Locks

package:weblocks 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:weblocks 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 beta builds of the Dart SDK.

Apart from that, dart pub add weblocks 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:weblocks/weblocks.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.

Development

To work on this package, consider adding the hooks section in the pubspec.yaml that is currently commented out to use a debug build of the native code for the current host.