Real-time Operating Systems (RTOS)

RTOS

A real-time operating system (RTOS) environment, the command will respond within a specified time. The actual time can be as the system response to small all instantly. A real-time operating system (RTOS) compresses two components, viz. "Real Time" and "operating system". Is the operating system (OS) but call a collection of systems or functions that offer an interface between hardware and application programs. To manage the hardware resources and run applications on your host computer.

A real-time application on an application that both precise results and the additional restrictions on the period is available. RTOS operating system is compatible with real-time applications and supply a logical consequence of the right time is essential. The basic structure is similar to the normal operating system, but also mechanisms to create enabling real-time programs. Must correspond to respond in real time, limited time, or to respond to serious consequences, including failure. Real-time systems are so hard, soft or hard classified.

Basic OS Functions:-

1. Process Management, 
2. Resources Management,
3. Device Management, 
4. I/O Devices subsystems 
5. Network Devices and subsystems management

Some generally used RTOS scheduling algorithms are:-

1. Cooperative scheduling

2. Preemptive scheduling

(I) Rate-monotonic scheduling
(II) Round-robin scheduling
(III) Fixed priority pre-emptive scheduling, an implementation of preemptive time slicing
(IV) Fixed-Priority Scheduling with Deferred Preemption
(V) Fixed-Priority Non-preemptive Scheduling
(VI) Critical section preemptive scheduling
(VII) Static time scheduling

3. Earliest Deadline First approach

4. Stochastic digraphs with multi-threaded graph traversal

For Information About DBMS Guide Check:- http://dbmsbook.blogspot.com
For Information About Spectroscopy Book Check:- http://spectroscopybook.blogspot.com/
For Information About Operating System (OS) Book Check:- http://operatingsystembook.blogspot.com

Check Labels For more Similar Jobs:-

Threads

Despite of the information that a thread must carry out in process, the process and its linked threads are diverse concept. Processes are accustomed to group resources jointly and threads are the entities scheduled for carrying out on the CPU.

A thread is a single series stream within in a process. Because threads have a few of the properties of processes, they are at times known as lightweight processes. In a process, threads permit many executions of streams. In lots of respect, threads are admired way to improve application through parallelism. The CPU switches quickly back and forth among the threads giving false impression that the threads are running in parallel.

Advantages of Threads over Multiple Processes:-

Context Switching:- Threads are very inexpensive to make and obliterate, and they are inexpensive to represent. For example, they need space to store, the PC, the SP, and the general-purpose register, but they do not need space to share memory information, Information about open files of I/O devices in use, etc. With so small context, it is much quicker to switch between threads. In extra words, it is comparatively easier for a context switch using threads.

Sharing:-  Treads permit the sharing of a lot resources that cannot be shared in process, for example, sharing code section, information section, Operating System resources like open file etc.

Disadvantages of Threads over Multiple Processes:-

Blocking:- The main disadvantage if that if the kernel is single threaded, a system call of one thread will block the whole process and CPU may be idle during the blocking time.

Security:- Since there is, an general sharing among threads there is a potential difficulty of security. It is quite possible that one thread over write the stack of another thread (or damaged shared data) although it is very not likely since threads are meant to cooperate on a single task.