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.
Q. Consider the demand-paged computer system where the level of multiprogramming is currently fixed at four. The system was recently deliberate to determine utilization of CPU and
General Graph Directory A serious trouble with using an acyclic graph structure is making sure that there are no cycles. When links are further added to an existing tree struc
List five services provided by an operating system. Explain how each provides convenience to the users. Explain also in which cases it would be impossible for user-level programs t
Suppose your process starts up, and allocates some memory with malloc(). The allocator will then give part of a memory page to your process. The OS then updates the corresponding p
Determine an imperative statement Imperative statement points out an action to be carried out during execution of assembled program
What is critical section problem? Consider a system consists of 'n' processes. Every process has segment of code called a critical section, in which the process might be changi
Developing Code with Threads Writing code to support a thread-based implementation is very straightforward. Simple APIs are presented to the developer for each threads package.
Signal handling A signal is used in UNIX systems to inform a process that a particular event has occurred. 1. A signal is produced by the occurrence of a particular event.
What are three conditions that a solution for the critical section problem must satisfy? The three conditions are as following:- a) Mutual exclusion :- if a process is
what is the use of valid invalid bits in paging
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