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);
Question: (a) Explain the similarities and differences between two different threads running in the same process and two independent processes. When would you want to use two t
Assume there are only 4 page frames in the physical memory, for the following reference string: 1, 2, 3, 4, 5, 3, 4, 1, 6, 7, 8, 7, 8, 9, 7, 8, 9, 5, 4, 5, 4, 2, 8. a) What i
Q. Is disk scheduling except FCFS scheduling useful in a single-user environment? describe your answer. Answer: In a single-user environment the I/O queue typically is empty.
Organizational, Structural, Logical and Execution Relationships Between Important System Components in Linux Kernel Subsystems A. Description of the Project You are require
socket based fortune teller sever.your program should create a server that listens to a specific port when a client receives a connection the server should respond with a random fo
Performance of demand paging Demand paging can have an important effect on the performance of a computer system. As long as there are no page faults, the effective access time
Q. Presume that we agree that 1 kilobyte is 1,024 bytes 1 megabyte is 1,0242 bytes and 1 gigabyte is 1,0243 bytes. This progression carries on through terabytes, petabytes, and ex
fork and join syntax in java
Briefly explain the process management in UNIX. UNIX makes use of the easy but powerful process facility that is visible to the user. UNIX follows the model in which the majori
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