Advantage of one to one thread model

In this article, we will learn about the advantages of one to one thread model. Before starting you must have a basic knowledge of threads, types of thread, and types of multithreading models.

Thread Overview :

• A thread is a flow of execution via the method code, with its personal software counter that continues music of which coaching to execute next, machine registers which preserve its present-day running variables, and a stack which incorporates the execution history.
• A thread is the smallest unit in multi-threading and it is known as a lightweight process. Through parallelism, it offers a manner to enhance software overall performance.
• Each thread represents a separate float of control. 
• Threads were effectively utilized in imposing community servers and network servers. 
• They additionally offer an appropriate basis for the parallel execution of programs on shared reminiscence multiprocessors. The following parent indicates the running of a single-threaded and a multithreaded system.

Types of thread :
Types of thread in an operating system are as follows.

1. User Level Threads – 
   The user-level threads are applied with the aid of using customers and the kernel isn’t always privy to the lifestyles of those threads. It handles them as though they have been single-threaded processes. User-degree threads are small and plenty quicker than kernel-level threads. They are represented with the aid of using a software counter(PC), stack, registers, and a small manner manipulate a block. Also, there may be no kernel involvement in synchronization for user-degree threads.
    
2. Kernel Level Threads – 
   Kernel-level threads are treated through the working gadget immediately and the thread control is accomplished through the kernel. The context facts for the procedure in addition to the procedure threads are all controlled through the kernel, and that is the reason that the kernel-level threads are slower than user-level threads.

Multithreading Models :
Some working devices offer a mixed consumer degree thread and Kernel level thread facility. Solaris is a great instance of this mixed approach. In a mixed device, more than one thread inside the equal utility can run in parallel on more than one processor, and blocking off device name want now no longer blocks the complete process. 

Types of Multithreading Models :
Types of multithreading models are as follows.

1. Many to many – 
   This version multiplexes any quantity of person threads onto an identical or smaller quantity of kernel threads.
    
2. Many to one – 
   Maps many person-level threads to at least one Kernel-level thread. Thread control is completed in a personal area with the aid of using the thread library. When the thread makes a blockading machine call, the complete procedure may be blocked. Only one thread can get the right of entry to the Kernel at a time, so multiple threads aren’t capable of run in parallel on multiprocessors.
    
3. One to one – 
   There is one-to-one courting of user-level thread to the kernel-level thread. This version gives greater concurrency than the many-to-one version. It additionally permits any other thread to run while a thread makes a blocking off gadget call. It helps more than one thread to execute in parallel on microprocessors.

Advantages of one to one Model : 
The advantages of one to one model are as follows.

• Scalable parallelism – 
  It is because every kernel thread is truly a specific kernel-schedulable entity, a couple of threads can run simultaneously on specific processors. Thus, multithreaded packages written below the one-to-one version can attain tremendous speedups while migrated from uniprocessors to multiprocessors.
   
• Multithreaded OS interface –  
  It is not like the many-to-one model, threads blocking off withinside the kernel do now no longer hinder technique development below the one-to-one model. When one person thread and its kernel thread block, the alternative person threads can preserve to execute given that their kernel threads are unaffected.

Disadvantages :
The disadvantage of this version is that the developing person thread calls for the corresponding Kernel thread. OS/2, home windows NT and home windows 2000 use one to at least one courting version.