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. What is Multiprogramming? Multiprogramming When two or more programs are in memory at the same instance, sharing the processor is referred to multiprogramming opera
Virtual File System serves two important functions. 1. It divides file-system-generic operations from their execution by defining a clean VFS interface. 2. The VFS is based
Explain about threading issues? The fork and exec system calls In a multithreaded program of few UNIX systems have chosen to have two versions of fork, one that duplicates e
Entry-sequenced file organization The records in an entry-sequenced file are store up in the order they are written into the file. New records are for all time appended to
MEMORY MANAGEMENT USING LINK LISTS The first one is for showing it is process or hole, second is for starting address and third is for length of the process and last is a point
What are batch systems? Early computers were physically huge machines run from a console. The general input devices were card readers and tape drivers. The common output device
OPERATING SYSTEM 1. Describe the term operating system. Write down the functions of operating system. 2. Explain Thread? Write down the advantages and disadvantages of threa
What is an I/O subsystem? The control of devices connected to the computer is a main issue while designing operating systems. Because I/O deices differ widely in their function
A practical task specified in the Study Guide, Computer architecture, was to record your computer's specifications. Submit the data you recorded, which will contain the following d
advantages and disadvantages
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