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.
mention the three problems that mat be caused by wrong initialization and placement of wait() and signal()operations in the use of semaphore
properies of Batch oriented and interactive operating system.
What is virtual file system? A Virtual file system switch (VFS) or Virtual file system is an abstraction layer on top of a more concrete file system. The purpose of a VFS
Operating Systems 1. Illustrate the Microkernel Architecture with suitable diagram. 2. When Deadlock occurs? What are the Necessary Conditions for Deadlock? 3. Describe f
Virtual addresses are made up of two parts: the ?rst part is the page number, and the second part is an offset inside that page. Suppose our pages are 4kb (4096 = 212 bytes) long,
8(5-3)-20=
What are threads? A thread is alike to sequential programs. Single threads have a beginning, sequence and end. At any given point in time during the runtime of the thread there
Question: (a) Red Hat Linux is distributed under the Open Source agreement. Explain what you understand by Open Source distribution system. (b) Write a short note on the L
How does communication takes place in a distributed system? Distributed systems depend on the networking for their functionality. A network is a communication path among two
what is cpu
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