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Add fast-path for accessing the current thread id#143069

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jsimmons:current-thread-id-accessor
Oct 1, 2025
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Add fast-path for accessing the current thread id#143069
bors merged 1 commit intorust-lang:masterfrom
jsimmons:current-thread-id-accessor

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@jsimmons jsimmons commented Jun 26, 2025 •
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Accessing the thread id is often used in profiling and debugging, as well as some approaches for sound single-threaded access to shared data.

Currently the only way to access the thread id is by first obtaining a handle to the current thread. While this is not exactly slow, it does require an atomic inc-ref and dec-ref operation, as well as the injection of Thread's drop code into the caller.

This publicly exposes the existing fast-path for accessing the current thread id.

edit: ACP: rust-lang/libs-team#650

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r? @jhpratt

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@rustbot rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-libs Relevant to the library team, which will review and decide on the PR/issue. labels Jun 26, 2025
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workingjubilee commented Jun 26, 2025

r? libs-api

@rustbot rustbot added the T-libs-api Relevant to the library API team, which will review and decide on the PR/issue. label Jun 26, 2025
@rustbot rustbot assigned m-ou-se and unassigned jhpratt Jun 26, 2025
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bors commented Aug 7, 2025

☔ The latest upstream changes (presumably #115746) made this pull request unmergeable. Please resolve the merge conflicts.

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tgross35 commented Sep 2, 2025

Note: I have no idea how these kinds of proposals usually go, but an acp felt overkill for a tiny code change so here we are :)

Could you submit one anyway? It's the easiest way to get something on the radar, and it should be trivial.

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tgross35 commented Sep 5, 2025

r? tgross35 for after that is done
@rustbot author for the ACP

@rustbot rustbot assigned tgross35 and unassigned m-ou-se Sep 5, 2025
@rustbot rustbot added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Sep 5, 2025
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rustbot commented Sep 5, 2025

Reminder, once the PR becomes ready for a review, use @rustbot ready.

@tgross35 tgross35 added the S-waiting-on-ACP Status: PR has an ACP and is waiting for the ACP to complete. label Sep 5, 2025
@jsimmons jsimmons mentioned this pull request Sep 7, 2025
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@jsimmons jsimmons force-pushed the current-thread-id-accessor branch from 175584f to 82eb244 Compare September 7, 2025 19:47
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joshtriplett commented Sep 13, 2025

r=me once the ACP is approved.

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joshtriplett commented Sep 13, 2025

@bors delegate+

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bors commented Sep 13, 2025

✌️ @jsimmons, you can now approve this pull request!

If @joshtriplett told you to "r=me" after making some further change, please make that change, then do @bors r=@joshtriplett

@Dylan-DPC Dylan-DPC removed the S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. label Sep 26, 2025
@jsimmons jsimmons mentioned this pull request Sep 30, 2025
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jsimmons commented Sep 30, 2025

ACP Accepted: rust-lang/libs-team#650

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jsimmons commented Sep 30, 2025

@bors r=@joshtriplett

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bors commented Sep 30, 2025

📌 Commit 82eb244 has been approved by joshtriplett

It is now in the queue for this repository.

@bors bors added the S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. label Sep 30, 2025
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joboet commented Sep 30, 2025

@bors r-
The tracking issue number is missing from the #[unstable] attributes.

@bors bors added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. labels Sep 30, 2025
@jsimmons jsimmons force-pushed the current-thread-id-accessor branch from 82eb244 to 5400f9e Compare September 30, 2025 18:19
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jfrimmel
jfrimmel reviewed Sep 30, 2025
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library/std/src/thread/current.rs Outdated
/// });
///
/// let other_thread_id = other_thread.join().unwrap();
/// assert!(thread::current_id() != other_thread_id);
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Suggested change
/// assert!(thread::current_id() != other_thread_id);
/// assert_ne!(thread::current_id(), other_thread_id);

@tgross35 tgross35 removed the S-waiting-on-ACP Status: PR has an ACP and is waiting for the ACP to complete. label Sep 30, 2025
@jsimmons jsimmons force-pushed the current-thread-id-accessor branch from 5400f9e to c081c87 Compare September 30, 2025 18:40
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rustbot commented Sep 30, 2025

This PR was rebased onto a different master commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

@jsimmons
Add fast-path for accessing the current thread id
cbaec31 
Accessing the thread id is often used in profiling and debugging, as
well as some approaches for sound single-threaded access to data.

Currently the only way to access the thread id is by first obtaining a
handle to the current thread. While this is not exactly slow, it does
require an atomic inc-ref and dec-ref operation, as well as the
injection of `Thread`'s drop code into the caller.

This publicly exposes the existing fast-path for accessing the current
thread id.
@jsimmons jsimmons force-pushed the current-thread-id-accessor branch from c081c87 to cbaec31 Compare September 30, 2025 18:51
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tgross35 commented Sep 30, 2025

@bors r=joshtriplett,tgross35

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bors commented Sep 30, 2025

📌 Commit cbaec31 has been approved by joshtriplett,tgross35

It is now in the queue for this repository.

@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-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Sep 30, 2025
@matthiaskrgr matthiaskrgr mentioned this pull request Sep 30, 2025
Merged
bors added a commit that referenced this pull request Sep 30, 2025
@bors
Auto merge of #147198 - matthiaskrgr:rollup-b0ryvvu, r=matthiaskrgr
df77923 
Rollup of 6 pull requests

Successful merges:

 - #143069 (Add fast-path for accessing the current thread id)
 - #146518 (Improve the documentation around `ZERO_AR_DATE`)
 - #146596 (Add a dummy codegen backend)
 - #146617 (Don’t suggest foreign `doc(hidden)` types in "the following other types implement trait" diagnostics)
 - #146635 (cg_llvm: Stop using `as_c_char_ptr` for coverage-related bindings)
 - #147184 (Fix the bevy implied bounds hack for the next solver)

r? `@ghost`
`@rustbot` modify labels: rollup
bors added a commit that referenced this pull request Oct 1, 2025
@bors
Auto merge of #147198 - matthiaskrgr:rollup-b0ryvvu, r=matthiaskrgr
1e1a394 
Rollup of 6 pull requests

Successful merges:

 - #143069 (Add fast-path for accessing the current thread id)
 - #146518 (Improve the documentation around `ZERO_AR_DATE`)
 - #146596 (Add a dummy codegen backend)
 - #146617 (Don’t suggest foreign `doc(hidden)` types in "the following other types implement trait" diagnostics)
 - #146635 (cg_llvm: Stop using `as_c_char_ptr` for coverage-related bindings)
 - #147184 (Fix the bevy implied bounds hack for the next solver)

r? `@ghost`
`@rustbot` modify labels: rollup
@bors bors merged commit 3e621b3 into rust-lang:master Oct 1, 2025
10 checks passed
@rustbot rustbot added this to the 1.92.0 milestone Oct 1, 2025
rust-timer added a commit that referenced this pull request Oct 1, 2025
@rust-timer
Unrolled build for #143069
f2008fc 
Rollup merge of #143069 - jsimmons:current-thread-id-accessor, r=joshtriplett,tgross35

Add fast-path for accessing the current thread id

Accessing the thread id is often used in profiling and debugging, as well as some approaches for sound single-threaded access to shared data.

Currently the only way to access the thread id is by first obtaining a handle to the current thread. While this is not exactly slow, it does require an atomic inc-ref and dec-ref operation, as well as the injection of `Thread`'s drop code into the caller.

This publicly exposes the existing fast-path for accessing the current thread id.

edit: ACP: rust-lang/libs-team#650
@jsimmons jsimmons deleted the current-thread-id-accessor branch October 4, 2025 18:46
github-actions bot pushed a commit to model-checking/verify-rust-std that referenced this pull request Oct 9, 2025
@bors
Auto merge of rust-lang#147198 - matthiaskrgr:rollup-b0ryvvu, r=matth…
8c21d93 
…iaskrgr

Rollup of 6 pull requests

Successful merges:

 - rust-lang#143069 (Add fast-path for accessing the current thread id)
 - rust-lang#146518 (Improve the documentation around `ZERO_AR_DATE`)
 - rust-lang#146596 (Add a dummy codegen backend)
 - rust-lang#146617 (Don’t suggest foreign `doc(hidden)` types in "the following other types implement trait" diagnostics)
 - rust-lang#146635 (cg_llvm: Stop using `as_c_char_ptr` for coverage-related bindings)
 - rust-lang#147184 (Fix the bevy implied bounds hack for the next solver)

r? `@ghost`
`@rustbot` modify labels: rollup
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