Question 1

5.14 Describe how the compare and swap() instruction can be used to provide mutual exclusion that satisfies the bounded-waiting

Naddik [55]

Answer:

Explained below

Explanation:

Compare and Swap(C&S) is simply an atomic operation whereby the compare and swap operations are automatically executed.

Now compare and Swap basically needs 3 arguments namely:

- 2 old values which we will label X and Y

- 1 new value which is written in X that we will call Z

Thus, we now have; C & S = {X, Y, Z}

To explain this well, let X be a variable where X has a value of 7.

Now, if a programmer gives a program me that X be multiplied by 2,then what C&S operation will do is;

I) Y = X where Y is a new variable.

II) Result = C&S(X, Y, X*7)

Variable X is global and this means that mere than one process and more than 1 thread can see the variable X.

Now, if a process named P1 wants multiply the variable X by 7 using C&S operation, it will first make a local copy of variable X (which in this case is now the new variable Y). After that it will atomically compare X & Y and if they are equal, it will replace X with 10X.

However, if they are not equal, P1 will re-read value of X into Y and carry of C&S instruction again.

8 0

3 years ago

A custom window shade designer charges a base fee of $50 per shade. In addition, charges are added for certain styles, sizes, an

jeka94

Answer:

Check the explanation

Explanation:

* Filename: ShadeDesigner.java

* Programmer: Jamin A. Bishop

* Date: 3/31/2012

* version 1.00 2012/4/2

*/

import java. awt.*;

import java. awt. event.*;

import java. text. DecimalFormat;

import javax. swing.*;

import javax. swing. event. ListSelectionEvent;

import javax. swing. event. ListSelectionListener;

public class ShadeDesigner extends JFrame

{

private String[] styles = {"Regular Shades", "Folding Shades", "Roman Shades"};

private String[] size = {"25 Inches Wide", "27 Inches Wide",

"32 Inches Wide", "40 Inches Wide"};

private String[] colors = {"Natural", "Blue", "Teal",

"Red", "Green"};

private JLabel banner;// To display a banner

private JPanel bannerPanel;// To hold the banner

private JPanel stylesPanel;//

private JPanel sizePanel;//

private JPanel colorPanel;

private JPanel buttonPanel;//

private JList stylesList;

private JList sizeList;

private JList colorList;

private JTextField Styles;

private JTextField Size;

private JTextField Color;

private JButton calcButton;

private JButton ExitButton;

private double totalCharges = 50.00;

//Constants

private final int ROWS = 5;

private final double regularCost = 0.00;//base price for the blinds

private final double foldingCost = 10.00;//extra cost for folding blinds

private final double romanCost = 15.00;//extra cost for roman blinds

private final double twentyfiveInCost = 0.00; //extra cost for 25" blinds

private final double twentySevenInCost = 2.00;//extra cost for 27" blinds

private final double thirtyTwoInCost = 4.00;//extra cost for 32" blinds

private final double fourtyInCost = 6.00;//extra cost for 40" blinds

private final double naturalColorCost = 5.00;//extra cost for color

public ShadeDesigner()

{

//display a title

setTitle("Shade Designer");

// Specify what happens when the close button is clicked.

setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

// Create the banner on a panel and add it to the North region.

buildBannerPanel();

add(bannerPanel, BorderLayout. NORTH);

stylesPanel();

add(stylesPanel, BorderLayout. WEST);

sizePanel();

add(sizePanel, BorderLayout. CENTER);

colorPanel();

add(colorPanel, BorderLayout. EAST);

buttonPanel();

add(buttonPanel, BorderLayout. SOUTH);

pack();

setVisible(true);

}

//build the bannerpanel

private void buildBannerPanel()

{

bannerPanel = new JPanel();

bannerPanel.setLayout(new FlowLayout(FlowLayout.CENTER));

banner = new JLabel("Shade Designer");

banner.setFont(new Font("SanSerif", Font.BOLD, 24));

bannerPanel.add(banner);

}

//stylepanel

private void stylesPanel()

{

JLabel styleTitle = new JLabel("Select a Style.");

stylesPanel = new JPanel();

stylesPanel. setBorder(BorderFactory. createEmptyBorder(5,5,5,5));

stylesList = new JList (styles);

stylesList.setVisibleRowCount(ROWS);

JScrollPane stylesScrollPane = new JScrollPane(stylesList);

stylesList. setSelectionMode(ListSelectionModel.SINGLE_SELECTION);

stylesList. addListSelectionListener(new stylesListListener());

stylesPanel. setLayout(new BorderLayout());

stylesPanel. add(styleTitle, BorderLayout. NORTH);

stylesPanel. add(stylesScrollPane, BorderLayout. CENTER);

Styles = new JTextField (5);

Styles. setEditable(false);

//stylesPanel. add(StylesLabel, BorderLayout. CENTER);

stylesPanel. add(Styles, BorderLayout. SOUTH);

}

private class stylesListListener implements ListSelectionListener

{

public void valueChanged (ListSelectionEvent e)

{

String selection = (String) stylesList. getSelectedValue();

Styles. setText(selection);

}

//size panel

private void sizePanel()

{

JLabel sizeTitle = new JLabel("Select a Size.");

sizePanel = new JPanel();

sizePanel. setBorder(BorderFactory. createEmptyBorder(5,5,5,5));

sizeList = new JList (size);

sizeList.setVisibleRowCount(ROWS);

JScrollPane stylesScrollPane = new JScrollPane(sizeList);

sizeList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);

sizeList.addListSelectionListener(new sizeListListener());

sizePanel. setLayout(new BorderLayout());

sizePanel. add(sizeTitle, BorderLayout. NORTH);

sizePanel. add(stylesScrollPane, BorderLayout. CENTER);

//sizeLabel = new JLabel("Style Selected: ");

Size = new JTextField (5);

Size.setEditable(false);

//stylesPanel. add(StylesLabel, BorderLayout. CENTER);

sizePanel. add(Size, BorderLayout. SOUTH);

}

private class sizeListListener implements ListSelectionListener

{

public void valueChanged (ListSelectionEvent e)

{

String selection = (String) sizeList. getSelectedValue();

Size. setText(selection);

}

6 0

3 years ago

Me brown uses a modern technological machine to till his lands and preform task that require high power. This machine has a GDP

tresset_1 [31]

Answer:

you can look it up if you want to just look up modern technological machine and u will get it.

8 0

3 years ago

Why is the ROUND function used in Excel? Group of answer choices to ensure that the values generated are always positive to ensu

777dan777 [17]

Answer:

The Microsoft Excel ROUND function returns a number rounded to a specified number of digits.

The ROUND function is a built-in function in Excel that is categorized as a Math/Trig Function. It can be used as a worksheet function (WS) in Excel. As a worksheet function, the ROUND function can be entered as part of a formula in a cell of a worksheet.

The syntax for the ROUND function in Microsoft Excel is:

ROUND( number, digits )

7 0

3 years ago

Read 2 more answers

What are three ways that functions can be useful when you are writing programs

grin007 [14]

Answer:

Reduces the overall complexity of your program

Allows you to easily call a function from different parts of your program after defining it.

Helps break a problem into logical chunks

Explanation:

5 0

2 years ago