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);
Q. Present an algorithm for reconstructing a logical ring after a process in the ring fails? Answer: Typically distributed systems utilize a coordinator process that performs
Question 1 Explain (a) tightly coupled systems (b) Loosely coupled system Question 2 Describe the RPC model Question 3 Write a note o
Q. Explain the File-system manipulation? File-system manipulation there is several details in file allocation, creation, deletion and naming that users should not have to perfo
Q. Definition of Operating System? Definition of Operating System: • An Operating system is a program which controls execution of application programs and acts as an interfa
Suppose a logic-based agent in the wumpus world has found that locations (1,1) and (2,1) do not contain a stench, but that locations (3,1) and (2,2) do contain a stench. Can the ag
1. How is reliability enhanced with the microkernel approach to system design? 2. In a virtual machine design where guest operating systems are independent virtual machines sup
describe main points of multiuser and multi tasking operating systems.
shell program for Armstrong number
How can the index blocks be implemented in the indexed allocation scheme? The index block can be implemented as follows a. Multilevel scheme b. Linked scheme c. Combin
Define FIFO Page Replacement Algorithm This policy simply eliminates pages in the order they arrived in the main memory. By using this policy we simply remove a page based upo
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