rbuckton
Exclusive Refs?
With this proposal would it be possible to create an exclusive reference where you can guarantee a binding/Reference has exclusive access to a variable. I'm more just poking at the ideas of smart pointers and trying to see how they would work with this proposal.
Do you have an example of this behavior in another language you could point to so I could better understand the requirements?
@rbuckton I was specifically thinking about http://www.cplusplus.com/reference/memory/shared_ptr/ . Being able to ensure async control flow in JS does not interleave in odd ways would be nice:
if (foo === 1) {
await bar();
// foo is not guaranteed to be 1 here currently
}
C#/.NET has the concepts of ThreadLocal and AsyncLocal values, which isolate a value to a thread of execution, or an async call context, respectively. While something like ThreadLocal isn't currently necessary for JS (since JS is single threaded), I was hoping that the Zones proposal would provide something akin to an async call context such that AsyncLocal (or something similar) could eventually be implemented.
I haven't considered other aspects of something like shared_ptr.
For other scenarios, I've often used various async coordination primitives to synchronize access to shared resources across different async operations.
As I said above, I think AsyncLocal would be needed to address this case: https://github.com/legendecas/proposal-async-context#asynclocal. Aside from that or an external coordination primitive, I don't see a way to support an exclusive reference as you've described, though I am open to suggestions.