Chapter3 OS Essentials Essays - 633 Words

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†¦show more content†¦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 â€Å"at most once† or â€Å"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 â€Å"at most once† or â€Å"at least once† semantics for performing a withdrawal or deposit. However, an inquiry i nto 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 theShow MoreRelatedNatural Language Processing ( Nlp )7704 Words   |  31 Pagesappropriately reflected by the phrase mining knowledge from data. However, once coined, this term has been used for decades and analysts have become accustomed to this word. Also known as Knowledge Discovery from Data, or KDD, Data Mining is an essential step in knowldege discovery. Regarding the actual Sentiment Analyzer, Python will be used. Python is part of a winning formula for productivity, software quality, and maintainability at many companies and institutions across the globe. It s extensivelyRead MoreExxon Mobile Capstone40455 Words   |  162 Pagesbuyer A1 high A2 high Sc 5 R1 1 R2 Reason Buyer Power 1 All oil refineries produce the same oil with standard grades. The buyers are the households and commercial transportation. They are price sensitive. Transportation is essential to households and commercial transportation industry. Hence product is significantly important to the buyer. Electricity and household use of natural gas too is important to households With the rising oil prices, households are increasingly paying