What is Multithreading?
Multithreading is a technique of executing multiple threads simultaneously. It does not let the process or an operating system generate multiple copies of the program running in the computer rather it manages multiple users or multiple requests by the same user at the same time, without creating multiple copies of the program. This article will give you an insight on Multithreading and will give you a basic idea about why and how it is an important technology to learn. A thread is a lightweight process and the smallest unit of processing, and running multiple threads simultaneously is called multithreading. So basically it is a method to use a single set of code by multiple processors.
There are two terms that need to be understood for the understanding of multithreading.
- Thread: Thread is the independent or basic unit of a process.
- Process: A program which is being executed is called a process, multiple threads exist in a process.
The execution in multithreading is both concurrent and parallel.
- Concurrent Execution: If the processor can switch execution resources between threads in a multithreaded process on a single processor, then it is said to be a concurrent execution.
- Parallel Execution: When each thread in the process can run on a separate processor at the same time in the same multithreaded process, then it is said to be a parallel execution.
Types of Thread
- User-level Thread: They are created and managed by users. They are used at the application level. There is no involvement of the OS. A good example is when we use threading in programming like in Java, C#, Python, etc, we use user threads.
There are some unique data incorporated in each thread which helps to identify them, such as:
- Program counter: A program counter is responsible for keeping the track of instructions and to tell which instruction to execute next.
- Register: System registers are there to keep the track of the current working variable of a thread.
- Stack: It contains the history of thread execution.
- Kernel-level Thread: They are implemented and supported by the operating system. They generally take more time to execute than user threads. For example Window Solaris.
Multithreading models are of three types
- Many to many
- Many to one
- One to on
Many to many: Any number of user threads can interact with an equal or lesser number of kernel threads.
Many to one: It maps many user-level threads to one Kernel-level thread.
One to one: Relationship between the user-level thread and the kernel-level thread is one to one.
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Uses of Multithreading
Multithreading is a way to introduce parallelism in the system or program. So, you can use it anywhere you see parallel paths (where two threads are not dependent on the result of one another) to make it fast and easy.
- Processing of large data where it can be divided into parts and get it done using multiple threads.
- Applications which involve mechanism like validate and save, produce and consume, read and validate are done in multiple threads. Few examples of such applications are online banking, recharges, etc.
- It can be used to make games where different elements are running on different threads.
- In Android, it is used to hit the APIs which are running in the background thread to save the application from stopping.
- In web applications, it is used when you want your app to get asynchronous calls and perform asynchronously.
Advantages of Multithreading
- Economical: It is economical as they share the same processor resources. It takes lesser time to create threads.
- Resource sharing: It allows the threads to share resources like data, memory, files, etc. Therefore, an application can have multiple threads within the same address space.
- Responsiveness: It increases the responsiveness to the user as it allows the program to continue running even if a part of it is performing a lengthy operation or is blocked.
- Scalability: It increases parallelism on multiple CPU machines. It enhances the performance of multi-processor machines.
- It makes the usage of CPU resources better.
Why should we use Multithreading?
We should use Multithreading because of the following reasons:
- To increase parallelism
- To make most of the available CPU resources.
- To improve application responsiveness and give better interaction with the user.
Prerequisites for learning Multithreading
If you know to code and how to write single-threaded programs efficiently, you are ready to learn and apply Multithreading.
Scope of Multithreading
In today’s technical world software development is not done as it used to be done in historical software.
- Many-core machines are common and we can reduce the computational cost by using multiple threads.
- Modern applications fetch information from a variety of sources.
These two factors are simply telling us that information will be available in asynchronous fashion. So in the near future, what would matter is not multithreading but a way to deal with asynchrony, and asynchrony can only be dealt with multithreading.
Who should learn Multithreading?
People doing coding and developing applications or software or processors should learn multithreading as this is the only way to make use of your CPUs and handle asynchrony.
Career growth in Multithreading
This technique will never die because it has some unique advantages which cannot be performed by any other technique. Companies are looking for developers who can code in threads as well to make the most of the resources and to reduce the cost. Therefore, it has a good career growth and opportunities.
In the computer world when we talk about parallelism, we talk about multithreading. Implementing multithreading is reasonably effective and straightforward as it makes the work cheaper. Its specialty to deal with asynchrony makes it unique. Therefore, it is in demand and it is a worthful technology to learn.
This has been a guide to What is Multithreading. Here we discussed the Types, Uses, Advantages, and Career growth of Multithreading. You can also go through our other suggested articles to learn more –