|
| Home |
|
|
Real-TimeThe term real-time is often used but seldom defined. One possible definition is given here: Real-time software must deliver computation results under application specific time constraints. When a result is made available too late (or too early in some systems), the software has failed, even if the result is otherwise correct. This definition says nothing about multitasking. Multitasking is not necessarily required to develop real-time software; however, usually multitasking will simplify real-time software development. Multitasking can achieve excellent response times even when other jobs must be performed in parallel to the real-time processing. Prerequisites for real-time processing are a sufficiently small interrupt latency, a constant task switch time (which should be as small as possible), and, in many cases, preemptive scheduling. Therefore, complex operations with non-deterministic run-time requirements (e.g., loading a process from disk) cannot be performed by a real-time system during a task switch.
|
