$1$

Homework $3$

$1.(5$ pts$)$ What events do the following components generate in either Swing or FX:

$$ JButton or Button

$$ JTextField or TextField

$$ JComboBox or ComboBox

$2.(5$ pts$)$ What methods does JTable implement which are required by the interfaces implemented by

the JTable class beyond those interfaces implemented by the various parent classes of JTable?

$3.(5$ pts$)$ Address how the differences among these various layout managers, focusing on their behavior

as their container is resized:

a$.$ FlowPane in FX $($or FlowLayout in Swing$)$

b$.$ GridPane in FX $($or GridLayout in Swing$)$

c$.$ AncherPane

d$.$ TilePane

e$.$ Any other layout of your choice in FX or Swing.

$4.(10$ pts$)($Ex $1\mathrm{.}8\mathrm{.}2)$ The dining philosophers problem was invented by E$.$ W$.$ Dijkstra, a concurrency

pioneer, to clarify the notions of deadlock and starvation freedom. Imagine five philosophers who spend

their lives just thinking and feasting. They sit around a circular table with five chairs. The table has a big

plate of rice. However, there are only five chopsticks $($in the original formulation forks$)$ available, as

shown in Fig. $1\mathrm{.}5.$ Each philosopher thinks. When he gets hungry, he sits down and picks up the two

chopsticks that are closest to him. If a philosopher can pick up both chopsticks, he can eat for a while.

After a philosopher finishes eating, he puts down the chopsticks and again starts to think.

a$.$ What is wrong with everybody doing the following $-$ other than that the philosophers never get up

from the table?

$2$

$1.$ think for a while

$2.$ get left chopstick

$3.$ get right chopstick

$4.$ eat for a while

$5.$ return left chopstick

$6.$ return right chopstick

$7.$ return to $1$

b$.$ How can the above be fixed to avoid deadlocks?

c$.$ Is your solution starvation free? Literally!

$5.(10$ pts$)$ What methods must a class implementing the java.util.concurrent.locks.Lock interface

implement? Describe some of the expected characteristics of each of the methods of this interface?

$6.(5$ pts$)$ Explain what the JVM does when it encounters a synchronized directive. Hint: consider

carefully what is synchronized.

$7.(10$ pts$)$ What is the difference between Lock Interface and synchronized keyword?

Grading Rubric:

Attribute Meets Does not meet

Problem $15$ points

Lists the events associated with each

provided component.

$0$ points

Does not list the events associated with

each provided component.

Problem $25$ points

Lists the methods JTable implements.

Lists the methods which are required

by the interfaces implemented by the

JTable class beyond those interfaces

implemented by the various parent

classes of JTable.

$0$ points

Does not list the methods JTable

implements.

Does not list the methods which are

required by the interfaces implemented

by the JTable class beyond those

interfaces implemented by the various

parent classes of JTable.

Problem $35$ points

Addresses the differences among the

various layout managers.

Focuses on their behavior as their

container is resized.

$0$ points

Does not address the differences among

the various layout managers.

Does not focus on their behavior as their

container is resized.

Problem $410$ points

Explains what is wrong with

$0$ points

Does not explain what is wrong with

everybody doing the actions provided.

$3$

everybody doing the actions

provided.

Explains how the actions be fixed to

avoid deadlocks.

Explains if the solution provided is

starvation free.

Does not explain how the actions be fixed

to avoid deadlocks.

Does not explain if the solution provided is

starvation free.

Problem $510$ points

Explains what methods a class

implementing the

java.util.concurrent.locks.Lock

interface must implement.

Describes some of the expected

characteristics of each of the

methods of this interface.

$0$ points

Does not explain what methods a class

implementing the

java.util.concurrent.locks.Lock interface

must implement.

Does not describe some of the expected

characteristics of each of the methods of

this interface.

Problem $65$ points

Explains what the JVM does when it

encounters a synchronized directive.

$0$ points

Does not explain what the JVM does when

it encounters a synchronized directive.

Problem $710$ points

Explains difference between Lock

interface and synchronized keyword.

$0$ points

Does not explains difference between

Lock interface and synchronized keyword.