Introduction To Multithreading Interview Questions And Answers
Multithreading is basically defined as a CPU (central processing unit) ability to process multiple threads concurrently. It plays an important role in Computer Architecture. There are mainly three types of Multithreading models present.
- Many to Many Model: In the case of many to many model relationships, it multiplies a different number or set of threads onto an equal set of kernel threads.
- Many to One Model: In this case, it relates different kinds of users level threads onto one kernel-level thread. With the implementation of this process, only one thread will be eligible to access the thread at a time, and thus multiple types of threads will not be able to execute parallel at the same point of time.
- One to One Model: In the case of one to one model, a direct relationship exists between a user-level thread and the kernel-level thread. It actually provides more concurrent implementation than the many to one model. It also provides support parallel execution of multi-threads.
If you are looking for a job related to multithreading, you need to prepare for the 2020 multithreading interview questions. Every interview is different from the different job profiles, but still, to clear the interview, you need to have a good and clear knowledge of multithreading processes. Here, we have prepared the important multithreading interview questions and answers that will help you succeed in your interview.
Below are the 10 important 2020 multithreading interview questions and answers that are frequently asked in an interview. These questions are divided into two parts are as follows:
Part 1 –Multithreading Interview Questions (Basic)
This first part covers basic Interview Questions and Answers.
1. Explain the differences between multithreading and multiprocessing?
In the case of multithreading, the application processes and threads use to share the single or multiple core resources that include CPU caches, translation lookaside buffer and the computing units. But in the case of multiprocessing, the application implements multiple complete processing units in one or more cores. This is the basic difference between multithreading and multiprocessing since multithreading aims to implement more single-core utilization with the help of thread-level and instruction-level parallelism.
2. Explain different types of multithreading?
This is the common Multithreading Interview Questions which is frequently asked in an interview. There are mainly three types of multithreading processes.
- Interleaved Multithreading: This type of multithreading is mainly processed to make the execution pipeline independent of any dependency by removing all the data dependency stalls from the same.
- Coarse-grained Multithreading: This is a multithreading type where one thread can continue to execute until it is blocked by a normal event that would process a long latency stall.
- Simultaneous Multithreading: This is the new and advanced type of multithreading process. In this case, the multithreading process is mainly implemented towards the superscalar processors.
3. Explain different types of thread states?
Find below the different types of thread states.
- Runnable: In this state, a thread is used to remain in a running an executable state
- Terminated: In this state, the thread should be terminated and should not remain in the current executable phase.
- Waiting: In this state, the thread is used to wait for another thread to perform the specified activity.
- Timed Waiting: In this state, the thread is dependent on time-consuming and should wait for another thread to implement the specified action.
- Blocked: In this state, the thread is used to remain in the blocked state concerning its current execution phase and is waiting for a monitor lock based on its current assigned tasks.
4. Explain the wait () and sleep () methods?
The wait () method is described in the object class and is implemented to release the lock system during the code coverage purpose. The sleep () method is described in the thread class and is used to pause the current thread execution for a given specified time.
5. Explain different methods for threads?
Below are the few important methods for threads:
- Start(): This method is used to start the thread execution process. This is the basic method that should be used to start any multithreading processes.
- getName(): It is used to get the name of a thread
- setpoint(Int new priority): This method is used to change the priorities of the thread
- yield(): This method is used to pause the execution of the current thread while the other thread will carry on the normal execution phase.
Part 2 – Multithreading Interview Questions (Advanced)
Let us now have a look at the advanced Interview Questions and Answers.
6. Explain the thread synchronization process?
In the case of multithreading, there is a presence of asynchronous behaviour in programs that can be balanced and manipulated properly through the synchronization process. Often, it has been found when multiple threads perform both read and write activities simultaneously, and then there is a chance of creating confusion. So, to prevent this inconsistency, the thread synchronization process has been implemented. In this process, when the thread gets inside the synchronized block, then it becomes unreachable for others, and no other thread can call that method.
7. Explain the differences between User-level and Kernel level thread?
Find below the differences between user-level and kernel-level threads.
- User-level threads are faster than kernel-level threads from the creation and managing perspective.
- User-level threads are generic, whereas the kernel-level threads are more specific to the concerned operating system.
- In the case of the user level, the multithreading process can’t be implemented on multiprocessing, whereas kernel level can themselves be multithreaded.
8. What do you mean by the lightweight process?
This is the advanced Multithreading Interview Questions asked in an interview. The thread is also known as a lightweight process. It is basically a flow of information and its execution across the process code concerning its own integrated programs. It improves performance by using parallelism.
9. What do you mean by Livelock?
When all the threads are in a blocked state and execution is stopped due to resource unavailability, then that situation is termed as livelock.
10. Explain the pros and cons of multithreading?
Find below the pros and cons of multithreading.
- It can be easily extended to multiprocessors.
- It provides impendent action support to pass or fail accordingly.
- The wait/Sleep method can be implemented more easily and cleanly.
- Careful synchronization is required.
- Sometimes create space-related issues in case of blocked threads.
This has been a guide to List Of Multithreading Interview Questions and Answers so that the candidate can crackdown these Interview Questions easily. Here in this post, we have studied top Multithreading Interview Questions, which are often asked in interviews. You may also look at the following articles to learn more –