Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
How could we implement locks? No matter how we choose to implement them, we must have some hardware support. One possibility for implementing locks on a uniprocessor machine is is to disable interrupts when testing/setting locks. With interrupts disabled on a single processor machine, the processor cannot switch processes, and so we can guarantee that only the active process will have access to the shared data. Another option would be to make use of atomic operations, such as test and set. This type of operation (which usually corresponds to a single atomic assembly instruction) behaves as if it used the following C function, atomically:
int test_and_set(int x) // let x be strictly either 0 or 1.{if (x) { return 1; } else { x=1; return 0; }}
All this needs to be implemented atomically, in hardware. Using this type of atomic operation, one could implement thread lock(l) simply as while test_and_set(l) {
; // do nothing} // spinlock version of thread_lock()and thread unlock(l) simply asl = 0; // we need this to be an atomic clear (or assign) instruction
The assembly instruction test and set can bemade to be atomic acrossmultiple processors. An equivalent option would be an atomic compare and swap assembly instruction. These low-level hardware solutions are then built up into high-level functions, either built into the languages, or in libraries. In general, do not implement your own locking functions, but rather use functions from a tested library. Getting things right can be tricky, and your own solution is also likely to be non-portable.
Define the features are needed to implement top down parsing Source string marker, Prediction making mechanism and Matching and Backtracking mechanism
Process termination A process terminates when it finishes implementing its final statement and asks the operating system to delete it by using the exit system call. At that tim
What are the services provided by the operating systems? Program Development It provides a variety of services and facilities, such as debuggers and editor, to help the
Problem: a) Define a ‘file' and list the objectives of the file management system. b) List the ways in which programs access files and determine for what file types you woul
Suppose we want to program a Web server; we could easily do so without using concurrency, as follows: while(true) wait connection read from socket and parse url look up url cont
The field that consists of a segment index or an internal index is known as Target datum is field that consists of a segment index or an internal index.
Optimal page replacement An optimal page replacement algorithm has the least page fault rate of all algorithms. The algorithm states that a 'replace the page that will not be
Locks (also known as mutexes, short for mutual exclusion locks) provide mutual exclusion to shared data inside a critical session. They are implemented by means of two atomic routi
swapping technique
Q. Palm OS provides no signifies of concurrent processing. Discuss three major complications that concurrent processing adds to an operating system. Answer: a. A meth
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd