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);
COMPARISON OF DISK SCHEDULING ALGORITHMS Name Description Remarks (Selection according to requestor) RSS Random scheduling fo
Explain the Real Time Operating System A real-time operating system comprises definite, fixed time constraints. Processing should be done in the defined constraints, or the sys
expalin about the design issues of network operating system
Problem: (a) Modern operating systems are interrupt driven. If there are no processes to execute, no I/O devices to service, and no users to whom to respond, an operating syste
Question: (a) Red Hat Linux is distributed under the Open Source agreement. Explain what you understand by Open Source distribution system. (b) Write a short note on the L
Processes and Programs Process is a dynamic entity which is a program in execution. A process is a sequence of information executions. Process exists in a limited span of t
Write a note on deadlocks. The proper definition of deadlock A set of processes is deadlocked if every process in the set is waiting for an event that only a proces
As mentioned above, page tables, are lookup tables mapping a process' virtual pages to physical pages in RAM. How would one implement these page tables? The most straightforward
What is the exclusive feature of UNIX Shell is the exclusive feature of UNIX.
Multiprocessing - An Operating System proficient of utilizing and supporting more than one computer processor. Below are some instances of multiprocessing Operating Systems. Li
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