Question 1

Dining philosophers problem is important because it represents a class of problems where multiple processes need to share multiple resources.

Accepted Answer

A) True 
 B)False  True

Question 2

A reader-writer lock is useful when

Accepted Answer

A)  there are a significantly large number of processes attempting to enter a critical section. 
B)  there are a significantly large number of consumer processes attempting to read data from a bounded buffer. 
C)  there are a significantly small number of reader processes attempting to read in the critical section. 
D)  there are a significantly large number of reader processes attempting to read in the critical section. 
A)  there are a significantly large number of processes attempting to enter a critical section. 
B)  there are a significantly large number of consumer processes attempting to read data from a bounded buffer. 
C)  there are a significantly small number of reader processes attempting to read in the critical section. 
D)  there are a significantly large number of reader processes attempting to read in the critical section. D

Question 3

Explain the relationship between the state of a dispatcher object and the state of a thread in Windows.

Accepted Answer

When a thread blocks on a dispatcher object in a nonsignaled state its state changes from ready to waiting. When the state for a dispatcher object moves to signaled, the kernel checks whether any
threads are waiting on the object. If so, the kernel moves one thread-or possibly more-from the waiting state to the ready state, where they can resume executing.

Question 4

Which of the following statements is not true about spinlocks in Linux?

Accepted Answer

A)  Spinlocks cannot be used on single processor machines. 
B)  A thread may disable kernel preemption on Symmetric Multi Processing machines instead of acquiring spinlocks. 
C)  A thread that acquires a spinlock cannot acquire the same lock a second time without first releasing the lock. 
D)  The Linux kernel is designed so that the spinlock is held only for only short durations. 
A)  Spinlocks cannot be used on single processor machines. 
B)  A thread may disable kernel preemption on Symmetric Multi Processing machines instead of acquiring spinlocks. 
C)  A thread that acquires a spinlock cannot acquire the same lock a second time without first releasing the lock. 
D)  The Linux kernel is designed so that the spinlock is held only for only short durations.

Question 5

A solution to the readers-writers problem that avoids starvation and allows some concurrency among readers is not possible.

Accepted Answer

A) True 
 B)False

Question 6

A notify( ) operation in Java monitors

Accepted Answer

A)  removes a process from the wait set and puts it in the entry set. 
B)  removes a process from the entry set and puts it in the wait set. 
C)  removes a process from the entry set and provides the lock for the object to that process. 
D)  removes a process from the wait set and provides the lock for the object to that process. 
A)  removes a process from the wait set and puts it in the entry set. 
B)  removes a process from the entry set and puts it in the wait set. 
C)  removes a process from the entry set and provides the lock for the object to that process. 
D)  removes a process from the wait set and provides the lock for the object to that process.

Question 7

Describe the mechanisms used for synchronization in Windows kernel in single and multiprocessor systems. Explain why Windows uses different mechanisms for the two systems.

Accepted Answer

On single processor systems, Windows tem

Question 8

In JAVA monitors, when a thread is placed in the entry set, is that thread guaranteed to own the object lock some time in future.

Accepted Answer

The JAVA specification does not require

Question 9

When the state for a dispatcher object moves to signaled, the Windows kernel

Accepted Answer

A)  moves all threads waiting on that object to ready state if the dispatcher object is a mutex object. 
B)  moves a fixed number of threads (possibly greater than one) waiting on that object to ready state if the dispatcher object is a mutex object. 
C)  moves all threads waiting on that object to ready state if the dispatcher object is an event object. 
D)  moves a fixed number of threads (possibly greater than one) waiting on that object to ready state if the dispatcher object is an event object. 
A)  moves all threads waiting on that object to ready state if the dispatcher object is a mutex object. 
B)  moves a fixed number of threads (possibly greater than one) waiting on that object to ready state if the dispatcher object is a mutex object. 
C)  moves all threads waiting on that object to ready state if the dispatcher object is an event object. 
D)  moves a fixed number of threads (possibly greater than one) waiting on that object to ready state if the dispatcher object is an event object.

Question 10

In an asymmetric solution for the dining philosophers problem, deadlock is avoided, because

Accepted Answer

A)  there is no contention for acquiring chopsticks. 
B)  neighboring philosophers will never get hungry at the same time. 
C)  any neighboring philosophers would have already acquired one of their chopsticks before attempting to acquire the shared chopstick. 
D)  a philosopher will release a chopstick in case she is unable to acquire the other chopstick. 
A)  there is no contention for acquiring chopsticks. 
B)  neighboring philosophers will never get hungry at the same time. 
C)  any neighboring philosophers would have already acquired one of their chopsticks before attempting to acquire the shared chopstick. 
D)  a philosopher will release a chopstick in case she is unable to acquire the other chopstick.

Question 11

Which of the following is true about the two versions of readers-writers problem?

Accepted Answer

A)  In the first readers-writers problem, a writer may starve if a continuous series of readers arrive before the earlier readers exit their critical section. 
B)  In the second readers-writers problem, a reader may starve if a continuous series of readers arrive before the earlier readers exit their critical section. 
C)  In the first readers-writers problem, a writer may starve if a continuous series of writers arrive before the earlier writers exit their critical section. 
D)  In the second readers-writers problem, a writer may starve if a continuous series of readers arrive before the earlier readers exit their critical section. 
A)  In the first readers-writers problem, a writer may starve if a continuous series of readers arrive before the earlier readers exit their critical section. 
B)  In the second readers-writers problem, a reader may starve if a continuous series of readers arrive before the earlier readers exit their critical section. 
C)  In the first readers-writers problem, a writer may starve if a continuous series of writers arrive before the earlier writers exit their critical section. 
D)  In the second readers-writers problem, a writer may starve if a continuous series of readers arrive before the earlier readers exit their critical section.

Question 12

Does nested critical sections in OpenMP provide any utility? Explain why.

Accepted Answer

Since at most one thread may be active a

Question 13

In functional programming languages,

Accepted Answer

A)  race conditions cannot occur. 
B)  there is no need to maintain program state. 
C)  deadlocks cannot occur. 
D)  All of the above. 
A)  race conditions cannot occur. 
B)  there is no need to maintain program state. 
C)  deadlocks cannot occur. 
D)  All of the above.

Question 14

Allowing at most four philosophers to sit simultaneously prevents deadlock.

Accepted Answer

A) True 
 B)False

Question 15

If a thread has the ownership of a Reentrant lock, it will block forever if it calls lock( ) before calling unlock( ).

Accepted Answer

A) True 
 B)False

Question 16

Semaphores in JAVA can be initialized to a negative value.

Accepted Answer

A) True 
 B)False

Question 17

In Windows, a thread may get preempted while holding a spinlock.

Accepted Answer

A) True 
 B)False

Question 18

POSIX named semaphores

Accepted Answer

A)  can easily be used by multiple unrelated processes. 
B)  can be initialized during creation time. 
C)  uses sem_wait( ) and sem_post( ) to acquire and release a semaphore respectively. 
D)  All of the above. 
A)  can easily be used by multiple unrelated processes. 
B)  can be initialized during creation time. 
C)  uses sem_wait( ) and sem_post( ) to acquire and release a semaphore respectively. 
D)  All of the above.

Question 19

In the solution for dining philosophers problem using monitors, provide a scenario in which a philosopher may starve to death.

Accepted Answer

Consider a scenario where philosopher 2

Question 20

The solution for bounded buffer problem provided in

Accepted Answer

A) True 
 B)False

Dining philosophers problem is important because it represents a class of problems where multiple processes need to share multiple resources.

A reader-writer lock is useful when

Explain the relationship between the state of a dispatcher object and the state of a thread in Windows.

Which of the following statements is not true about spinlocks in Linux?

A solution to the readers-writers problem that avoids starvation and allows some concurrency among readers is not possible.

A notify( ) operation in Java monitors

Describe the mechanisms used for synchronization in Windows kernel in single and multiprocessor systems. Explain why Windows uses different mechanisms for the two systems.

In JAVA monitors, when a thread is placed in the entry set, is that thread guaranteed to own the object lock some time in future.

When the state for a dispatcher object moves to signaled, the Windows kernel

In an asymmetric solution for the dining philosophers problem, deadlock is avoided, because

Which of the following is true about the two versions of readers-writers problem?

Does nested critical sections in OpenMP provide any utility? Explain why.

In functional programming languages,

Allowing at most four philosophers to sit simultaneously prevents deadlock.

If a thread has the ownership of a Reentrant lock, it will block forever if it calls lock( ) before calling unlock( ).

Semaphores in JAVA can be initialized to a negative value.

In Windows, a thread may get preempted while holding a spinlock.

POSIX named semaphores

In the solution for dining philosophers problem using monitors, provide a scenario in which a philosopher may starve to death.

The solution for bounded buffer problem provided in

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

Dining philosophers problem is important because it represents a class of problems where multiple processes need to share multiple resources.

A reader-writer lock is useful when

Explain the relationship between the state of a dispatcher object and the state of a thread in Windows.

Which of the following statements is not true about spinlocks in Linux?

A solution to the readers-writers problem that avoids starvation and allows some concurrency among readers is not possible.

A notify( ) operation in Java monitors

Describe the mechanisms used for synchronization in Windows kernel in single and multiprocessor systems. Explain why Windows uses different mechanisms for the two systems.

In JAVA monitors, when a thread is placed in the entry set, is that thread guaranteed to own the object lock some time in future.

When the state for a dispatcher object moves to signaled, the Windows kernel

In an asymmetric solution for the dining philosophers problem, deadlock is avoided, because

Which of the following is true about the two versions of readers-writers problem?

Does nested critical sections in OpenMP provide any utility? Explain why.

In functional programming languages,

Allowing at most four philosophers to sit simultaneously prevents deadlock.

If a thread has the ownership of a Reentrant lock, it will block forever if it calls lock( ) before calling unlock( ).

Semaphores in JAVA can be initialized to a negative value.

In Windows, a thread may get preempted while holding a spinlock.

POSIX named semaphores

In the solution for dining philosophers problem using monitors, provide a scenario in which a philosopher may starve to death.

The solution for bounded buffer problem provided in

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