Concept
Time Sharing
Time sharing is a CPU scheduling technique where the processor time is divided into small time intervals and allocated to multiple processes in rotation
Context Switch
A context switch is when the CPU stops executing one process and starts executing another
Before stop executing, CPU will save the current executing context into the process. This way, CPU can continue the process in the next time slice for this process
Example
Ready Queue
Ready queue stores the instruction that wants to be executed by the CPU. The instruction must first store all required data in the memory before entering the queue
CPU
When the CPU is empty, it’ll select an instruction from the ready queue and start executing.
The execution will end in two conditions:
- The time slice ends
- The instruction needs to grab data from hard disk
Event Queue
We store the request for hard disk data in this queue
Event
Hard disk reading and copying data to memory
