MCQs on Multithreading and Asynchronous Programming | C#
This set of 30 multiple-choice questions (MCQs) delves into the key concepts of Multithreading and Asynchronous Programming in C#. Topics covered include basic threading principles, Task Parallel Library (TPL), async/await, and handling common threading issues like deadlocks and race conditions. These MCQs aim to test your understanding and practical knowledge of multithreading and concurrency management in C#.
1. Introduction to Multithreading
- What is the primary purpose of multithreading in C#?
- A) To improve application UI performance
- B) To perform multiple operations simultaneously
- C) To run a single operation faster
- D) To execute code sequentially
- In C#, which class represents a thread?
- A) ThreadInfo
- B) Thread
- C) Task
- D) WorkerThread
- Which of the following is true about multithreading?
- A) It allows a single process to perform multiple tasks concurrently
- B) It is only useful in desktop applications
- C) It makes programs run slower
- D) It is only applicable to server-side programming
- Which of these is NOT a feature of threading in C#?
- A) Each thread has its own memory space
- B) Threads in the same process share memory space
- C) Threads can only be used in console applications
- D) Threads can run independently
- What method is used to start a thread in C#?
- A) Thread.Start()
- B) Thread.Run()
- C) Thread.Begin()
- D) Thread.Execute()
2. Threading Basics
- Which property of the Thread class specifies whether a thread is currently running?
- A) Thread.IsRunning
- B) Thread.IsAlive
- C) Thread.Status
- D) Thread.State
- Which method is used to pause a thread in C#?
- A) Thread.Pause()
- B) Thread.Sleep()
- C) Thread.Hold()
- D) Thread.Wait()
- In C#, how do you set the priority of a thread?
- A) Thread.SetPriority()
- B) Thread.Priority
- C) Thread.ChangePriority()
- D) Thread.Prioritize()
- What is the default priority of a thread in C#?
- A) Low
- B) High
- C) Normal
- D) Critical
- Which method in C# is used to abort a thread?
- A) Thread.Terminate()
- B) Thread.Abort()
- C) Thread.Stop()
- D) Thread.ForceStop()
3. The Task Parallel Library (TPL)
- What is the Task Parallel Library (TPL) used for in C#?
- A) To manage memory more efficiently
- B) To simplify parallel programming
- C) To handle file I/O operations
- D) To increase application security
- Which class is the basic unit of work in the TPL?
- A) Task
- B) Thread
- C) Job
- D) Action
- Which method in TPL is used to run a task asynchronously?
- A) Task.Start()
- B) Task.Run()
- C) Task.Begin()
- D) Task.Execute()
- What does Task.WhenAll() do in C#?
- A) It runs tasks sequentially
- B) It waits for all tasks to complete
- C) It cancels all tasks
- D) It runs a task in the background
- Which TPL class is used to perform parallel loops or tasks in C#?
- A) Parallel
- B) Async
- C) Worker
- D) Concurrency
4. Asynchronous Programming (async/await)
- What keyword in C# is used to define an asynchronous method?
- A) async
- B) await
- C) asyncTask
- D) runAsync
- Which keyword is used in C# to wait for the completion of an asynchronous task?
- A) wait
- B) await
- C) async
- D) pause
- What is the main advantage of using async/await in C#?
- A) It allows tasks to run synchronously
- B) It increases CPU utilization
- C) It improves the performance of I/O-bound operations
- D) It reduces the memory usage of an application
- Which of the following types can be returned from an asynchronous method in C#?
- A) void
- B) Task
- C) Task<T>
- D) Both B and C
- What happens if you forget to use the await keyword in an async method?
- A) It throws a compile-time error
- B) It executes asynchronously without waiting
- C) The method executes synchronously
- D) It causes a runtime error
5. Handling Deadlocks and Race Conditions
- What is a deadlock in multithreading?
- A) A situation where threads stop working due to a lack of memory
- B) A situation where threads are locked in an infinite loop
- C) A situation where two or more threads are blocked, waiting for each other to release resources
- D) A situation where threads are not executed in order
- How can deadlocks be prevented in C#?
- A) By using locks in the correct order
- B) By increasing thread priority
- C) By avoiding async methods
- D) By using multiple threads for each task
- What is a race condition in multithreading?
- A) A situation where multiple threads work independently on the same task
- B) A situation where threads execute in a predictable order
- C) A situation where multiple threads access shared data at the same time, causing unpredictable results
- D) A situation where threads compete for CPU time
- What is the purpose of a lock in C#?
- A) To allow multiple threads to access a resource simultaneously
- B) To prevent deadlocks from occurring
- C) To synchronize access to shared resources and prevent race conditions
- D) To increase thread execution speed
- What type of lock in C# ensures only one thread can access a critical section at a time?
- A) Mutex
- B) Semaphore
- C) Monitor
- D) SpinLock
6. Cancellation Tokens
- What is the purpose of a cancellation token in C#?
- A) To cancel a thread’s execution at any time
- B) To enable the cancellation of asynchronous tasks
- C) To manage thread priorities
- D) To handle task failures
- How can a task check for cancellation in C#?
- A) By checking the cancellation token
- B) By calling the Task.Stop() method
- C) By checking for errors
- D) By using the Monitor class
- Which method is used to signal the cancellation of a task in C#?
- A) cancellationToken.Notify()
- B) cancellationToken.Cancel()
- C) cancellationToken.Signal()
- D) cancellationToken.Stop()
- How do you handle a task cancellation exception in C#?
- A) By using a try-catch block to catch OperationCanceledException
- B) By calling Task.Abort()
- C) By using a lock
- D) By checking the task status
- When should you use CancellationTokens in C#?
- A) To prevent memory leaks
- B) To cancel long-running asynchronous operations
- C) To synchronize threads
- D) To increase CPU utilization
Answer Key
| Qno | Answer (Option with Text) |
|---|---|
| 1 | B) To perform multiple operations simultaneously |
| 2 | B) Thread |
| 3 | A) It allows a single process to perform multiple tasks concurrently |
| 4 | C) Threads can only be used in console applications |
| 5 | A) Thread.Start() |
| 6 | B) Thread.IsAlive |
| 7 | B) Thread.Sleep() |
| 8 | B) Thread.Priority |
| 9 | C) Normal |
| 10 | B) Thread.Abort() |
| 11 | B) To simplify parallel programming |
| 12 | A) Task |
| 13 | B) Task.Run() |
| 14 | B) It waits for all tasks to complete |
| 15 | A) Parallel |
| 16 | A) async |
| 17 | B) await |
| 18 | C) It improves the performance of I/O-bound operations |
| 19 | D) Both B and C |
| 20 | C) The method executes synchronously |
| 21 | C) A situation where two or more threads are blocked, waiting for each other to release resources |
| 22 | A) By using locks in the correct order |
| 23 | C) A situation where multiple threads access shared data at the same time, causing unpredictable results |
| 24 | C) To synchronize access to shared resources and prevent race conditions |
| 25 | C) Monitor |
| 26 | B) To enable the cancellation of asynchronous tasks |
| 27 | A) By checking the cancellation token |
| 28 | B) cancellationToken.Cancel() |
| 29 | A) By using a try-catch block to catch OperationCanceledException |
| 30 | B) To cancel long-running asynchronous operations |