Exam 21: Multithreading

The thread that calls signalAll must own the lock that belongs to the condition object on which signalAll is called. Otherwise, a(n) _______ ________ is thrown.

What is the relationship between synchronized code and code that is locked using a ReentrantLock object?

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

Insert the statement that would start the following thread. Thread firstThread = new Thread(myRunnable); ____________________

Which of the following definitely indicates that a thread has terminated? I The run method has completed II The method Thread.interrupted returns true III The run method catches an InterruptedException

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();

Consider the following change to the deposit method in Section 21.4: public void deposit(double amount) { BalanceChangeLock.lock(); Try { Double newBalance = balance + amount; Balance = newBalance; } Finally { BalanceChangeLock.unlock(); } System.out.println("Depositing " + amount + ", new balance is " + balance); } What is the consequence of this change?

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

The ____________ occurs when a thread that is not running is interrupted.

The sleep method is terminated with a(n) __________ whenever a sleeping thread is interrupted.

Assume two threads share a BankAccount object with balance of zero (0), and that the BankAccount class provides synchronized deposit and withdraw methods. Thread one deposits $10 ten times and, concurrently, thread two withdraws $10 ten times. Which statement regarding the balance after all thread calls is definitely true? public synchronized void deposit(int dollars) { Int newBalance = balance + dollars; System.out.println("depositing"); Balance = newBalance; } Public synchronized void withdraw(int dollars) { Int newBalance = balance - dollars; System.out.println("withdrawing"); Balance = newBalance; }

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 { . . . }

Which of the following definitely indicates that a thread has been interrupted by another thread? I The run method has completed II The method Thread.interrupted returns true III The run method catches an InterruptedException

The ________ method is called by a thread that has just changed the state of some shared data in a way that may benefit waiting threads.

What happens when a thread calls the signalAll method of a Condition object connected to a lock, if no other thread had called await on that Condition object?

Which argument(s) present(s) the best case(s) for using the Runnable interface rather than extending the Thread class? I Thread sub-classes are harder to write II Runnable objects can be passed into thread pools III Less time is wasted in creating and destroying thread objects

____ allow a thread to temporarily release a lock, so that another thread can proceed, and to regain the lock at a later time.

Under what circumstances will a call to signalAll not release a blocked thread that has called await?