Locks #

package:async_lock is a mutex implementation that:

• works across isolates on native platforms, and across tabs and workers on the web.
• is asynchronous.
• supports shared and exclusive access to locks.
• identifies mutexes by name, and doesn't require prior communication.
• can query the state of mutexes.

On the web, package:async_lock is implemented with of the Web Locks API. On native platforms, dart:ffi is used with a native lock implementation written in Rust. Of course, both platforms use an identical API, and behave similarly.

Getting started #

Note that this package requires the native-assets experiment, meaning that it is currently only available on dev builds of the Dart SDK.

Apart from that, dart pub add async_lock is the only step to install this package. Build hooks will automatically download native sources where required.

Usage #

The LockManager interface is the main entrypoint to request locks, available through the lockManager getter:

import 'package:async_lock/async_lock.dart';

void main() async {
  final lockName = 'my-lock';

  final held = await lockManager.request(lockName).completion;
  print('Holds lock: ${held != null}'); // true

  held!.release();
}

For more details, see the documentation or the full example.