Difference between Semaphore and Condition Variable Last Updated : 26 Dec, 2022 Summarize Comments Improve Suggest changes Share Like Article Like Report 1. Semaphore :Semaphore, as name suggests, is basically an object that includes counter, waiting list of process and supports two different operations i.e., wait and signal. Its type includes counting semaphores and binary semaphores. It is simply a synchronization tool that can be used to deal with critical-section problem. It provides simple abstraction for controlling access to a common resource in programming environment.2. Condition Variable :Condition Variable, as name suggests, is simply a synchronization primitive that allows threads to wait until particular condition occurs. It includes two operations i.e., wait and signal. It just allows thread to be signaled when something of interest to that threads occurs and is mostly used when one wants to know when something happens.Difference between Semaphore and Condition Variable : Semaphore Condition Variable It does not allow threads to wait. Instead, each thread keeps running and last thread that will set semaphore value to zero will go to sleep.It allows threads to wait until particular condition occurs. It is generally used to solve problem of some critical sections in process synchronization. It is generally used with mutex to signal changing states from one thread to another one.Its main aim is to control access to common resource by multiple processes and avoid critical section problems in concurrent system like multitasking operating system. Its main aim is to support operations that wake one or wake all waiting threads. It can be used anywhere except in a monitor. It can only be used in monitors. In this, wait () does not always block its caller. In this, wait () usually blocks its caller always. They are sticky as they have memory and sem_post() will increment semaphore even if no one has called sem_wait(). They are non-sticky as signal () is not saved if there is no one waiting for signal (). It is simply a counter + mutex + wait queue. It is simply a wait-queue. It can be used as a conditional variable and therefore is more lightweight and flexible. It cannot be used as a semaphore and therefore is not flexible. In this, we cannot unlock all waiting threads in same instant using broadcast unlocking. In this, we can unlock all waiting threads in same instant using broadcast unlocking. Signals are not lost even if there is nobody waiting on the queue. Signals are lost if there is nobody waiting on the queue. Comment More infoAdvertise with us Next Article Difference between Binary Semaphore and Mutex M madhurihammad Follow Improve Article Tags : Operating Systems Difference Between Similar Reads Difference Between Counting and Binary Semaphores Semaphores are signaling devices used in computer systems to facilitate the control of access to common resources. For it is employed to prevent several processes (or programs) from conflicting with one another when all of them are competing for the same resource. There are two main types of semapho 5 min read Difference between Spinlock and Semaphore Semaphore is just a shared, non-negative variable that is used by multiple threads. A semaphore is a signalling device, and another thread may signal a thread that is awaiting a semaphore. It uses two atomic actions for process synchronisation: 1) wait, and 2) signal. In accordance with how it is co 5 min read Difference between Binary Semaphore and Mutex Binary Semaphore and Mutex are both synchronization mechanisms used in concurrent programming to control access to shared resources and prevent race conditions. However, they have different characteristics and use cases Binary SemaphoreBinary semaphores are semaphores that can only assume the values 3 min read Difference between Test Scenario and Test Condition in Software Engineering 1. Test Scenario: A test Scenario refers to all possible ways of testing a software application. Each probable way or method tests any part of the application like all possible functionalities, attributes, features, and aspects of the software. Some examples of Test scenarios are – Check if Admin is 3 min read Difference Between && and ; chaining operators in Linux Logical AND operator(&&): The second command will only execute if the first command has executed successfully i.e, its exit status is zero. This operator can be used to check if the first command has been successfully executed. This is one of the most used commands in the command line. Synta 3 min read Difference Between grep() vs. grepl() in R In this article, we will discuss the difference between grep() and grepl() in R programming language. grep() This grep() function in R Language allows programmers to search for a match of a particular pattern in the given collection of strings. The syntax is given below, Syntax:  grep(stringPattern, 4 min read Like