export interface LockFs {
    mkdirSync(p: string, opts?: {
        recursive?: boolean;
    }): unknown;
    writeFileSync(p: string, data: string): void;
    readFileSync(p: string): string | Buffer;
    rmSync(p: string, opts?: {
        recursive?: boolean;
        force?: boolean;
    }): void;
    renameSync(from: string, to: string): void;
}
export interface LockDeps {
    fs?: LockFs;
    now?: () => number;
    sleep?: (ms: number) => Promise<void>;
    pid?: number;
    hostname?: string;
    /** Whether a pid is alive on THIS host (only consulted for same-hostname metadata). */
    isPidAlive?: (pid: number) => boolean;
    /** Start a repeating timer; returns a stop function. Default: unref'd setInterval. */
    startInterval?: (fn: () => void, ms: number) => () => void;
}
export interface AcquireLockOptions {
    /** The lock directory itself (created exclusively; its existence IS the lock). */
    dir: string;
    /** Max time to wait for the lock before giving up (default 10 min). */
    waitMs?: number;
    /** Poll interval while waiting (default 1 s). */
    pollMs?: number;
    /** Holder heartbeat refresh interval (default 30 s). */
    heartbeatMs?: number;
    /** Heartbeat age beyond which a contender may take over (default 5 min). */
    staleMs?: number;
    deps?: LockDeps;
}
export interface LockHandle {
    /** Stop the heartbeat and remove the lock dir. Safe to call twice. */
    release(): void;
}
/**
 * Acquire the advisory lock at `dir`, waiting up to `waitMs`. Returns a
 * handle whose `release()` frees the lock, or `null` when the wait elapsed
 * with the lock still held by a live owner.
 */
export declare function acquireLock(options: AcquireLockOptions): Promise<LockHandle | null>;
/**
 * Run `fn` while holding the lock, releasing on both success and throw.
 * Returns `null` without running `fn` when the lock could not be acquired
 * within the wait bound.
 */
export declare function withLock<T>(options: AcquireLockOptions, fn: () => Promise<T> | T): Promise<{
    acquired: boolean;
    result?: T;
}>;
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