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.
DESIGN GOALS OF WINDOWS XP.DESCRIBE IN DETAIL.
SEGMENTATION In a memory management system that is properly a programmer views a program to be collection of program components called as segments . Every segment is a logical
Define the Global vs. local variables It is also important to discuss the scope of resources being granted to the application program. Variable scoping is defined as the acces
The scheduling technique in which CPU is allocated to the process with least CPU-burst time is known as Shortest job first Scheduling is a scheduling technique in which CPU i
What is the different between basic synchronization and high level synchronization
Usually memory is allocated from a large pool of unused memory area called the heap. In C++, dynamic allocation/deallocation must be manually performed using commands like malloc,
Q. Give an instance of an application in which data in a file should be accessed in the following order: a. Sequentially b. Randomly Answer: a. Print the content of
What are the advantages of Contiguous allocation? The advantages are a. Supports direct access b. Supports sequential access c. Number of disk seeks is minimal.
Q. Describe why SSTF scheduling tends to favour middle cylinders over the innermost and outermost cylinders. Answer: The middle of the disk is the location having the smalles
What is logical address space and physical address space? The set of all logical addresses formed by a program is known as a logical address space; the set of all physical addr
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