Feature request: Web Locks API

[sgwilym]

https://developer.mozilla.org/en-US/docs/Web/API/Web_Locks_API

The Web Locks API allows scripts running in one tab or worker to asynchronously acquire a lock, hold it while work is performed, then release it. While held, no other script executing in the same origin can acquire the same lock, which allows a web app running in multiple tabs or workers to coordinate work and the use of resources.

I've been looking for some ways to manage access to a single resource, and this seems like it could fill quite a lot of the gap left by shared workers.

[kitsonk]

The biggest problem is we don't have the concept of "same origin" in a lot of cases. It would effectively only work across workers of the same runtime instance.

Can you provide a specific use case you think this would solve? You say "access to a single resource" but that is very vague and a specific use case might help make the need clearer.

[sgwilym]

The biggest problem is we don't have the concept of "same origin" in a lot of cases. It would effectively only work across workers of the same runtime instance.

That would suit me just fine.

My use case is managing many class instances' access to a single database. The value of new inserts into this database is based on data that came before it, so writes must be strictly sequential. Concurrent access would result in an invalid state.

Additionally, this same codebase is used in the browser where many tabs are accessing the same IndexedDB. That I can use Deno to develop and test these features and confidently ship them to the browser is a huge deal.

I've been told I can also use SharedBufferArray and Atomics for this purpose, but I'd love a higher-level API for this job.

[iuioiua]

This would be great for distributed locks in Redis.

[pubkey]

I think the weblocks API in deno should behave similar to the Deno BroadcastChannel.
There the messaging works accross instances and so should the web locks API. This would allow to run things exactly once, like database migrations or other tasks that must not be run multiple times in multiple instances.