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);
Tree structured directories: This is the main common directory structure. The tree has a root directory as well as every file in the system has a unique path name. A directory
Regard as a computer system that runs 5000 jobs per month with no deadlock-prevention or deadlock-avoidance scheme. Deadlocks take place about twice per month and the operator must
How can an index file be used to speed up the access in direct-access files? Have an index in memory; the index gives the key and the disk location of its corresponding record.
What is the main function of the memory-management unit? The runtime mapping from virtual to physical addresses is done by a hardware device known as a memory management unit (
explain function of computer operating system?
Question: (a) The actual use and scope groups depend on the mode in which a domain is running. There are two domain modes in which you can run a Windows 2000 domain. List and d
Gang Scheduling : A set of related process is scheduled to execute on a set of processors at the similar time, on a 1-to-1 basis. Closely related processes or threads may be sched
Q. What is the occupation of the object manager? Answer: Substance present a generic set of kernel mode interfaces to user mode programs. Objects are influenced by the execut
What is an I/O subsystem? The control of devices connected to the computer is a main issue while designing operating systems. Since I/O devices differ widely in their function
Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4
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