tailieunhanh - Operating System Basics

Operating System Basics .What is an Operating System • Resource Manager - Resource include: CPU, memory, disk, network - OS allocates and de-allocates these resources • Virtual Machine - provides an abstraction of a larger (or | lesson 11 Operating System Basics Resource Manager - Resource include: CPU, memory, disk, network - OS allocates and de-allocates these resources Virtual Machine - provides an abstraction of a larger (or just different machine) - Example: - Virtual memory: looks like more memory - Java: pseudo machine that looks like a stack machine - IBM VM: a complete virtual machine Multiplexor - allows sharing of resources and protection What is an Operating System Provider of Services - includes most of the things in the above definitions - provide “common” subroutes for the programmer - windowing systems - memory management The software that is always loaded/running - generally refers to the OS kernel - small protected piece of software All of these definitions are correct - but not all operating have all of these features What is OS (cont.) Robustness - accept all valid input - detect and gracefully handle all invalid input - should not be possible to crash the OS Consistency - same operation | lesson 11 Operating System Basics Resource Manager - Resource include: CPU, memory, disk, network - OS allocates and de-allocates these resources Virtual Machine - provides an abstraction of a larger (or just different machine) - Example: - Virtual memory: looks like more memory - Java: pseudo machine that looks like a stack machine - IBM VM: a complete virtual machine Multiplexor - allows sharing of resources and protection What is an Operating System Provider of Services - includes most of the things in the above definitions - provide “common” subroutes for the programmer - windowing systems - memory management The software that is always loaded/running - generally refers to the OS kernel - small protected piece of software All of these definitions are correct - but not all operating have all of these features What is OS (cont.) Robustness - accept all valid input - detect and gracefully handle all invalid input - should not be possible to crash the OS Consistency - same operation should mean the same thing * read from a file or a network should look the same * a “-” flag should be the same in different commands - conventions * define the convention * follow the convention when adding new items Usability Goals Proportionality - simple, common cases are easy and fast * good default values - complex, rare cases are possible but more complex and slower * “rm” should give a warning * formatting the disk should not be on the desktop next to the trash can Usability Goals (cont.) This lesson includes the following sections: The User Interface Running Programs Managing Files Managing Hardware Utility Software Graphical User Interfaces (GUIs) GUI Tools Applications and the Interface Menus Dialog Boxes Command-Line Interfaces The User Interface Graphical User Interfaces (GUIs) GUI Tools Applications and the Interface Menus Dialog Boxes Command-Line Interfaces The User Interface Most modern operating systems, like Windows and the Macintosh OS, provide a graphical user .