/**
 * File-lock acquisition and management for the Telegram poller.
 *
 * Only one MCP instance may poll Telegram at a time. This module provides
 * a file-system–based lock (with stale-lock detection via PID check) so
 * multiple instances can coordinate without conflicts.
 */
/** Check whether a PID is still alive. */
export declare function isPidAlive(pid: number): boolean;
export declare function readLock(): Promise<{
    pid: number;
    ts: number;
} | null>;
/**
 * Outcome of a lock-refresh attempt.
 *
 * - `refreshed`: the lock timestamp was successfully updated on disk.
 * - `lost`: the lock is missing or now owned by a different PID — ownership
 *   has genuinely changed, so the caller must step down.
 * - `io-error`: a transient filesystem error (e.g. Windows EPERM/EBUSY from an
 *   antivirus/indexer briefly holding the file) prevented the timestamp update,
 *   but ownership is unchanged. The caller still owns the lock and should keep
 *   running; the next refresh will retry.
 */
export type LockRefreshResult = "refreshed" | "lost" | "io-error";
/**
 * Write (refresh) the lock file, but only if we still own it.
 * Prevents a TOCTOU race where two pollers run simultaneously:
 * if another process stole the lock between our check and write,
 * we must not overwrite their lock.
 *
 * Ownership is defined solely by the PID recorded in the lock file — NOT by
 * the timestamp. A transient inability to update the timestamp therefore does
 * not imply ownership loss, so it is reported as `io-error` (non-fatal) rather
 * than conflated with a genuine handover (`lost`).
 */
export declare function refreshLock(): Promise<LockRefreshResult>;
export declare function removeLock(): void;
/**
 * Try to acquire the poller lock, retrying up to `maxAttempts` times with
 * `delayMs` between attempts. Handles the Windows race where a just-killed
 * process still appears alive briefly to process.kill(pid, 0).
 */
export declare function tryAcquireLockWithRetry(maxAttempts?: number, delayMs?: number): Promise<boolean>;
export declare function tryAcquireLock(): Promise<boolean>;
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