Question 1

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

Question 2

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 only one method - public void run(). The other two methods mentioned, public void run(Runnable runnable) and public void start(), are part of the Thread class and not the Runnable interface.

Question 3

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, a java.lang.InterruptedException is generated.

Question 4

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

The answer of Which of the following class declarations could...

Question 5

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

The Runnable interface is the best choice for constructing an object from a class to start a thread. This is because the Runnable interface defines a single method called run() that contains the code to be executed in the thread. When a class implements this interface and its run() method, an object of this class can be passed to the constructor of the Thread class to create a new thread.

Question 6

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

Accepted Answer

The Runnable interface has a single method called run which must be implemented to define the entry point for the thread.

Question 7

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) is used to create a new thread and associates it with the provided Runnable object. This constructor is commonly used for implementing the Runnable interface, which defines a single method run() that gets executed when the thread starts.

Question 8

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, it is necessary to extend the Thread class and add a run() method to it. Although it is possible to add a run() method to any class, it will not create a new thread unless it is extended from the Thread class. Therefore, option II is the correct choice. The Runnable interface is an alternative way to create a new thread, but it is not necessary.

Question 9

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

For threads of equal priority, the thread scheduler guarantees that all threads will get time on the CPU, but it does not guarantee that they will get exactly equal time on the CPU. Also, the order threads run in the CPU may not always be the same. Therefore, only option I is correct.

Question 10

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 answer of Which method(s) are part of the Thread...

Question 11

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

With a two-CPU machine, two threads can execute in parallel simultaneously on each CPU, allowing for a total of four threads to execute concurrently.

Question 12

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 most common response is to terminate the "run" method, as this is the method where the thread's main logic is executed. Depending on the implementation, the "sleep" and "await" methods may also throw an InterruptedException when interrupted, but they are not terminated as a result. The "thread" method is not relevant in this context as it is simply a factory method for creating a new thread.

Question 13

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

I does not create an object that can run in a thread. It creates a variable of type Runnable, but it is not initialized and cannot be used to run in a thread. II and III both create objects of MyRunnable class that can run in a thread.

Question 14

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 Runnable interface is designed specifically to represent a sequence of statements that can be executed in parallel with other tasks, without the system-level overhead associated with threads. The other options are either not relevant (MyRunnable) or relate specifically to threads (Thread and Threadable).

Question 15

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 stops the current thread for a given number of milliseconds. The other options mentioned (run, await, delay) do not have this functionality.

Question 16

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

Accepted Answer

InterruptedException must be caught or declared when calling the sleep method because it is a checked exception that can occur when a sleeping thread is interrupted by another 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. Therefore, choice C is the correct answer.

Question 18

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

InterruptedException is thrown in the run() method when a sleeping thread is interrupted. Therefore, it should be caught and handled in the run() method.

Question 19

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 code is simply calling the run() method on the objects run1 and run2. Since run() is not a separate thread, both run1 and run2 will execute sequentially in the current thread of execution, rather than as separate independent threads. To create new threads, we need to use the start() method instead of the run() method.

Question 20

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 sleep method is used to make a thread ineligible to run on the CPU for a set number of milliseconds. The start method is used to start a new thread, the wait method is used to suspend the current thread until another thread notifies it, and the await method is used in conjunction with the Java Concurrency API to wait for the completion of a set of operations. Therefore, the best choice is D.

Quiz 20: Multithreading

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

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

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

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 { . . . }

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

The Runnable interface has a single method called ____________.

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

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

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

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()

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

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

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.

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

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

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

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

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() ;

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