Fix `thread` `park`/`unpark` synchronization
Previously the code below would not be guaranteed to exit when the
second unpark took the `return, // already unparked` path because there
was no write to synchronize with a read in `park`.
EDIT: doesn't actually require third thread
```
use std::sync::atomic::{AtomicBool, Ordering};
use std:🧵:{current, spawn, park};
static FLAG: AtomicBool = AtomicBool::new(false);
fn main() {
let thread_0 = current();
spawn(move || {
thread_0.unpark();
FLAG.store(true, Ordering::Relaxed);
thread_0.unpark();
});
while !FLAG.load(Ordering::Relaxed) {
park();
}
}
```
I have some other ideas on how to improve the performance of `park` and `unpark` using fences, avoiding any atomic RMW when the state is already `NOTIFIED`, and also how to avoid calling `notify_one` without the mutex locked. But I need to write some micro benchmarks first, so I'll submit those changes at a later date if they prove to be faster.
Fixes https://github.com/rust-lang/rust/issues/53366 I hope.
Update to a new pinning API.
~~Blocked on #53843 because of method resolution problems with new pin type.~~
@r? @cramertj
cc @RalfJung @pythonesque anyone interested in #49150
Use `HybridBitSet` in `SparseBitMatrix`.
This fixes most of the remaining NLL memory regression.
r? @pnkfelix, because you reviewed #54286.
cc @nikomatsakis, because NLL
cc @Mark-Simulacrum, because this removes `array_vec.rs`
cc @lqd, because this massively improves `unic-ucd-name`, and probably other public crates
By introducing a new map that tracks the errors reported and the
`Place`s that spawned those errors against the move out that the error
was referring to, we are able to silence duplicate errors by emitting
only the error which corresponds to the most specific `Place` (that which
other `Place`s which reported errors are prefixes of).
This generally is an improvement, however there is a case -
`liveness-move-in-while` - where the output regresses.
OsStr: Document that it's not NUL terminated
I somehow got confused into thinking this was the case, but
it's definitely not. Let's help the common case of people who
have an `OsStr` and need to call e.g. Unix APIs.
Remove README with now-out-of-date docs about docs.
These docs haven't really been touched in years, and from what I tried, the `rustdoc` commands don't work. Seems like we don't need this?
Issue 54246
I added the option of providing a help message for deprecated features, that takes precedence over the default `help: remove this attribute` message, along with messages for the features that mention replacements in the reason for deprecation.
Fixes#54246.
add `-Z dont-buffer-diagnostics`
Add `-Z dont-buffer-diagnostics`, a way to force NLL to immediately its diagnostics.
This is mainly intended for developers who want to see the error in its original context in the control flow. Two uses cases for that are:
1. `-Z treat-err-as-bug` (which then allows extraction of a stack-trace to the origin of the error)
2. RUST_LOG=... rustc, in which case it is often useful to see the logging statements that occurred immediately prior to the point where the diagnostic was signalled.
Regression test for rust-lang/rust#53675.
(Includes a couple variations on the theme. I confirmed that the ones
in `in_expression_position` and `what_if_we_use_panic_directly_in_expr`
both failed back on "rustc 1.30.0-nightly (0f063aef6 2018-09-03)".)
Fix#53675
Add doc for impl From for Addr
As part of issue #51430 (cc @skade).
The impl is very simple, let me know if we need to go into any details.
Additionally, I added `#[inline]` for the conversion method, let me know if it is un-necessary or might break something.
This requires adding a few extra methods to `HybridBitSet`. (These are
tested in a new unit test.)
This commit reduces the `max-rss` for `nll-check` builds of `html5ever`
by 46%, `ucd` by 45%, `clap-rs` by 23%, `inflate` by 14%. And the
results for the `unic-ucd-name` crate are even more impressive: a 21%
reduction in instructions, a 60% reduction in wall-time, a 96%
reduction in `max-rss`, and a 97% reduction in faults!
Fixes#52028.
`SparseBitSet` is the only remaining user of `ArrayVec`. This commit
switches it to using `SmallVec`, and removes `array_vec.rs`.
Why the switch? Although `SparseBitSet` is size-limited and doesn't need
the ability to spill to the heap, `SmallVec` has many more features than
`ArrayVec`. In particular, it's now possible to keep `SparseBitSet`'s
elements in sorted order, which gives in-order iteration, which is a
requirement for the next commit.
Merge `bitvec.rs` and `indexed_set.rs`
Because it's not good to have two separate implementations. Also, I will combine the best parts of each to improve NLL memory usage on some benchmarks significantly.
I somehow got confused into thinking this was the case, but
it's definitely not. Let's help the common case of people who
have an `OsStr` and need to call e.g. Unix APIs.
Clean up dependency tracking in Rustbuild [2/2]
Make `clear_if_dirty` calls in `Builder::cargo` with stamp dependencies for the given Mode.
Continuation of #50904
Ref issue #50509
r? @Mark-Simulacrum
- Rename `BitSet::data` and `BitMatrix::vector` as `words`, because that's
what they are.
- Remove `BitSet::words_mut()`, which is no longer necessary.
- Better distinguish multiple meanins of "word", i.e. "word index" vs
"word ref" vs "word" (i.e. the value itself).
`BitwiseOperator` is an unnecessarily low-level thing. This commit
replaces it with `BitSetOperator`, which works on `BitSet`s instead of
words. Within `bit_set.rs`, the commit eliminates `Intersect`, `Union`,
and `Subtract` by instead passing a function to `bitwise()`.
Currently we have two files implementing bitsets (and 2D bit matrices).
This commit combines them into one, taking the best features from each.
This involves renaming a lot of things. The high level changes are as
follows.
- bitvec.rs --> bit_set.rs
- indexed_set.rs --> (removed)
- BitArray + IdxSet --> BitSet (merged, see below)
- BitVector --> GrowableBitSet
- {,Sparse,Hybrid}IdxSet --> {,Sparse,Hybrid}BitSet
- BitMatrix --> BitMatrix
- SparseBitMatrix --> SparseBitMatrix
The changes within the bitset types themselves are as follows.
```
OLD OLD NEW
BitArray<C> IdxSet<T> BitSet<T>
-------- ------ ------
grow - grow
new - (remove)
new_empty new_empty new_empty
new_filled new_filled new_filled
- to_hybrid to_hybrid
clear clear clear
set_up_to set_up_to set_up_to
clear_above - clear_above
count - count
contains(T) contains(&T) contains(T)
contains_all - superset
is_empty - is_empty
insert(T) add(&T) insert(T)
insert_all - insert_all()
remove(T) remove(&T) remove(T)
words words words
words_mut words_mut words_mut
- overwrite overwrite
merge union union
- subtract subtract
- intersect intersect
iter iter iter
```
In general, when choosing names I went with:
- names that are more obvious (e.g. `BitSet` over `IdxSet`).
- names that are more like the Rust libraries (e.g. `T` over `C`,
`insert` over `add`);
- names that are more set-like (e.g. `union` over `merge`, `superset`
over `contains_all`, `domain_size` over `num_bits`).
Also, using `T` for index arguments seems more sensible than `&T` --
even though the latter is standard in Rust collection types -- because
indices are always copyable. It also results in fewer `&` and `*`
sigils in practice.
Temporarily prohibit proc macro attributes placed after derives
... and also proc macro attributes used together with `#[test]`/`#[bench]`.
Addresses item 6 from https://github.com/rust-lang/rust/pull/50911#issuecomment-411605393.
The end goal is straightforward predictable left-to-right expansion order for attributes.
Right now derives are expanded last regardless of their relative ordering with macro attributes and right now it's simpler to temporarily prohibit macro attributes placed after derives than changing the expansion order.
I'm not sure whether the new beta is already released or not, but if it's released, then this patch needs to be backported, so the solution needs to be minimal.
How to fix broken code (derives):
- Move macro attributes above derives. This won't change expansion order, they are expanded before derives anyway.
Using attribute macros on same items with `#[test]` and `#[bench]` is prohibited for similar expansion order reasons, but this one is going to be reverted much sooner than restrictions on derives.
How to fix broken code (test/bench):
- Enable `#![feature(plugin)]` (don't ask why).
r? @ghost
This is mainly intended for `rustc` developers who want to see a
diagnostic in its original context in the control flow. Two uses
cases for that are:
* `-Z treat-err-as-bug` which then allows extraction of a stack-trace to the origin of the error
(a case that is so important that we make that flag imply this one, effectively).
* `RUST_LOG=... rustc`, in which case it is often useful to see the logging statements that
occurred immediately prior to the point where the diagnostic was signalled.
Drive-by: Added some documentation pointing future devs at
HandlerFlags, and documented the fields of `HandlerFlags` itself.
Note it requires MIR-borrowck to be enabled to actually do anything.
Note also that it implicitly turns off our AST-based check for
mutation in guards.
Make rustc::middle::region::Scope's fields public
This PR makes the following changes to `rustc::middle::region::Scope`:
- [x] Makes `region::Scope`'s fields public
- [x] Removes the `impl Scope` block with constructors (as per [this comment](https://github.com/rust-lang/rust/pull/54032#discussion_r216618208))
- [x] Updates call sites throughout the compiler
Closes#54122.
miri engine: keep around some information for dead allocations
We use it to test if a dangling ptr is aligned and non-NULL. This makes some code pass that should pass (writing a ZST to a properly aligned dangling pointer), and makes some code fail that should fail (writing a ZST to a pointer obtained via pointer arithmetic from a real location, but ouf-of-bounds -- that pointer could be NULL, so we cannot allow writing to it).
CTFE does not allow these operations; tests are added to miri with https://github.com/solson/miri/pull/453.
