Tracking issue for ptr::{read,write}_volatile #31756

alexcrichton · 2016-02-18T18:57:58Z

alexcrichton · 2016-02-18T18:58:10Z

cc @Amanieu, would you be interested in implementing?

Amanieu · 2016-02-18T19:03:54Z

I'll give it a go when I find some free time, hopefully this weekend.

Tracking issue: #31756 RFC: rust-lang/rfcs#1467 I've made these unstable for now. Should they be stabilized straight away since we've had plenty of experience with people using the unstable intrinsics?

oli-obk · 2016-03-08T16:00:04Z

write_volatile can still end up triggering a llvm assertion: #29663

alexcrichton · 2016-03-11T18:11:02Z

🔔 This issue is now entering its cycle-long final comment period for tentative stabilization in 1.9 🔔

The libs team is comfortable with these APIs as-is, but we're pretty worried about stabilizing with the LLVM assert being a known downside. If the assert hasn't been fixed by the time the 1.9 beta release rolls around we'll likely just punt on stabilization of these APIs.

Zoxc · 2016-03-12T08:17:17Z

How will volatile reads/writes not supported by the platform be reported back to the user?

nodakai · 2016-03-12T10:25:46Z

Should T be restricted to Copy? I'm not sure

jonas-schievink · 2016-03-12T11:07:01Z

@nodakai ptr::read isn't restricted in that way, so my guess is no

@Zoxc ...they can be not supported? How? Or did you confuse this with atomic reads and writes?

Amanieu · 2016-03-13T16:42:51Z

The assert should be fixed by #32233

Zoxc · 2016-03-17T19:36:24Z

Hm.. it seems LLVM will implicitly split volatile operations that aren't supported. I'm not sure that is desirable semantics.

Amanieu · 2016-03-17T19:42:59Z

C does the same thing so I think it's fine.

aturon · 2016-04-05T16:56:58Z

cc @rust-lang/compiler @rust-lang/lang -- the libs team will be meeting soon to reach a stabilization decision. This API cuts across your concerns as well, so please have a look!

huonw · 2016-04-06T11:40:44Z

Since we don't really have a memory model/Rust abstract machine, we don't have a strong model for what volatile means (the C definition is essentially "execute exactly the operations the C abstract machine would execute"). I imagine this isn't particularly problematic in practice, but it seems like something to keep in mind.

Also, we may want to make sure the documentation doesn't tie the behaviour of these functions to LLVM's definition of volatile? (It currently refers to the LLVM docs, a reference we may want to either remove or explicitly state is non-binding.)

alexcrichton · 2016-04-07T17:25:38Z

The libs team discussed this during triage yesterday and the decision was to stabilize.

We discussed what the documentation would look like and we concluded that we should point to C11 instead of LLVM and also add a note saying that the memory model for Rust isn't formally defined so the precise semantics are subject to change, but it's likely to be "suitable as an equivalent to volatile in C" or something like that.

This commit applies all stabilizations, renamings, and deprecations that the library team has decided on for the upcoming 1.9 release. All tracking issues have gone through a cycle-long "final comment period" and the specific APIs stabilized/deprecated are: Stable * `std::panic` * `std::panic::catch_unwind` (renamed from `recover`) * `std::panic::resume_unwind` (renamed from `propagate`) * `std::panic::AssertUnwindSafe` (renamed from `AssertRecoverSafe`) * `std::panic::UnwindSafe` (renamed from `RecoverSafe`) * `str::is_char_boundary` * `<*const T>::as_ref` * `<*mut T>::as_ref` * `<*mut T>::as_mut` * `AsciiExt::make_ascii_uppercase` * `AsciiExt::make_ascii_lowercase` * `char::decode_utf16` * `char::DecodeUtf16` * `char::DecodeUtf16Error` * `char::DecodeUtf16Error::unpaired_surrogate` * `BTreeSet::take` * `BTreeSet::replace` * `BTreeSet::get` * `HashSet::take` * `HashSet::replace` * `HashSet::get` * `OsString::with_capacity` * `OsString::clear` * `OsString::capacity` * `OsString::reserve` * `OsString::reserve_exact` * `OsStr::is_empty` * `OsStr::len` * `std::os::unix::thread` * `RawPthread` * `JoinHandleExt` * `JoinHandleExt::as_pthread_t` * `JoinHandleExt::into_pthread_t` * `HashSet::hasher` * `HashMap::hasher` * `CommandExt::exec` * `File::try_clone` * `SocketAddr::set_ip` * `SocketAddr::set_port` * `SocketAddrV4::set_ip` * `SocketAddrV4::set_port` * `SocketAddrV6::set_ip` * `SocketAddrV6::set_port` * `SocketAddrV6::set_flowinfo` * `SocketAddrV6::set_scope_id` * `<[T]>::copy_from_slice` * `ptr::read_volatile` * `ptr::write_volatile` * The `#[deprecated]` attribute * `OpenOptions::create_new` Deprecated * `std::raw::Slice` - use raw parts of `slice` module instead * `std::raw::Repr` - use raw parts of `slice` module instead * `str::char_range_at` - use slicing plus `chars()` plus `len_utf8` * `str::char_range_at_reverse` - use slicing plus `chars().rev()` plus `len_utf8` * `str::char_at` - use slicing plus `chars()` * `str::char_at_reverse` - use slicing plus `chars().rev()` * `str::slice_shift_char` - use `chars()` plus `Chars::as_str` * `CommandExt::session_leader` - use `before_exec` instead. Closes rust-lang#27719 cc rust-lang#27751 (deprecating the `Slice` bits) Closes rust-lang#27754 Closes rust-lang#27780 Closes rust-lang#27809 Closes rust-lang#27811 Closes rust-lang#27830 Closes rust-lang#28050 Closes rust-lang#29453 Closes rust-lang#29791 Closes rust-lang#29935 Closes rust-lang#30014 Closes rust-lang#30752 Closes rust-lang#31262 cc rust-lang#31398 (still need to deal with `before_exec`) Closes rust-lang#31405 Closes rust-lang#31572 Closes rust-lang#31755 Closes rust-lang#31756

std: Stabilize APIs for the 1.9 release This commit applies all stabilizations, renamings, and deprecations that the library team has decided on for the upcoming 1.9 release. All tracking issues have gone through a cycle-long "final comment period" and the specific APIs stabilized/deprecated are: Stable * `std::panic` * `std::panic::catch_unwind` (renamed from `recover`) * `std::panic::resume_unwind` (renamed from `propagate`) * `std::panic::AssertUnwindSafe` (renamed from `AssertRecoverSafe`) * `std::panic::UnwindSafe` (renamed from `RecoverSafe`) * `str::is_char_boundary` * `<*const T>::as_ref` * `<*mut T>::as_ref` * `<*mut T>::as_mut` * `AsciiExt::make_ascii_uppercase` * `AsciiExt::make_ascii_lowercase` * `char::decode_utf16` * `char::DecodeUtf16` * `char::DecodeUtf16Error` * `char::DecodeUtf16Error::unpaired_surrogate` * `BTreeSet::take` * `BTreeSet::replace` * `BTreeSet::get` * `HashSet::take` * `HashSet::replace` * `HashSet::get` * `OsString::with_capacity` * `OsString::clear` * `OsString::capacity` * `OsString::reserve` * `OsString::reserve_exact` * `OsStr::is_empty` * `OsStr::len` * `std::os::unix::thread` * `RawPthread` * `JoinHandleExt` * `JoinHandleExt::as_pthread_t` * `JoinHandleExt::into_pthread_t` * `HashSet::hasher` * `HashMap::hasher` * `CommandExt::exec` * `File::try_clone` * `SocketAddr::set_ip` * `SocketAddr::set_port` * `SocketAddrV4::set_ip` * `SocketAddrV4::set_port` * `SocketAddrV6::set_ip` * `SocketAddrV6::set_port` * `SocketAddrV6::set_flowinfo` * `SocketAddrV6::set_scope_id` * `<[T]>::copy_from_slice` * `ptr::read_volatile` * `ptr::write_volatile` * The `#[deprecated]` attribute * `OpenOptions::create_new` Deprecated * `std::raw::Slice` - use raw parts of `slice` module instead * `std::raw::Repr` - use raw parts of `slice` module instead * `str::char_range_at` - use slicing plus `chars()` plus `len_utf8` * `str::char_range_at_reverse` - use slicing plus `chars().rev()` plus `len_utf8` * `str::char_at` - use slicing plus `chars()` * `str::char_at_reverse` - use slicing plus `chars().rev()` * `str::slice_shift_char` - use `chars()` plus `Chars::as_str` * `CommandExt::session_leader` - use `before_exec` instead. Closes #27719 cc #27751 (deprecating the `Slice` bits) Closes #27754 Closes #27780 Closes #27809 Closes #27811 Closes #27830 Closes #28050 Closes #29453 Closes #29791 Closes #29935 Closes #30014 Closes #30752 Closes #31262 cc #31398 (still need to deal with `before_exec`) Closes #31405 Closes #31572 Closes #31755 Closes #31756

This commit applies all stabilizations, renamings, and deprecations that the library team has decided on for the upcoming 1.9 release. All tracking issues have gone through a cycle-long "final comment period" and the specific APIs stabilized/deprecated are: Stable * `std::panic` * `std::panic::catch_unwind` (renamed from `recover`) * `std::panic::resume_unwind` (renamed from `propagate`) * `std::panic::AssertUnwindSafe` (renamed from `AssertRecoverSafe`) * `std::panic::UnwindSafe` (renamed from `RecoverSafe`) * `str::is_char_boundary` * `<*const T>::as_ref` * `<*mut T>::as_ref` * `<*mut T>::as_mut` * `AsciiExt::make_ascii_uppercase` * `AsciiExt::make_ascii_lowercase` * `char::decode_utf16` * `char::DecodeUtf16` * `char::DecodeUtf16Error` * `char::DecodeUtf16Error::unpaired_surrogate` * `BTreeSet::take` * `BTreeSet::replace` * `BTreeSet::get` * `HashSet::take` * `HashSet::replace` * `HashSet::get` * `OsString::with_capacity` * `OsString::clear` * `OsString::capacity` * `OsString::reserve` * `OsString::reserve_exact` * `OsStr::is_empty` * `OsStr::len` * `std::os::unix::thread` * `RawPthread` * `JoinHandleExt` * `JoinHandleExt::as_pthread_t` * `JoinHandleExt::into_pthread_t` * `HashSet::hasher` * `HashMap::hasher` * `CommandExt::exec` * `File::try_clone` * `SocketAddr::set_ip` * `SocketAddr::set_port` * `SocketAddrV4::set_ip` * `SocketAddrV4::set_port` * `SocketAddrV6::set_ip` * `SocketAddrV6::set_port` * `SocketAddrV6::set_flowinfo` * `SocketAddrV6::set_scope_id` * `<[T]>::copy_from_slice` * `ptr::read_volatile` * `ptr::write_volatile` * The `#[deprecated]` attribute * `OpenOptions::create_new` Deprecated * `std::raw::Slice` - use raw parts of `slice` module instead * `std::raw::Repr` - use raw parts of `slice` module instead * `str::char_range_at` - use slicing plus `chars()` plus `len_utf8` * `str::char_range_at_reverse` - use slicing plus `chars().rev()` plus `len_utf8` * `str::char_at` - use slicing plus `chars()` * `str::char_at_reverse` - use slicing plus `chars().rev()` * `str::slice_shift_char` - use `chars()` plus `Chars::as_str` * `CommandExt::session_leader` - use `before_exec` instead. Closes rust-lang#27719 cc rust-lang#27751 (deprecating the `Slice` bits) Closes rust-lang#27754 Closes rust-lang#27780 Closes rust-lang#27809 Closes rust-lang#27811 Closes rust-lang#27830 Closes rust-lang#28050 Closes rust-lang#29453 Closes rust-lang#29791 Closes rust-lang#29935 Closes rust-lang#30014 Closes rust-lang#30752 Closes rust-lang#31262 cc rust-lang#31398 (still need to deal with `before_exec`) Closes rust-lang#31405 Closes rust-lang#31572 Closes rust-lang#31755 Closes rust-lang#31756

alexcrichton added B-RFC-approved Blocker: Approved by a merged RFC but not yet implemented. T-libs-api Relevant to the library API team, which will review and decide on the PR/issue. labels Feb 18, 2016

Amanieu mentioned this issue Feb 18, 2016

Implement read_volatile and write_volatile #31761

Merged

emberian added the B-unstable Blocker: Implemented in the nightly compiler and unstable. label Mar 6, 2016

alexcrichton removed the B-RFC-approved Blocker: Approved by a merged RFC but not yet implemented. label Mar 9, 2016

sfackler added the I-nominated label Mar 9, 2016

alexcrichton added final-comment-period In the final comment period and will be merged soon unless new substantive objections are raised. and removed I-nominated labels Mar 11, 2016

alexcrichton mentioned this issue Apr 7, 2016

std: Stabilize APIs for the 1.9 release #32804

Merged

bors closed this as completed in #32804 Apr 12, 2016

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Tracking issue for ptr::{read,write}_volatile #31756

Tracking issue for ptr::{read,write}_volatile #31756

alexcrichton commented Feb 18, 2016

alexcrichton commented Feb 18, 2016

Amanieu commented Feb 18, 2016

oli-obk commented Mar 8, 2016

alexcrichton commented Mar 11, 2016

Zoxc commented Mar 12, 2016

nodakai commented Mar 12, 2016

jonas-schievink commented Mar 12, 2016

Amanieu commented Mar 13, 2016

Zoxc commented Mar 17, 2016

Amanieu commented Mar 17, 2016

aturon commented Apr 5, 2016

huonw commented Apr 6, 2016

alexcrichton commented Apr 7, 2016

Tracking issue for ptr::{read,write}_volatile #31756

Tracking issue for ptr::{read,write}_volatile #31756

Comments

alexcrichton commented Feb 18, 2016

alexcrichton commented Feb 18, 2016

Amanieu commented Feb 18, 2016

oli-obk commented Mar 8, 2016

alexcrichton commented Mar 11, 2016

Zoxc commented Mar 12, 2016

nodakai commented Mar 12, 2016

jonas-schievink commented Mar 12, 2016

Amanieu commented Mar 13, 2016

Zoxc commented Mar 17, 2016

Amanieu commented Mar 17, 2016

aturon commented Apr 5, 2016

huonw commented Apr 6, 2016

alexcrichton commented Apr 7, 2016