Pull requests

• fix(pool): avoid race conditions when a task is submitted while the pool is stopping by @alitto in https://github.com/alitto/pond/pull/105
• feat(pool): add non-blocking submission methods and dropped tasks metric by @alitto in https://github.com/alitto/pond/pull/107

Changes

• Ensure closed atomic bool is toggled and checked while holding the mutex to avoid race conditions.
• Ensure workersWaitGroup.Add() is always called while holding the mutex to avoid race conditions.
• Improve comments on submit methods to clarify the behavior when the pool is stopped.
• Refactor trySubmit method to make it simpler and more clear.
• Centralize worker launch in a new method called launchWorker.
• Replace subpoolSubmit with subpoolWorker method.
• Add methods to submit individual tasks in a non-blocking fashion (TrySubmit and TrySubmitErr). Requested in https://github.com/alitto/pond/issues/103
• Expose new DroppedTasks metric that reflects the number of tasks that were not executed because the queue was full. Issue reported in https://github.com/alitto/pond/issues/100
• SubmittedTasks metric now includes dropped tasks and it stops being updated once the pool is stopped.

Fixes

• Decrement workerCount counter when the pool context is cancelled.
• Resize() now supports setting maxConcurrency to 0 (no limit)

Full Changelog: https://github.com/alitto/pond/compare/v2.3.0...v2.3.1