Operating System Essay Example | Topics and Well Written Essays - 1750 words

Operating System - Essay Example (e.g. for a system call). This mechanism is used to prevent programming mistakes with system resources. It also shares common system resources in an appropriate manner under OS control. It prevents accessibility to protected memory segments. It also identifies instructions that can cause error conditions and inconsistent system state. Memory location of interrupt handler that signifies interrupts and also will save them in a queue if multiple interrupts are in processing, is called interrupt vector. The interrupt vector is a matrix of pointers to specific interrupt-handling routines. A hardware part that is called the device controller along with any device makes up the computer system. The device controllers basically acts as an interface between the device and the OS of that computer. Device controllers is also responsible of transferring data from other devices that controls it and the local buffers. To store and execute necessary commands in device controller, registers and buffers are integrated in the device controller. To provide interface between a device controller and OS, there is a device driver in OS that presents a steady interface into the device. First the device driver is introduced in to the OS to which the device is to be connected and then User and the system can exchange data with help of device through the device itself. In multiprocessor, two copies of the same data may reside in the local cache of each CPU. If one of the CPU changes the data, the Caches of the other cache coherency includes. Storing the data in multiple caches signifies one of the best ways of storing data. In this kind of shared memory, there is different cache memory for each of the processors. It is possible that many copies of one direction operand would exist on multiple caches that would exist on different processors. If one copy is changed, all the copies that are present on the other

Petroleum paper Essay Example | Topics and Well Written Essays - 750 words

Petroleum paper - Essay Example It is believed that the heat converted the remains of the animals and sea-plants trapped on the seabed to petroleum. When refined, petroleum separates into various fractions of useful hydrocarbons. Thus, petroleum is not beneficial in the raw form. The economic resource category of the petroleum is the land. The common petroleum products and derivatives, which average American family uses and interacts with include shoe polish, nail polish, lipstick, toothpaste, antiseptics, shampoos, mineral spirits, dyes, insecticides, and crayons. The products and derivatives satisfy the needs of the American families in many ways. Toothpaste is a petroleum derivative, and every American uses the product on a daily basis. Americans use the toothpaste to clean their teeth. In effect, the toothpaste protects the teeth against cavities, yellowing, as well as accumulation of tartar. It removes the bacteria that tend to grow on teeth and cause gum disease and cavities. Shoe polish comprises of turpentine, naphtha, and dyes. The product is used to polish, as well as shine leather shoes. Shoe polish protects, maintains, restores, and improves the appearance of the footwear. Every American use shoe polish daily. Nail polish contains petroleum constituents such as adhesive polymers, plasticizers, and pigments. People use the polish to decorate their nails. The nail polish is a key product in the cosmetic industry, and average American uses it. The scientific name for clove is Cinnamomum verum. The product has antiseptic, as well as analgesic effects. Clove cleans open wounds and surfaces of objects such as toilets. Thus, the Americans use clove as a therapeutic agent against deadly microorganisms. The main uses of shampoo entail removal of dirt, oils, dandruff, skin particles, and contaminants that accumulate in the hair. In effect, shampoo protects the hair and makes it manageable. The product is useful in the cosmetic and beauty industry. Mineral spirit is a