What are semaphores, Computer Engineering

Assignment Help:

What are semaphores?

Semaphore: A semaphore is a synchronization tool which gives a general-purpose solution to controlling access to critical sections. It s an abstract data type (ADT) which defines a nonnegative integer variable that, apart from initialization, is accessed simply through two standard operations that are: wait and signal. The typical definition of wait in pseudo code is

wait(S){

          while(S<=0)

                 // do nothing

                          S--; }

The classical definitions of signal in pseudo code is signal(S){

                    S++; }

While one process modifies the semaphore value, anno one process can concurrently modify that similar semaphore value. As well, in the case of the wait(S), the testing of the integer value of S (i.e. S<=0), and its possible modification(S--), should also be executed without interruption.


Related Discussions:- What are semaphores

How many lines of address bus used for memory of 2048 bytes, How many lines...

How many lines of address bus must be used to access 2048 bytes of memory when available RAM chips 128 × 8.  How many lines of these will be common to each chip? Ans. AS chips

What is an on"*-input filed" statement, What is an on"*-input filed" statem...

What is an on"*-input filed" statement? ON *-INPUT The ABAP/4 module is known as if the user has entered the "*" in the first character of the field, and the field has th

Determine the equivalent in octal of decimal number, Convert decimal 153 to...

Convert decimal 153 to octal. Equivalent in octal will be ? Ans. (153) 10 = (231) 8

What is direct addressing mode, Computer Organization and Architecture ...

Computer Organization and Architecture 1. Draw the block diagram of von Neumann Architecture and describe about its parts in brief. 2. Draw block diagram of Intel 8085 CPU o

System requirements for chip design, The Peripheral interface chip system r...

The Peripheral interface chip system requires the construction of the interface chip circuit, which is controlled by main micro-controller via the user interface. I also need set

Show the spawned program, Q. Show the spawned program? include "pvm3.h"...

Q. Show the spawned program? include "pvm3.h"  main() {    int ptid, msgtag;    char buf[100];    ptid = pvm_parent();    strcpy(buf, "hello, world from ");

What will be its digital output of an 8-bit ADC, An 8-bit successive approx...

An 8-bit successive approximation ADC has a resolution of 20mV.  What will be its digital output for an analog input of 2.17V? Ans: Given data Resolution =20mv Analog input =2.

What is flag, Flag is a flip-flop used to kept the information about the st...

Flag is a flip-flop used to kept the information about the status of a processor and the status of the instruction implemented most recently A software or hardware mark that si

C programming, Find out useless nonterminal symbols use c program.

Find out useless nonterminal symbols use c program.

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

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!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd