Part of the #403/#404 Phase A push. Two tabs sharing the origin-global OPFS working copy can currently clear each other's project, interleave snapshot writes, and restore each other's work.
Phase A ships the guard, not the architecture: acquire an exclusive Web Lock for the editing lifetime (navigator.locks.request(..., {ifAvailable: true})); a second tab that fails to acquire shows a read-only "This project is open in another tab" banner and disables editing/autosave. Web Locks release automatically on tab death, which is the browser's process-liveness equivalent — a crashed owner's work directory becomes a recovery candidate on next boot.
Deferred to Phase B (tracked in the follow-up umbrella): per-project work directories, BroadcastChannel focus/fork UX, recovery chooser. Web Locks require a secure context and are available from Safari 15.4.
Part of the #403/#404 Phase A push. Two tabs sharing the origin-global OPFS working copy can currently clear each other's project, interleave snapshot writes, and restore each other's work.
Phase A ships the guard, not the architecture: acquire an exclusive Web Lock for the editing lifetime (
navigator.locks.request(..., {ifAvailable: true})); a second tab that fails to acquire shows a read-only "This project is open in another tab" banner and disables editing/autosave. Web Locks release automatically on tab death, which is the browser's process-liveness equivalent — a crashed owner's work directory becomes a recovery candidate on next boot.Deferred to Phase B (tracked in the follow-up umbrella): per-project work directories, BroadcastChannel focus/fork UX, recovery chooser. Web Locks require a secure context and are available from Safari 15.4.