Question 1

The signal( ) operation in the example using JAVA condition variables ensures that the thread with the thread number turn

Accepted Answer

A)  that is blocked on await( ) is unblocked. 
B)  that may be blocked on await( ) is unblocked. 
C)  does not block on await( ) even if hasn't yet called this function. 
D)  blocks on await( ) if it hasn't yet called this function. 
A)  that is blocked on await( ) is unblocked. 
B)  that may be blocked on await( ) is unblocked. 
C)  does not block on await( ) even if hasn't yet called this function. 
D)  blocks on await( ) if it hasn't yet called this function.

Question 2

What is the difference between software transactional memory and hardware transactional memory?

Accepted Answer

Software transactional memory (STM) impl

Question 3

In JAVA, when a thread calls wait( ) inside a synchronized method,

Accepted Answer

A)  the thread releases the object lock and continues its execution. 
B)  the thread releases the object lock, blocks and is put in the entry set. 
C)  the thread releases the object lock, blocks and is put in the wait set. 
D)  the thread continues its execution without releasing the object lock. 
A)  the thread releases the object lock and continues its execution. 
B)  the thread releases the object lock, blocks and is put in the entry set. 
C)  the thread releases the object lock, blocks and is put in the wait set. 
D)  the thread continues its execution without releasing the object lock.

Question 4

A critical-section object in Windows

Accepted Answer

A)  is particularly efficient when there is lots of contention for the object. 
B)  completely avoids kernel intervention. 
C)  uses spinlocks on single processor systems. 
D)  None of the above. 
A)  is particularly efficient when there is lots of contention for the object. 
B)  completely avoids kernel intervention. 
C)  uses spinlocks on single processor systems. 
D)  None of the above.

Question 5

Emergence of multicore systems has put greater emphasis on developing novel techniques for concurrency problems, because

Accepted Answer

A)  some fundamentally new concurrency problems have arisen that cannot be solved using traditional techniques such as mutex locks, semaphores, and monitors. 
B)  race conditions are much more difficult to solve in multicore systems. 
C)  deadlocks are much more difficult to prevent or avoid in multicore systems. 
D)  with increased number of processing cores, there is an increased risk of race conditions and deadlocks. 
A)  some fundamentally new concurrency problems have arisen that cannot be solved using traditional techniques such as mutex locks, semaphores, and monitors. 
B)  race conditions are much more difficult to solve in multicore systems. 
C)  deadlocks are much more difficult to prevent or avoid in multicore systems. 
D)  with increased number of processing cores, there is an increased risk of race conditions and deadlocks.

Question 6

JAVA provides support for both named and unnamed condition variables.

Accepted Answer

A) True 
 B)False

Question 7

A difference between software transactional memory (STM) and hardware transactional memory (HTM) is that

Accepted Answer

A)  HTM uses cache hierarchy and cache coherency protocols while STM uses software implementation in addition to the cache hierarchy and cache coherency protocols. 
B)  STM requires no special code instrumentation and thus has less overhead than HTM. 
C)  In HTM, code is inserted by a compiler, while in STM, user enters the appropriate code. 
D)  HTM requires existing cache hierarchies and cache coherency protocols be modified, while STM does not. 
A)  HTM uses cache hierarchy and cache coherency protocols while STM uses software implementation in addition to the cache hierarchy and cache coherency protocols. 
B)  STM requires no special code instrumentation and thus has less overhead than HTM. 
C)  In HTM, code is inserted by a compiler, while in STM, user enters the appropriate code. 
D)  HTM requires existing cache hierarchies and cache coherency protocols be modified, while STM does not.

Question 8

Explain the key limitation of wait( ) and notify( ) operations of Java monitors that Java condition variables remedy.

Accepted Answer

Each Java monitor is associated with jus

Question 9

Describe a scenario when using a reader-writer lock is more appropriate than another synchronization tool such as a semaphore.

Accepted Answer

A tool such as a semaphore only allows o

Question 10

In the solution for bounded buffer problem using JAVA monitors (Figure 7.9), functions insert( ) and remove( ) are synchronized to ensure that

Accepted Answer

A)  a thread may insert an item and different thread may remove an item from a different location in the buffer simultaneously. 
B)  at most one thread may enter or remove an item at any time. 
C)  at most one thread may enter an item at any time, but multiple threads may remove items from different locations at the same time. 
D)  multiple thread may enter items at different locations at the same time, but at most one thread may remove an item at the same time. 
A)  a thread may insert an item and different thread may remove an item from a different location in the buffer simultaneously. 
B)  at most one thread may enter or remove an item at any time. 
C)  at most one thread may enter an item at any time, but multiple threads may remove items from different locations at the same time. 
D)  multiple thread may enter items at different locations at the same time, but at most one thread may remove an item at the same time.

Question 11

Explain how can a POSIX unnamed semaphore be shared between multiple processes.

Accepted Answer

The unnamed semaphore must be created us

Question 12

Transactional memory may particularly be useful for multicore systems.

Accepted Answer

A) True 
 B)False

Question 13

A reader-writer lock gives preference to writer processes in the readers-writers problem.

Accepted Answer

A) True 
 B)False

Question 14

Atomic integers in Linux are useful when

Accepted Answer

A)  several variables are involved in a race condition. 
B)  a single process access several variable involved in a race condition. 
C)  an integer variable needs to be updated. 
D)  All of the above. 
A)  several variables are involved in a race condition. 
B)  a single process access several variable involved in a race condition. 
C)  an integer variable needs to be updated. 
D)  All of the above.

Question 15

A call to pthread_cond_signal() (used by POSIX threads, called Pthread) releases the associated mutex lock.

Accepted Answer

A) True 
 B)False

Question 16

In the monitor solution for dining-philosophers problem (Figure 7.7), a philosopher may start eating

Accepted Answer

A)  at the end of the pickup( ) function before exiting the function. 
B)  in the beginning of the putdown( ) function 
C)  after exiting the pickup( ) function and before entering the putdown( ) function. 
D)  All of the above. 
A)  at the end of the pickup( ) function before exiting the function. 
B)  in the beginning of the putdown( ) function 
C)  after exiting the pickup( ) function and before entering the putdown( ) function. 
D)  All of the above.

Question 17

Each critical section must be assigned a different name in OpenMP.

Accepted Answer

A) True 
 B)False

The signal( ) operation in the example using JAVA condition variables ensures that the thread with the thread number turn

What is the difference between software transactional memory and hardware transactional memory?

In JAVA, when a thread calls wait( ) inside a synchronized method,

A critical-section object in Windows

Emergence of multicore systems has put greater emphasis on developing novel techniques for concurrency problems, because

JAVA provides support for both named and unnamed condition variables.

A difference between software transactional memory (STM) and hardware transactional memory (HTM) is that

Explain the key limitation of wait( ) and notify( ) operations of Java monitors that Java condition variables remedy.

Describe a scenario when using a reader-writer lock is more appropriate than another synchronization tool such as a semaphore.

In the solution for bounded buffer problem using JAVA monitors (Figure 7.9), functions insert( ) and remove( ) are synchronized to ensure that

Explain how can a POSIX unnamed semaphore be shared between multiple processes.

Transactional memory may particularly be useful for multicore systems.

A reader-writer lock gives preference to writer processes in the readers-writers problem.

Atomic integers in Linux are useful when

A call to pthread_cond_signal() (used by POSIX threads, called Pthread) releases the associated mutex lock.

In the monitor solution for dining-philosophers problem (Figure 7.7), a philosopher may start eating

Each critical section must be assigned a different name in OpenMP.

Introduction

Operating-System Structures

Processes

Threads Concurrency

Cpu Scheduling

Synchronization Tools

Deadlocks

Main Memory

Virtual Memory

Mass-Storage Structure

Io Systems

File-System Interface

File-System Implementation

File-System Internals

Security

Protection

Filters

Exam 7: Synchronization Examples

The signal( ) operation in the example using JAVA condition variables ensures that the thread with the thread number turn

What is the difference between software transactional memory and hardware transactional memory?

In JAVA, when a thread calls wait( ) inside a synchronized method,

A critical-section object in Windows

Emergence of multicore systems has put greater emphasis on developing novel techniques for concurrency problems, because

JAVA provides support for both named and unnamed condition variables.

A difference between software transactional memory (STM) and hardware transactional memory (HTM) is that

Explain the key limitation of wait( ) and notify( ) operations of Java monitors that Java condition variables remedy.

Describe a scenario when using a reader-writer lock is more appropriate than another synchronization tool such as a semaphore.

In the solution for bounded buffer problem using JAVA monitors (Figure 7.9), functions insert( ) and remove( ) are synchronized to ensure that

Explain how can a POSIX unnamed semaphore be shared between multiple processes.

Transactional memory may particularly be useful for multicore systems.

A reader-writer lock gives preference to writer processes in the readers-writers problem.

Atomic integers in Linux are useful when

A call to pthread_cond_signal() (used by POSIX threads, called Pthread) releases the associated mutex lock.

In the monitor solution for dining-philosophers problem (Figure 7.7), a philosopher may start eating

Each critical section must be assigned a different name in OpenMP.

Introduction

Operating-System Structures

Processes

Threads Concurrency

Cpu Scheduling

Synchronization Tools

Deadlocks

Main Memory

Virtual Memory

Mass-Storage Structure

Io Systems

File-System Interface

File-System Implementation

File-System Internals

Security

Protection

Filters