Mutual exclusion, Operating System

With software algorithms for mutual exclusion, such as Dekker's algorithm, Peterson's algorithm, or Lamport's bakery algorithm, note that optimizing compilers and out-of-order execution by processors could invalidate most of these algorithms because such "optimization" does not take into account that the value of a shared variable can be changed by something other than the immediately evident code. This overly-simplistic characterization also happens with I/O devices, especially simple programmed I/O where data or control register contents changes as a result of the state of the device, not as a consequence of execution of processor instructions, as well as with clocks where the current time register changes continually. It also happens when DMA is used to input blocks of data, which is slightly more complex because the addresses whose value changes are not evident literally. What does this imply about device drivers?

Posted Date: 2/22/2013 1:37:50 AM | Location : United States

Related Discussions:- Mutual exclusion, Assignment Help, Ask Question on Mutual exclusion, Get Answer, Expert's Help, Mutual exclusion Discussions

Write discussion on Mutual exclusion
Your posts are moderated
Related Questions
explain hierarchical,hashed and inverted paging

Q. Several CPUs provide for more than two modes of operation. What are two probable uses of these multiple modes? Answer: Although most systems merely distinguish between use

Q. Explain the File-system manipulation? File-system manipulation there is several details in file allocation, creation, deletion and naming that users should not have to perfo

Q. Consider the two-dimensional array A: int A[][] = new int[100][100]; Whereas A [0][0] is at location 200 in a paged memory system with pages of size 200. A little process

Define Segmentation  The memory allocation method subject to “external” fragmentation is Segmentation.

Question 1: a) Briefly explain each of the following terms: (i) Distributed systems. (ii) Real time systems. (iii) Multiprocessor. b) What is the impo

Q. Provide two programming instances in which multithreading provides better performance than a single-threaded solution. Answer: (1) A Web server that services every request

#questionThe Fibonacci sequence is the series of numbers 0,1,1,2,3,5,8,… Formally, it can be expressed as: fib0 = 0 fib1 = 1 fibn = fib n-1 + fib n-2 Write a C program u