Synchronization and Deadlocks: A Comprehensive Guide for Computer Science Students

Question 1

What is the primary purpose of a semaphore in synchronization?

Accepted Answer

To control access to shared resources

Answer

To prevent deadlocks

Answer

To ensure mutual exclusion

Answer

To synchronize threads

Question 2

What is the key difference between a semaphore and a mutex in synchronization?

Accepted Answer

Semaphores can be used for counting, while mutexes are used for mutual exclusion

Answer

Mutexes can be used for signaling, while semaphores are used for synchronization

Answer

Semaphores are implemented using hardware, while mutexes are implemented using software

Answer

There is no difference between a semaphore and a mutex

Question 3

What is the primary function of a deadlock detection algorithm?

Accepted Answer

To identify deadlocks in a system

Answer

To recover from deadlocks

Answer

To prevent deadlocks from occurring

Answer

To optimize resource utilization

Question 4

Which issue can arise when using a priority inheritance protocol?

Accepted Answer

Priority inversion

Answer

Deadlock

Answer

Resource starvation

Answer

Code complexity

Question 5

In operating systems, what is the key distinction between optimistic and pessimistic concurrency control approaches?

Accepted Answer

Optimistic approaches assume data remains unmodified during execution, while pessimistic approaches assume data modification.

Answer

Optimistic approaches assume exclusive data access, while pessimistic approaches allow concurrent access.

Answer

Optimistic approaches prevent deadlocks, while pessimistic approaches recover from deadlocks.

Question 6

Which of the following is NOT a synchronization mechanism in the context of operating systems?

Accepted Answer

Thread

Answer

Semaphore

Answer

Mutex

Answer

Critical section

Question 7

Deadlock in an operating system occurs when:

Accepted Answer

Multiple processes hold resources and wait for each other to release them

Answer

A single process holds all necessary resources

Answer

Resources are allocated in a last-in, first-out manner

Answer

Processes share memory without proper synchronization

Question 8

In operating systems, what is the primary purpose of a semaphore?

Accepted Answer

To control access to shared resources

Answer

To synchronize processes

Answer

To detect deadlocks

Answer

To allocate memory

Question 9

What is the Banker's algorithm primarily used for in the context of operating systems?

Accepted Answer

Preventing deadlocks

Answer

Detecting deadlocks

Answer

Resolving deadlocks

Answer

Simulating resource allocation scenarios

Question 10

Which of the following is NOT a deadlock recovery technique in operating systems?

Accepted Answer

Deadlock avoidance

Answer

Process termination

Answer

Resource preemption

Answer

Starvation

Question 11

What is the key distinction between semaphores and mutexes in operating systems?

Accepted Answer

Semaphores can be used for both synchronization and resource control, while mutexes are used primarily for synchronization

Answer

Mutexes can be used for both synchronization and resource control, while semaphores are used primarily for resource control

Answer

Semaphores are implemented in hardware, while mutexes are implemented in software

Answer

Mutexes are implemented in hardware, while semaphores are implemented in software

Question 12

In operating systems, what is the primary purpose of a deadlock detection algorithm?

Accepted Answer

To identify and terminate processes involved in a deadlock

Answer

To prevent deadlocks from occurring in the first place

Answer

To recover from deadlocks by restarting the affected processes

Answer

To simulate deadlock scenarios and test recovery techniques

Question 13

Which of the following is not used as a synchronization mechanism in operating systems?

Accepted Answer

Threads

Answer

Semaphores

Answer

Mutexes

Answer

Locks

Question 14

What is the primary purpose of a semaphore?

Accepted Answer

To ensure exclusive access to shared resources

Answer

To signal events between processes

Answer

To prevent deadlocks

Answer

To manage memory allocation

Question 15

What is the purpose of the Banker's algorithm?

Accepted Answer

Deadlock prevention

Answer

Deadlock detection

Answer

Resource allocation

Answer

Process scheduling

Question 16

True or False: A mutex is a type of binary semaphore.

Accepted Answer

True

Answer

False

Question 17

What is the key difference between a lock and a semaphore?

Accepted Answer

Locks are used for binary synchronization, while semaphores can be used for counting.

Answer

Semaphores are used for binary synchronization, while locks can be used for counting.

Answer

Locks and semaphores are essentially the same.

Answer

Neither of the above statements is true.

Question 18

True or False: Deadlocks can occur exclusively in multithreaded programs.

Accepted Answer

False

Answer

True

Question 19

Which of the following is not a fundamental synchronization mechanism in operating systems?

Accepted Answer

Message queues

Answer

Semaphores

Answer

Mutexes

Answer

Barriers

Question 20

In the context of operating systems, which of the following statements about deadlocks is accurate?

Accepted Answer

Semaphores can be used to prevent deadlocks.

Answer

Deadlocks only occur in systems with multiple threads.

Answer

Deadlocks are always permanent and cannot be resolved.

Answer

Deadlocks do not affect the performance of the system.

Question 21

Which of the following is a synchronization mechanism in which one process must wait for another to release a shared resource?

Accepted Answer

Mutex

Answer

Interrupt

Answer

Sleep

Answer

Polling

Question 22

What is the defining characteristic of a deadlock?

Accepted Answer

A set of processes that are waiting indefinitely for resources held by each other.

Answer

A set of processes that have finished executing.

Answer

A set of processes that are using the same resources without any conflicts.

Question 23

Which of the following is a technique used to prevent deadlocks?

Accepted Answer

Banker's algorithm

Answer

Lottery scheduling

Answer

First-come first-served scheduling

Answer

Priority scheduling

Question 24

Which of the following is a type of semaphore that can have a value greater than 1?

Accepted Answer

Counting semaphore

Answer

Spinlock

Answer

Binary semaphore

Answer

Mutex

Question 25

Which of the following is a common deadlock avoidance technique?

Accepted Answer

Resource ordering

Answer

Deadlock detection

Answer

Priority inversion prevention

Answer

Starvation avoidance

Question 26

What is the state of a process that is waiting to acquire a lock that is currently held by another process?

Accepted Answer

Blocked

Answer

Ready

Answer

Running

Answer

Sleeping

Question 27

What is a key difference between a semaphore and a mutex?

Accepted Answer

Semaphores can be used to control access to multiple resources, while mutexes can only control access to a single resource.

Answer

Mutexes are more efficient than semaphores.

Answer

Semaphores can be used for inter-process synchronization, while mutexes are only used for intra-process synchronization.

Question 28

Which of the following is NOT a consequence of deadlocks?

Accepted Answer

Improved system performance

Answer

Livelock

Answer

Reduced throughput

Answer

Starvation

Question 29

Which of the following is NOT a valid synchronization mechanism?

Accepted Answer

Busy waiting

Answer

Mutex

Answer

Semaphore

Question 30

A deadlock occurs when a set of processes are waiting indefinitely for each other to release resources. Which of the following conditions is necessary for a deadlock to occur?

Accepted Answer

Circular waiting

Answer

Process termination

Answer

Resource starvation

Answer

Concurrency

Question 31

A process that is unable to proceed due to waiting for a resource is said to be in which state?

Accepted Answer

Blocked state

Answer

Critical section

Answer

Ready state

Question 32

Which deadlock recovery technique involves restoring the system to a previous state?

Accepted Answer

Rollback

Answer

Livelock

Answer

Priority inversion

Answer

Starvation

Question 33

Which of the following is a disadvantage of using busy waiting?

Accepted Answer

Wasted CPU cycles

Answer

Potential for starvation

Answer

Increased program complexity

Answer

Reduced code readability

Question 34

What is the primary function of a semaphore in synchronization?

Accepted Answer

Control access to shared resources

Answer

Schedule processes

Answer

Detect deadlocks

Question 35

Which of the following is a necessary condition for a deadlock?

Accepted Answer

All resources are held by processes and are requested by other processes

Answer

Some resources are held by processes

Answer

No resources are held by processes

Answer

Resources are held by multiple processes

Question 36

What is the purpose of the Banker's Algorithm?

Accepted Answer

Deadlock avoidance

Answer

Deadlock detection

Answer

Deadlock recovery

Answer

Synchronization

Question 37

What is the primary role of a mutex in software synchronization?

Accepted Answer

Ensure exclusive access to critical sections of code

Answer

Detect deadlocks

Answer

Control resource allocation

Question 38

Which of the following is a common symptom of a deadlock?

Accepted Answer

Processes are waiting indefinitely for resources

Answer

Processes are executing normally

Answer

Processes are terminated prematurely

Question 39

What is the primary goal of deadlock recovery?

Accepted Answer

Terminate deadlocked processes and reclaim system resources

Answer

Detect deadlocks only

Answer

Prevent deadlocks from occurring

Question 40

Which of the following is a potential disadvantage of synchronization?

Accepted Answer

Reduced efficiency

Answer

Reduced race conditions

Answer

Improved code readability

Answer

Ensured data consistency

Question 41

What distinguishes a distributed deadlock from other types of deadlocks?

Accepted Answer

Involves processes executing on multiple computers

Answer

Involves only a single process

Answer

Involves processes executing on the same computer

Question 42

What is the primary function of a semaphore in operating systems?

Accepted Answer

Controlling access to shared resources by multiple processes.

Answer

Preventing deadlocks from occurring.

Answer

Ensuring fair scheduling of processes.

Answer

Managing memory allocation for processes.

Question 43

When a process holds the lock for a shared resource, it is considered to be in the:

Accepted Answer

Critical Section

Answer

Terminated State

Answer

Ready State

Answer

Waiting State

Question 44

Which of these is the most effective approach to avoid deadlocks in an operating system?

Accepted Answer

Implementing deadlock prevention algorithms.

Answer

Relying solely on deadlock detection and recovery techniques.

Answer

Ignoring potential deadlocks and allowing them to resolve themselves.

Answer

Completely avoiding resource sharing between processes.

Question 45

What is the main purpose of semaphores in operating systems?

Accepted Answer

To regulate access to shared resources and synchronize concurrent processes.

Answer

To allocate memory to processes during execution.

Answer

To manage the scheduling of processes for execution.

Question 46

What is the key difference between a semaphore and a mutex?

Accepted Answer

A semaphore can have a value greater than 1, allowing multiple processes to access a resource concurrently, while a mutex can only have a value of 0 or 1, ensuring exclusive access.

Answer

Mutexes are used for synchronization between processes, while semaphores are used within a single process.

Answer

Semaphores are implemented in hardware, while mutexes are implemented in software.

Question 47

What is a deadlock in the context of operating systems?

Accepted Answer

A situation where two or more processes are stuck indefinitely, each waiting for a resource held by another process.

Answer

A condition where a process is blocked from accessing a resource due to permission restrictions.

Question 48

The Banker's Algorithm is primarily used for:

Accepted Answer

Avoiding deadlocks in resource allocation systems by carefully managing resource requests.

Answer

Detecting deadlocks that have already occurred in an operating system.

Answer

Scheduling processes in multiprocessor systems for efficient execution.

Question 49

Which of the following is a telltale sign of a deadlock in an operating system?

Accepted Answer

Processes become blocked indefinitely, unable to proceed.

Answer

Memory usage reaches extremely high levels.

Answer

CPU usage remains consistently low.

Answer

Processes experience slow execution speeds.

Question 50

What is the main purpose of a deadlock detection algorithm in an operating system?

Accepted Answer

To identify when a deadlock has occurred and take appropriate action to resolve it.

Answer

To prevent deadlocks from happening in the first place.

Answer

To recover from deadlocks after they have happened.

Question 51

What is the primary objective of synchronization in operating systems?

Accepted Answer

Ensuring that multiple processes can safely and orderly access shared resources without conflicts.

Answer

Improving the overall performance of the operating system.

Answer

Preventing errors from occurring in user programs.