Fix TcpStream::connect_timeout on linux
Linux appears to set POLLOUT when a conection's refused, which is pretty
weird. Invert the check to look for an error explicitly. Also add an
explict test for this case.
Closes#45265.
r? @alexcrichton
Do some cleanups for hashmaps
@mystor noticed some things whilst reading through the hashmap RawTable code.
Firstly, in RawTable we deal with this hash_offset value that is the offset of the list of hashes from the buffer start. This is always zero, and this isn't consistently used (which means that we would have bugs if we set it to something else). We should just remove this since it doesn't help us at all.
Secondly, the probing length tag is not copied when cloning a raw table. This is minor and basically means we do a bit more work than we need on further inserts on a cloned hashmap.
r? @Gankro
Add x86_64-unknown-linux-gnux32 target
This adds X32 ABI support for Linux on X86_64. Let's package and dist it so we can star testing libc, libstd, etc.
Fixes https://github.com/rust-lang/rfcs/issues/1339
Linux appears to set POLLOUT when a conection's refused, which is pretty
weird. Invert the check to look for an error explicitly. Also add an
explict test for this case.
Closes#45265.
This isn't strictly necessary for hashmap cloning to work. The tag is
used to hint for an upcoming resize, so it's good to copy this
information over.
(We can do cleverer things like actually resizing the hashmap when we
see the tag, or even cleaning up the entry order, but this requires
more thought and might not be worth it)
This offset is always zero, and we don't consistently take it into
account. This is okay, because it's zero, but if it ever changes we're
going to have bugs (e.g. in the `dealloc` call, where we don't take it
into account).
It's better to remove this for now; if we ever have a need for a
nonzero offset we can add it back, and handle it properly when we do so.
That requirement makes sense for containers like `Arc` that don't
uniquely own their contents, but `RwLock` is not one of those.
This restriction was added in
380d23b5d4,
but it's not clear why.
Improve performance of spsc_queue and stream.
This PR makes two main changes:
1. It switches the `spsc_queue` node caching strategy from keeping a shared
counter of the number of nodes in the cache to keeping a consumer only counter
of the number of node eligible to be cached.
2. It separates the consumer and producers fields of `spsc_queue` and `stream` into
a producer cache line and consumer cache line.
Overall, it speeds up `mpsc` in `spsc` mode by 2-10x.
Variance is higher than I'd like (that 2-10x speedup is on one benchmark), I believe this is due to the drop check in `send` (`fn stream::Queue::send:107`). I think this check can be combined with the sleep detection code into a version which only uses 1 shared variable, and only one atomic access per `send`, but I haven't looked through the select implementation enough to be sure.
The code currently assumes a cache line size of 64 bytes. I added a CacheAligned newtype in `mpsc` which I expect to reuse for `shared`. It doesn't really belong there, it would probably be best put in `core::sync::atomic`, but putting it in `core` would involve making it public, which I thought would require an RFC.
Benchmark runner is [here](3eca46279c/shootout), benchmarks [here](3eca46279c/queue_bench/src/lib.rs (L170-L293)).
Fixes#44512.
Remove support for the PNaCl target (le32-unknown-nacl)
This removes support for the `le32-unknown-nacl` target which is currently supported by rustc on tier 3. Despite the "nacl" in the name, the target doesn't output native code (x86, ARM, MIPS), instead it outputs binaries in the PNaCl format.
There are two reasons for the removal:
* Google [has announced](https://blog.chromium.org/2017/05/goodbye-pnacl-hello-webassembly.html) deprecation of the PNaCl format. The suggestion is to migrate to wasm. Happens we already have a wasm backend!
* Our PNaCl LLVM backend is provided by the fastcomp patch set that the LLVM fork used by rustc contains in addition to vanilla LLVM (`src/llvm/lib/Target/JSBackend/NaCl`). Upstream LLVM doesn't have PNaCl support. Removing PNaCl support will enable us to move away from fastcomp (#44006) and have a lighter set of patches on top of upstream LLVM inside our LLVM fork. This will help distribution packagers of Rust.
Fixes#42420
zircon: the type of zx_handle_t is now unsigned
This is a kernel ABI change that landed today. I noticed some other ABI
issues and have left a note to cleanup once they are better defined.
Add read_to_end implementation to &[u8]'s Read impl
The default impl for read_to_end does a bunch of bookkeeping
that isn't necessary for slices and is about 4 times slower
on my machine.
The following benchmark takes about 30 ns before this change and about 7 ns after:
```
#[bench]
fn bench_read_std(b: &mut Bencher) {
let data = vec![0u8; 100];
let mut v = Vec::with_capacity(200);
b.iter(|| {
let mut s = data.as_slice();
v.clear();
s.read_to_end(&mut v).unwrap();
});
}
```
This solves the easy part of https://github.com/rust-lang/rust/issues/44819 (I think extending this to `Take<&[u8]> `would require specialization)
Fix TcpStream::local_addr docs example code
The local address's port is not 8080 in this example, that's the remote peer address port. On my machine, the local address is different every time, so I've changed `assert_eq` to only test the IP address
Implement `and_modify` on `Entry`
## Motivation
`Entry`s are useful for allowing access to existing values in a map while also allowing default values to be inserted for absent keys. The existing API is similar to that of `Option`, where `or` and `or_with` can be used if the option variant is `None`.
The `Entry` API is, however, missing an equivalent of `Option`'s `and_then` method. If it were present it would be possible to modify an existing entry before calling `or_insert` without resorting to matching on the entry variant.
Tracking issue: https://github.com/rust-lang/rust/issues/44733.
replace libc::res_init with res_init_if_glibc_before_2_26
The previous workaround for gibc's res_init bug is not thread-safe on
other implementations of libc, and it can cause crashes. Use a runtime
check to make sure we only call res_init when we need to, which is also
when it's safe. See https://github.com/rust-lang/rust/issues/43592.
~This PR is returning an InvalidData IO error if the glibc version string fails to parse. We could also have treated that case as "not glibc", and gotten rid of the idea that these functions could return an error. (Though I'm not a huge fan of ignoring error returns from `res_init` in any case.) Do other folks agree with these design choices?~
I'm pretty new to hacking on libstd. Is there an easy way to build a toy rust program against my changes to test this, other than doing an entire `sudo make install` on my system? What's the usual workflow?
The previous workaround for gibc's res_init bug is not thread-safe on
other implementations of libc, and it can cause crashes. Use a runtime
check to make sure we only call res_init when we need to, which is also
when it's safe. See https://github.com/rust-lang/rust/issues/43592.
* Use size_t where size_t is used, while it's not critical on our
specifically supported architectures, this is more accurate.
* Update HND_SPECIAL_COUNT to the correct value, and give it the size
that enum is likely to be.
