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.
When programming with threads, there are three very common mistakes that programmers often make: 1. locking twice (depending on the system and type of lock, can cause crashes, h
What are the operations of processes? Process creation A process may create several new processes. The creating process is called as parent process, where as the new proce
What are scheduling queues? Since the processes enter the system they are put into job queue. This queue contains all processes in the system. The processes that are exist in m
Clocks in distributed systems : a. Why are clocks difficult to synchronize in distributed systems? b. What features in a system assume that the clocks are (reasonably) synchr
list trhe various classification of model and types?
Q. Explain Message passing among systems? Communications- Message passing among systems requires messages to be turned into packets of information and sent to the network contr
Operating Systems have evolved tremendously in the last few decades. The first approach for building Operating Systems, taken during the 40s through early 60s, was to allow only on
are ''ASIC'' embeded systems
What do you mean by first fit? First fit allocates the first hole that is big sufficient .Searching can either start at the starting of the set of holes or where the previous f
what is independent process? distinguished between independent process and co-operating process
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