C:\UMBC\331\java> java.ext.dirs=C:\JDK1.2\JRE\lib\ext java.io.tmpdir=C:\WINDOWS\TEMP\ os.name=Windows 95 java.vendor=Sun Microsystems Inc. java.awt.printerjob=sun.awt.windows.WPrinterJob java.library.path=C:\JDK1.2\BIN;.;C:\WINDOWS\SYSTEM;C:\... java.vm.specification.vendor=Sun Microsystems Inc. sun.io.unicode.encoding=UnicodeLittle file.encoding=Cp1252 java.specification.vendor=Sun Microsystems Inc. user.language=en user.name=nicholas java.vendor.url.bug=http://java.sun.com/cgi-bin/bugreport... java.vm.name=Classic VM java.class.version=46.0 java.vm.specification.name=Java Virtual Machine Specification sun.boot.library.path=C:\JDK1.2\JRE\bin os.version=4.10 java.vm.version=1.2 java.vm.info=build JDK-1.2-V, native threads, symcjit java.compiler=symcjit path.separator=; file.separator=\ user.dir=C:\UMBC\331\java sun.boot.class.path=C:\JDK1.2\JRE\lib\rt.jar;C:\JDK1.2\JR... user.name=nicholas user.home=C:\WINDOWS C:\UMBC\331\java>java envSnoop -- listing properties -java.specification.name=Java Platform API Specification awt.toolkit=sun.awt.windows.WToolkit java.version=1.2 java.awt.graphicsenv=sun.awt.Win32GraphicsEnvironment user.timezone=America/New_York java.specification.version=1.2 java.vm.vendor=Sun Microsystems Inc. user.home=C:\WINDOWS java.vm.specification.version=1.0 os.arch=x86 java.awt.fonts= java.vendor.url=http://java.sun.com/ user.region=US file.encoding.pkg=sun.io java.home=C:\JDK1.2\JRE java.class.path=C:\Program Files\PhotoDeluxe 2.0\Adob... line.separator=
View full slide show




I/O Structure  After I/O starts, control returns to user program without waiting for I/O completion  System call – request to the operating system to allow user to wait for I/O completion  Device-status table contains entry for each I/O device indicating its type, address, and state  Operating system indexes into I/O device table to determine device status and to modify table entry to include interrupt Operating System Concepts with Java – 8th Edition 1.13 Silberschatz, Galvin and Gagne ©2009
View full slide show




I/O Structure After I/O starts, control returns to user program only upon I/O completion  Wait instruction idles the CPU until the next interrupt  Wait loop (contention for memory access)  At most one I/O request is outstanding at a time, no simultaneous I/O processing  After I/O starts, control returns to user program without waiting for I/O completion  System call – request to the operating system to allow user to wait for I/O completion  Device-status table contains entry for each I/O device indicating its type, address, and state  Operating system indexes into I/O device table to determine device status and to modify table entry to include interrupt  Operating System Concepts – 8th Edition 1.15 Silberschatz, Galvin and Gagne ©2009
View full slide show




Chapter 2: Operating-System Structures  Operating System Services  User Operating System Interface  System Calls  Types of System Calls  System Programs  Operating System Design and Implementation  Operating System Structure  Virtual Machines  Operating System Debugging  Operating System Generation  System Boot Operating System Concepts – 8th Edition 2.2 Silberschatz, Galvin and Gagne ©2009
View full slide show




Chapter 2: Operating-System Structures  Operating System Services  User Operating System Interface  System Calls  Types of System Calls  System Programs  Operating System Design and Implementation  Operating System Structure  Virtual Machines  Operating System Debugging  Operating System Generation  System Boot Operating System Concepts – 8th Edition 2.2 Silberschatz, Galvin and Gagne ©2009
View full slide show




Chapter 2: Operating-System Structures  Operating System Services  User Operating System Interface  System Calls  Types of System Calls  System Programs  Operating System Design and Implementation  Operating System Structure  Virtual Machines  Operating System Debugging  Operating System Generation  System Boot Operating System Concepts Essentials – 8th Edition 2.2 Silberschatz, Galvin and Gagne ©2011
View full slide show




Types of System Calls (Cont.)    Device management  request device, release device  read, write, reposition  get device attributes, set device attributes  logically attach or detach devices Information maintenance  get time or date, set time or date  get system data, set system data  get and set process, file, or device attributes Communications  create, delete communication connection  send, receive messages  transfer status information  attach and detach remote devices Operating System Concepts – 8th Edition 2.21 Silberschatz, Galvin and Gagne ©2009
View full slide show




Types of System Calls (Cont.)    Device management  request device, release device  read, write, reposition  get device attributes, set device attributes  logically attach or detach devices Information maintenance  get time or date, set time or date  get system data, set system data  get and set process, file, or device attributes Communications  create, delete communication connection  send, receive messages  transfer status information  attach and detach remote devices Operating System Concepts Essentials – 8th Edition 2.21 Silberschatz, Galvin and Gagne ©2011
View full slide show




Chapter 2: Operating-System Structures  Operating System Services  User Operating System Interface  System Calls  Types of System Calls  System Programs  Operating System Design and Implementation  Operating System Structure  Operating System Debugging  System Boot Operating System Concepts – 9th Edition 2.2 Silberschatz, Galvin and Gagne
View full slide show




Operating System Services  Operating systems provide an environment for execution of programs and services to programs and users  One set of operating-system services provides functions that are helpful to the user:  User interface - Almost all operating systems have a user interface (UI).  Varies between Command-Line (CLI), Graphics User Interface (GUI), Batch  Program execution - The system must be able to load a program into memory and to run that program, end execution, either normally or abnormally (indicating error)  I/O operations - A running program may require I/O, which may involve a file or an I/O device  File-system manipulation - The file system is of particular interest. Programs need to read and write files and directories, create and delete them, search them, list file Information, permission management. Operating System Concepts – 8th Edition 2.4 Silberschatz, Galvin and Gagne ©2009
View full slide show




I/O Structure   After I/O starts, control returns to user program only upon I/O completion  Wait instruction idles the CPU until the next interrupt  Wait loop (contention for memory access)  At most one I/O request is outstanding at a time, no simultaneous I/O processing After I/O starts, control returns to user program without waiting for I/O completion  System call – request to the OS to allow user to wait for I/O completion  Device-status table contains entry for each I/O device indicating its type, address, and state  OS indexes into I/O device table to determine device status and to modify table entry to include interrupt Operating System Concepts – 9th Edition 1.16 Silberschatz, Galvin and Gagne ©2013
View full slide show




Operating System Providing Mandatory Access Control  Operating system has the TCB; Data manager is untrusted Unclassified device Secret device TopSecret device  An instance of the data manager is created at each level (e.g., U, S, TS); note: only one data manager (e.g., Oracle) but multiple instances (processes)  Secret user/device enters data and the Secret instance will write the data to the Secret operating system file Multilevel  Operating system will control the write operation to the operating system file Data Manager  Secret user/device queries for data Unclassified Data Secret Data TopSecret Data  Secret instance will open both Secret and Unclassified operating system files and read from them, recombine the data and give the data to the Secret user  Operating system will control the read operation to the operating system files
View full slide show




Computer-System Operation  I/O devices and the CPU can execute concurrently  Each device controller is in charge of a particular device type  Each device controller has a local buffer  CPU moves data from/to main memory to/from local buffers  I/O is from the device to local buffer of controller  Device controller informs CPU that it has finished its operation by causing an interrupt Operating System Concepts with Java – 8th Edition 1.9 Silberschatz, Galvin and Gagne ©2009
View full slide show