General-Purpose Operating Systems (GPOSes) are being used more and more extensively to support interactive, real-time, and distributed applications, as found in the multimedia domain. In fact, the wide availability of supported multimedia devices and protocols, together with the wide availability of libraries and tools for handling multimedia contents, make them an almost ideal platform for the development of this kind of complex applications. However, contrarily to Real-Time Operating Systems, General-Purpose ones used to lack some important functionality needed for providing proper scheduling guarantees to application processes. Recently, the increasing use of GPOSes for multimedia applications is gradually pushing OS developers towards enriching the kernel of a GPOS so as to provide more and more real-time functionality, thus enhancing the performance and responsiveness of hosted time-sensitive applications. In this chapter, an overview is performed over the efforts done in the direction of enriching GPOSes with real-time capabilities, with a particular focus on the Linux OS. Due to its open-source nature and wide diffusion and availability, Linux is one of the most widely used OSes for such experimentations.
Open Source Real Time Operating Systems Overview