Examples of real-time operating systems. Examples of network operating systems

The real-time operating system (RTOS) is an OS that guarantees a certain ability for a given time interval. For example, it can be designed to show that an object has become available to the robot on the assembly line. Such shells are classified into "hard" and "soft".

Rigid real-time operating systems assume that the calculation can not be performed if the object is not available at the scheduled time (such an operation will fail).

In a soft operating system, in real time, the assembly line will continue to function under such conditions, but the production volume may be lower, since the objects are not able to be available at the appointed time, as a result of which the robot will be temporarily unproductive.

Before you give examples of real-time operating systems, you need to understand the features of their use. Some such OSs are created for a special application, others for a more general one. In addition, some general-purpose shells are also sometimes used to operate in real-time mode. As examples of operating systems of this type can come out well-known Windows 2000 or IBM Microsoft / 390. That is, even if the OS does not meet certain requirements, it may have characteristics that allow it to be viewed as a solution for a particular application task in real time.

Examples of operating systems and their characteristics

In general, real-time operating systems have the following characteristics:

• Multitasking.
• Technological flows that can be a priority.
• A sufficient number of interrupt levels.

The real-time OS is often used in small embedded shells that are used in the format of micro-devices. For example, some kernels can be considered as single-tasking operating systems (examples: kernels in IOS, Android, etc.) in real time. However, to perform their tasks, other components of the device, for example, drivers, are required. That's why a full-fledged real-time operating system, as a rule, happens more than just a kernel.

A typical example of an RTOS application is an HDTV receiver and display. It must read the digital signal, decode it and display it as incoming data. Any delay will be noticeable as pixel video and / or distorted sound.

However, when the request "give examples of operating systems of this type" sounds, the most well-known names are mentioned. What is included in this group?

VxWorks from WindRiver

VxWorks is a real-time operating system developed as proprietary software with the help of WindRiver. Originally released in 1987, VxWorks was originally designed to be used in embedded systems that require real-time and deterministic performance. Thus, examples of operating systems of this type find application in the areas of security and safety, various industries (especially aerospace and defense), the production of medical devices, industrial equipment, robotics, energy, transport management, network infrastructure, and the improvement of automotive and consumer electronics.

VxWorks supports Intel (x86, including the new version of IntelQuarkSoC and x86-64), MIPS, PowerPC, SH-4 and ARM-architecture. This RTOS comes with a powerful kernel, middleware, support for additional paid packages and third-party hardware technologies. In its latest release - VxWorks 7 - the system was upgraded for modularity and upgrade so that the OS kernel is kept separate from middleware, applications and other packages.

QNX Neutrino

Also classic examples of operating systems of this type are some Unix-like shells. This is QNX Neutrino, originally developed in the early 1980s by the Canadian company Quantum Software Systems. Ultimately, the development was purchased by BlackBerry in 2010. QNX is one of the first commercially successful microkernel operating systems that is used in various devices, including auto- and mobile phones.

FreeRTOS

FreeRTOS is a popular nuclear OS in real-time for embedded devices, which is loaded by 35 microcontrollers. It is distributed under the GPL with an additional restriction and optional exceptions. The restriction prohibits benchmarking, while the exception allows you to use your own user code along with the closed source, while keeping the kernel itself. This makes it easier to use FreeRTOS in your own applications.

Windows CE

Windows Embedded Compact is the operating system of the subfamily, developed by Microsoft Corporation within the Windows Embedded family of products. Unlike Windows Embedded Standard, which is based on Windows NT, these operating system examples use an exclusive hybrid core. Microsoft provides Windows CE licenses to original equipment manufacturers who can modify and create their own user interfaces, providing a technical basis for this.