Many embedded developers who are familiar with real-time operating systems (RTOS) consider the Unix process model to be cumbersome. On the other hand, they see a similarity between an RTOS task and a Linux thread and they have a tendency to transfer an existing design using a one-to-one mapping of RTOS tasks to threads. I have, on several occasions, seen designs in which the entire application is implemented with one process containing 40 or more threads. I want to spend some time considering whether this is a good idea or not. Let's begin with some definitions.
A process is a memory address space and a thread of execution, as shown in the following diagram. The address space is private to the process and so threads running ...
