How do you implement a copy on write?

To implement copy-on-write, a smart pointer to the real content is used to encapsulate the object’s value, and on each modification an object reference count is checked; if the object is referenced more than once, a copy of the content is created before modification.

Where is Windows most used?

In the desktop world, Microsoft Windows is the most installed operating system and controls 82% of desktops.

Why do we need paging in operating system?

Paging is used for faster access to data. When a program needs a page, it is available in the main memory as the OS copies a certain number of pages from your storage device to main memory. Paging allows the physical address space of a process to be noncontiguous.

What are the advantages of Windows as an operating system explain?

The user interface of windows is also easy to use than UNIX and MAC. Software support: Windows platform is best suited for game and software developers. Windows have large number audience so developers prefer to make utilities, games and software for windows OS.

How does copy on write work?

The idea behind a copy-on-write is that when a parent process creates a child process then both of these processes initially will share the same pages in memory and these shared pages will be marked as copy-on-write which means that if any of these processes will try to modify the shared pages then only a copy of these …

What hardware does Windows work with?

Processor: 1 gigahertz (GHz) or faster. RAM: 1 gigabyte (GB) (32-bit) or 2 GB (64-bit) Free hard disk space: 16 GB. Graphics card: Microsoft DirectX 9 graphics device with WDDM driver.

What are the advantages and disadvantages of Unix operating system?


  • Full multitasking with protected memory.
  • Very efficient virtual memory, so many programs can run with a modest amount of physical memory.
  • Access controls and security.
  • A rich set of small commands and utilities that do specific tasks well — not cluttered up with lots of special options.

What is virtual memory and its advantages and disadvantages?

Disadvantages of Virtual Memory Offers lesser hard drive space for your use. It reduces system stability. It allows larger applications to run in systems that don’t offer enough physical RAM alone to run them. It doesn’t offer the same performance as RAM.

What do you mean by demand paging in OS?

In computer operating systems, demand paging (as opposed to anticipatory paging) is a method of virtual memory management. It follows that a process begins execution with none of its pages in physical memory, and many page faults will occur until most of a process’s working set of pages are located in physical memory.

What is spooling and its advantages?

Spooling is useful because devices access data at different rates. The spool buffer provides a waiting station where data can rest while a slower device, such as a printer, catches up. When the slower device is ready to handle a new job, it can read another batch of information from the spool buffer.

What are the uses of Windows operating system?

For example, you can use Windows to browse the Internet, check your email, edit digital photos, listen to music, play games, and do much more. Windows is also used in many offices because it gives you access to productivity tools such as calendars, word processors, and spreadsheets.

What is the copy on write feature and under what circumstances is it beneficial to use this feature?

What is the hardware support required to implement this feature? Answer: Copy on Write allows processes to share pages rather than each having a separate copy of the pages. However, when one process tried to write to a shared page, then a trap is generated and the OS makes a separate copy of the page for each process.

What are the three most common operating systems?

The three most common operating systems for personal computers are Microsoft Windows, macOS, and Linux. Operating systems use a graphical user interface, or GUI (pronounced gooey), that lets your mouse click buttons, icons, and menus, and displays graphics and text clearly on your screen.

What is paging and its advantages?

Allocating memory is easy and cheap. Any free page is ok, OS can take first one out of list it keeps. Eliminates external fragmentation. Data (page frames) can be scattered all over PM. Pages are mapped appropriately anyway.

What is the advantage and disadvantage of operating system?

It is safe like – windows have windows defender which detects any type of harmful files and removes them. By this, we can install any game or software and run them. Some operating systems (like – LINUX) are open source, we can run them on free on my computer. This increases the working efficiency of our system.

What is operating system and its services?

An Operating System provides services to both the users and to the programs. It provides programs an environment to execute. It provides users the services to execute the programs in a convenient manner.

What are the advantages and disadvantages of Windows operating system?

Advantages of using Windows:

  • Ease of use. Users familiar with earlier versions of Windows will probably also find the more modern ones easy to work with.
  • Available software.
  • Backwards compatibility.
  • Support for new hardware.
  • Plug & Play.
  • Games.
  • Compatibility with MS driven websites.

What are 3 devices that use Windows OS?

  • NEW Surface Laptop Go.
  • NEW Surface Go 2.
  • Surface Laptop 3.
  • Surface Pro 7.
  • NEW Surface Book 3.
  • Surface Pro X.
  • Surface Studio 2.
  • Dell XPS 15 7590.

Why do we need paging in operating system explain its advantages and disadvantages?

Advantages and Disadvantages of Paging Paging reduces external fragmentation, but still suffer from internal fragmentation. Paging is simple to implement and assumed as an efficient memory management technique. Due to equal size of the pages and frames, swapping becomes very easy.

What is an operating system and give examples?

An operating system, or “OS,” is software that communicates with the hardware and allows other programs to run. Every desktop computer, tablet, and smartphone includes an operating system that provides basic functionality for the device. Common desktop operating systems include Windows, OS X, and Linux.

Why is an OS important?

An operating system is the most important software that runs on a computer. It manages the computer’s memory and processes, as well as all of its software and hardware. It also allows you to communicate with the computer without knowing how to speak the computer’s language.

What are the three main purpose of an operating system?

An operating system has three main functions: (1) manage the computer’s resources, such as the central processing unit, memory, disk drives, and printers, (2) establish a user interface, and (3) execute and provide services for applications software.

What else is a command interpreter called?

Command interpreter is an important part of any operating system. It provides an interface between the user and the computer. A command interpreter is often also called a command shell or simply a shell.

What is the cause of thrashing How does the system?

In computer science, thrashing occurs when a computer’s virtual memory resources are overused, leading to a constant state of paging and page faults, inhibiting most application-level processing. This causes the performance of the computer to degrade or collapse.

What is paging with example?

In Operating Systems, Paging is a storage mechanism used to retrieve processes from the secondary storage into the main memory in the form of pages. The main idea behind the paging is to divide each process in the form of pages. The main memory will also be divided in the form of frames.

What is the need of page replacement?

In an operating system that uses paging for memory management, a page replacement algorithm is needed to decide which page needs to be replaced when new page comes in.

What is copy on write in operating system?

Copy-on-write or CoW is a technique to efficiently copy data resources in a computer system. If a unit of data is copied but not modified, the “copy” can exist as a reference to the original data. Only when the copied data is modified is a copy created, and new bytes are actually written.

What is operating system and give two examples?

Examples of Operating Systems Some examples include versions of Microsoft Windows (like Windows 10, Windows 8, Windows 7, Windows Vista, and Windows XP), Apple’s macOS (formerly OS X), Chrome OS, BlackBerry Tablet OS, and flavors of Linux, an open-source operating system.

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