diff options
Diffstat (limited to 'compiler/rustc_data_structures/src')
| -rw-r--r-- | compiler/rustc_data_structures/src/marker.rs | 2 | ||||
| -rw-r--r-- | compiler/rustc_data_structures/src/sharded.rs | 25 | ||||
| -rw-r--r-- | compiler/rustc_data_structures/src/sync.rs | 316 | ||||
| -rw-r--r-- | compiler/rustc_data_structures/src/sync/lock.rs | 276 | ||||
| -rw-r--r-- | compiler/rustc_data_structures/src/sync/worker_local.rs | 6 |
5 files changed, 392 insertions, 233 deletions
diff --git a/compiler/rustc_data_structures/src/marker.rs b/compiler/rustc_data_structures/src/marker.rs index f8c06f9a814..b067f9d4502 100644 --- a/compiler/rustc_data_structures/src/marker.rs +++ b/compiler/rustc_data_structures/src/marker.rs @@ -92,7 +92,6 @@ cfg_if!( [std::collections::BTreeMap<K, V, A> where K: DynSend, V: DynSend, A: std::alloc::Allocator + Clone + DynSend] [Vec<T, A> where T: DynSend, A: std::alloc::Allocator + DynSend] [Box<T, A> where T: ?Sized + DynSend, A: std::alloc::Allocator + DynSend] - [crate::sync::Lock<T> where T: DynSend] [crate::sync::RwLock<T> where T: DynSend] [crate::tagged_ptr::CopyTaggedPtr<P, T, CP> where P: Send + crate::tagged_ptr::Pointer, T: Send + crate::tagged_ptr::Tag, const CP: bool] [rustc_arena::TypedArena<T> where T: DynSend] @@ -171,7 +170,6 @@ cfg_if!( [std::collections::BTreeMap<K, V, A> where K: DynSync, V: DynSync, A: std::alloc::Allocator + Clone + DynSync] [Vec<T, A> where T: DynSync, A: std::alloc::Allocator + DynSync] [Box<T, A> where T: ?Sized + DynSync, A: std::alloc::Allocator + DynSync] - [crate::sync::Lock<T> where T: DynSend] [crate::sync::RwLock<T> where T: DynSend + DynSync] [crate::sync::OneThread<T> where T] [crate::sync::WorkerLocal<T> where T: DynSend] diff --git a/compiler/rustc_data_structures/src/sharded.rs b/compiler/rustc_data_structures/src/sharded.rs index 52ab5a7fb14..0f769c1f3bf 100644 --- a/compiler/rustc_data_structures/src/sharded.rs +++ b/compiler/rustc_data_structures/src/sharded.rs @@ -2,9 +2,12 @@ use crate::fx::{FxHashMap, FxHasher}; #[cfg(parallel_compiler)] use crate::sync::{is_dyn_thread_safe, CacheAligned}; use crate::sync::{Lock, LockGuard}; +#[cfg(parallel_compiler)] +use itertools::Either; use std::borrow::Borrow; use std::collections::hash_map::RawEntryMut; use std::hash::{Hash, Hasher}; +use std::iter; use std::mem; // 32 shards is sufficient to reduce contention on an 8-core Ryzen 7 1700, @@ -70,19 +73,27 @@ impl<T> Sharded<T> { } } - pub fn lock_shards(&self) -> Vec<LockGuard<'_, T>> { + #[inline] + pub fn lock_shards(&self) -> impl Iterator<Item = LockGuard<'_, T>> { match self { - Self::Single(single) => vec![single.lock()], + #[cfg(not(parallel_compiler))] + Self::Single(single) => iter::once(single.lock()), + #[cfg(parallel_compiler)] + Self::Single(single) => Either::Left(iter::once(single.lock())), #[cfg(parallel_compiler)] - Self::Shards(shards) => shards.iter().map(|shard| shard.0.lock()).collect(), + Self::Shards(shards) => Either::Right(shards.iter().map(|shard| shard.0.lock())), } } - pub fn try_lock_shards(&self) -> Option<Vec<LockGuard<'_, T>>> { + #[inline] + pub fn try_lock_shards(&self) -> impl Iterator<Item = Option<LockGuard<'_, T>>> { match self { - Self::Single(single) => Some(vec![single.try_lock()?]), + #[cfg(not(parallel_compiler))] + Self::Single(single) => iter::once(single.try_lock()), + #[cfg(parallel_compiler)] + Self::Single(single) => Either::Left(iter::once(single.try_lock())), #[cfg(parallel_compiler)] - Self::Shards(shards) => shards.iter().map(|shard| shard.0.try_lock()).collect(), + Self::Shards(shards) => Either::Right(shards.iter().map(|shard| shard.0.try_lock())), } } } @@ -101,7 +112,7 @@ pub type ShardedHashMap<K, V> = Sharded<FxHashMap<K, V>>; impl<K: Eq, V> ShardedHashMap<K, V> { pub fn len(&self) -> usize { - self.lock_shards().iter().map(|shard| shard.len()).sum() + self.lock_shards().map(|shard| shard.len()).sum() } } diff --git a/compiler/rustc_data_structures/src/sync.rs b/compiler/rustc_data_structures/src/sync.rs index 25a08237346..2ec509b9118 100644 --- a/compiler/rustc_data_structures/src/sync.rs +++ b/compiler/rustc_data_structures/src/sync.rs @@ -26,7 +26,8 @@ //! | `AtomicU64` | `Cell<u64>` | `atomic::AtomicU64` | //! | `AtomicUsize` | `Cell<usize>` | `atomic::AtomicUsize` | //! | | | | -//! | `Lock<T>` | `RefCell<T>` | `parking_lot::Mutex<T>` | +//! | `Lock<T>` | `RefCell<T>` | `RefCell<T>` or | +//! | | | `parking_lot::Mutex<T>` | //! | `RwLock<T>` | `RefCell<T>` | `parking_lot::RwLock<T>` | //! | `MTLock<T>` [^1] | `T` | `Lock<T>` | //! | `MTLockRef<'a, T>` [^2] | `&'a mut MTLock<T>` | `&'a MTLock<T>` | @@ -40,11 +41,16 @@ //! [^2] `MTLockRef` is a typedef. pub use crate::marker::*; +use parking_lot::Mutex; +use std::any::Any; use std::collections::HashMap; use std::hash::{BuildHasher, Hash}; use std::ops::{Deref, DerefMut}; use std::panic::{catch_unwind, resume_unwind, AssertUnwindSafe}; +mod lock; +pub use lock::{Lock, LockGuard}; + mod worker_local; pub use worker_local::{Registry, WorkerLocal}; @@ -75,6 +81,13 @@ mod mode { } } + // Whether thread safety might be enabled. + #[inline] + #[cfg(parallel_compiler)] + pub fn might_be_dyn_thread_safe() -> bool { + DYN_THREAD_SAFE_MODE.load(Ordering::Relaxed) != DYN_NOT_THREAD_SAFE + } + // Only set by the `-Z threads` compile option pub fn set_dyn_thread_safe_mode(mode: bool) { let set: u8 = if mode { DYN_THREAD_SAFE } else { DYN_NOT_THREAD_SAFE }; @@ -92,16 +105,48 @@ mod mode { pub use mode::{is_dyn_thread_safe, set_dyn_thread_safe_mode}; +/// A guard used to hold panics that occur during a parallel section to later by unwound. +/// This is used for the parallel compiler to prevent fatal errors from non-deterministically +/// hiding errors by ensuring that everything in the section has completed executing before +/// continuing with unwinding. It's also used for the non-parallel code to ensure error message +/// output match the parallel compiler for testing purposes. +pub struct ParallelGuard { + panic: Mutex<Option<Box<dyn Any + std::marker::Send + 'static>>>, +} + +impl ParallelGuard { + pub fn run<R>(&self, f: impl FnOnce() -> R) -> Option<R> { + catch_unwind(AssertUnwindSafe(f)) + .map_err(|err| { + *self.panic.lock() = Some(err); + }) + .ok() + } +} + +/// This gives access to a fresh parallel guard in the closure and will unwind any panics +/// caught in it after the closure returns. +#[inline] +pub fn parallel_guard<R>(f: impl FnOnce(&ParallelGuard) -> R) -> R { + let guard = ParallelGuard { panic: Mutex::new(None) }; + let ret = f(&guard); + if let Some(panic) = guard.panic.into_inner() { + resume_unwind(panic); + } + ret +} + cfg_if! { if #[cfg(not(parallel_compiler))] { + use std::ops::Add; + use std::cell::Cell; + pub unsafe auto trait Send {} pub unsafe auto trait Sync {} unsafe impl<T> Send for T {} unsafe impl<T> Sync for T {} - use std::ops::Add; - /// This is a single threaded variant of `AtomicU64`, `AtomicUsize`, etc. /// It has explicit ordering arguments and is only intended for use with /// the native atomic types. @@ -186,67 +231,38 @@ cfg_if! { where A: FnOnce() -> RA, B: FnOnce() -> RB { - (oper_a(), oper_b()) + let (a, b) = parallel_guard(|guard| { + let a = guard.run(oper_a); + let b = guard.run(oper_b); + (a, b) + }); + (a.unwrap(), b.unwrap()) } #[macro_export] macro_rules! parallel { - ($($blocks:block),*) => { - // We catch panics here ensuring that all the blocks execute. - // This makes behavior consistent with the parallel compiler. - let mut panic = None; - $( - if let Err(p) = ::std::panic::catch_unwind( - ::std::panic::AssertUnwindSafe(|| $blocks) - ) { - if panic.is_none() { - panic = Some(p); - } - } - )* - if let Some(panic) = panic { - ::std::panic::resume_unwind(panic); - } - } + ($($blocks:block),*) => {{ + $crate::sync::parallel_guard(|guard| { + $(guard.run(|| $blocks);)* + }); + }} } pub fn par_for_each_in<T: IntoIterator>(t: T, mut for_each: impl FnMut(T::Item) + Sync + Send) { - // We catch panics here ensuring that all the loop iterations execute. - // This makes behavior consistent with the parallel compiler. - let mut panic = None; - t.into_iter().for_each(|i| { - if let Err(p) = catch_unwind(AssertUnwindSafe(|| for_each(i))) { - if panic.is_none() { - panic = Some(p); - } - } - }); - if let Some(panic) = panic { - resume_unwind(panic); - } + parallel_guard(|guard| { + t.into_iter().for_each(|i| { + guard.run(|| for_each(i)); + }); + }) } pub fn par_map<T: IntoIterator, R, C: FromIterator<R>>( t: T, mut map: impl FnMut(<<T as IntoIterator>::IntoIter as Iterator>::Item) -> R, ) -> C { - // We catch panics here ensuring that all the loop iterations execute. - let mut panic = None; - let r = t.into_iter().filter_map(|i| { - match catch_unwind(AssertUnwindSafe(|| map(i))) { - Ok(r) => Some(r), - Err(p) => { - if panic.is_none() { - panic = Some(p); - } - None - } - } - }).collect(); - if let Some(panic) = panic { - resume_unwind(panic); - } - r + parallel_guard(|guard| { + t.into_iter().filter_map(|i| guard.run(|| map(i))).collect() + }) } pub use std::rc::Rc as Lrc; @@ -255,15 +271,11 @@ cfg_if! { pub use std::cell::Ref as MappedReadGuard; pub use std::cell::RefMut as WriteGuard; pub use std::cell::RefMut as MappedWriteGuard; - pub use std::cell::RefMut as LockGuard; pub use std::cell::RefMut as MappedLockGuard; pub use std::cell::OnceCell; use std::cell::RefCell as InnerRwLock; - use std::cell::RefCell as InnerLock; - - use std::cell::Cell; pub type MTLockRef<'a, T> = &'a mut MTLock<T>; @@ -313,7 +325,6 @@ cfg_if! { pub use parking_lot::RwLockWriteGuard as WriteGuard; pub use parking_lot::MappedRwLockWriteGuard as MappedWriteGuard; - pub use parking_lot::MutexGuard as LockGuard; pub use parking_lot::MappedMutexGuard as MappedLockGuard; pub use std::sync::OnceLock as OnceCell; @@ -355,7 +366,6 @@ cfg_if! { } } - use parking_lot::Mutex as InnerLock; use parking_lot::RwLock as InnerRwLock; use std::thread; @@ -372,7 +382,12 @@ cfg_if! { let (a, b) = rayon::join(move || FromDyn::from(oper_a.into_inner()()), move || FromDyn::from(oper_b.into_inner()())); (a.into_inner(), b.into_inner()) } else { - (oper_a(), oper_b()) + let (a, b) = parallel_guard(|guard| { + let a = guard.run(oper_a); + let b = guard.run(oper_b); + (a, b) + }); + (a.unwrap(), b.unwrap()) } } @@ -407,28 +422,10 @@ cfg_if! { // of a single threaded rustc. parallel!(impl $fblock [] [$($blocks),*]); } else { - // We catch panics here ensuring that all the blocks execute. - // This makes behavior consistent with the parallel compiler. - let mut panic = None; - if let Err(p) = ::std::panic::catch_unwind( - ::std::panic::AssertUnwindSafe(|| $fblock) - ) { - if panic.is_none() { - panic = Some(p); - } - } - $( - if let Err(p) = ::std::panic::catch_unwind( - ::std::panic::AssertUnwindSafe(|| $blocks) - ) { - if panic.is_none() { - panic = Some(p); - } - } - )* - if let Some(panic) = panic { - ::std::panic::resume_unwind(panic); - } + $crate::sync::parallel_guard(|guard| { + guard.run(|| $fblock); + $(guard.run(|| $blocks);)* + }); } }; } @@ -439,34 +436,18 @@ cfg_if! { t: T, for_each: impl Fn(I) + DynSync + DynSend ) { - if mode::is_dyn_thread_safe() { - let for_each = FromDyn::from(for_each); - let panic: Lock<Option<_>> = Lock::new(None); - t.into_par_iter().for_each(|i| if let Err(p) = catch_unwind(AssertUnwindSafe(|| for_each(i))) { - let mut l = panic.lock(); - if l.is_none() { - *l = Some(p) - } - }); - - if let Some(panic) = panic.into_inner() { - resume_unwind(panic); - } - } else { - // We catch panics here ensuring that all the loop iterations execute. - // This makes behavior consistent with the parallel compiler. - let mut panic = None; - t.into_iter().for_each(|i| { - if let Err(p) = catch_unwind(AssertUnwindSafe(|| for_each(i))) { - if panic.is_none() { - panic = Some(p); - } - } - }); - if let Some(panic) = panic { - resume_unwind(panic); + parallel_guard(|guard| { + if mode::is_dyn_thread_safe() { + let for_each = FromDyn::from(for_each); + t.into_par_iter().for_each(|i| { + guard.run(|| for_each(i)); + }); + } else { + t.into_iter().for_each(|i| { + guard.run(|| for_each(i)); + }); } - } + }); } pub fn par_map< @@ -478,46 +459,14 @@ cfg_if! { t: T, map: impl Fn(I) -> R + DynSync + DynSend ) -> C { - if mode::is_dyn_thread_safe() { - let panic: Lock<Option<_>> = Lock::new(None); - let map = FromDyn::from(map); - // We catch panics here ensuring that all the loop iterations execute. - let r = t.into_par_iter().filter_map(|i| { - match catch_unwind(AssertUnwindSafe(|| map(i))) { - Ok(r) => Some(r), - Err(p) => { - let mut l = panic.lock(); - if l.is_none() { - *l = Some(p); - } - None - }, - } - }).collect(); - - if let Some(panic) = panic.into_inner() { - resume_unwind(panic); - } - r - } else { - // We catch panics here ensuring that all the loop iterations execute. - let mut panic = None; - let r = t.into_iter().filter_map(|i| { - match catch_unwind(AssertUnwindSafe(|| map(i))) { - Ok(r) => Some(r), - Err(p) => { - if panic.is_none() { - panic = Some(p); - } - None - } - } - }).collect(); - if let Some(panic) = panic { - resume_unwind(panic); + parallel_guard(|guard| { + if mode::is_dyn_thread_safe() { + let map = FromDyn::from(map); + t.into_par_iter().filter_map(|i| guard.run(|| map(i))).collect() + } else { + t.into_iter().filter_map(|i| guard.run(|| map(i))).collect() } - r - } + }) } /// This makes locks panic if they are already held. @@ -542,81 +491,6 @@ impl<K: Eq + Hash, V: Eq, S: BuildHasher> HashMapExt<K, V> for HashMap<K, V, S> } } -#[derive(Debug)] -pub struct Lock<T>(InnerLock<T>); - -impl<T> Lock<T> { - #[inline(always)] - pub fn new(inner: T) -> Self { - Lock(InnerLock::new(inner)) - } - - #[inline(always)] - pub fn into_inner(self) -> T { - self.0.into_inner() - } - - #[inline(always)] - pub fn get_mut(&mut self) -> &mut T { - self.0.get_mut() - } - - #[cfg(parallel_compiler)] - #[inline(always)] - pub fn try_lock(&self) -> Option<LockGuard<'_, T>> { - self.0.try_lock() - } - - #[cfg(not(parallel_compiler))] - #[inline(always)] - pub fn try_lock(&self) -> Option<LockGuard<'_, T>> { - self.0.try_borrow_mut().ok() - } - - #[cfg(parallel_compiler)] - #[inline(always)] - #[track_caller] - pub fn lock(&self) -> LockGuard<'_, T> { - if ERROR_CHECKING { - self.0.try_lock().expect("lock was already held") - } else { - self.0.lock() - } - } - - #[cfg(not(parallel_compiler))] - #[inline(always)] - #[track_caller] - pub fn lock(&self) -> LockGuard<'_, T> { - self.0.borrow_mut() - } - - #[inline(always)] - #[track_caller] - pub fn with_lock<F: FnOnce(&mut T) -> R, R>(&self, f: F) -> R { - f(&mut *self.lock()) - } - - #[inline(always)] - #[track_caller] - pub fn borrow(&self) -> LockGuard<'_, T> { - self.lock() - } - - #[inline(always)] - #[track_caller] - pub fn borrow_mut(&self) -> LockGuard<'_, T> { - self.lock() - } -} - -impl<T: Default> Default for Lock<T> { - #[inline] - fn default() -> Self { - Lock::new(T::default()) - } -} - #[derive(Debug, Default)] pub struct RwLock<T>(InnerRwLock<T>); diff --git a/compiler/rustc_data_structures/src/sync/lock.rs b/compiler/rustc_data_structures/src/sync/lock.rs new file mode 100644 index 00000000000..62cd1b993de --- /dev/null +++ b/compiler/rustc_data_structures/src/sync/lock.rs @@ -0,0 +1,276 @@ +//! This module implements a lock which only uses synchronization if `might_be_dyn_thread_safe` is true. +//! It implements `DynSend` and `DynSync` instead of the typical `Send` and `Sync` traits. +//! +//! When `cfg(parallel_compiler)` is not set, the lock is instead a wrapper around `RefCell`. + +#[cfg(not(parallel_compiler))] +use std::cell::RefCell; +#[cfg(parallel_compiler)] +use { + crate::cold_path, + crate::sync::DynSend, + crate::sync::DynSync, + parking_lot::lock_api::RawMutex, + std::cell::Cell, + std::cell::UnsafeCell, + std::fmt, + std::intrinsics::{likely, unlikely}, + std::marker::PhantomData, + std::mem::ManuallyDrop, + std::ops::{Deref, DerefMut}, +}; + +#[cfg(not(parallel_compiler))] +pub use std::cell::RefMut as LockGuard; + +#[cfg(not(parallel_compiler))] +#[derive(Debug)] +pub struct Lock<T>(RefCell<T>); + +#[cfg(not(parallel_compiler))] +impl<T> Lock<T> { + #[inline(always)] + pub fn new(inner: T) -> Self { + Lock(RefCell::new(inner)) + } + + #[inline(always)] + pub fn into_inner(self) -> T { + self.0.into_inner() + } + + #[inline(always)] + pub fn get_mut(&mut self) -> &mut T { + self.0.get_mut() + } + + #[inline(always)] + pub fn try_lock(&self) -> Option<LockGuard<'_, T>> { + self.0.try_borrow_mut().ok() + } + + #[inline(always)] + #[track_caller] + pub fn lock(&self) -> LockGuard<'_, T> { + self.0.borrow_mut() + } +} + +/// A guard holding mutable access to a `Lock` which is in a locked state. +#[cfg(parallel_compiler)] +#[must_use = "if unused the Lock will immediately unlock"] +pub struct LockGuard<'a, T> { + lock: &'a Lock<T>, + marker: PhantomData<&'a mut T>, +} + +#[cfg(parallel_compiler)] +impl<'a, T: 'a> Deref for LockGuard<'a, T> { + type Target = T; + #[inline] + fn deref(&self) -> &T { + // SAFETY: We have shared access to the mutable access owned by this type, + // so we can give out a shared reference. + unsafe { &*self.lock.data.get() } + } +} + +#[cfg(parallel_compiler)] +impl<'a, T: 'a> DerefMut for LockGuard<'a, T> { + #[inline] + fn deref_mut(&mut self) -> &mut T { + // SAFETY: We have mutable access to the data so we can give out a mutable reference. + unsafe { &mut *self.lock.data.get() } + } +} + +#[cfg(parallel_compiler)] +impl<'a, T: 'a> Drop for LockGuard<'a, T> { + #[inline] + fn drop(&mut self) { + // SAFETY: We know that the lock is in a locked + // state because it is a invariant of this type. + unsafe { self.lock.raw.unlock() }; + } +} + +#[cfg(parallel_compiler)] +union LockRawUnion { + /// Indicates if the cell is locked. Only used if `LockRaw.sync` is false. + cell: ManuallyDrop<Cell<bool>>, + + /// A lock implementation that's only used if `LockRaw.sync` is true. + lock: ManuallyDrop<parking_lot::RawMutex>, +} + +/// A raw lock which only uses synchronization if `might_be_dyn_thread_safe` is true. +/// It contains no associated data and is used in the implementation of `Lock` which does have such data. +/// +/// A manual implementation of a tagged union is used with the `sync` field and the `LockRawUnion` instead +/// of using enums as it results in better code generation. +#[cfg(parallel_compiler)] +struct LockRaw { + /// Indicates if synchronization is used via `opt.lock` if true, + /// or if a non-thread safe cell is used via `opt.cell`. This is set on initialization and never changed. + sync: bool, + opt: LockRawUnion, +} + +#[cfg(parallel_compiler)] +impl LockRaw { + fn new() -> Self { + if unlikely(super::mode::might_be_dyn_thread_safe()) { + // Create the lock with synchronization enabled using the `RawMutex` type. + LockRaw { + sync: true, + opt: LockRawUnion { lock: ManuallyDrop::new(parking_lot::RawMutex::INIT) }, + } + } else { + // Create the lock with synchronization disabled. + LockRaw { sync: false, opt: LockRawUnion { cell: ManuallyDrop::new(Cell::new(false)) } } + } + } + + #[inline(always)] + fn try_lock(&self) -> bool { + // SAFETY: This is safe since the union fields are used in accordance with `self.sync`. + unsafe { + if likely(!self.sync) { + if self.opt.cell.get() { + false + } else { + self.opt.cell.set(true); + true + } + } else { + self.opt.lock.try_lock() + } + } + } + + #[inline(always)] + fn lock(&self) { + if super::ERROR_CHECKING { + // We're in the debugging mode, so assert that the lock is not held so we + // get a panic instead of waiting for the lock. + assert_eq!(self.try_lock(), true, "lock must not be hold"); + } else { + // SAFETY: This is safe since the union fields are used in accordance with `self.sync`. + unsafe { + if likely(!self.sync) { + if unlikely(self.opt.cell.replace(true)) { + cold_path(|| panic!("lock was already held")) + } + } else { + self.opt.lock.lock(); + } + } + } + } + + /// This unlocks the lock. + /// + /// Safety + /// This method may only be called if the lock is currently held. + #[inline(always)] + unsafe fn unlock(&self) { + // SAFETY: The union use is safe since the union fields are used in accordance with + // `self.sync` and the `unlock` method precondition is upheld by the caller. + unsafe { + if likely(!self.sync) { + debug_assert_eq!(self.opt.cell.get(), true); + self.opt.cell.set(false); + } else { + self.opt.lock.unlock(); + } + } + } +} + +/// A lock which only uses synchronization if `might_be_dyn_thread_safe` is true. +/// It implements `DynSend` and `DynSync` instead of the typical `Send` and `Sync`. +#[cfg(parallel_compiler)] +pub struct Lock<T> { + raw: LockRaw, + data: UnsafeCell<T>, +} + +#[cfg(parallel_compiler)] +impl<T> Lock<T> { + #[inline(always)] + pub fn new(inner: T) -> Self { + Lock { raw: LockRaw::new(), data: UnsafeCell::new(inner) } + } + + #[inline(always)] + pub fn into_inner(self) -> T { + self.data.into_inner() + } + + #[inline(always)] + pub fn get_mut(&mut self) -> &mut T { + self.data.get_mut() + } + + #[inline(always)] + pub fn try_lock(&self) -> Option<LockGuard<'_, T>> { + if self.raw.try_lock() { Some(LockGuard { lock: self, marker: PhantomData }) } else { None } + } + + #[inline(always)] + pub fn lock(&self) -> LockGuard<'_, T> { + self.raw.lock(); + LockGuard { lock: self, marker: PhantomData } + } +} + +impl<T> Lock<T> { + #[inline(always)] + #[track_caller] + pub fn with_lock<F: FnOnce(&mut T) -> R, R>(&self, f: F) -> R { + f(&mut *self.lock()) + } + + #[inline(always)] + #[track_caller] + pub fn borrow(&self) -> LockGuard<'_, T> { + self.lock() + } + + #[inline(always)] + #[track_caller] + pub fn borrow_mut(&self) -> LockGuard<'_, T> { + self.lock() + } +} + +#[cfg(parallel_compiler)] +unsafe impl<T: DynSend> DynSend for Lock<T> {} +#[cfg(parallel_compiler)] +unsafe impl<T: DynSend> DynSync for Lock<T> {} + +#[cfg(parallel_compiler)] +impl<T: fmt::Debug> fmt::Debug for Lock<T> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + match self.try_lock() { + Some(guard) => f.debug_struct("Lock").field("data", &&*guard).finish(), + None => { + struct LockedPlaceholder; + impl fmt::Debug for LockedPlaceholder { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.write_str("<locked>") + } + } + + f.debug_struct("Lock").field("data", &LockedPlaceholder).finish() + } + } + } +} + +impl<T: Default> Default for Lock<T> { + #[inline] + fn default() -> Self { + Lock::new(T::default()) + } +} diff --git a/compiler/rustc_data_structures/src/sync/worker_local.rs b/compiler/rustc_data_structures/src/sync/worker_local.rs index 27d687c3cfe..1f838cc4648 100644 --- a/compiler/rustc_data_structures/src/sync/worker_local.rs +++ b/compiler/rustc_data_structures/src/sync/worker_local.rs @@ -1,4 +1,4 @@ -use crate::sync::Lock; +use parking_lot::Mutex; use std::cell::Cell; use std::cell::OnceCell; use std::ops::Deref; @@ -35,7 +35,7 @@ impl RegistryId { struct RegistryData { thread_limit: usize, - threads: Lock<usize>, + threads: Mutex<usize>, } /// Represents a list of threads which can access worker locals. @@ -65,7 +65,7 @@ thread_local! { impl Registry { /// Creates a registry which can hold up to `thread_limit` threads. pub fn new(thread_limit: usize) -> Self { - Registry(Arc::new(RegistryData { thread_limit, threads: Lock::new(0) })) + Registry(Arc::new(RegistryData { thread_limit, threads: Mutex::new(0) })) } /// Gets the registry associated with the current thread. Panics if there's no such registry. |