Abstract
- Generated by the executing program itself. To accomplish User Space to Kernel Space control transfers
- A CPU Feature
- Synchronous
- Can be generated by Instruction like Trap Interrupt (陷入)
- An example is Alarm Signal
Mechanism
- Causes Process (进程) to temporarily suspend
- Save its Register on the Stack
- When Interrupt Handler is done, the running Process (进程) is restarted in the state it was in just before the signal
Benefits
Better Security
- Programs in User Space switching themselves is dangerous
- With Software Interrupt, the CPU is preconfigured by OS with where in the OS code to jump to
Examples
Alarm Signal
- Sent after a specified number of seconds has elapsed to notify a Process (进程) of an event
- Signal (Software Interrupt)