Everything To Know About Thread In Operating System

October 5, 2023

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Thread in Operating systems has become a hot topic of discussion for several reasons. As we know, within a program, a thread connotes a separate execution path. Moreover, it’s a lightweight process that the OS can schedule and run at the same time as other threads. Moreover, it’s also worth noting that the OS creates and manages threads, and they also share the same type of memory and resources as the program that made them. So, this is exactly what enables multiple threads to collaborate and work within a single program.

One should also note that a thread is a single sequence stream that works within a process. We also know this as a lightweight process as it possesses some of the properties of these processes. In fact, each thread belongs to one process as we can tell you. In an OS that supports multithreading capabilities, this process can consist of many threads. That said, the thread can also become an effective means if the CPU is more than 1. Otherwise, you need to have two threads to context switch for a single CPU.

Table of Contents

Reasons Why We Need Thread

So, there are a lot of reasons why we need threads in the operating system. Let’s take a look at the reasons now:

First of all, threads that run in parallel improve the application performance. In fact, such threads possess their own CPU state and stack. On the other hand, they share the same address space of the process, and also the environment.

Next, Threads in the Operating System can also share common data so that they don’t need to use interprocess communications. Likewise the process threads may also have states like read, blocked, executing, and more.

One should note that one can assign priority to the threads just like the process. The highest priority thread is scheduled first, as we can tell you.

Each thread has its own TCB or Thread Control Back. Like the process, a context switch may also occur for the thread. Thereafter, it can register contents that are saved in TCB. Moreover, threads that share the same address space and resources, and also synchronisation requires for the various activities of the thread in question.

Multi-Threading And Its Details

So, now that we know why we need threads in Operating Systems, it’s time to take a look at what multi-threading is, and how it works. According to the reports, we know thread as a lightweight process. As such, the idea is to achieve a sense of parallelism by dividing the process into multiple threads. For instance, let’s say, you are using a browser.

You can open multiple tabs in different threads. Likewise, you can also open multiple tabs on MS Word. In fact, MS Word uses multiple threads, such as one thread to format the text, another to process the inputs, and more. There are multiple advantages of multithreading as well.

So, as we know, multithreading is a foolproof technique we normally use in the US to improve the overall performance and responsiveness of computer systems. Multi-threading in an OS allows multiple threads to share the same resources of a single process, for example, the CPU, I/O Devices, and Memory.

The Key Differences between Process And Thread

So, now that we have an idea about threading and process, it’s time to look at the main differences between these two. If you are someone who wants to know the answer to this question, you are in the right place. According to the reports, the main difference between these two is that threads within the same process can run in a shared memory space.

Moreover, one should note that threads aren’t independent of one another like the processes that they are, and that’s why threads generally share with the other threads their code section, OS resources, and data section. However, like multiple processes, a thread may have its own program counter, stack space, and register set.

Know The Advantages Of Thread

Many people may like to know that there are many advantages of using thread in Operating systems. If you are curious about knowing the advantages of thread in an operating system, then you are at the right place. So, the following points elaborate on the advantages of thread:

The Responsiveness Of Thread:

So, users must know that if the process is divided into multiple threads, and if the thread completes its execution, then the output can be returned immediately.

Faster Context Switch:

There are a lot of people who might like to know that thread in the operating system provides a faster context switch time. In fact, the context switch time between threads is a lot lower compared to the process context switch that we know. Moreover, process context switching requires more overheard from the CPU as many users have mentioned.

Effective Utilisation Of Multiprocessor System:

Having multiple threads in a single process allows one to schedule multiple threads on multiple processors. So, people may like to know that this only makes the process execution a lot faster.

Resource Sharing:

If you are curious about the thread in the operating system and its advantages, then you are at the right place. So, as we know, resources such as code, data, and files can be shared among all sorts of threads within a process. On this note, stacks and registers cannot be shared among the threads. As such, each thread has its own register and stack.

Advantages Of Communication

Next, the communication between different threads is easier because threads generally share a common address space in a computer. While in the process we need to follow some proper communication techniques for the communication between these two processes.

Enhanced Throughput Of The system

Next, if we can divide the process into multiple threads and the function of each thread is considered as one task, then the number of jobs completed per unit of time becomes greater. In other words, it increases the throughput of the system.

Different Types Of Threads

So, now that we know the threads, it’s time to take a look at how many of them exist. People might like to know that there are two primary types of threads: 1) User Level Thread, and 2) Kernel Level Thread.

User Level Thread

So, first of all, let’s take a look at the user-level thread. According to the reports, it’s a type of thread that we do not create using system calls. In fact, the kernel has no work in this thread’s management. You can easily implement a user-level thread. However, when the user-level threads are single-handed processes, that’s when the kernel-level threads come to manage them.

There are several advantages and disadvantages of using user-level threads. Let’s take a look at the advantages now.

It’s easier to complete than Kernel Level Thread.

Context Switch is applicable, and thus it takes less time in the user-level thread.

This thread is more efficient than the Kernel Level Thread.

Because of the presence of only one program counter, stack space, and register set, User Level Thread has a simple representation.

Disadvantages of User Level Thread:

Now, the first disadvantage of using a user-level thread is the lack of coordination between a thread and a Kernel.
In case of a fault of a page, the whole process can get blocked.

Kernel Level Thread

As we know, there’s another type of thread in the Operating System that we know as Kernel Level Thread. According to the reports, it’s a type of thread that can recognize the OS easily. Moreover, this thread also has its own thread table which keeps track of the entire system.

In fact, the OS kernel helps in managing threads. People might like to know that the Kernel Threads have a longer context switching time, and it helps in the management of threads. Just like the User Level Thread, this one also has some advantages and disadvantages to showcase.

Here are the advantages of Kernel Level Threads:

One of the biggest perks of Kernel Level Thread is that it has all the up-to-date info on all threads.

Moreover, the apps that block frequency are generally handled by the Kernel Level Threads.

Whenever a process requires more time to process, this thread can provide more time for it.

Disadvantages of using Kernel Level Threads:

Users may like to know that it’s slower than the user-level thread.

Using this type of thread is slightly more complex than a user-level thread.

Components Of Threads

So, there are some basic components of OS, namely:

Stack Space
Program Counter
Register Set

Conclusion

In the end, using Thread in the Operating system has a lot of advantages and disadvantages. Moreover, this article also explained the different types of threads and their usage.