Novos FCFS: First Come, First Served Scheduling Environment – Basic Cooperative Multitasking
An Application Framework for First Come First Served architectures
A cooperatively scheduled, FCFS multitasking environment is one of the easiest to control and use. Background tasks are scheduled into the order of their arrival. Each of the Background tasks maintains control of the CPU only for as long as is necessary for it to do whatever portion of its work is required at that time. Interference from other Background tasks is eliminated, which simplifies debugging and testing.
Novos FCFS Event Action Routines and Deferred Interrupt Handlers add pre-emptive, priority scheduling of Foreground entities. This pre-emptive Foreground feature offers Hard Real-Time capabilities More
Why use the Novos FCFS Environment?
The Novos FCFS Environment also supports pre-emptive scheduling of Foreground tasks (FG tasks), which operate at higher priorities than the FCFS scheduled BG tasks. Any FG task can pre-empt a BG task but a BG task cannot pre-empt another BG task because all BG tasks, except the Idle Task, have the same priority level.
The mixed capability of the Novos FCFS Environment provides a very clean, provable operating environment that covers a broad spectrum of applications, including some that are mission critical.
Provable Hard Real-Time Performance
If there is a requirement for deterministic, hard real-time operations in the application, the Novos FCFS Environment includes Foreground tasks (FG tasks). When FG tasks are used in conjunction with Rate Monotonic Analysis, the Foreground entities in the Novos FCFS Environment can yield hard real-time performance with provable schedulability. More
It’s the easy way to develop application code quickly and efficiently
Novos FCFS provides:
- multitasking of Background tasks
- pre-emptive scheduling of all Foreground execution entities
- each BG task to has its own stack
- one stack for all Foreground entities
- data passing between the execution entities, including interrupt service routines
- recognition and synchronization of application code with external or internal events
- a standard model for interrupt servicing
- handling of time-based operations
- complete documentation available for sustainable system development and evolution
Robust Two-Level Interrupt Service Model
The Novos FCFS Application Framework uses two-level interrupt Service model that is common to all Novos Frameworks, providing a robust design and ease of handling interrupts. More
Minimized Event Jitter
“Jitter” can be defined as the variable response time to each instance of an event. Novos virtually eliminates jitter by supporting preemptively scheduled Foreground activities such as Event Action Routines (EARs) that respond to events in a timely, predictable manner. More
Highly Flexible Services
The Novos FCFS Application Framework embodies a set of 76 Services that support ten classes. View the Services Matrix
The Novos FCFS Environment is fully documented. We offer two separately available volumes of documentation for the Novos FCFS Environment, for a small charge. A System Reference Guide explains the Novos FCFS Environment design, its classes and how to use it. A Services Reference Guide gives a complete description of each Novos FCFS Environment API. Get the code and the docs and see how all of it can help on your next application.