import type { Duration } from "./types.js";
export declare function isSignalAborted(signal: AbortSignal | undefined): boolean;
export declare function signalAbortReason(signal: AbortSignal | undefined): unknown;
/** Monotonic clock for elapsed-time budgets; wall-clock jumps must not alter them. */
export declare function monotonicNow(): number;
export declare function clearTimerSafely(timer: ReturnType<typeof setTimeout> | undefined): void;
export declare class RouterTimerError extends Error {
    readonly code = "timer_unavailable";
    constructor(cause: unknown);
}
export declare class RouterCancellationError extends Error {
    readonly code = "cancellation_unavailable";
    constructor(cause: unknown);
}
export declare function createAbortControllerSafely(): AbortController;
export declare function abortControllerSafely(controller: AbortController, reason: unknown): void;
export declare function scheduleTimer(callback: () => void, delay: number): ReturnType<typeof setTimeout>;
export declare class RouterTimeoutError extends Error {
    readonly code: "attempt_timeout" | "first_content_timeout" | "total_timeout";
    readonly durationMs: number;
    constructor(code: RouterTimeoutError["code"], durationMs: number);
}
export declare function durationMs(value: Duration | number | undefined): number | undefined;
export declare function effectiveTimeout(attemptTimeout: number | undefined, remaining: number | undefined): number | undefined;
export declare function jitteredBackoff(maximumMs: number | undefined, signal?: AbortSignal): Promise<void>;