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!
Write a note on semaphores
A semaphore is a tool meant for synchronizing multiple processes trying to access a shared variable. That is a semaphore is used to deal with the critical section problem or in other words to evade the race condition. A semaphore S is in fact an integer variable that apart from initialization is accessed only through two standard atomic operations:
*Wait and signal.
The traditional definition of wait in pseudo code is:
wait (S) {
while (S<=0)
; // no-op
S--;
}
The traditional definition of signal in pseudo code is:
signal (S) {
S++;
For each process P,
do {
WAIT
Critical Section
SIGNALS
} while (1);
A semaphore is able to be defined as:
typedef struct {
int value;
struct process *L;
} semphore;
Once more, the wait semaphore operation can be defined as:
void wait (semaphore S) {
S.value--;
if (S.value < 0) {
add this process to S.L;
block();
As well, the signal semaphore operation is able to be defined as:
void signal( semaphore S) {
S.value++;
if (S.value <= 0) {
remove a process P from S.L;
wakeup(P);
examples of classification of models
Write a short note on peer-to-peer computing. Peer-to-peer (P2P) system model is a kind of distributed OS. In this model, clients and servers aren't distinguished from one anot
Q. Explain some of the ways an application can use memory via the Win32 API. Answer: (1) Virtual memory offers several functions that allow an application to reserve and rele
Explain hierarchy level directory
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
What is meant by arm-stickiness? If one or a few processes have a high access rate to data on single track of a storage disk, then they might be monopolizing the device by repe
List three ways of allocating storage, and give advantages of each. a. Contiguous allocation. Fastest, if no changes are to be made. Also simplest for random access files. b
In this project, you will implement the Chandy and Misra's (CM) algorithm using POSIX Threads (Pthreads). The algorithm is a distributed algorithm to solve a generalized dining
Q. Give the reasons why Windows XP, Solaris and Linux implement multiple locking mechanisms. Explain the circumstances under which they use mutexes, spinlocks, semaphores, adaptiv
what topic i choose for os research proposal
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