Operating Systems Question Bank with Answers 19

What are the differences between a trap and an interrupt? What is the use of each function?

Question:

What are the differences between a trap and an interrupt? What is the use of each function?

Answer:

A trap is an exception that is reported immediately following the execution of the trapping instruction. It is a software-generated interrupt and is triggered by a user program to invoke operating system functionality.

An interrupt is a hardware-generated signal that changes the flow within the system. An interrupt handler is summoned to deal with the cause of the interrupt; control is then returned to the interrupted context and instruction.

An interrupt can be used to signal the completion of I/O so that the CPU doesn't have to spend cycles polling the device. A trap can be used to catch arithmetic errors or to call system routines.

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