NoModificationAllowedError: Failed to execute 'createSyncAccessHandle' on 'FileSystemFileHandle'

[raineorshine]

Steps to Reproduce

Fully synced 100k or 1m thoughtspace on Chrome. Reproducible in Normal mode and Live mode.

1. Open https://partykit-em.finkef.partykit.dev/100k
2. Refresh

Current Behavior

About 50% of the time I get NoModificationAllowedError: Failed to execute 'createSyncAccessHandle' on 'FileSystemFileHandle'

Expected Behavior

No error

[finkef]

This occurs as far as I can tell during heavy refreshing when there are expensive operations (e.g. inserting a batch of operations during a full sync) still ongoing or interrupted at the same time as we're trying to open the file for a new connection from the new worker.
I have already implemented connection closing on page beforeunload (although there is no guarantee that this will actually run before the context is destroyed) and a lock to prevent simultaneous opens which is another common race condition and contention issue with wa-sqlite. This already all seems to help and I can only reproduce after several attempts of refreshing during heavy operations. Note, that this does not occur when initially opening the page.

The proper way to circumvent this (and also allow multi-tab interactions) is to move from a regular Worker to a SharedWorker or even ServiceWorker. This adds quite some overhead since we now need to manage both DB- and tab-multiplexing, allowing multiple different clients working in multiple different thoughtspaces via the same shared worker instance. This is certainly possible and only adds coordination efforts rather than CRDT-related efforts, hence calling this out-of-scope for this PoC.

Also see: https://github.com/rhashimoto/wa-sqlite/blob/6f40f89e34b3e4d766925fd56bcf6ce61145ce3b/demo/SharedService/SharedService.js