CS 311 Fall 2010

CS 311- Fall 2010Midterm ReviewAgendaPart 1 quick review of resources, I/O, kernel, interrupts

Part 2 processes, threads, synchronization, concurrency

Part 3 specific synchronization considerations, concerns and techniques

Part 4 classic synchronization problems, examples, and algorithms

Part 5 Review of old exams

Abstract View of System 2004, D. J. Foreman3User SpaceO/S SpaceApplication Programming InterfaceTopicsBasic functions of an OSDev mgmtProcess & resource mgmtMemory mgmtFile mgmtFunctional organizationGeneral implementation methodologiesPerformanceTrusted softwareUNIX & WindowsNT organization 2004, D. J. Foreman4Design ConstraintsPerformanceSecurityCorrectnessMaintainabilityCost and "sell-ability"StandardsUsability 2004, D. J. Foreman5Resource ManagementResourcesMemoryCPU cyclesI/OIncludes networks, robot arms, motorsThat is, any means of getting information (or signals) into or out of the computer

2004, D. J. Foreman6Resource SharingWhy do we need to share?Greater throughputLowers cost of resourcesAllows more resources to be available

2004, D. J. Foreman7Executing User ProgramsBatch Programming (olden days)Scheduled tasksMaximize throughput

Multiprogramming (modern OS)Multiple user programsTimesharingMaximize response time

I/O TechniquesProgrammed I/OProcessor repeatedly check I/O status registerInterrupt-Driven I/OI/O interrupts processor when I/O is readyProcessor interrupted and involved in every word of data in the Read/WriteDMAProcessor delegates the work to the I/O deviceI/O interrupts processor only upon completionMemoryHierarchyregisters