ATOMICS AND SharedArrayBuffer

When a SharedArrayBuffer is accessed by multiple contexts, race conditions can occur when operations on the buffer are performed simultaneously. The Atomics API allows multiple contexts to safely read and write to a single SharedArrayBuffer by forcing buffer operations to occur only one at a time. The Atomics API was defined in the ES2017 specification.

You will notice that the Atomics API in many ways resembles a stripped-down instruction set architecture (ISA)—this is no accident. The nature of atomic operations precludes some optimizations that the operating system or computer hardware would normally perform automatically (such as instruction reordering). Atomic operations also make concurrent memory access impossible, which obviously can slow program execution when improperly applied. Therefore, the Atomics API was designed to enable sophisticated multithreaded JavaScript programs to be architected out of a minimal yet robust collection of atomic...