Fix incorrect io::Take's limit resulting from io::copy specialization
The specialization introduced in #75272 fails to update `io::Take` wrappers after performing the copy syscalls which bypass those wrappers. The buffer flushing before the copy does update them correctly, but the bytes copied after the initial flush weren't subtracted.
The fix is to subtract the bytes copied from each `Take` in the chain of wrappers, even when an error occurs during the syscall loop. To do so the `CopyResult` enum now has to carry the bytes copied so far in the error case.
Provide IntoInnerError::into_parts
Hi. This is an updated version of the IntoInnerError bits of my previous portmanteau MR #78689. Thanks to `@jyn514` and `@m-ou-se` for helpful comments there.
I have made this insta-stable since it seems like it will probably be uncontroversial, but that is definitely something that someone from the libs API team should be aware of and explicitly consider.
I included a tangentially-related commit providing documentation of the buffer full behaviiour of `&mut [u8] as Write`; the behaviour I am documenting is relied on by the doctest for `into_parts`.
In particular, IntoIneerError only currently provides .error() which
returns a reference, not an owned value. This is not helpful and
means that a caller of BufWriter::into_inner cannot acquire an owned
io::Error which seems quite wrong.
Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
disable a ptr equality test on Miri
This test relies on deduplication of constants. I do not think that this is a *guarantee* that Rust currently makes, and indeed Miri does not deduplicate constants the same way that rustc does, leading to different behavior in this test.
For now, I propose we simply disable this test in Miri.
Use more std:: instead of core:: in docs for consistency
``@rustbot`` label T-doc
Some cleanup work to use `std::` instead of `core::` in docs as much as possible. This helps with terminology and consistency, especially for newcomers from other languages that have often heard of `std` to describe the standard library but not of `core`.
Edit: I also added more intra doc links when I saw the opportunity.
These tests write to the same filenames in /tmp and in some cases these
files don't get cleaned up properly. This caused issues for us when
different users run the tests on the same system, e.g.:
```
---- sys::unix::kernel_copy::tests::bench_file_to_file_copy stdout ----
thread 'sys::unix::kernel_copy::tests::bench_file_to_file_copy' panicked at 'called `Result::unwrap()` on an `Err` value: Os { code: 13, kind: PermissionDenied, message: "Permission denied" }', library/std/src/sys/unix/kernel_copy/tests.rs:71:10
---- sys::unix::kernel_copy::tests::bench_file_to_socket_copy stdout ----
thread 'sys::unix::kernel_copy::tests::bench_file_to_socket_copy' panicked at 'called `Result::unwrap()` on an `Err` value: Os { code: 13, kind: PermissionDenied, message: "Permission denied" }', library/std/src/sys/unix/kernel_copy/tests.rs💯10
```
Use `std::sys_common::io__test::tmpdir()` to solve this.
unix: Extend UnixStream and UnixDatagram to send and receive file descriptors
Add the functions `recv_vectored_fds` and `send_vectored_fds` to `UnixDatagram` and `UnixStream`. With this functions `UnixDatagram` and `UnixStream` can send and receive file descriptors, by using `recvmsg` and `sendmsg` system call.
std::io: Use sendfile for UnixStream
`UnixStream` was forgotten in #75272 .
Benchmark yields the following results.
Before:
`running 1 test
test sys::unix::kernel_copy::tests::bench_file_to_uds_copy ... bench: 54,399 ns/iter (+/- 6,817) = 2409 MB/s`
After:
`running 1 test
test sys::unix::kernel_copy::tests::bench_file_to_uds_copy ... bench: 18,627 ns/iter (+/- 6,007) = 7036 MB/s`
