Question 1

Which method(s) are part of the Thread class?
I public void run(Runnable runnable)
II public void start(Runnable runnable)
III public void start()
A) I
B) II
C) III
D) II and III

Accepted Answer

The `start()` method is part of the Thread class and is used to begin the execution of a thread. The other methods listed do not exist in the Thread class.

Question 2

When a sleeping thread is interrupted, an InterruptedException is generated. Where do you catch that exception?
A) in the start() method.
B) in the sleep() method.
C) in the run() method.
D) in the interrupt() method.

Accepted Answer

The InterruptedException is generated due to the sleeping thread being interrupted while it is running the code in the run() method, so this is where the exception should be caught.

Question 3

Which constructor can be used to create a new thread associated with a Runnable object?
A) public Thread(Runnable r)
B) public Thread()
C) public Runnable(Thread t)
D) public Thread(String s)

Accepted Answer

The constructor public Thread(Runnable r) can be used to create a new thread associated with a Runnable object. This constructor takes a Runnable object as a parameter, and the thread that is created will execute the run() method of the Runnable object when started.

Question 4

Which of the following does not create an object that can run in a thread, assuming the following MyRunnable class declaration? public class MyRunnable implements Runnable { . . . }
I Runnable runnable = new Runnable();
II Runnable runnable = new MyRunnable();
III MyRunnable runnable = new MyRunnable();
A) I
B) III
C) I and II
D) II and III

Accepted Answer

The statement "Runnable runnable = new Runnable();" is incorrect because Runnable is an interface and cannot be instantiated directly.

Question 5

Which of the following class declarations could run in a thread?
I public interface MyRunnable extends Runnable { . . . }
II public class MyRunnable extends Runnable { . . . }
III public class MyRunnable implements Runnable { . . . }
A) II
B) III
C) I and II
D) II and III

Accepted Answer

A class can run in a thread if it implements the Runnable interface. Option III correctly implements Runnable, while option II incorrectly attempts to extend an interface, which is not allowed in Java.

Question 6

The ________ method stops the current thread for a given number of milliseconds.
A) run
B) await
C) sleep
D) delay

Accepted Answer

The sleep method is used in Java to make the current thread stop executing for a specified amount of time measured in milliseconds. The other options, run, await, and delay do not have this functionality for stopping a thread.

Question 7

The Runnable interface includes which method(s)?
I public void run(Runnable runnable)
II public void run()
III public void start()
A) I
B) II
C) I and II
D) II and III

Accepted Answer

The Runnable interface includes the public void run() method, which is used to define the code that will be executed when the thread is started.

Question 8

Suppose run1 and run2 are objects of the class MyRunnable, which implements the Runnable interface. What is the result of the following calls? run1.run();
Run2.run();
A) run1 and run2 execute as independent threads.
B) Syntax error
C) Only run1 executes as an independent thread.
D) run1 and run2 run sequentially, not as independent threads.

Accepted Answer

The run() method is called directly, so it executes in the current thread sequentially, not as independent threads. To run them as independent threads, you would need to create Thread objects and call start() on them.

Question 9

When a thread is interrupted, the most common response is to terminate the ____________ method.
A) run
B) thread
C) sleep
D) await

Accepted Answer

When a thread is interrupted, the interrupt status flag of the thread is set to true. The thread checks this flag periodically while executing its code. If the flag is detected to be true, the run() method of the thread terminates the thread's execution. The sleep() and await() methods can also throw an InterruptedException when the thread is interrupted, but it is up to the developer to decide how to handle this exception in their code. The thread() method is not relevant to interrupting a thread.

Question 10

When a sleeping thread is interrupted, a(n) ____________________ is generated.
A) ThreadInterruptedException
B) ThreadException
C) ThreadSleepException
D) InterruptedException

Accepted Answer

When a sleeping thread is interrupted, an InterruptedException is generated. This allows the thread to wake up and handle the interruption in an appropriate way. The other options (ThreadInterruptedException, ThreadException, and ThreadSleepException) are not valid exception types in Java.

Question 11

If you do not use the Runnable interface, then what is necessary to create a new thread?
I Implement the Threadable interface
II Extend the Thread class and add a run() method to it
III Add a run method to any class
A) I
B) II
C) III
D) II and III

Accepted Answer

To create a new thread without using the Runnable interface, you can extend the Thread class and override its run() method.

Question 12

To start a thread, you should first construct an object from a class that implements the ____________ interface.
A) Thread
B) Threadable
C) Run
D) Runnable

Accepted Answer

To start a thread, you need to implement the Runnable interface and create an object of a class that implements it. The Runnable interface has only one method called run() which needs to be implemented. The Thread class then provides the method to start the execution of the thread.

Question 13

For threads of equal priority, which is guaranteed by the thread scheduler that is part of the Java Virtual Machine?
I All will get time on the CPU
II All will get exactly equal time on the CPU
III The order threads run in the CPU will always be the same
A) I
B) II
C) I and III
D) II and III

Accepted Answer

The Java thread scheduler guarantees that all threads of equal priority will get time on the CPU, but it does not guarantee equal time or a consistent order.

Question 14

Given a two-CPU machine and four threads, how many of the threads can execute in parallel?
A) Only 1 can execute at a time.
B) 2 can execute in parallel.
C) 3 can execute in parallel.
D) All 4 can execute in parallel.

Accepted Answer

A two-CPU machine can execute two threads in parallel, therefore two threads can run on each CPU, resulting in a total of four threads being able to execute simultaneously.

Question 15

Which exception must be caught or declared when calling the sleep method?
A) IOException
B) IllegalStateMonitorException
C) InterruptedException
D) SleepException

Accepted Answer

The sleep method is declared to throw an InterruptedException, so it must be caught or declared. A, B, and D are all incorrect exceptions for the sleep method.

Question 16

The Runnable interface has a single method called ____________.
A) run
B) start
C) sleep
D) wait

Accepted Answer

The Runnable interface in Java has a single method called `run()`, which is intended to contain the code executed by a thread.

Question 17

In which method are the tasks that are performed by a thread coded?
A) start
B) main
C) run
D) init

Accepted Answer

The tasks that are performed by a thread are coded in the `run` method. The `start` method is used to start a new thread and the `main` method is the entry point of an application in Java. The `init` method is used in applets to initialize them.

Question 18

The _____________ interface is designed to encapsulate the concept of a sequence of statements that can run in parallel with other tasks, without equating it with the concept of a thread, a potentially expensive resource that is managed by the operating system.
A) Thread
B) Runnable
C) MyRunnable
D) Threadable

Accepted Answer

The description specifically states that the interface is "not equating it with the concept of a thread," so options A, C, and D, which all include variations of "Thread," are not the best choices. Therefore, the best choice is B, which is the actual name of the interface.

Question 19

Which method do you call to make a thread ineligible to run on the CPU for a set number of milliseconds?
A) start
B) wait
C) await
D) sleep

Accepted Answer

The method to make a thread ineligible to run on the CPU for a set number of milliseconds is to call the sleep() method. The wait() and await() methods are used for different purposes and the start() method is used to start a thread.

Question 20

Given a single CPU and four threads, how many of the threads can execute in parallel?
A) Only 1 can execute at a time.
B) 2 can execute in parallel.
C) 3 can execute in parallel.
D) All 4 can execute in parallel.

Accepted Answer

A single CPU core can execute only one thread at a time. Multiple threads can be managed through time-slicing, but they do not execute in parallel on a single core.

Quiz 21: Multithreading

Which method(s) are part of the Thread class? I public void run(Runnable runnable) II public void start(Runnable runnable) III public void start()

When a sleeping thread is interrupted, an InterruptedException is generated. Where do you catch that exception?

Which constructor can be used to create a new thread associated with a Runnable object?

Which of the following class declarations could run in a thread? I public interface MyRunnable extends Runnable { . . . } II public class MyRunnable extends Runnable { . . . } III public class MyRunnable implements Runnable { . . . }

The ________ method stops the current thread for a given number of milliseconds.

The Runnable interface includes which method(s) ? I public void run(Runnable runnable) II public void run() III public void start()

Suppose run1 and run2 are objects of the class MyRunnable, which implements the Runnable interface. What is the result of the following calls? run1.run() ; Run2.run() ;

When a thread is interrupted, the most common response is to terminate the ____________ method.

When a sleeping thread is interrupted, a(n) ____________________ is generated.

If you do not use the Runnable interface, then what is necessary to create a new thread? I Implement the Threadable interface II Extend the Thread class and add a run() method to it III Add a run method to any class

To start a thread, you should first construct an object from a class that implements the ____________ interface.

For threads of equal priority, which is guaranteed by the thread scheduler that is part of the Java Virtual Machine? I All will get time on the CPU II All will get exactly equal time on the CPU III The order threads run in the CPU will always be the same

Given a two-CPU machine and four threads, how many of the threads can execute in parallel?

Which exception must be caught or declared when calling the sleep method?

The Runnable interface has a single method called ____________.

In which method are the tasks that are performed by a thread coded?

The _____________ interface is designed to encapsulate the concept of a sequence of statements that can run in parallel with other tasks, without equating it with the concept of a thread, a potentially expensive resource that is managed by the operating system.

Which method do you call to make a thread ineligible to run on the CPU for a set number of milliseconds?

Given a single CPU and four threads, how many of the threads can execute in parallel?