//#region src/server/instrumentation-runtime.d.ts
/**
 * Lazy, idempotent instrumentation initialisation.
 *
 * The generated App Router RSC entry calls this on the first request instead
 * of embedding the bookkeeping directly in codegen. This keeps the entry
 * module thin (it only describes the app shape) while the actual runtime
 * behaviour lives in a normal typed module that can be unit-tested.
 *
 * ## Why lazy?
 *
 * A top-level `await` at module evaluation time blocks the entire V8 isolate
 * startup phase. On Cloudflare Workers that latency is added to every cold
 * start. Moving the `register()` call into the first request handler keeps
 * module evaluation synchronous while still guaranteeing that instrumentation
 * runs before any request is handled.
 *
 * ## Why idempotent?
 *
 * The same handler may be invoked concurrently (e.g. on a warm Worker).
 * A module-level `initialized` flag + a shared promise ensure that
 * `register()` is called exactly once even when multiple requests race.
 *
 * ## Next.js semantics
 *
 * Next.js calls `register()` once when the server process starts, before any
 * request handling. Our lazy init preserves that guarantee because the first
 * request cannot proceed past this call until `register()` has resolved.
 *
 * References:
 * - https://nextjs.org/docs/app/building-your-application/optimizing/instrumentation
 */
/**
 * Ensure the instrumentation module's `register()` and `onRequestError`
 * hooks have been applied exactly once.
 *
 * @param instrumentationModule - The imported `instrumentation.ts` module.
 *   Passed as an argument so the generated entry can import it normally
 *   without this helper needing to know the module path.
 */
declare function ensureInstrumentationRegistered(instrumentationModule: Record<string, unknown>): Promise<void>;
//#endregion
export { ensureInstrumentationRegistered };
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