Add new_count_waker

[Thomasdezeeuw]

This is an alternative API to WakeCounter, see #1384.

I didn't touch the old API, but it might be a bit confusing that there are two different API's to do the same thing. I'll leave it up to someone else to decide whether to deprecate/remove/leave it.

Closes #1384.

/cc @Nemo157

[Thomasdezeeuw]

Some more notes:

The atomic ordering might be overkill, but since it's a test API I don't think the performance impact matters too much. Also I didn't add a test, but the example tests the entire API already.

[Nemo157]

LGTM, we should settle on just a single API before 0.3 is released, but having both for now seems fine to me.

[Thomasdezeeuw]

I think the Travis failure is unrelated, from the log:

error[E0463]: can't find crate for `std`
  |
  = note: the `thumbv6m-none-eabi` target may not be installed

Other architectures are fine.

[Nemo157]

Yeah, it’s #1396, I would fix it but I don’t really know if there’s a way to do so that doesn’t break other stuff.

[Thomasdezeeuw]

I've force pushed a rebase on master, the CI should pass now as the failure was fixed in #1407.

[cramertj]

Seems good to me! I'd prefer we replaced the old one at the same time, though, or at least marked it as deprecated and switched our internal usage. No reason to let tech debt sit around on an alpha version of the library.

[cramertj]

I think Deref<Target = usize> would also be handy.

[Thomasdezeeuw]

How can I do that? I don't think AtomicUsize has any methods that allow you to get a reference to the inner usize. I tried the following

impl Deref for AwokenCount {
    type Target = usize;

    fn deref(&self) -> &usize {
        &self.inner.count.load(Ordering::SeqCst)
    }
}

But that gives the cannot return reference to temporary value error, which makes sense.

I could add back the get(&self) -> usize method

[cramertj]

ah, yeah, you're right-- get would be great.

[Thomasdezeeuw]

@cramertj I'm going to address the comments now, to respond to your comment in the other issue.

[cramertj]

sg, thanks!

[Thomasdezeeuw]

Pushed 2 commits to changes the tests and remove the old WakeCounter. Should I implement the get(&self) -> usize method?

[cramertj]

Yeah, get sounds good. Thanks!

[Thomasdezeeuw]

@cramertj I think the test will pass (they work on my machine ™), if your OK with the API then I'm going to bed now.

[cramertj]

Yup, looks good, thanks for the changes!