From 41756b4424f45167d13f18dd5f86532e1bc1b67d Mon Sep 17 00:00:00 2001 From: mo khan Date: Sun, 24 Jan 2021 13:39:24 -0700 Subject: add notes --- doc/1.md | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/doc/1.md b/doc/1.md index b912a6b..cd5008f 100644 --- a/doc/1.md +++ b/doc/1.md @@ -148,3 +148,10 @@ the users can interact with each program while it is running. A program laoded into memory and executing is called a process. When a process executes, it typically executes for only a short time before it either finishes or needs to perform I/O. + +Modern operating systems are interrupt driven. +Events are almost always signaled by the occurrence of an interrupt or a trap. + +A trap, or an exception, is a software generated interrupt caused either by +an error or by a specific request from a user program that an operating-system +service be performed. -- cgit v1.2.3