they're not being run without need.
我知道这并不能解决问题本身，而是从给出的信息开始.
I know this isn't solving the problem itself, but its a start with the information given.
while 循环是一个无限循环，导致 for 循环运行，其中检查数组中的每个项目以查看其是否已重置.您可以将其替换为观察者模式，其中当对象被重置时，它会通知观察对象，然后观察对象执行该组步骤.这样您就没有无限循环，并且减少了 .isReset() 的使用.这是在 Class 1 的 main 方法中.
The while loop is an infinite loop causing a for loop to run in which every item in an array has been checked to see if its been reset. You can replace this with an observer pattern where when an object is reset, it notifies the observing object which then performs that set of steps. This way you don't have an infinite loop and you cut down on the usage of .isReset(). This is in the main method of Class 1.
编辑 2:这是 实施观察者 模式的示例，该模式在维基百科上.
Edit 2: Here's the example of an implementation of the observer pattern which is on wikipedia.
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