[whatwg] WebWorkers and images

[Marijn Haverbeke]

> To preserve shared-nothingness, the passed object (and the object's children) could be made unreachable (somehow, don't ask me) in the sending context as soon as passed to the worker. Perhaps other constraints might need to exist, e.g. perhaps no methods allowed in these objects.

This is a hairy, deep, programming-language theory problem, and I'd
say the chances of getting it right on top of JavaScript are slim.

I think agressive optimization of the copying code is a more hopeful
direction. After all, we're not dealing with huge chunks of data here.
In an ideal case, memory-to-memory copy takes less than half a
millisecond per megabyte.