How does the system scheduler schedule request processing?

The system scheduler in an operating system is responsible for allocating CPU time among processes and threads. The main principles of scheduling are:

• Priorities: processes with higher priority are given preference.
• Time quantum: each process is allocated a specific time slice (quantum), after which control is transferred to another process.
• Scheduling policies: various algorithms exist, such as Round Robin (cyclic traversal), FIFO, priority scheduling, multi-level queues.
• Process state consideration: the scheduler considers whether a process is ready to run or waiting for input/output.

In Go, the goroutine scheduler operates on a similar principle, distributing goroutines across system threads using M:N scheduling. It aims to efficiently utilize available cores by switching goroutines during blocking or after quantum expiration.

An example of a simplified Round Robin algorithm:

1. Place all ready processes in a queue.
2. Allocate the CPU to the first process in the queue for a quantum.
3. After the quantum, if the process is not finished, return it to the end of the queue.
4. Repeat as long as there are ready processes.

Thus, the scheduler ensures fair and efficient resource distribution.