Slide
... • A task created by the OS, running in a restricted virtual machine environment –a virtual CPU, virtual memory environment, interface to the OS via system calls • Sequential, instruction-at-a-time execution of a program. Operating system abstraction to represent what is needed to run a single, multi ...
... • A task created by the OS, running in a restricted virtual machine environment –a virtual CPU, virtual memory environment, interface to the OS via system calls • Sequential, instruction-at-a-time execution of a program. Operating system abstraction to represent what is needed to run a single, multi ...
ComputersandFiles
... Computers and Files What you need to know before we start making web pages ...
... Computers and Files What you need to know before we start making web pages ...
slides.01.pdf
... Problem: the execution of a program requires the allocation of resources (CPU, disks, etc) needed by that program. We therefore need to keep track of these allocations. Model: however, a program is just a series of instructions: you can’t allocate anything to that. Instead, we construct a representa ...
... Problem: the execution of a program requires the allocation of resources (CPU, disks, etc) needed by that program. We therefore need to keep track of these allocations. Model: however, a program is just a series of instructions: you can’t allocate anything to that. Instead, we construct a representa ...
ICS 143 - Introduction to Operating Systems
... resulting in 100’s of concurrent program threads sharing system resources ...
... resulting in 100’s of concurrent program threads sharing system resources ...
Lecture 01 Introduction
... • A microkerner architecture assigns only a few essential functions to the kernel, such as – Address spaces – Interprocess communication – Basic scheduling ...
... • A microkerner architecture assigns only a few essential functions to the kernel, such as – Address spaces – Interprocess communication – Basic scheduling ...
Document
... If user programs execute with the mode bit clear, and do not have privilege to set it, how can they invoke the OS so that it can run with the mode bit set? ...
... If user programs execute with the mode bit clear, and do not have privilege to set it, how can they invoke the OS so that it can run with the mode bit set? ...
course syllabus
... By the end of the semester, students in this course would have developed their own basic functions of an operating system through the completion of a series of laboratory assignment. The lectures will help to familiarize students with the main concepts of an operating system. Technical Requirements: ...
... By the end of the semester, students in this course would have developed their own basic functions of an operating system through the completion of a series of laboratory assignment. The lectures will help to familiarize students with the main concepts of an operating system. Technical Requirements: ...
Lecture 5
... • An OS abstracts away the details of hardware from programmers and users who do not need to know these details. • High-level languages are very hard to implement without an OS. Platform-independence is not practical. • In a system without an OS, such as a microcontroller used with a small embedded ...
... • An OS abstracts away the details of hardware from programmers and users who do not need to know these details. • High-level languages are very hard to implement without an OS. Platform-independence is not practical. • In a system without an OS, such as a microcontroller used with a small embedded ...
Operating Systems I: Chapter 3
... – Main memory is a volatile storage device. It loses its contents in the case of system failure – It is a repository of quickly accessible data shared by the CPU and I/O devices For a program to be executed it must be mapped to absolute addresses and loaded into main memory – To improve CPU utilizat ...
... – Main memory is a volatile storage device. It loses its contents in the case of system failure – It is a repository of quickly accessible data shared by the CPU and I/O devices For a program to be executed it must be mapped to absolute addresses and loaded into main memory – To improve CPU utilizat ...
System Calls
... user interface (GUI) All operating systems have an interface to it that is accessible by users/user programs ...
... user interface (GUI) All operating systems have an interface to it that is accessible by users/user programs ...
3 Operating Systems
... Every time the operator had to do something like enter data on switches or rewind a tape, the CPU would be left idle. Since operators wouldn't know how long it would take to translate a program, or assemble it, or run it, they couldn't be instantly ready to start the next step in the process. So tim ...
... Every time the operator had to do something like enter data on switches or rewind a tape, the CPU would be left idle. Since operators wouldn't know how long it would take to translate a program, or assemble it, or run it, they couldn't be instantly ready to start the next step in the process. So tim ...
ch01-1
... program: A set of instructions that are to be carried out by a computer. program execution: The act of carrying out the instructions contained in a program. ...
... program: A set of instructions that are to be carried out by a computer. program execution: The act of carrying out the instructions contained in a program. ...
Operating Systems and File Management Learning Steps LAP CC
... examples of file management utilities provided by operating systems. f) These utilities allow you to find, rename, copy, move, and delete files and folders. In addition they allow you to perform file management activities with more than one file at a time. The way that data is actually stored is ref ...
... examples of file management utilities provided by operating systems. f) These utilities allow you to find, rename, copy, move, and delete files and folders. In addition they allow you to perform file management activities with more than one file at a time. The way that data is actually stored is ref ...
CITS2002 Systems Programming An Introduction to Operating
... The trend was towards many small mid-range personal computers, rather than a single mainframe. Early minicomputers and microcomputers were simple in their hardware architectures, and so there was some regression to earlier operating system ideas (single user, no pre-emption, no multiprogramming). Fo ...
... The trend was towards many small mid-range personal computers, rather than a single mainframe. Early minicomputers and microcomputers were simple in their hardware architectures, and so there was some regression to earlier operating system ideas (single user, no pre-emption, no multiprogramming). Fo ...
Interfacing with the Operating System
... space and actual memory locations. • We can see how this works by considering computers with a very small amount of memory – le’ts say 4096 bytes. • If the processor used 2 byte integers to hold addresses it could in principle refer to 65536 (2 ** 16) locations. • But only 4096 of these could actual ...
... space and actual memory locations. • We can see how this works by considering computers with a very small amount of memory – le’ts say 4096 bytes. • If the processor used 2 byte integers to hold addresses it could in principle refer to 65536 (2 ** 16) locations. • But only 4096 of these could actual ...
Programming Languages
... Determines the memory locations that code from each module will occupy and relocates instructions by adjusting absolute references Resolves references among files Chapter 17 Programming Tools ...
... Determines the memory locations that code from each module will occupy and relocates instructions by adjusting absolute references Resolves references among files Chapter 17 Programming Tools ...
1 - Shrek
... command to recompile them. The decision is mainly based on “last modified time” of different sources and objects. The make utility uses a file usually named Makefile or makefile to represent dependencies between source files. Makefile consists of command like these: Rule_name:[list of rule dependenc ...
... command to recompile them. The decision is mainly based on “last modified time” of different sources and objects. The make utility uses a file usually named Makefile or makefile to represent dependencies between source files. Makefile consists of command like these: Rule_name:[list of rule dependenc ...
Introduction - Portal UniMAP
... More than 80% of the software budget went to maintenance (only the remaining 20% for new software development). ...
... More than 80% of the software budget went to maintenance (only the remaining 20% for new software development). ...
Unit I Introduction
... • The programs can access directly to some function in superivor mode throught a System ...
... • The programs can access directly to some function in superivor mode throught a System ...
Operating System Structures
... • Services that operating system provides to programs • Program execution (loading into memory and starting) • I/O operations — because programs can not usually access peripheral devices directly, operating system must offer services for it • File system manipulation — file creation, deletion, readi ...
... • Services that operating system provides to programs • Program execution (loading into memory and starting) • I/O operations — because programs can not usually access peripheral devices directly, operating system must offer services for it • File system manipulation — file creation, deletion, readi ...
Authentication is the process of determining whether someone or
... A condition imposed by an operating system in 207 which only one process can hold a resource. In computer science, mutual exclusion refers to the requirement of ensuring that no two concurrent processes[a] are in their critical section at the same time; it is a basic requirement in concurrency contr ...
... A condition imposed by an operating system in 207 which only one process can hold a resource. In computer science, mutual exclusion refers to the requirement of ensuring that no two concurrent processes[a] are in their critical section at the same time; it is a basic requirement in concurrency contr ...
Slides
... Abstract Factory groups object factories that have a common theme. Builder constructs complex objects by separating construction and representation. Factory Method creates objects without specifying the exact class to create. Prototype creates objects by cloning an existing object. Singleton restric ...
... Abstract Factory groups object factories that have a common theme. Builder constructs complex objects by separating construction and representation. Factory Method creates objects without specifying the exact class to create. Prototype creates objects by cloning an existing object. Singleton restric ...
Library (computing)
In computer science, a library is a collection of non-volatile resources used by computer programs, often to develop software. These may include configuration data, documentation, help data, message templates, pre-written code and subroutines, classes, values or type specifications. In IBM's OS/360 and its successors they are referred to as partitioned data sets.In computer science, a library is a collection of implementations of behavior, written in terms of a language, that has a well-defined interface by which the behavior is invoked. This means that as long as a higher level program uses a library to make system calls, it does not need to be re-written to implement those system calls over and over again. In addition, the behavior is provided for reuse by multiple independent programs. A program invokes the library-provided behavior via a mechanism of the language. For example, in a simple imperative language such as C, the behavior in a library is invoked by using C's normal function-call. What distinguishes the call as being to a library, versus being to another function in the same program, is the way that the code is organized in the system. Library code is organized in such a way that it can be used by multiple programs that have no connection to each other, while code that is part of a program is organized to only be used within that one program. This distinction can gain a hierarchical notion when a program grows large, such as a multi-million-line program. In that case, there may be internal libraries that are reused by independent sub-portions of the large program. The distinguishing feature is that a library is organized for the purposes of being reused by independent programs or sub-programs, and the user only needs to know the interface, and not the internal details of the library.The value of a library is the reuse of the behavior. When a program invokes a library, it gains the behavior implemented inside that library without having to implement that behavior itself. Libraries encourage the sharing of code in a modular fashion, and ease the distribution of the code. The behavior implemented by a library can be connected to the invoking program at different program lifecycle phases. If the code of the library is accessed during the build of the invoking program, then the library is called a static library. An alternative is to build the executable of the invoking program and distribute that, independently from the library implementation. The library behavior is connected after the executable has been invoked to be executed, either as part of the process of starting the execution, or in the middle of execution. In this case the library is called a dynamic library. A dynamic library can be loaded and linked as part of preparing a program for execution, by the linker. Alternatively, in the middle of execution, an application may explicitly request that a module be loaded.Most compiled languages have a standard library although programmers can also create their own custom libraries. Most modern software systems provide libraries that implement the majority of system services. Such libraries have commoditized the services which a modern application requires. As such, most code used by modern applications is provided in these system libraries.