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A semaphore is a shared integer variable __________

A semaphore is a shared integer variable __________ Correct Answer that can not drop below zero

A semaphore is a shared integer variable that can not drop below zero. In binary semaphore, if the value of the semaphore variable is zero that means there is a process that uses a critical resource and no other process can access the same critical resource until it is released. In Counting semaphore, if the value of the semaphore variable is zero that means there is no resource available.

Related Questions

A shared variable x, initialized to zero, is operated on by four concurrent processes W, X, Y, Z as follows. Each of the processes W and X reads x from memory, increments by one, stores it to memory, and then terminates. Each of the processes Y and Z reads x from memory, decrements by two, stores it to memory, and then terminates. Each process before reading x invokes the P operation (i.e., wait) on a counting semaphore S and invokes the V operation (i.e., signal) on the semaphore S after storing x to memory. Semaphore S is initialized to two. What is the maximum possible value of x after all processes complete execution?
Consider the following solution to the producer-consumer synchronization problem. The shared buffer size is ?. Three semaphores empty, full and mutex are defined with respective initial values of 0, ? and 1. Semaphore empty denotes the number of available slots in the buffer, for the consumer to read from. Semaphore denotes the number of available slots in the buffer, for the producer to write to. The placeholder variables, denoted by P, Q, R, and S, in the code below can be assigned either empty or full. The valid semaphore operations are: wait ( ) and signal ( ). Producer: Consumer: do {         wait (P) ;         wait (mutex) ;         //Add item to buffer         signal (mutex) ;         signal (Q) ; } while (1) ; do {          wait (R) ;          wait (mutex) ;          //Consume item from buffer          signal (mutex) ;          signal (S) ; } while (1) ;   Which one of the following assignments to P, Q, R and S will yield the correct solution?
At a particular time of computation the value of a counting semaphore is 7.Then 20 P operations and 15 V operations were completed on this semaphore. The resulting value of the semaphore is? (GATE 1987)
A binary semaphore is a semaphore with integer values ____________
A particular BNF definition for a “word” is given by the following rules. ∷ = | | ∷ = |  ∷ = |  ∷ = a | b | c | ….. |y| z  ∷ = 0 |1|2| …… | 9 Which of the following lexical entries can be derived from < word > ? l. pick II. picks lll. c44
Consider the procedure below for the Producer-Consumer problem which uses semaphores: semaphore n = 0; semaphore s = 1;   void producer() { while(true) { produce(); semWait(s); addToBuffer(); semSignal(s); semSignal(n); } }         void consumer() {            while(true)            {             semWait(s);             semWait(n);             removeFromBuffer();             semSignal(s);              consume();              } }   Which one of the following is TRUE?
The sum o three integers is 40. The largest integer is 3 times the middle integer, and the smallest integer is 23 less than the largest integer. what is the product of the three integers?
Suppliers(Sid: integer, sname:string, city:string, street:string) Parts(pid:integer, pname:string, color:string) Catalog(sid:integer, pid:integer, cost:real) Consider the following relational query on the above database: SELECT S.sname FROM Suppliers S  WHERE S.sid NOT IN (SELECT C.sid FROM Catalog C WHERE C.pid NOT IN (SELECT P.pid FROM Parts P WHERE P.color < > ‘blue’)) Assume that relations corresponding to the above schema are not empty. Which of the following is the correct interpretation of the above query?
Consider the following relational schema. Students(rollno: integer, sname: string) Courses(courseno: integer, cname: string) Registration(rollno: integer, courseno: integer, percent: real) Which of the following queries are equivalent to this query in English? “Find the distinct names of all students who score more than 90% in the course numbered 107” (I) SELECT DISTINCT S.sname FROM Students as S, Registration as R WHERE R.rollno=S.rollno AND R.courseno=107 AND R.percent >90 (II) Πsname (σcourseno = 107∧percent>90 (Registration ⋈ Students)) (III) {T | ∃S ∈ Students, ∃R ∈ Registration (S.rollno = R.rollno ∧R. courseno = 107 ∧ R.percent > 90 ∧ T.sname = S. sname)} (IV) {〈SN〉 | ∃SR∃RP(〈SR, SN〉 ∈ Students ∧ 〈SR, 107, RP〉 ∈ Registration ∧ RP > 90)}
When a certain positive integer P is divided by another positive integer, the remainder is $${r_{1}}$$ . When a second positive integer Q is divided by the same integer, the remainder is $${r_{2}}$$ and when (P + Q) is divided by the same divisor, the remainder is $${r_{3}}$$ . Then the divisor may be :