Thread-safe async lazy initializer that runs a factory once, shares the in-flight operation, and caches the result. Supports Task and ValueTask factories with optimized synchronous paths and optional reset.

Primitive for representing deferred, stateful async action invocations with zero closure allocations.

A lightweight, async-safe, allocation-free one-time initialization gate. Ensures a given asynchronous initialization routine runs exactly once, even under concurrent callers, with support for cancellation, safe publication, and disposal.

Primitive for representing deferred, stateful async function invocations with zero closure allocations.

A fast, safe lock that supports both async and synchronous use, optimized for low allocations and correct concurrency.