Synchronization The simplest hardware primitive that greatly facilitates synchronization implementations (locks, barriers, etc.) is an atomic read-modify-write Atomic exchange: swap contents of register and …

Synchronization may have different needs at different times Lock accessed with low or high contention Different requirements: low latency, high throughput, fairness

Components of a Synchronization Event Acquire method (enter critical section, proceed past event) Waiting algorithm (busy waiting, blocking) Release method (enable others to proceed)

How to sync N clocks with a global clock or with each other? How time in real world is actually measured? The interval that it takes the cesium 133 atom to make exactly 9,192,631,770 transitions. …

In the next sections, we will discuss the various synchronization mechanisms and techniques that are commonly used in operating systems and programming languages to achieve proper synchronization …

The problem is that two concurrent threads (or processes) accessed a shared resource (account) without any synchronization Known as a race condition (memorize this buzzword)

Lecture 19: Coherence and Synchronization • Topics: synchronization primitives (Sections 5.4-5.5)