Multithreading in Operating System

A thread is a path that is followed during a program’s execution. The majority of programs written nowadays run as a single thread. For example, a program is not capable of reading keystrokes while making drawings. These tasks cannot be executed by the program at the same time. This problem can be solved through multitasking so that two or more tasks can be executed simultaneously.

What is Multithreading?

Multithreading is a feature in operating systems that allows a program to do several tasks at the same time. Think of it like having multiple hands working together to complete different parts of a job faster. Each "hand" is called a thread, and they help make programs run more efficiently. Multithreading makes your computer work better by using its resources more effectively, leading to quicker and smoother performance for applications like web browsers, games, and many other programs you use every day.

How Does Multithreading Work?

Multithreading works by allowing a computer's processor to handle multiple tasks at the same time. Even though the processor can only do one thing at a time, it switches between different threads from various programs so quickly that it looks like everything is happening all at once.

Here's how it simplifies:

• Processor Handling : The processor can execute only one instruction at a time, but it switches between different threads so fast that it gives the illusion of simultaneous execution.
• Thread Synchronization : Each thread is like a separate task within a program. They share resources and work together smoothly, ensuring programs run efficiently.
• Efficient Execution : Threads in a program can run independently or wait for their turn to process, making programs faster and more responsive.
• Programming Considerations : Programmers need to be careful about managing threads to avoid problems like conflicts or situations where threads get stuck waiting for each other.

What is Multitasking?

Multitasking is the ability of an operating system to run multiple programs or tasks at the same time. It allows you to perform different activities simultaneously on your computer. For example, you can listen to music while browsing the internet and typing a document all at once.

Multitasking is of two types: Processor-based and thread-based. Processor-based multitasking is managed by the OS, however, multitasking through multithreading can be controlled by the programmer to some extent. The concept of multi-threading needs a proper understanding of these two terms - a process and a thread. A process is a program being executed. A process can be further divided into independent units known as threads. A thread is like a small light-weight process within a process. Or we can say a collection of threads is what is known as a process. Applications: Threading is used widely in almost every field. Most widely it is seen over the internet nowadays where we are using transaction processing of every type like recharges, online transfer, banking etc. Threading is a segment which divide the code into small parts that are of very light weight and has less burden on CPU memory so that it can be easily worked out and can achieve goal in desired field. The concept of threading is designed due to the problem of fast and regular changes in technology and less the work in different areas due to less application. Then as says “need is the generation of creation or innovation” hence by following this approach human mind develop the concept of thread to enhance the capability of programming.

Multithreading vs Multitasking

Lifecycle of a Thread

There are various stages in the lifecycle of a thread. Following are the stages a thread goes through in its whole life.

• New: The lifecycle of a born thread (new thread) starts in this state. It remains in this state till a program starts.
• Runnable : A thread becomes runnable after it starts. It is considered to be executing the task given to it.
• Waiting : While waiting for another thread to perform a task, the currently running thread goes into the waiting state and then transitions back again after receiving a signal from the other thread.
• Timed Waiting: A runnable thread enters into this state for a specific time interval and then transitions back when the time interval expires or the event the thread was waiting for occurs.
• Terminated (Dead) : A thread enters into this state after completing its task.

Types of Execution in OS

There are two types of execution:

• Concurrent Execution: This occurs when a processor is successful in switching resources between threads in a multithreaded process on a single processor.
• Parallel Execution: This occurs when every thread in the process runs on a separate processor at the same time and in the same multithreaded process

Drawbacks of Multithreading

Multithreading is complex and many times difficult to handle. It has a few drawbacks. These are:

• If you don’t make use of the locking mechanisms properly, while investigating data access issues there is a chance of problems arising like data inconsistency and dead-lock.
• If many threads try to access the same data, then there is a chance that the situation of thread starvation may arise. Resource contention issues are another problem that can trouble the user.
• Display issues may occur if threads lack coordination when displaying data.

Benefits of Multithreading

• Multithreading can improve the performance and efficiency of a program by utilizing the available CPU resources more effectively. Executing multiple threads concurrently, it can take advantage of parallelism and reduce overall execution time.
• Multithreading can enhance responsiveness in applications that involve user interaction. By separating time-consuming tasks from the main thread, the user interface can remain responsive and not freeze or become unresponsive.
• Multithreading can enable better resource utilization. For example, in a server application, multiple threads can handle incoming client requests simultaneously, allowing the server to serve more clients concurrently.
• Multithreading can facilitate better code organization and modularity by dividing complex tasks into smaller, manageable units of execution. Each thread can handle a specific part of the task, making the code easier to understand and maintain.

Conclusion

In conclusion, multithreading is an important feature in operating systems that allows a program to do multiple tasks at the same time. By dividing tasks into smaller threads, it helps make programs run faster and more efficiently. This means better performance and a smoother experience for users. Understanding and using multithreading can greatly improve how well software and applications perform.