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 function invocations with zero closure allocations.

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

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.