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merged 1 commit into from
Jun 6, 2018
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Add Future and task system to the standard library #51263

merged 1 commit into from
Jun 6, 2018

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cramertj
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This adds preliminary versions of the std::future and std::task modules in order to unblock development of async/await (#50547). These shouldn't be considered as final forms of these libraries-- design questions about the libraries should be left on rust-lang/rfcs#2418. Once that RFC (or a successor) is merged, these APIs will be adjusted as necessary.

r? @aturon

@cramertj cramertj requested a review from withoutboats May 31, 2018 23:47
@rust-highfive rust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label May 31, 2018
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aturon
aturon reviewed Jun 5, 2018
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src/liballoc/task.rs Outdated
/// be `poll`ed. This function is like `wake`, but can only be called from the
/// thread on which this `Wake` was created.
///
/// Executors generally maintain a queue of "ready" tasks; `wake` should place
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wake_local

aturon
aturon approved these changes Jun 5, 2018
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Looks great! I quite like the way the LocalWaker pieces have worked out.

aturon
aturon reviewed Jun 5, 2018
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src/liballoc/task.rs Outdated
/// is local to the current thread. The resulting `LocalWaker` will call
/// `wake.wake()` when awoken.
#[inline]
pub fn local_waker_from_nonlocal<W: Wake + 'static>(wake: Arc<W>) -> LocalWaker {
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Could this be a From coercion? Or do you prefer to keep it explicit?

The fact that we can't add it as an inherent constructor is a shame. But we can iterate on this later.

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LocalWaker isn't defined in liballoc, so we can't add a From<impl Wake + 'static> for LocalWaker here. In any case, I think it might be a bit too tricky for users to figure out that wake_local won't be called via the From impl.

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👍

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aturon commented Jun 6, 2018

@bors: r+

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bors commented Jun 6, 2018

📌 Commit 83b69db has been approved by aturon

@bors bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Jun 6, 2018
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bors commented Jun 6, 2018

⌛ Testing commit 83b69db209f461c1bdd2e3631838e6af295d1b01 with merge 37bd8b0c04855cd0d082c2d1899763b4531a748b...

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bors commented Jun 6, 2018

💔 Test failed - status-travis

@bors bors added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. labels Jun 6, 2018
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[01:10:15] error[E0432]: unresolved import `arc`
[01:10:15] --> liballoc/task.rs:13:5
[01:10:15]    |
[01:10:15]    | use arc::Arc;
[01:10:15] 
[01:10:15] error[E0207]: the type parameter `T` is not constrained by the impl trait, self type, or predicates[0m
[01:10:15] --> liballoc/task.rs:74:6
[01:10:15]    | impl<T> From<Arc<T>> for Waker

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cramertj commented Jun 6, 2018

TIL Arc is cfg'd out on some platforms...

@bors bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Jun 6, 2018
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bors commented Jun 6, 2018

📌 Commit a6055c8 has been approved by aturon

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bors commented Jun 6, 2018

⌛ Testing commit a6055c8 with merge 19d0b53...

bors added a commit that referenced this pull request Jun 6, 2018
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Auto merge of #51263 - cramertj:futures-in-core, r=aturon
19d0b53 
Add Future and task system to the standard library

This adds preliminary versions of the `std::future` and `std::task` modules in order to unblock development of async/await (#50547). These shouldn't be considered as final forms of these libraries-- design questions about the libraries should be left on rust-lang/rfcs#2418. Once that RFC (or a successor) is merged, these APIs will be adjusted as necessary.

r? @aturon
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bors commented Jun 6, 2018

☀️ Test successful - status-appveyor, status-travis
Approved by: aturon
Pushing 19d0b53 to master...

@bors bors merged commit a6055c8 into rust-lang:master Jun 6, 2018
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@cramertj cramertj deleted the futures-in-core branch June 6, 2018 22:46
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@fluxxu fluxxu mentioned this pull request Jun 8, 2018
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