A key job of the operating system (OS) is to schedule runnable tasks. The POSIX standard states that a POSIX-complaint OS must provide (at least) three scheduling policies. A scheduling policy is really the scheduling algorithm used by the OS to schedule tasks. In this book, we will not delve into such details, but we do need the application developer to be aware of the scheduling policies available. These are as follows:
- SCHED_FIFO
- SCHED_RR
- SCHED_OTHER (also known as SCHED_NORMAL)
Our discussions on this, naturally, will be solely with regard to the Linux OS.
The first important thing to understand is that the vanilla Linux OS is not an RTOS; it does not support hard real-time and is classified as a General Purpose ...