Make Barrier::new() const

[Jules-Bertholet]

I guess this was just missed in #97791?

@rustbot label T-libs-api -T-libs

[rustbot]

r? @thomcc

(rustbot has picked a reviewer for you, use r? to override)

[thomcc]

Seems fine to me but needs libs-api.

r? libs-api

[dtolnay]

@rust-lang/libs-api:
@rfcbot fcp merge

This enables using std::sync::Barrier in static, as was recently done for Mutex and some other synchronization types.

use std::sync::Barrier;
use std::thread;
use std::time::Duration;

static BARRIER: Barrier = Barrier::new(3);

fn main() {
    loop {
        thread::spawn(|| {
            BARRIER.wait();
            println!("{:?}", thread::current().id());
        });
        thread::sleep(Duration::from_millis(300));
    }
}

[rfcbot]

Team member @dtolnay has proposed to merge this. The next step is review by the rest of the tagged team members:

• @Amanieu
• @BurntSushi
• @dtolnay
• @joshtriplett
• @m-ou-se

No concerns currently listed.

Once a majority of reviewers approve (and at most 2 approvals are outstanding), this will enter its final comment period. If you spot a major issue that hasn't been raised at any point in this process, please speak up!

See this document for info about what commands tagged team members can give me.

[rfcbot]

🔔 This is now entering its final comment period, as per the review above. 🔔

[rfcbot]

The final comment period, with a disposition to merge, as per the review above, is now complete.

As the automated representative of the governance process, I would like to thank the author for their work and everyone else who contributed.

This will be merged soon.

[dtolnay]

Thank you!

[dtolnay]

@bors r+

[bors]

📌 Commit 3c9aa69 has been approved by dtolnay

It is now in the queue for this repository.

[bors]

⌛ Testing commit 3c9aa69 with merge 8f359be...

[bors]

☀️ Test successful - checks-actions
Approved by: dtolnay
Pushing 8f359be to master...

[rust-timer]

Finished benchmarking commit (8f359be): comparison URL.

Overall result: ❌ regressions - no action needed

@rustbot label: -perf-regression

Instruction count

This is a highly reliable metric that was used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	1.3%	[1.3%, 1.3%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

This benchmark run did not return any relevant results for this metric.

Cycles

This benchmark run did not return any relevant results for this metric.

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 650.231s -> 648.482s (-0.27%)
Artifact size: 310.96 MiB -> 310.98 MiB (0.01%)