Question 1

Which of the following scenarios may not always cause a deadlock among two threads?
i.Thread one is in an infinite loop and has acquired a lock
II.Both threads are in an infinite loop, and one thread has acquired a lock
III.Both threads are in an infinite loop, and both threads have acquired locks

Accepted Answer

A)  Only I
B)  Only II
C)  Only III
D)  I, II, or IIIE) A) and D)
F) A) and B)

Question 2

Consider the following change to the deposit method in Section 22.4:  What is the consequence of this change?

Accepted Answer

A)  The bank account balances may no longer be correctly updated.
B)  The printouts may become intermingled.
C)  The printouts may no longer display the correct balances.
D)  All of the above.E) A) and B)
F) B) and C) C

Question 3

lock objects ensure that shared data are in a consistent state when several threads access them.What is a deadlock?

Accepted Answer

A)  When multiple threads try to use the same shared data at the same time, and the threads become undone
B)  When multiple threads copy the same shared data in order to proceed, consequently leaving the original lock object useless
C)  When multiple threads intertwine multiple times and the lock object is lost, or unreachable
D)  When multiple threads are not proceeding because they are currently waiting to acquire the same lockE) A) and B)
F) B) and C)

Question 4

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

Accepted Answer

A)  Only I
B)  Only II
C)  I and III
D)  II and IIIE) C) and D)
F) B) and D)

Question 5

Examine the SharedData class shown below.Suppose two threads are created so that each has access to the same SharedData object.Thread one calls setSharedData eight times with values 1...8 respectively, sleeping for 30 milliseconds between calls.Thread two calls getSharedData eight times, also sleeping for 30 milliseconds between calls.Which of the following orders of values is not possible for thread two to receive?

Accepted Answer

A)  1,2,3,4,5,6,7,8
B)  1,2,2,4,5,6,7,8
C)  1,2,3,4,5,6,8,8
D)  1,2,3,4,5,6,8,7E) A) and B)
F) B) and C)

Question 6

Assume two threads share a BankAccount object with balance of zero (0) , and that the BankAccount class provides deposit and withdraw methods as shown below.Thread one deposits $10 ten times and, concurrently, thread two withdraws $10 ten times.If the balance after all thread calls is 0, which statement is definitely true?

Accepted Answer

A)  The calls were interleaved: thread one, thread two, thread one, thread two, …
B)  The first call was to the deposit method.
C)  The last call was to the withdraw method.
D)  Each individual call to the deposit and withdraw methods ran to completion.E) A) and C)
F) B) and D)

Question 7

Why does the textbook recommend signallAll over the signal method?

Accepted Answer

A)  The signalAll method is always more efficient
B)  signal can lead to deadlocks when not every waiting thread is able to proceed
C)  signalAll notifies the waiting threads that sufficient funds is absolutely available, while signal only notifies one at a time
D)  None of the aboveE) C) and D)
F) B) and C)

Question 8

The ____ method is useful only if you know that a waiting thread can actually proceed.

Accepted Answer

A)  run
B)  signal
C)  await
D)  interruptedE) None of the above
F) B) and D) B

Question 9

Class MyClass has a single ReentrantLock object, myLock.Suppose thread one calls myLock.lock()  as it enters methodX and immediately completes its CPU time slice.What will happen as thread two calls methodY and attempts to call myLock.lock() ?

Accepted Answer

A)  Thread two will wait for the lock.
B)  Thread two will acquire the lock.
C)  Deadlock will occur.
D)  Thread two causes the IllegalStateMonitorException.E) A) and D)
F) B) and D)

Question 10

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

Accepted Answer

A)  public Thread(Runnable r) 
B)  public Thread() 
C)  public Runnable(Thread t) 
D)  public Thread(String s) E) B) and D)
F) None of the above

Question 11

Assume two threads share a BankAccount object with balance of zero (0) , and that the BankAccount class provides deposit and withdraw methods as shown below.Thread one deposits $10 ten times and, concurrently, thread two withdraws $10 ten times.Suppose a race condition occurs, and the race is finished first by thread one.What would you expect balance to be after all thread calls?

Accepted Answer

A)  $10
B)  $20
C)  $0
D)  a negative amountE) A) and B)
F) B) and C)

Question 12

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

Accepted Answer

A)  start
B)  wait
C)  await
D)  sleepE) All of the above
F) A) and B)

Question 13

If you do not use the Runnable interface, 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

Accepted Answer

A)  Only I
B)  Only II
C)  Only III
D)  I and IIIE) B) and C)
F) C) and D)

Question 14

Assume three threads share a BankAccount object with a balance initially zero (0) , a ReentrantLock named myLock, and a condition object on myLock named insufficientFunds, as shown below.Thread one calls withdraw(30) , then thread two calls withdraw(20)  and thread three calls deposit(45) .What is the balance after the three calls and after the waiting threads have had a chance to run?

Accepted Answer

A)  0
B)  15 or 25
C)  45
D)  -5E) C) and D)
F) B) and D) B

Question 15

Which are ways that a thread can be blocked?
i.when it is sleeping
II.waiting for a lock to be available
III.waiting after calling the await method

Accepted Answer

A)  Only I
B)  I and II
C)  I and III
D)  I, II, and IIIE) A) and B)
F) None of the above

Question 16

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

Accepted Answer

A)  run
B)  await
C)  sleep
D)  delayE) B) and D)
F) A) and B)

Question 17

Which phrase best describes the purpose of a lock used in an object in one or more of its methods?

Accepted Answer

A)  increased sharing
B)  mutual exclusion
C)  speed increase
D)  privacy protectionE) A) and D)
F) A) and C)

Question 18

What is the difference between calling the sleep method versus the await method?

Accepted Answer

A)  sleep makes the current thread wait and allows another thread to acquire the lock object while the await pauses the current thread for a set time
B)  await makes the current thread wait and allows another thread to acquire the lock object while the sleep pauses the current thread for a set time
C)  sleep handles the current thread while the await handles the next thread
D)  sleep and await are the sameE) A) and C)
F) B) and D)

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() ;

Accepted Answer

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.E) A) and C)
F) None of the above

Question 20

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

Accepted Answer

A)  IOException
B)  IllegalStateMonitorException
C)  InterruptedException
D)  SleepExceptionE) B) and C)
F) B) and D)

Exam 22: Multithreading

Which of the following scenarios may not always cause a deadlock among two threads? i.Thread one is in an infinite loop and has acquired a lock II.Both threads are in an infinite loop, and one thread has acquired a lock III.Both threads are in an infinite loop, and both threads have acquired locks

Correct Answer
verified

Consider the following change to the deposit method in Section 22.4: What is the consequence of this change?

Correct Answer
verified
C

lock objects ensure that shared data are in a consistent state when several threads access them.What is a deadlock?

Correct Answer
verified

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

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Why does the textbook recommend signallAll over the signal method?

Correct Answer
verified

The ____ method is useful only if you know that a waiting thread can actually proceed.

Correct Answer
verified
B

Class MyClass has a single ReentrantLock object, myLock.Suppose thread one calls myLock.lock() as it enters methodX and immediately completes its CPU time slice.What will happen as thread two calls methodY and attempts to call myLock.lock() ?

Correct Answer
verified

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

Correct Answer
verified

Correct Answer
verified

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

Correct Answer
verified

If you do not use the Runnable interface, 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

Correct Answer
verified

Correct Answer
verified
B

Which are ways that a thread can be blocked? i.when it is sleeping II.waiting for a lock to be available III.waiting after calling the await method

Correct Answer
verified

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

Correct Answer
verified

Which phrase best describes the purpose of a lock used in an object in one or more of its methods?

Correct Answer
verified

What is the difference between calling the sleep method versus the await method?

Correct Answer
verified

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() ;

Correct Answer
verified

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

Correct Answer
verified

Exam 22: Multithreading

Which of the following scenarios may not always cause a deadlock among two threads? i.Thread one is in an infinite loop and has acquired a lock II.Both threads are in an infinite loop, and one thread has acquired a lock III.Both threads are in an infinite loop, and both threads have acquired locks

Correct AnswerverifiedShow Answer

Consider the following change to the deposit method in Section 22.4: What is the consequence of this change?

Correct AnswerverifiedC

lock objects ensure that shared data are in a consistent state when several threads access them.What is a deadlock?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Why does the textbook recommend signallAll over the signal method?

Correct AnswerverifiedShow Answer

The ____ method is useful only if you know that a waiting thread can actually proceed.

Correct AnswerverifiedB

Class MyClass has a single ReentrantLock object, myLock.Suppose thread one calls myLock.lock() as it enters methodX and immediately completes its CPU time slice.What will happen as thread two calls methodY and attempts to call myLock.lock() ?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

If you do not use the Runnable interface, 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

Correct AnswerverifiedShow Answer

Correct AnswerverifiedB

Which are ways that a thread can be blocked? i.when it is sleeping II.waiting for a lock to be available III.waiting after calling the await method

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Which phrase best describes the purpose of a lock used in an object in one or more of its methods?

Correct AnswerverifiedShow Answer

What is the difference between calling the sleep method versus the await method?

Correct AnswerverifiedShow Answer

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() ;

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified
C

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
B

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
B

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified