///
/**
* @license
* Copyright Google LLC All Rights Reserved.
*
* Use of this source code is governed by an MIT-style license that can be
* found in the LICENSE file at https://angular.io/license
*/
import { Logger } from '../../../src/ngtsc/logging';
import { LockFile } from './lock_file';
/**
* AsyncLocker is used to prevent more than one instance of ngcc executing at the same time,
* when being called in an asynchronous context.
*
* * When ngcc starts executing, it creates a file in the `compiler-cli/ngcc` folder.
* * If it finds one is already there then it pauses and waits for the file to be removed by the
* other process. If the file is not removed within a set timeout period given by
* `retryDelay*retryAttempts` an error is thrown with a suitable error message.
* * If the process locking the file changes, then we restart the timeout.
* * When ngcc completes executing, it removes the file so that future ngcc executions can start.
*/
export declare class AsyncLocker {
private lockFile;
protected logger: Logger;
private retryDelay;
private retryAttempts;
constructor(lockFile: LockFile, logger: Logger, retryDelay: number, retryAttempts: number);
/**
* Run a function guarded by the lock file.
*
* @param fn The function to run.
*/
lock(fn: () => Promise): Promise;
protected create(): Promise;
}