A safe API for interacting with the world from web threads

[worktycho]

You're right, lifetime is the big issue. It may be that the only truly safe solution is node.js style continuations, where a callback is not guaranteed to be executed immediately. As for hook callbacks, the original design was that you wouldn't call this from within hooks, however if you where to make it part of the API, then you'd have to modify the hook calling code to do the resumption.