Threads

A thread is a single sequence stream within a process. Threads are also called lightweight processes as they possess some of the properties of processes.

Each thread belongs to exactly one process. In an operating system that supports multithreading, the process can consist of many threads. But threads can be effective only if the CPU is more than 1 otherwise two threads have to context switch for that single CPU.

What is Thread in Operating Systems?

In a process, a thread refers to a single sequential activity being executed. these activities are also known as thread of execution or thread control. Now, any operating system process can execute a thread. we can say, that a process can have multiple threads.

Why Do We Need Thread?

• Threads run in parallel improving the application performance. Each such thread has its own CPU state and stack, but they share the address space of the process and the environment. 
• Threads can share common data so they do not need to use inter-process communication 
• . Like the processes, threads also have states like ready, executing, blocked, etc. 
• Priority can be assigned to the threads just like the process, and the highest priority thread is scheduled first.
• Each thread has its own Thread control 
• . Like the process, a context switch occurs for the thread, and register contents are saved. As threads share the same address space and resources, synchronization is also required for the various activities of the thread.

Components of Threads

These are the basic components of the Operating System.

• Stack Space
• Register Set