Add provided methods `Seek::{stream_len, stream_position}`
This adds two new, provided methods to the `io::Seek` trait:
- `fn stream_len(&mut self) -> Result<u64>`
- `fn stream_position(&mut self) -> Result<u64>`
Both are added for convenience and to improve readability in user code. Reading `file.stream_len()` is much better than to manually seek two or three times. Similarly, `file.stream_position()` is much more clear than `file.seek(SeekFrom::Current(0))`.
You can find prior discussions [in this internals thread](https://internals.rust-lang.org/t/pre-rfc-idea-extend-io-seek-with-convenience-methods-with-e-g-stream-len/9262). I think I addressed all concerns in that thread.
I already wrote three RFCs to add a small new API to libstd but I noticed that many public changes to libstd happen without an RFC. So I figured I can try opening a PR directly without going through RFCs first. After all, we do have rfcbot here too. If you think this change is too big to merge without an RFC, I can still close this PR and write an RFC.
Add new test case for possible bug in BufReader
When reading a large chunk from a BufReader, if all the bytes from the buffer have been already consumed, the internal buffer is bypassed entirely. However, it is not invalidated, and it's possible to access its contents using the `seek_relative` method, because it tries to reuse the existing buffer.
Stabilize Range*::contains.
Closes https://github.com/rust-lang/rust/issues/32311. There's also a bit of rustfmt on range.rs thrown in for good measure (I forgot to turn off format-on-save in VSCode).
Make std time tests more robust for platform differences
Previously, `time::tests::since_epoch` and `time::tests::system_time_math` would fail if the platform represents a SystemTime as unix epoch + `u64` nanoseconds.
r? @sfackler
A few improvements to comments in user-facing crates
Not too many this time, and all concern comments (almost all doc comments) in user-facing crates (libstd, libcore, liballoc).
r? @steveklabnik
SGX target: Expose thread id function in os module
In order to call `std::os::fortanix_sgx::usercalls::send`, you need the thread id. This exposes it through another function in `std::os::fortanix_sgx`.
I looked at how other platforms do this. On Windows and `cfg(unix)` you can get the OS handle from a `thread::JoinHandle`, but that's not sufficient, I need it for a `thread::Thread`. In the future, this functionality could be added to `thread::Thread` and this platform can follow suit.
r? @joshtriplett
Change `std::fs::copy` to use `copyfile` on MacOS and iOS
`copyfile` on MacOS is similar to `CopyFileEx` on Windows. It supports copying resource forks, extended attributes, and file ACLs, none of which are copied by the current generic unix implementation.
The API is available from MacOS 10.7 and iOS 4.3 (and possibly earlier but I haven't checked).
Closes#58895.
std: Spin for a global malloc lock on wasm32
There's lots of comments in the code, but the main gist of this commit
is that the acquisition of the global malloc lock on the
`wasm32-unknown-unknown` target when threads are enabled will not spin
on contention rather than block.
std: Delete a by-definition spuriously failing test
This commit deletes the `connect_timeout_unbound` test from the standard
library which, unfortunately, is by definition eventually going to be a
spuriously failing test. There's no way to reserve a port as unbound so
we can rely on ecosystem testing for this feature for now.
Closes#52590
overhaul unused doc comments lint
This PR contains a number of improvements to the `unused_doc_comments` lint.
- Extends the span to cover the entire comment when using sugared doc comments.
- Triggers the lint for all unused doc comments on a node, instead of just the first one.
- Triggers the lint on macro expansions, and provides a help note explaining that doc comments must be expanded by the macro.
- Adds a label pointing at the node that cannot be documented.
Furthermore, this PR fixes any instances in rustc where a macro expansion was erroneously documented.
This commit deletes the `connect_timeout_unbound` test from the standard
library which, unfortunately, is by definition eventually going to be a
spuriously failing test. There's no way to reserve a port as unbound so
we can rely on ecosystem testing for this feature for now.
Closes#52590
race condition in thread local storage example
The example had a potential race condition that would still pass the test.
If the thread which was supposed to modify it's own thread local was slower than the instruction to
modify in the main thread, then the test would pass even in case of a failure.
This is would be minor if the child thread was waited for since it check using an `assert_eq` for the
same thing, but vice versa.
However, if the `assert_eq` failed this would trigger a panic, which is not at all caught by the
example since the thread is not waited on.
Signed-off-by: benaryorg <binary@benary.org>
There are two moments when a BufRead object needs to empty it's internal
buffer:
- In a seek call;
- In a read call when all data in the internal buffer had been already
consumed and the output buffer has a greater or equal size than the
internal buffer.
In both cases, the buffer was not being properly emptied, but only
marked as consumed (self.pos = self.cap). That should be no problem if
the inner reader is only Read, but if it is Seek as well, then it's
possible to access the data in the buffer by using the seek_relative
method. In order to prevent this from happening, both self.pos and
self.cap should be set to 0.
Two test cases were added to detect that failure:
- test_buffered_reader_invalidated_after_read
- test_buffered_reader_invalidated_after_seek
Both tests are very similar to each other. The inner reader contains the
following data: [5, 6, 7, 0, 1, 2, 3, 4]. The buffer capacity is 3
bytes.
- First, we call fill_buffer, which loads [5, 6, 7] into the internal
buffer, and then consume those 3 bytes.
- Then we either read the 5 remaining bytes in a single read call or we
move to the end of the stream by calling seek. In both cases the
buffer should be emptied to prevent the previous data [5, 6, 7] from
being read.
- We now call seek_relative(-2) and read two bytes, which should give us
the last 2 bytes of the stream: [3, 4].
Before this commit, the the seek_relative method would consider that
we're still in the range of the internal buffer, so instead of fetching
data from the inner reader, it would return the two last bytes that were
incorrectly still in the buffer: [6, 7]. Therefore, the test would fail.
Now, when seek_relative is called the buffer is empty. So the expected
data [3, 4] is fetched from the inner reader and the test passes.
There's lots of comments in the code, but the main gist of this commit
is that the acquisition of the global malloc lock on the
`wasm32-unknown-unknown` target when threads are enabled will not spin
on contention rather than block.
The example had a potential race condition that would still pass the test.
If the thread which was supposed to modify it's own thread local was slower than the instruction to
modify in the main thread, then the test would pass even in case of a failure.
This is would be minor if the child thread was waited for since it check using an `assert_eq` for
the same thing, but vice versa.
However, if the `assert_eq` failed this would trigger a panic, which is not at all caught by the
example since the thread is not waited on.
Signed-off-by: benaryorg <binary@benary.org>
Use the correct stderr when testing libstd
When compiling the unit tests for libstd, there are two copies of `std` in existence, see [lib.rs](919cf42/src/libstd/lib.rs (L335-L341)). This means there are two copies of everything, including thread local variable definitions. Before this PR, it's possible that libtest would configure a stderr sink in one of those copies, whereas the panic logic would inspect the sink in the other copy, resulting in libtest missing the relevant panic message. This PR makes sure that when testing, the panic logic always accesses the stderr sink from “realstd”, using the same logic that libtest uses.
