rust/library/std/src/sys/thread_local/guard/key.rs, branch 1.89.0https://github.com/rust-lang/rust
http://git.dreamy.place/mirrors/rust/atom?h=1.89.02025-05-22T14:47:36+00:00docs: fix typos2025-05-22T14:47:36+00:00Dannyyy93dannymotydnd@gmail.com2025-05-22T14:47:36+00:00urn:sha1:d6dc08c3f4c32744c7163561da1a16825d1eed2dstd: make `thread::current` available in all `thread_local!` destructors2024-10-02T16:04:21+00:00joboetjonasboettiger@icloud.com2024-07-18T11:59:48+00:00urn:sha1:d868fdce6b9ddef6abcc8de86b3ba8459def36a2Reformat using the new identifier sorting from rustfmt2024-09-22T23:11:29+00:00Michael Gouletmichael@errs.io2024-09-22T23:05:04+00:00urn:sha1:c682aa162b0d41e21cc6748f4fecfe01efb69d1fstd: separate TLS key creation from TLS access2024-06-25T16:30:49+00:00joboetjonasboettiger@icloud.com2024-06-25T16:30:49+00:00urn:sha1:e8516f8b52d8ae49c2e0b2ff2cb5faf28b1a6526
Currently, `std` performs an atomic load to get the OS key on every access to `StaticKey` even when the key is already known. This PR thus replaces `StaticKey` with the platform-specific `get` and `set` function and a new `LazyKey` type that acts as a `LazyLock<Key>`, allowing the reuse of the retreived key for multiple accesses.
std: update TLS module documentation2024-06-17T13:58:06+00:00joboetjonasboettiger@icloud.com2024-06-17T13:58:06+00:00urn:sha1:35f050b8dafc19233f4ecfabd1ac4aa117a491b9std: refactor the TLS implementation2024-06-15T15:47:35+00:00joboetjonasboettiger@icloud.com2024-06-15T15:47:35+00:00urn:sha1:f3facf11758af878bcfaf47fc773962dbb565024
As discovered by Mara in #110897, our TLS implementation is a total mess. In the past months, I have simplified the actual macros and their expansions, but the majority of the complexity comes from the platform-specific support code needed to create keys and register destructors. In keeping with #117276, I have therefore moved all of the `thread_local_key`/`thread_local_dtor` modules to the `thread_local` module in `sys` and merged them into a new structure, so that future porters of `std` can simply mix-and-match the existing code instead of having to copy the same (bad) implementation everywhere. The new structure should become obvious when looking at `sys/thread_local/mod.rs`.
Unfortunately, the documentation changes associated with the refactoring have made this PR rather large. That said, this contains no functional changes except for two small ones:
* the key-based destructor fallback now, by virtue of sharing the implementation used by macOS and others, stores its list in a `#[thread_local]` static instead of in the key, eliminating one indirection layer and drastically simplifying its code.
* I've switched over ZKVM (tier 3) to use the same implementation as WebAssembly, as the implementation was just a way worse version of that
Please let me know if I can make this easier to review! I know these large PRs aren't optimal, but I couldn't think of any good intermediate steps.
@rustbot label +A-thread-locals