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.
The idea of reference counting is to maintain, for every object, the total number of references to that object, i.e. the number of "incoming" pointers. Whenever the number of refer
explain how response time are reduced by allowing time sharing on top of multiprogramming
what are reasons for cooperating processes
Which is most common phase structured grammar? Most common phase structured grammar is Context – Sensitive
What are the characteristics of SRS? i. Correct - The SRS should be made up to date when appropriate requirements are identified. ii. Unambiguous - When the requirements are
Write note on process, process state? A process is in excess of the program code which is sometimes known as text section. It as well includes the current activity as represent
Process Description A process in UNIX is a somewhat complex set of data structures that provides the operating system with all of the information necessary to dispatch and manag
To explore the UNIX file system, use basic UNIX commands and use a text editor. Task: 1. Logon to Linux. 2. Create a directory "Unix" under your home d
Define deadlock prevention. Deadlock prevention is a set of process for ensuring that at least one of the four essential conditions like mutual exclusion, hold and wait, no pr
Extend task 1 so that the requests are issued by the clients instead of the server. The server now do not use the "all_requests.dat" file. Instead every client thread reads from
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