Basics of Operating System

Modern computer automation systems usually work under management operating rooms systems real time (RTOS), which allow simultaneously decide row necessary tasks and provide the required response to events occurring in the system. The main task in such systems is the timeliness of execution processing data. RTOS obliged support multithreading, guaranteed response time to an external event, easy access to timer and external devices. Ability guarantee time reactions is an distinctive sign similar systems. However It is important to keep in mind the distinction between certainty and simply high performance and low overhead. Not everyone algorithms and technical solutions, even and providing excellent average time reactions suitable for RTOS.
AT the present time users offered large choice RTOS of various manufacturers, which differ in their technical economic characteristics. AT last review "Real Time magazine" (NN 2-3.97) It was mentioned near sixty systems. AT Appendix A lists the technical characteristics of some of them. RTOS more more, if have in mind non-commercial operating rooms systems real time. However herself specifics applications real-time operating systems require guarantees of reliability, and guarantees in volume including and legal - this, apparently can explain the fact that among non-commercial real-time systems no any popular. Among commercial systems real time can highlight group leading systems - on volumes sales and on popularity. These systems: VxWorks, OS9, psos, LynxOS, qnx, VRTX. Choosing an RTOS for a particular application is very important. For this purpose, it is necessary to analyze the subject area of the RTOS, give fundamental definitions and detailed interpretations of individual terms consider structure RTOS and highlight most common and generally recognized.