Fix `checked_{add,sub}_duration` incorrectly returning `None` when `other` has more than `i64::MAX` seconds
Use `checked_{add,sub}_unsigned` in `checked_{add,sub}_duration` so that the correct result is returned when adding/subtracting durations with more than `i64::MAX` seconds.
avoid duplicating TLS state between test std and realstd
This basically re-lands https://github.com/rust-lang/rust/pull/100201 and https://github.com/rust-lang/rust/pull/106638, which got reverted by https://github.com/rust-lang/rust/pull/110861. This works around 2 Miri limitations:
- Miri doesn't support the magic linker section that our Windows TLS support relies on, and instead knows where in std to find the symbol that stores the thread callback.
- For macOS, Miri only supports at most one destructor to be registered per thread.
The 2nd would not be very hard to fix (though the intended destructor order is unclear); the first would be a lot of work to fix. Neither of these is a problem for regular Rust code, but in the std test suite we have essentially 2 copies of the std code and then these both become issues. To avoid that we have the std test crate import the TLS code from the real std instead of having its own copy.
r? ``````@m-ou-se``````
Replace generic thread parker with explicit no-op parker
With #98391 merged, all platforms supporting threads now have their own parking implementations. Therefore, the generic implementation can be removed. On the remaining platforms (really just WASM without atomics), parking is not supported, so calls to `thread::park` now return instantly, which is [allowed by their API](https://doc.rust-lang.org/nightly/std/thread/fn.park.html). This is a change in behaviour, as spurious wakeups do not currently occur since all platforms guard against them. It is invalid to depend on this, but I'm still going to tag this as libs-api for confirmation.
````@rustbot```` label +T-libs +T-libs-api +A-atomic
r? rust-lang/libs
Implement tuple<->array convertions via `From`
This PR adds the following impls that convert between homogeneous tuples and arrays of the corresponding lengths:
```rust
impl<T> From<[T; 1]> for (T,) { ... }
impl<T> From<[T; 2]> for (T, T) { ... }
/* ... */
impl<T> From<[T; 12]> for (T, T, T, T, T, T, T, T, T, T, T, T) { ... }
impl<T> From<(T,)> for [T; 1] { ... }
impl<T> From<(T, T)> for [T; 2] { ... }
/* ... */
impl<T> From<(T, T, T, T, T, T, T, T, T, T, T, T)> for [T; 12] { ... }
```
IMO these are quite uncontroversial but note that they are, just like any other trait impls, insta-stable.
Some data-independent timing vector instructions may have subtle data-dependent
timing due to MXCSR configuration; dependent on (potentially secret) data
instruction retirement may be delayed by one cycle.
This can be done by simply changing the `\??\` prefix to `\\?\` and then attempting to convert to a user path.
Currently it simply strips off the prefix which could lead to the wrong path being returned (e.g. if it's not a drive path or if the path contains trailing spaces, etc).
Remove `all` in target_thread_local cfg
I think it was left there by mistake after the previous refactoring. I just came across it while rebasing to master.
Make sure the implementation of TcpStream::as_raw_fd is fully inlined
Currently the following function:
```rust
use std::os::fd::{AsRawFd, RawFd};
use std::net::TcpStream;
pub fn as_raw_fd(socket: &TcpStream) -> RawFd {
socket.as_raw_fd()
}
```
Is optimized to the following:
```asm
example::as_raw_fd:
push rax
call qword ptr [rip + <std::net::tcp::TcpStream as std::sys_common::AsInner<std::sys_common::net::TcpStream>>::as_inner@GOTPCREL]
mov rdi, rax
call qword ptr [rip + std::sys_common::net::TcpStream::socket@GOTPCREL]
mov rdi, rax
pop rax
jmp qword ptr [rip + _ZN73_$LT$std..sys..unix..net..Socket$u20$as$u20$std..os..fd..raw..AsRawFd$GT$9as_raw_fd17h633bcf7e481df8bbE@GOTPCREL]
```
I think it would make more sense to inline trivial functions used within `TcpStream::AsRawFd`.
update wasi_clock_time_api ref.
Closes#110809
>Preview0 corresponded to the import module name wasi_unstable. It was also called snapshot_0 in some places. It was short-lived, and the changes to preview1 were minor, so the focus here is on preview1.
we use the `preview1` doc according to the above quote form [WASI legacy Readme](https://github.com/WebAssembly/WASI/blob/main/legacy/README.md) .
Add 64-bit `time_t` support on 32-bit glibc Linux to `set_times`
Add support to `set_times` for 64-bit `time_t` on 32-bit glibc Linux platforms which have a 32-bit `time_t`. Split from #109773.
Tracking issue: #98245
std docs: edit `PathBuf::set_file_name` example
To make explicit that `set_file_name` might replace or remove the
extension, not just the file stem.
Also edit docs for `Path::with_file_name`, which calls `set_file_name`.
Document `const {}` syntax for `std::thread_local`.
It exists and is pretty cool. More people should use it.
It was added in #83416 and stabilized in #91355 with the tracking issue #84223.
If opening a directory with `FILE_LIST_DIRECTORY` access fails then we should try opening without requesting that access. We may still be able to delete it if it's empty or a link.
Change memory ordering in System wrapper example
Currently, the `SeqCst` ordering is used, which seems unnecessary:
+ Even `Relaxed` ordering guarantees that all updates are atomic and are executed in total order
+ User code only reads atomic for monitoring purposes, no "happens-before" relationships with actual allocations and deallocations are needed for this
If argumentation above is correct, I propose changing ordering to `Relaxed` to clarify that no synchronization is required here, and improve performance (if somebody copy-pastes this example into their code).
Correct `std::prelude` comment
(Read the changed file first for context.)
First, `alloc` has no prelude.
Second, the docs for `v1` don't matter since the [prelude module] already has all the doc links. The `rust_2021` module for instance also doesnt have a convenient doc page. However as I understand glob imports still cant be used because the items dont have the same stabilisation versions.
[prelude module]: https://doc.rust-lang.org/std/prelude/index.html
docs(std): clarify remove_dir_all errors
When using `remove_dir_all`, I assumed that the function was idempotent and that I could always call it to remove a directory if it existed. That's not the case and it bit me in production, so I figured I'd submit this to clarify the docs.
Restructure and rename std thread_local internals to make it less of a maze
Every time I try to work on std's thread local internals, it feels like I'm trying to navigate a confusing maze made of macros, deeply nested modules, and types with multiple names/aliases. Time to clean it up a bit.
This PR:
- Exports `Key` with its own name (`Key`), instead of `__LocalKeyInner`
- Uses `pub macro` to put `__thread_local_inner` into a (unstable, hidden) module, removing `#[macro_export]`, removing it from the crate root.
- Removes the `__` from `__thread_local_inner`.
- Removes a few unnecessary `allow_internal_unstable` features from the macros
- Removes the `libstd_thread_internals` feature. (Merged with `thread_local_internals`.)
- And removes it from the unstable book
- Gets rid of the deeply nested modules for the `Key` definitions (`mod fast` / `mod os` / `mod statik`).
- Turns a `#[cfg]` mess into a single `cfg_if`, now that there's no `#[macro_export]` anymore that breaks with `cfg_if`.
- Simplifies the `cfg_if` conditions to not repeat the conditions.
- Removes useless `normalize-stderr-test`, which were left over from when the `Key` types had different names on different platforms.
- Removes a seemingly unnecessary `realstd` re-export on `cfg(test)`.
This PR changes nothing about the thread local implementation. That's for a later PR. (Which should hopefully be easier once all this stuff is a bit cleaned up.)
Spelling library
Split per https://github.com/rust-lang/rust/pull/110392
I can squash once people are happy w/ the changes. It's really uncommon for large sets of changes to be perfectly acceptable w/o at least some changes.
I probably won't have time to respond until tomorrow or the next day
Fix `std` compilation error for wasi+atomics
Fix https://github.com/rust-lang/rust/issues/109727
It seems that the `unsupported/once.rs` module isn't meant to exist at the same time as the `futex` module, as they have conflicting definitions.
I've solved this by defining the `once` module only if `not(target_feature = "atomics")`.
The `wasm32-unknown-unknown` target [similarly only defines the `once` module if `not(target_feature = "atomics")`](01c4f31927/library/std/src/sys/wasm/mod.rs (L69-L70)).
As show in [this block of code](01c4f31927/library/std/src/sys_common/once/mod.rs (L10-L34)), the `sys::once` module doesn't need to exist if `all(target_arch = "wasm32", target_feature = "atomics")`.
Update documentation wording on path 'try_exists' functions
Just eliminate the quadruple negation in `doesn't silently ignore errors unrelated to ... not existing.`
