diff options
Diffstat (limited to 'compiler/rustc_data_structures/src/sync.rs')
| -rw-r--r-- | compiler/rustc_data_structures/src/sync.rs | 316 |
1 files changed, 95 insertions, 221 deletions
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>); |