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Work towards thread safety in rustc #46779
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r? @estebank (rust_highfive has picked a reviewer for you, use r? to override) |
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Ok(vec.into()) | ||
}) | ||
} | ||
} |
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Missing trailing newline
src/libsyntax_pos/lib.rs
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@@ -163,10 +163,6 @@ impl SpanData { | |||
} | |||
} | |||
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// The interner in thread-local, so `Span` shouldn't move between threads. | |||
impl !Send for Span {} |
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Could you please make the interner thread-safe?
src/libsyntax_pos/symbol.rs
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@@ -83,10 +83,6 @@ impl Decodable for Ident { | |||
#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)] | |||
pub struct Symbol(u32); | |||
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// The interner in thread-local, so `Symbol` shouldn't move between threads. | |||
impl !Send for Symbol { } |
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Same here
@bjorn3 Thread-safety for the interners happens in a later commit. |
@Zoxc that commit doesnt seem to be included in this pr. |
It is in #45912. |
Each PR must leave the compiler in safe/valid state. Implementing |
@michaelwoerister The |
My concern is just that this PR, as it is, would leave the compiler in a state where I can send |
@@ -42,6 +42,8 @@ use std::cell::{RefCell, Cell}; | |||
use std::mem; | |||
use std::rc::Rc; | |||
use std::{error, fmt}; | |||
use std::sync::atomic::AtomicUsize; |
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err_count
probably needs to be done in a smarter way than here to assure thread-safety, so could you add a FIXME
? In any case this is better than the way before this.
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In which case is this not thread safe?
let files = self.codemap.files(); | ||
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if files.len() > 0 { | ||
if self.codemap.files().len() > 0 { |
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Don't we need a better locking discipline for the codemap? It feels like "too many locks, not enough discipline". Maybe just add a fixme to it?
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Given that I just convert all RefCell
s into locks, there's probably plenty of places where there are too many locks.
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ok
src/libsyntax_pos/lib.rs
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@@ -163,10 +163,6 @@ impl SpanData { | |||
} |
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How is this sound?
src/libsyntax_pos/symbol.rs
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@@ -384,8 +384,6 @@ impl<'a> ::std::cmp::PartialEq<InternedString> for &'a String { | |||
} |
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How is this sound?
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Oh, InternedString
storing a &'static str
isn't sound at all. I'll have to change it to using a u32
like Symbol.
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Well that made it unable to implement Deref<Target=str>
, so I went with the approach suggested in a FIXME and just leak interned strings.
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@bors r=arielb1 |
📌 Commit 84ce4f1 has been approved by |
Work towards thread safety in rustc This PR is split out from #45912. It contains changes which do not require the `sync` module.
☀️ Test successful - status-appveyor, status-travis |
slot.set(r + 1); | ||
r | ||
}); | ||
let id = NEXT_ATTR_ID.fetch_add(1, Ordering::SeqCst); |
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@rust-lang/compiler Not sure how I feel about this kind of stuff - it will behave non-deterministically in any process running multiple rustc threads in parallel (atm rustc "owns" a thread).
IMO all thread-locals should change to scoped thread locals initialized to point to some memory owned by the thread that started the compilation, if we want multiple threads per rustc "instance".
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Good point. I'll make this either a scoped thread local or put it in ParseSess
if that happens to be easy.
This PR is split out from #45912. It contains changes which do not require the
sync
module.