Computers as Components, 2nd Edition

294 CHAPTER 6 Processes and Operating Systems

We are particularly interested in real-time operating systems (RTOSs),which

are OSs that provide facilities for satisfying real-time requirements.A RTOS allocates

resources using algorithms that take real time into account. General-purpose OSs,

in contrast, generally allocate resources using other criteria like fairness. Trying to

allocate the CPU equally to all processes without regard to time can easily cause

processes to miss their deadlines.

In the next section, we will introduce the concepts of task and process.

Section 6.2 looks at how the RTOS implements processes. Section 6.3 develops algo-

rithms ...