In the operating system, a thread is referred to as one unit of CPU usage and consists of registers, stack and program counter. A thread is also referred to as a thread of execution or control because of its crucial role in the performance of tasks within the Central processing unit of the computer. A thread can function as a single unit or as multiple numbers of threads working together as a unit in a single process. In as much as threads can be incorporated in a single process altogether, every thread is entitled to its distinct program counter as well as a range of control blocks and activation records. Thread is in most cases called a lightweight process because, in its functioning, the process can be divided or broken down into multiple threads functioning differently but with a single source of command and instruction. Every thread found in the same process applies a distinct program counter and also makes use of specific stacks of control blocks and activation records.
The functioning of threads can be made effective through the recreation of threads within already existing threads. This is whereby another thread within a running process is created than beginning the whole process of creation of a new thread in a new process. It is quite hard to do so, and therefore, for convenience and fast execution of tasks, there is a need to create threads from already existing ones. It saves time and energy for the user of the software. The ease of creating a new thread in an already existing process is made possible by the fact that threads can share common data(Sharif et al., 2020). Therefore, in this case, they do not require the application of inter-process communication. This means that context switching within the same process is a faster process when one is performing specific tasks by the use of threads. In the same way, another justification for the creation of a thread within an existing process is because termination of threads is much easier and takes lesser time than the termination of a process, which is more complex and takes a longer time.
Threads in operating systems are made up of components. The components work together to realize the success of the functions of the threads. One of the components of the threads is a program counter. The program counter is a processor in the Centrak Processing Unit which carries the location of the programs being handled at each particular time. The other component is a register set which is a group of data holding avenues that form the microprocessors of the computer. In addition, another component is the stack space which is a memory applied in the storage of non-permanent data used in the execution of programs. The non-permanent data is stored in the stack space for the purposes of use in the other processes that will be executed in the future. The components of threads are very important because they synchronize the activities of the threads to realize the desired outcomes of the processes(Faccia, 2019). The components are responsible for the coordination of functions in the appropriate steps to ensure the final result of the processes is achieved with the yielding of the best results.
Operating systems have two types of threads. One of the threads is referred to as a user-level thread. This thread is not recognized by the operating system. Hence, the user-level threads are manipulated and implemented through a user’s execution. Therefore, the implementation process of the user-level threads relies on the user’s decision. When the user institutes a user-level thread blocking execution, the entire operation process is halted. In this regard, the kernel-level thread treats the user-level thread in a way that indicates they are single-threaded processes(Sysel, 2020). User-level threads are very important in many ways. Among the advantages is the ease of implementation compared to kernel threads, they are faster to execute, they have a shorter context switch time which makes them very convenient for the users. They do not depend on the operating systems and they also possess simplicity in creation, switching, and synchronization without the help of the other processes. On the other hand, the disadvantages are the lack of coordination between the user-level thread with the kernel-level threads and ease in the blockade of the whole process in the case of a page fault. This may be disastrous since it may lead to lose of ongoing programs.
Another thread of the operating system is the kernel-level thread. This thread works in coordination with the operating system. This thread has a control block in its systems that functions with each process and thread. This thread is under full control of the operating system and therefore, it is established by the operating system. Kernel carries out the management of threads through a system call which assists in the management of the threads. The implementation of this thread is complex compared to the user-level threads. In the same way, they have a longer context switch time(Sysel, 2020). Among the advantages of kernel-level threads is the full awareness of threads, they are perfect for applications characterized by blocking of frequency, and lastly, there is a possibility of using more CPU time since threads are large and numerous. The disadvantages of these threads are that the threads are slow compared to the user level, difficult to implement, and overworking as a result of management and scheduling of threads.
Therefore, threads are very important components of the operating systems. They offer an array of advantages to the operating systems. Threads increase the number of tasks carried out within a given period. The resultant effect of this is an improvement in the efficiency of the operation of the CPU. In the same way, threads are important because they make good use of the multiprocessing systems. When a process has multiple threads, there is a possibility it scheduling one thread in multiple professors. Another importance of threads is quick context switching. This has an advantage on the speed of the CPU in the execution of processes. Similarly, threads are good for the operating systems because they enhance responsiveness, hence ensuring that the user of the operating systems is aware of the processes ongoing in the processors, hence providing a chance for the user to monitor the ongoing processes in the computer. Additionally, through threads, communication is enhanced. This is because of the presence of multiple-thread links which are created through the sharing of the same location which boosts communication among the threads. Resource sharing is another advantage of threads whereby threads share data, codes, and files to realize success in their functions. These significant roles demonstrate the usefulness of threads in operating systems.
References
Faccia, A. (2019). Data and Information Flows: Assessing Threats and Opportunities to Ensure Privacy and Investment Returns. In Proceedings of the 2019 3rd International Conference on Cloud and Big Data Computing (pp. 54-59).
Sharif, K. H., Zeebaree, S. R., Haji, L. M., & Zebari, R. R. (2020). Performance measurement of processes and threads controlling, tracking and monitoring based on shared-memory parallel processing approach. In 2020 3rd International Conference on Engineering Technology and its Applications (IICETA) (pp. 62-67). IEEE.
Sysel, M. (2020). A Comparison of Processes and Threads Creation. In Proceedings of the Computational Methods in Systems and Software (pp. 990-997). Springer, Cham.