CHAPTER 3
Exercises
3.6 What are the differences among short-term, medium term, and long-term scheduling?
Answer:
The short-term scheduler selects from the ready processes the next process to run and gives it the CPU. The long-term scheduler selects from the pool of processes that are waiting on disk and loads the selected processes into memory. These processes have not yet begun their execution. The medium-term scheduler takes processes that are currently in memory and selects those to be swapped out to disk. These processes will be swapped back in at a later point. This is done to improve process mix or because of memory requirements like overcommitted and needs to free up memory.
A primary difference is in the frequency
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Describe the undesirable circumstances that could arise from not enforcing either the "at most once" or "exactly once" semantics. Describe possible uses for a mechanism that had neither of these guarantees.
Answer: If an RPC mechanism could not support either the “at most once” or “at least once” semantics, then the RPC server cannot guarantee that a remote procedure will not be invoked multiple occurrences. Consider if a remote procedure were withdrawing money from a bank account on a system that did not support these semantics. It is possible that a single invocation of the remote procedure might lead to multiple withdrawals on the server. For a system to support either of these semantics generally requires the server maintain some form of client state such as the timestamp described in the text. If a system were unable to support either of these semantics, then such a system could only safely provide remote procedures that do not alter data or provide time-sensitive results. Using our bank account as an example, we certainly require “at most once” or “at least once” semantics for performing a withdrawal or deposit. However, an inquiry into an account balance or other
3.12 Using the program shown in Figure 3.30, explain what the output will be at Line A.
Answer:
The output will be Parent: Value = 5. Once the
The problem I am going to work on is #68 on page 539 . The
1. The text states that the UCC has been adopted by all fifty states. What is the process by which these states adopted the UCC?
The unusual thing about the garden is where it’s located, because it’s located on top of a building surrounded by a city.
Computer technicians have an immense number of tools that they use to do their daily jobs. It can be as simple as a screwdriver or as sophisticated as a network toner and probe kit. In my opinion, one of these tools should be the Samsung Galaxy S5 phone. The Galaxy S5 is an important tool for a computer technician to have because it is fast, durable, and secure. It will be a tool that one would always come back to during their job.
From the figure, it can be seen that host1, host3, host 4 sends messages through the times say t1,t2,t3,t4 and the times are increasing.
1. You recently retired from government contracting work and established a consulting company (fully consistent with government ethics laws and rules, of course) with the primary focus of advising potential government contractors and subcontractors. Mr. Johnny Jones, of The Johnny Jones Flooring and Construction Company has approached you with a question. Jones and his company are potential subcontractors (they, obviously, specialize in flooring) on a federal construction contract worth a little over two million dollars ($ 2,000,000.00) recently awarded to the Jimmy Smith Construction Company (Jimmy Smith, the prime contractor). Neither Johnny nor his company have ever been part of a government contract
2. Working according to the agreed ways means following the organisation’s policy and procedures in relation to pressure areas. It also means following the individual care plans and respecting the instructions in place. For example making sure a resident is turned every two hours, applying Cavilon cream on areas; fill in turning charts, prompt fluid intake. Under the duty of care a care assistant must always be aware of and raise concerns regarding possible pressure areas. Always record information in care plans accurately and in confidentiality.
of it’s financial rope but has 500 excellent computers that it can sell for cheap in a 14 day period. On the
21. Your international company is scheduling a meeting among managers in Canada, the United States, Spain, Sweden, and Hong Kong on the basis of Greenwich Mean Time (GMT). What command enables you to display the current time in GMT?
1.1. When assessing development some factors need to be taken into account one of these is confidentiality, this means that you will need permission from a child’s parents/carers before doing observations, also when information is wrote down about a child is important that it is kept in a safe place were only the relevant people can access it. Also making sure that information about a child is only shared with parents/carers or colleagues and professionals that have the right to know. Another factor to take into account is a child’s wishes and feelings, this means to take into account the child’s wishes when doing an observation or assessment. The child may not want to be assessed at
1. You have obtained a new utility, called watchit, to monitor security on your computer,
You can download many utilities from the Internet. Examples of utilities are cp (copies a file), ls (lists information about files), ssh (securely connects to a remote computer), and df (lists information about free space on system devices such as hard disks).
In the workplace today there are many different options for operating systems be they providers of server related services or end-user desktops there is a different Linux distribution for many different applications. There are also a number of advantages and disadvantages to adding onto or switching network operating systems within a company. In the following pages I
What is Operating System Security, Operating system security is the process of ensuring OS integrity, confidentiality and availability also OS security refers to specified steps used to protect the OS from threats, viruses, worms, malware or remote hacker. OS security include all avoiding-control techniques, which safeguard any computer information from being stolen, edited or deleted if OS security is included. OS security allows different applications and programs to perform required tasks and stop unauthorized interference. OS security may be applied in many ways. We 're going to discuss following topics in this article. A brief description about security and what are the types of encryption and what is Authentication, One Time passwords, Program Threats, System Threats and Computer Security Classifications.
The Linux was originally founded by Linus Torvalds. In 1991, he was a second year computer science student in Finland. He sought after an operating system that was similar to the UNIX system, but both UNIX and the hardware it ran on were excessively expensive. A UNIX version called Minix was available for free, but it did not reasonably meet his needs as it was simply an operating system for students, designed primarily as a teaching tool rather than an industry strength operating system. As a result, Torvalds studied Minix and proceeded to set out to write a new version. After six months of working to produce the new operating system, Torvalds made very little progress toward the utility of the system.