When working with an arbitrary reader or writer, code that uses vectored
operations may end up being slower than code that copies into a single
buffer when the underlying reader or writer doesn't actually support
vectored operations. These new methods allow you to ask the reader or
witer up front if vectored operations are efficiently supported.
Currently, you have to use some heuristics to guess by e.g. checking if
the read or write only accessed the first buffer. Hyper is one concrete
example of a library that has to do this dynamically:
0eaf304644/src/proto/h1/io.rs (L582-L594)
This commit applies rustfmt with rust-lang/rust's default settings to
files in src/libstd/sys *that are not involved in any currently open PR*
to minimize merge conflicts. THe list of files involved in open PRs was
determined by querying GitHub's GraphQL API with this script:
https://gist.github.com/dtolnay/aa9c34993dc051a4f344d1b10e4487e8
With the list of files from the script in outstanding_files, the
relevant commands were:
$ find src/libstd/sys -name '*.rs' \
| xargs rustfmt --edition=2018 --unstable-features --skip-children
$ rg libstd/sys outstanding_files | xargs git checkout --
Repeating this process several months apart should get us coverage of
most of the rest of the files.
To confirm no funny business:
$ git checkout $THIS_COMMIT^
$ git show --pretty= --name-only $THIS_COMMIT \
| xargs rustfmt --edition=2018 --unstable-features --skip-children
$ git diff $THIS_COMMIT # there should be no difference
Attempt to create sockets with the WSA_FLAG_NO_HANDLE_INHERIT flag, and
handle the potential error gracefully (as the flag isn't support on
Windows 7 before SP1)
This renames `std::io::IoVec` to `std::io::IoSlice` and
`std::io::IoVecMut` to `std::io::IoSliceMut`, and stabilizes
`std::io::IoSlice`, `std::io::IoSliceMut`,
`std::io::Read::read_vectored`, and `std::io::Write::write_vectored`.
Closes#58452
This commit implements the `{read,write}_vectored` methods on more types
in the standard library, namely:
* `std::fs::File`
* `std::process::ChildStd{in,out,err}`
* `std::io::Std{in,out,err}`
* `std::io::Std{in,out,err}Lock`
* `std::io::Std{in,out,err}Raw`
Where supported the OS implementations hook up to native support,
otherwise it falls back to the already-defaulted implementation.
This commit removes the `rand` crate from the standard library facade as
well as the `__rand` module in the standard library. Neither of these
were used in any meaningful way in the standard library itself. The only
need for randomness in libstd is to initialize the thread-local keys of
a `HashMap`, and that unconditionally used `OsRng` defined in the
standard library anyway.
The cruft of the `rand` crate and the extra `rand` support in the
standard library makes libstd slightly more difficult to port to new
platforms, namely WebAssembly which doesn't have any randomness at all
(without interfacing with JS). The purpose of this commit is to clarify
and streamline randomness in libstd, focusing on how it's only required
in one location, hashmap seeds.
Note that the `rand` crate out of tree has almost always been a drop-in
replacement for the `rand` crate in-tree, so any usage (accidental or
purposeful) of the crate in-tree should switch to the `rand` crate on
crates.io. This then also has the further benefit of avoiding
duplication (mostly) between the two crates!
This commit fixes a mistake introduced in #31618 where overlapped handles were
leaked to child processes on Windows. On Windows once a handle is in overlapped
mode it should always have I/O executed with an instance of `OVERLAPPED`. Most
child processes, however, are not prepared to have their stdio handles in
overlapped mode as they don't use `OVERLAPPED` on reads/writes to the handle.
Now we haven't had any odd behavior in Rust up to this point, and the original
bug was introduced almost a year ago. I believe this is because it turns out
that if you *don't* pass an `OVERLAPPED` then the system will [supply one for
you][link]. In this case everything will go awry if you concurrently operate on
the handle. In Rust, however, the stdio handles are always locked, and there's
no way to not use them unlocked in libstd. Due to that change we've always had
synchronized access to these handles, which means that Rust programs typically
"just work".
Conversely, though, this commit fixes the test case included, which exhibits
behavior that other programs Rust spawns may attempt to execute. Namely, the
stdio handles may be concurrently used and having them in overlapped mode wreaks
havoc.
[link]: https://blogs.msdn.microsoft.com/oldnewthing/20121012-00/?p=6343Closes#38811
Automated conversion using the untry tool [1] and the following command:
```
$ find -name '*.rs' -type f | xargs untry
```
at the root of the Rust repo.
[1]: https://github.com/japaric/untry
Semantically there's actually no reason for us to spawn threads as part of the
call to `wait_with_output`, and that's generally an incredibly heavyweight
operation for just reading a few bytes (especially when stderr probably rarely
has bytes!). An equivalent operation in terms of what's implemented today would
be to just drain both pipes of all contents and then call `wait` on the child
process itself.
On Unix we can implement this through some convenient use of the `select`
function, whereas on Windows we can make use of overlapped I/O. Note that on
Windows this requires us to use named pipes instead of anonymous pipes, but
they're semantically the same under the hood.
This pushes the implementation detail of proxying `read_to_end` through to
`read_to_end_uninitialized` all the way down to the `FileDesc` and `Handle`
implementations on Unix/Windows. This way intermediate layers will also be able
to take advantage of this optimized implementation.
This commit also adds the optimized implementation for `ChildStdout` and
`ChildStderr`.
Most of this is platform-specific anyway, and we generally have to jump through
fewer hoops to do the equivalent operation on Windows. One benefit for Windows
today is that this new structure avoids an extra `DuplicateHandle` when creating
pipes. For Unix, however, the behavior should be the same.
Note that this is just a pure refactoring, no functionality was added or
removed.
* Delete `sys::unix::{c, sync}` as these are now all folded into libc itself
* Update all references to use `libc` as a result.
* Update all references to the new flat namespace.
* Moves all windows bindings into sys::c
This commit is an implementation of [RFC 1184][rfc] which tweaks the behavior of
the `#![no_std]` attribute and adds a new `#![no_core]` attribute. The
`#![no_std]` attribute now injects `extern crate core` at the top of the crate
as well as the libcore prelude into all modules (in the same manner as the
standard library's prelude). The `#![no_core]` attribute disables both std and
core injection.
[rfc]: https://github.com/rust-lang/rfcs/pull/1184
This commit is an implementation of [RFC 1174][rfc] which adds three new traits
to the standard library:
* `IntoRawFd` - implemented on Unix for all I/O types (files, sockets, etc)
* `IntoRawHandle` - implemented on Windows for files, processes, etc
* `IntoRawSocket` - implemented on Windows for networking types
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/1174-into-raw-fd-socket-handle-traits.mdCloses#27062
* Slate these features to be stable in 1.2 instead of 1.1 (not being backported)
* Have the `FromRawFd` implementations follow the contract of the `FromRawFd`
trait by taking ownership of the primitive specified.
* Refactor the implementations slightly to remove the `unreachable!` blocks as
well as separating the stdio representation of `std::process` from
`std::sys::process`.
Now that `std::old_io` has been removed for quite some time the naming real
estate here has opened up to allow these modules to move back to their proper
names.
This is an implementation of [RFC 578][rfc] which adds a new `std::env` module
to replace most of the functionality in the current `std::os` module. More
details can be found in the RFC itself, but as a summary the following methods
have all been deprecated:
[rfc]: https://github.com/rust-lang/rfcs/pull/578
* `os::args_as_bytes` => `env::args`
* `os::args` => `env::args`
* `os::consts` => `env::consts`
* `os::dll_filename` => no replacement, use `env::consts` directly
* `os::page_size` => `env::page_size`
* `os::make_absolute` => use `env::current_dir` + `join` instead
* `os::getcwd` => `env::current_dir`
* `os::change_dir` => `env::set_current_dir`
* `os::homedir` => `env::home_dir`
* `os::tmpdir` => `env::temp_dir`
* `os::join_paths` => `env::join_paths`
* `os::split_paths` => `env::split_paths`
* `os::self_exe_name` => `env::current_exe`
* `os::self_exe_path` => use `env::current_exe` + `pop`
* `os::set_exit_status` => `env::set_exit_status`
* `os::get_exit_status` => `env::get_exit_status`
* `os::env` => `env::vars`
* `os::env_as_bytes` => `env::vars`
* `os::getenv` => `env::var` or `env::var_string`
* `os::getenv_as_bytes` => `env::var`
* `os::setenv` => `env::set_var`
* `os::unsetenv` => `env::remove_var`
Many function signatures have also been tweaked for various purposes, but the
main changes were:
* `Vec`-returning APIs now all return iterators instead
* All APIs are now centered around `OsString` instead of `Vec<u8>` or `String`.
There is currently on convenience API, `env::var_string`, which can be used to
get the value of an environment variable as a unicode `String`.
All old APIs are `#[deprecated]` in-place and will remain for some time to allow
for migrations. The semantics of the APIs have been tweaked slightly with regard
to dealing with invalid unicode (panic instead of replacement).
The new `std::env` module is all contained within the `env` feature, so crates
must add the following to access the new APIs:
#![feature(env)]
[breaking-change]
In preparation for upcoming changes to the `Writer` trait (soon to be called
`Write`) this commit renames the current `write` method to `write_all` to match
the semantics of the upcoming `write_all` method. The `write` method will be
repurposed to return a `usize` indicating how much data was written which
differs from the current `write` semantics. In order to head off as much
unintended breakage as possible, the method is being deprecated now in favor of
a new name.
[breaking-change]
There are some explicit Send/Sync implementations for Window's types
that don't exist in Unix. While the end result will be the same, I
believe it's clearer if we keep the explicit implementations consistent
by making the os-specific types Send/Sync where needed and possible.
This commit addresses pipe
src/libstd/sys/unix/pipe.rs
unsafe impl Send for UnixListener {}
unsafe impl Sync for UnixListener {}
src/libstd/sys/windows/pipe.rs
unsafe impl Send for UnixStream {}
unsafe impl Sync for UnixStream {}
unsafe impl Send for UnixListener {}
unsafe impl Sync for UnixListener {}
unsafe impl Send for UnixAcceptor {}
unsafe impl Sync for UnixAcceptor {}
unsafe impl Send for AcceptorState {}
unsafe impl Sync for AcceptorState {}
This commit is an implementation of [RFC 494][rfc] which removes the entire
`std::c_vec` module and redesigns the `std::c_str` module as `std::ffi`.
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0494-c_str-and-c_vec-stability.md
The interface of the new `CString` is outlined in the linked RFC, the primary
changes being:
* The `ToCStr` trait is gone, meaning the `with_c_str` and `to_c_str` methods
are now gone. These two methods are replaced with a `CString::from_slice`
method.
* The `CString` type is now just a wrapper around `Vec<u8>` with a static
guarantee that there is a trailing nul byte with no internal nul bytes. This
means that `CString` now implements `Deref<Target = [c_char]>`, which is where
it gains most of its methods from. A few helper methods are added to acquire a
slice of `u8` instead of `c_char`, as well as including a slice with the
trailing nul byte if necessary.
* All usage of non-owned `CString` values is now done via two functions inside
of `std::ffi`, called `c_str_to_bytes` and `c_str_to_bytes_with_nul`. These
functions are now the one method used to convert a `*const c_char` to a Rust
slice of `u8`.
Many more details, including newly deprecated methods, can be found linked in
the RFC. This is a:
[breaking-change]
Closes#20444
This removes a large array of deprecated functionality, regardless of how
recently it was deprecated. The purpose of this commit is to clean out the
standard libraries and compiler for the upcoming alpha release.
Some notable compiler changes were to enable warnings for all now-deprecated
command line arguments (previously the deprecated versions were silently
accepted) as well as removing deriving(Zero) entirely (the trait was removed).
The distribution no longer contains the libtime or libregex_macros crates. Both
of these have been deprecated for some time and are available externally.
This commit is an implementation of [RFC 503][rfc] which is a stabilization
story for the prelude. Most of the RFC was directly applied, removing reexports.
Some reexports are kept around, however:
* `range` remains until range syntax has landed to reduce churn.
* `Path` and `GenericPath` remain until path reform lands. This is done to
prevent many imports of `GenericPath` which will soon be removed.
* All `io` traits remain until I/O reform lands so imports can be rewritten all
at once to `std::io::prelude::*`.
This is a breaking change because many prelude reexports have been removed, and
the RFC can be consulted for the exact list of removed reexports, as well as to
find the locations of where to import them.
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0503-prelude-stabilization.md
[breaking-change]
Closes#20068
