Are events delivered to all origins at once?

[martinthomson]

There's some discussion about whether delivering a global event to all origins at once is wise over at w3c/mediacapture-main#402 (in particular w3c/mediacapture-main#402 (comment)).

The counter argument is that the discovery that userx@origin1 and usery@origin2 is actually the same device is probably relatively easy to make if you were looking to make that connection.

[spanicker]

@martinthomson could you elaborate on what type of correlation might be problematic for memory pressure signal?
Let's say we send the memory pressure signal to both the foreground and background tab within a short time interval. What privacy-related correlation problems are anticipated.

[Akxe]

I would suggest to fire event only for active tabs. Inactive tabs usually get managed by browser if memory is problem, and theirs best time to react is on visibilitystate.

For security concerns I would suggest to fire events from the most memory consuming to the lowest with unspecified delay in between. Many implementations might be async thus require some time before the save will actually occurs.