Auto merge of #117107 - zachs18:mapped-mutex-guard, r=Amanieu
Implement `MappedMutexGuard`, `MappedRwLockReadGuard`, and `MappedRwLockWriteGuard`. ACP: https://github.com/rust-lang/libs-team/issues/260 Tracking issue: https://github.com/rust-lang/rust/issues/117108 <details> <summary> (Outdated) </summary> `MutexState`/`RwLockState` structs ~~Having `sys::(Mutex|RwLock)` and `poison::Flag` as separate fields in the `Mutex`/`RwLock` would require `MappedMutexGuard`/`MappedRwLockWriteGuard` to hold an additional pointer, so I combined the two fields into a `MutexState`/`RwLockState` struct. This should not noticeably affect perf or layout, but requires an additional field projection when accessing the former `.inner` or `.poison` fields (now `.state.inner` and `.state.poison`).~~ If this is not desired, then `MappedMutexGuard`/`MappedRwLockWriteGuard` can instead hold separate pointers to the two fields. </details> The doc-comments are mostly copied from the existing `*Guard` doc-comments, with some parts from `lock_api::Mapped*Guard`'s doc-comments. Unresolved question: Are more tests needed?
This commit is contained in:
bors
commit
a2f3c0cf88
6 changed files with 985 additions and 4 deletions
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@ -165,6 +165,8 @@ pub use core::sync::Exclusive;
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pub use self::barrier::{Barrier, BarrierWaitResult};
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#[stable(feature = "rust1", since = "1.0.0")]
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pub use self::condvar::{Condvar, WaitTimeoutResult};
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#[unstable(feature = "mapped_lock_guards", issue = "117108")]
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pub use self::mutex::MappedMutexGuard;
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#[stable(feature = "rust1", since = "1.0.0")]
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pub use self::mutex::{Mutex, MutexGuard};
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#[stable(feature = "rust1", since = "1.0.0")]
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@ -172,6 +174,8 @@ pub use self::mutex::{Mutex, MutexGuard};
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pub use self::once::{Once, OnceState, ONCE_INIT};
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#[stable(feature = "rust1", since = "1.0.0")]
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pub use self::poison::{LockResult, PoisonError, TryLockError, TryLockResult};
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#[unstable(feature = "mapped_lock_guards", issue = "117108")]
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pub use self::rwlock::{MappedRwLockReadGuard, MappedRwLockWriteGuard};
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#[stable(feature = "rust1", since = "1.0.0")]
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pub use self::rwlock::{RwLock, RwLockReadGuard, RwLockWriteGuard};
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@ -3,7 +3,10 @@ mod tests;
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use crate::cell::UnsafeCell;
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use crate::fmt;
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use crate::marker::PhantomData;
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use crate::mem::ManuallyDrop;
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use crate::ops::{Deref, DerefMut};
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use crate::ptr::NonNull;
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use crate::sync::{poison, LockResult, TryLockError, TryLockResult};
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use crate::sys::locks as sys;
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@ -213,6 +216,47 @@ impl<T: ?Sized> !Send for MutexGuard<'_, T> {}
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#[stable(feature = "mutexguard", since = "1.19.0")]
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unsafe impl<T: ?Sized + Sync> Sync for MutexGuard<'_, T> {}
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/// An RAII mutex guard returned by `MutexGuard::map`, which can point to a
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/// subfield of the protected data. When this structure is dropped (falls out
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/// of scope), the lock will be unlocked.
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///
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/// The main difference between `MappedMutexGuard` and [`MutexGuard`] is that the
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/// former cannot be used with [`Condvar`], since that
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/// could introduce soundness issues if the locked object is modified by another
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/// thread while the `Mutex` is unlocked.
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///
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/// The data protected by the mutex can be accessed through this guard via its
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/// [`Deref`] and [`DerefMut`] implementations.
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///
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/// This structure is created by the [`map`] and [`try_map`] methods on
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/// [`MutexGuard`].
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///
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/// [`map`]: MutexGuard::map
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/// [`try_map`]: MutexGuard::try_map
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/// [`Condvar`]: crate::sync::Condvar
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#[must_use = "if unused the Mutex will immediately unlock"]
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#[must_not_suspend = "holding a MappedMutexGuard across suspend \
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points can cause deadlocks, delays, \
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and cause Futures to not implement `Send`"]
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#[unstable(feature = "mapped_lock_guards", issue = "117108")]
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#[clippy::has_significant_drop]
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pub struct MappedMutexGuard<'a, T: ?Sized + 'a> {
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// NB: we use a pointer instead of `&'a mut T` to avoid `noalias` violations, because a
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// `MappedMutexGuard` argument doesn't hold uniqueness for its whole scope, only until it drops.
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// `NonNull` is covariant over `T`, so we add a `PhantomData<&'a mut T>` field
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// below for the correct variance over `T` (invariance).
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data: NonNull<T>,
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inner: &'a sys::Mutex,
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poison_flag: &'a poison::Flag,
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poison: poison::Guard,
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_variance: PhantomData<&'a mut T>,
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}
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#[unstable(feature = "mapped_lock_guards", issue = "117108")]
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impl<T: ?Sized> !Send for MappedMutexGuard<'_, T> {}
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#[unstable(feature = "mapped_lock_guards", issue = "117108")]
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unsafe impl<T: ?Sized + Sync> Sync for MappedMutexGuard<'_, T> {}
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impl<T> Mutex<T> {
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/// Creates a new mutex in an unlocked state ready for use.
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///
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@ -550,3 +594,178 @@ pub fn guard_lock<'a, T: ?Sized>(guard: &MutexGuard<'a, T>) -> &'a sys::Mutex {
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pub fn guard_poison<'a, T: ?Sized>(guard: &MutexGuard<'a, T>) -> &'a poison::Flag {
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&guard.lock.poison
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}
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impl<'a, T: ?Sized> MutexGuard<'a, T> {
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/// Makes a [`MappedMutexGuard`] for a component of the borrowed data, e.g.
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/// an enum variant.
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///
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/// The `Mutex` is already locked, so this cannot fail.
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///
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/// This is an associated function that needs to be used as
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/// `MutexGuard::map(...)`. A method would interfere with methods of the
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/// same name on the contents of the `MutexGuard` used through `Deref`.
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#[unstable(feature = "mapped_lock_guards", issue = "117108")]
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pub fn map<U, F>(orig: Self, f: F) -> MappedMutexGuard<'a, U>
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where
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F: FnOnce(&mut T) -> &mut U,
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U: ?Sized,
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{
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// SAFETY: the conditions of `MutexGuard::new` were satisfied when the original guard
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// was created, and have been upheld throughout `map` and/or `try_map`.
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// The signature of the closure guarantees that it will not "leak" the lifetime of the reference
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// passed to it. If the closure panics, the guard will be dropped.
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let data = NonNull::from(f(unsafe { &mut *orig.lock.data.get() }));
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let orig = ManuallyDrop::new(orig);
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MappedMutexGuard {
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data,
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inner: &orig.lock.inner,
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poison_flag: &orig.lock.poison,
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poison: orig.poison.clone(),
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_variance: PhantomData,
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}
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}
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/// Makes a [`MappedMutexGuard`] for a component of the borrowed data. The
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/// original guard is returned as an `Err(...)` if the closure returns
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/// `None`.
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///
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/// The `Mutex` is already locked, so this cannot fail.
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///
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/// This is an associated function that needs to be used as
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/// `MutexGuard::try_map(...)`. A method would interfere with methods of the
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/// same name on the contents of the `MutexGuard` used through `Deref`.
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#[doc(alias = "filter_map")]
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#[unstable(feature = "mapped_lock_guards", issue = "117108")]
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pub fn try_map<U, F>(orig: Self, f: F) -> Result<MappedMutexGuard<'a, U>, Self>
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where
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F: FnOnce(&mut T) -> Option<&mut U>,
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U: ?Sized,
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{
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// SAFETY: the conditions of `MutexGuard::new` were satisfied when the original guard
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// was created, and have been upheld throughout `map` and/or `try_map`.
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// The signature of the closure guarantees that it will not "leak" the lifetime of the reference
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// passed to it. If the closure panics, the guard will be dropped.
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match f(unsafe { &mut *orig.lock.data.get() }) {
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Some(data) => {
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let data = NonNull::from(data);
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let orig = ManuallyDrop::new(orig);
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Ok(MappedMutexGuard {
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data,
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inner: &orig.lock.inner,
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poison_flag: &orig.lock.poison,
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poison: orig.poison.clone(),
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_variance: PhantomData,
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})
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}
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None => Err(orig),
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}
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}
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}
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#[unstable(feature = "mapped_lock_guards", issue = "117108")]
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impl<T: ?Sized> Deref for MappedMutexGuard<'_, T> {
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type Target = T;
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fn deref(&self) -> &T {
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unsafe { self.data.as_ref() }
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}
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}
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#[unstable(feature = "mapped_lock_guards", issue = "117108")]
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impl<T: ?Sized> DerefMut for MappedMutexGuard<'_, T> {
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fn deref_mut(&mut self) -> &mut T {
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unsafe { self.data.as_mut() }
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}
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}
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#[unstable(feature = "mapped_lock_guards", issue = "117108")]
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impl<T: ?Sized> Drop for MappedMutexGuard<'_, T> {
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#[inline]
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fn drop(&mut self) {
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unsafe {
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self.poison_flag.done(&self.poison);
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self.inner.unlock();
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}
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}
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}
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#[unstable(feature = "mapped_lock_guards", issue = "117108")]
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impl<T: ?Sized + fmt::Debug> fmt::Debug for MappedMutexGuard<'_, T> {
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fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
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fmt::Debug::fmt(&**self, f)
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}
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}
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#[unstable(feature = "mapped_lock_guards", issue = "117108")]
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impl<T: ?Sized + fmt::Display> fmt::Display for MappedMutexGuard<'_, T> {
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fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
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(**self).fmt(f)
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}
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}
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impl<'a, T: ?Sized> MappedMutexGuard<'a, T> {
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/// Makes a [`MappedMutexGuard`] for a component of the borrowed data, e.g.
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/// an enum variant.
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///
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/// The `Mutex` is already locked, so this cannot fail.
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///
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/// This is an associated function that needs to be used as
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/// `MappedMutexGuard::map(...)`. A method would interfere with methods of the
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/// same name on the contents of the `MutexGuard` used through `Deref`.
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#[unstable(feature = "mapped_lock_guards", issue = "117108")]
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pub fn map<U, F>(mut orig: Self, f: F) -> MappedMutexGuard<'a, U>
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where
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F: FnOnce(&mut T) -> &mut U,
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U: ?Sized,
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{
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// SAFETY: the conditions of `MutexGuard::new` were satisfied when the original guard
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// was created, and have been upheld throughout `map` and/or `try_map`.
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// The signature of the closure guarantees that it will not "leak" the lifetime of the reference
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// passed to it. If the closure panics, the guard will be dropped.
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let data = NonNull::from(f(unsafe { orig.data.as_mut() }));
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let orig = ManuallyDrop::new(orig);
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MappedMutexGuard {
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data,
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inner: orig.inner,
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poison_flag: orig.poison_flag,
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poison: orig.poison.clone(),
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_variance: PhantomData,
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}
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}
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/// Makes a [`MappedMutexGuard`] for a component of the borrowed data. The
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/// original guard is returned as an `Err(...)` if the closure returns
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/// `None`.
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///
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/// The `Mutex` is already locked, so this cannot fail.
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///
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/// This is an associated function that needs to be used as
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/// `MappedMutexGuard::try_map(...)`. A method would interfere with methods of the
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/// same name on the contents of the `MutexGuard` used through `Deref`.
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#[doc(alias = "filter_map")]
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#[unstable(feature = "mapped_lock_guards", issue = "117108")]
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pub fn try_map<U, F>(mut orig: Self, f: F) -> Result<MappedMutexGuard<'a, U>, Self>
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where
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F: FnOnce(&mut T) -> Option<&mut U>,
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U: ?Sized,
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{
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// SAFETY: the conditions of `MutexGuard::new` were satisfied when the original guard
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// was created, and have been upheld throughout `map` and/or `try_map`.
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// The signature of the closure guarantees that it will not "leak" the lifetime of the reference
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// passed to it. If the closure panics, the guard will be dropped.
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match f(unsafe { orig.data.as_mut() }) {
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Some(data) => {
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let data = NonNull::from(data);
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let orig = ManuallyDrop::new(orig);
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Ok(MappedMutexGuard {
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data,
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inner: orig.inner,
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poison_flag: orig.poison_flag,
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poison: orig.poison.clone(),
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_variance: PhantomData,
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})
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}
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None => Err(orig),
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}
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}
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}
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@ -1,6 +1,6 @@
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use crate::sync::atomic::{AtomicUsize, Ordering};
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use crate::sync::mpsc::channel;
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use crate::sync::{Arc, Condvar, Mutex};
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use crate::sync::{Arc, Condvar, MappedMutexGuard, Mutex, MutexGuard, TryLockError};
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use crate::thread;
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struct Packet<T>(Arc<(Mutex<T>, Condvar)>);
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@ -188,6 +188,21 @@ fn test_mutex_arc_poison() {
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assert!(arc.is_poisoned());
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}
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#[test]
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fn test_mutex_arc_poison_mapped() {
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let arc = Arc::new(Mutex::new(1));
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assert!(!arc.is_poisoned());
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let arc2 = arc.clone();
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let _ = thread::spawn(move || {
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let lock = arc2.lock().unwrap();
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let lock = MutexGuard::map(lock, |val| val);
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assert_eq!(*lock, 2); // deliberate assertion failure to poison the mutex
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})
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.join();
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assert!(arc.lock().is_err());
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assert!(arc.is_poisoned());
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}
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#[test]
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fn test_mutex_arc_nested() {
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// Tests nested mutexes and access
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@ -236,3 +251,77 @@ fn test_mutex_unsized() {
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let comp: &[i32] = &[4, 2, 5];
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assert_eq!(&*mutex.lock().unwrap(), comp);
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}
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#[test]
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fn test_mapping_mapped_guard() {
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let arr = [0; 4];
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let mut lock = Mutex::new(arr);
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let guard = lock.lock().unwrap();
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let guard = MutexGuard::map(guard, |arr| &mut arr[..2]);
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let mut guard = MappedMutexGuard::map(guard, |slice| &mut slice[1..]);
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assert_eq!(guard.len(), 1);
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guard[0] = 42;
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drop(guard);
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assert_eq!(*lock.get_mut().unwrap(), [0, 42, 0, 0]);
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}
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#[test]
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fn panic_while_mapping_unlocked_poison() {
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let lock = Mutex::new(());
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let _ = crate::panic::catch_unwind(|| {
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let guard = lock.lock().unwrap();
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let _guard = MutexGuard::map::<(), _>(guard, |_| panic!());
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});
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match lock.try_lock() {
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Ok(_) => panic!("panicking in a MutexGuard::map closure should poison the Mutex"),
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Err(TryLockError::WouldBlock) => {
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panic!("panicking in a MutexGuard::map closure should unlock the mutex")
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}
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Err(TryLockError::Poisoned(_)) => {}
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}
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let _ = crate::panic::catch_unwind(|| {
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let guard = lock.lock().unwrap();
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let _guard = MutexGuard::try_map::<(), _>(guard, |_| panic!());
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});
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match lock.try_lock() {
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Ok(_) => panic!("panicking in a MutexGuard::try_map closure should poison the Mutex"),
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Err(TryLockError::WouldBlock) => {
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panic!("panicking in a MutexGuard::try_map closure should unlock the mutex")
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}
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Err(TryLockError::Poisoned(_)) => {}
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}
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let _ = crate::panic::catch_unwind(|| {
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let guard = lock.lock().unwrap();
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let guard = MutexGuard::map::<(), _>(guard, |val| val);
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let _guard = MappedMutexGuard::map::<(), _>(guard, |_| panic!());
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});
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match lock.try_lock() {
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Ok(_) => panic!("panicking in a MappedMutexGuard::map closure should poison the Mutex"),
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Err(TryLockError::WouldBlock) => {
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panic!("panicking in a MappedMutexGuard::map closure should unlock the mutex")
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}
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Err(TryLockError::Poisoned(_)) => {}
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}
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let _ = crate::panic::catch_unwind(|| {
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let guard = lock.lock().unwrap();
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let guard = MutexGuard::map::<(), _>(guard, |val| val);
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let _guard = MappedMutexGuard::try_map::<(), _>(guard, |_| panic!());
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});
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match lock.try_lock() {
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Ok(_) => panic!("panicking in a MappedMutexGuard::try_map closure should poison the Mutex"),
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Err(TryLockError::WouldBlock) => {
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panic!("panicking in a MappedMutexGuard::try_map closure should unlock the mutex")
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}
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Err(TryLockError::Poisoned(_)) => {}
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}
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drop(lock);
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}
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|
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@ -78,6 +78,7 @@ impl Flag {
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}
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}
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#[derive(Clone)]
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pub struct Guard {
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#[cfg(panic = "unwind")]
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panicking: bool,
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|
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@ -3,6 +3,8 @@ mod tests;
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|
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use crate::cell::UnsafeCell;
|
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use crate::fmt;
|
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use crate::marker::PhantomData;
|
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use crate::mem::ManuallyDrop;
|
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use crate::ops::{Deref, DerefMut};
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use crate::ptr::NonNull;
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use crate::sync::{poison, LockResult, TryLockError, TryLockResult};
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|
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@ -105,7 +107,7 @@ unsafe impl<T: ?Sized + Send + Sync> Sync for RwLock<T> {}
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#[cfg_attr(not(test), rustc_diagnostic_item = "RwLockReadGuard")]
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pub struct RwLockReadGuard<'a, T: ?Sized + 'a> {
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// NB: we use a pointer instead of `&'a T` to avoid `noalias` violations, because a
|
||||
// `Ref` argument doesn't hold immutability for its whole scope, only until it drops.
|
||||
// `RwLockReadGuard` argument doesn't hold immutability for its whole scope, only until it drops.
|
||||
// `NonNull` is also covariant over `T`, just like we would have with `&T`. `NonNull`
|
||||
// is preferable over `const* T` to allow for niche optimization.
|
||||
data: NonNull<T>,
|
||||
|
|
@ -144,6 +146,67 @@ impl<T: ?Sized> !Send for RwLockWriteGuard<'_, T> {}
|
|||
#[stable(feature = "rwlock_guard_sync", since = "1.23.0")]
|
||||
unsafe impl<T: ?Sized + Sync> Sync for RwLockWriteGuard<'_, T> {}
|
||||
|
||||
/// RAII structure used to release the shared read access of a lock when
|
||||
/// dropped, which can point to a subfield of the protected data.
|
||||
///
|
||||
/// This structure is created by the [`map`] and [`try_map`] methods
|
||||
/// on [`RwLockReadGuard`].
|
||||
///
|
||||
/// [`map`]: RwLockReadGuard::map
|
||||
/// [`try_map`]: RwLockReadGuard::try_map
|
||||
#[must_use = "if unused the RwLock will immediately unlock"]
|
||||
#[must_not_suspend = "holding a MappedRwLockReadGuard across suspend \
|
||||
points can cause deadlocks, delays, \
|
||||
and cause Futures to not implement `Send`"]
|
||||
#[unstable(feature = "mapped_lock_guards", issue = "117108")]
|
||||
#[clippy::has_significant_drop]
|
||||
pub struct MappedRwLockReadGuard<'a, T: ?Sized + 'a> {
|
||||
// NB: we use a pointer instead of `&'a T` to avoid `noalias` violations, because a
|
||||
// `MappedRwLockReadGuard` argument doesn't hold immutability for its whole scope, only until it drops.
|
||||
// `NonNull` is also covariant over `T`, just like we would have with `&T`. `NonNull`
|
||||
// is preferable over `const* T` to allow for niche optimization.
|
||||
data: NonNull<T>,
|
||||
inner_lock: &'a sys::RwLock,
|
||||
}
|
||||
|
||||
#[unstable(feature = "mapped_lock_guards", issue = "117108")]
|
||||
impl<T: ?Sized> !Send for MappedRwLockReadGuard<'_, T> {}
|
||||
|
||||
#[unstable(feature = "mapped_lock_guards", issue = "117108")]
|
||||
unsafe impl<T: ?Sized + Sync> Sync for MappedRwLockReadGuard<'_, T> {}
|
||||
|
||||
/// RAII structure used to release the exclusive write access of a lock when
|
||||
/// dropped, which can point to a subfield of the protected data.
|
||||
///
|
||||
/// This structure is created by the [`map`] and [`try_map`] methods
|
||||
/// on [`RwLockWriteGuard`].
|
||||
///
|
||||
/// [`map`]: RwLockWriteGuard::map
|
||||
/// [`try_map`]: RwLockWriteGuard::try_map
|
||||
#[must_use = "if unused the RwLock will immediately unlock"]
|
||||
#[must_not_suspend = "holding a MappedRwLockWriteGuard across suspend \
|
||||
points can cause deadlocks, delays, \
|
||||
and cause Future's to not implement `Send`"]
|
||||
#[unstable(feature = "mapped_lock_guards", issue = "117108")]
|
||||
#[clippy::has_significant_drop]
|
||||
pub struct MappedRwLockWriteGuard<'a, T: ?Sized + 'a> {
|
||||
// NB: we use a pointer instead of `&'a mut T` to avoid `noalias` violations, because a
|
||||
// `MappedRwLockWriteGuard` argument doesn't hold uniqueness for its whole scope, only until it drops.
|
||||
// `NonNull` is covariant over `T`, so we add a `PhantomData<&'a mut T>` field
|
||||
// below for the correct variance over `T` (invariance).
|
||||
data: NonNull<T>,
|
||||
inner_lock: &'a sys::RwLock,
|
||||
poison_flag: &'a poison::Flag,
|
||||
poison: poison::Guard,
|
||||
_variance: PhantomData<&'a mut T>,
|
||||
}
|
||||
|
||||
#[unstable(feature = "mapped_lock_guards", issue = "117108")]
|
||||
impl<T: ?Sized> !Send for MappedRwLockWriteGuard<'_, T> {}
|
||||
|
||||
#[unstable(feature = "mapped_lock_guards", issue = "117108")]
|
||||
unsafe impl<T: ?Sized + Sync> Sync for MappedRwLockWriteGuard<'_, T> {}
|
||||
|
||||
impl<T> RwLock<T> {
|
||||
/// Creates a new instance of an `RwLock<T>` which is unlocked.
|
||||
///
|
||||
|
|
@ -557,12 +620,40 @@ impl<T: ?Sized + fmt::Display> fmt::Display for RwLockWriteGuard<'_, T> {
|
|||
}
|
||||
}
|
||||
|
||||
#[unstable(feature = "mapped_lock_guards", issue = "117108")]
|
||||
impl<T: ?Sized + fmt::Debug> fmt::Debug for MappedRwLockReadGuard<'_, T> {
|
||||
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
||||
(**self).fmt(f)
|
||||
}
|
||||
}
|
||||
|
||||
#[unstable(feature = "mapped_lock_guards", issue = "117108")]
|
||||
impl<T: ?Sized + fmt::Display> fmt::Display for MappedRwLockReadGuard<'_, T> {
|
||||
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
||||
(**self).fmt(f)
|
||||
}
|
||||
}
|
||||
|
||||
#[unstable(feature = "mapped_lock_guards", issue = "117108")]
|
||||
impl<T: ?Sized + fmt::Debug> fmt::Debug for MappedRwLockWriteGuard<'_, T> {
|
||||
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
||||
(**self).fmt(f)
|
||||
}
|
||||
}
|
||||
|
||||
#[unstable(feature = "mapped_lock_guards", issue = "117108")]
|
||||
impl<T: ?Sized + fmt::Display> fmt::Display for MappedRwLockWriteGuard<'_, T> {
|
||||
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
||||
(**self).fmt(f)
|
||||
}
|
||||
}
|
||||
|
||||
#[stable(feature = "rust1", since = "1.0.0")]
|
||||
impl<T: ?Sized> Deref for RwLockReadGuard<'_, T> {
|
||||
type Target = T;
|
||||
|
||||
fn deref(&self) -> &T {
|
||||
// SAFETY: the conditions of `RwLockGuard::new` were satisfied when created.
|
||||
// SAFETY: the conditions of `RwLockReadGuard::new` were satisfied when created.
|
||||
unsafe { self.data.as_ref() }
|
||||
}
|
||||
}
|
||||
|
|
@ -585,6 +676,37 @@ impl<T: ?Sized> DerefMut for RwLockWriteGuard<'_, T> {
|
|||
}
|
||||
}
|
||||
|
||||
#[unstable(feature = "mapped_lock_guards", issue = "117108")]
|
||||
impl<T: ?Sized> Deref for MappedRwLockReadGuard<'_, T> {
|
||||
type Target = T;
|
||||
|
||||
fn deref(&self) -> &T {
|
||||
// SAFETY: the conditions of `RwLockReadGuard::new` were satisfied when the original guard
|
||||
// was created, and have been upheld throughout `map` and/or `try_map`.
|
||||
unsafe { self.data.as_ref() }
|
||||
}
|
||||
}
|
||||
|
||||
#[unstable(feature = "mapped_lock_guards", issue = "117108")]
|
||||
impl<T: ?Sized> Deref for MappedRwLockWriteGuard<'_, T> {
|
||||
type Target = T;
|
||||
|
||||
fn deref(&self) -> &T {
|
||||
// SAFETY: the conditions of `RwLockWriteGuard::new` were satisfied when the original guard
|
||||
// was created, and have been upheld throughout `map` and/or `try_map`.
|
||||
unsafe { self.data.as_ref() }
|
||||
}
|
||||
}
|
||||
|
||||
#[unstable(feature = "mapped_lock_guards", issue = "117108")]
|
||||
impl<T: ?Sized> DerefMut for MappedRwLockWriteGuard<'_, T> {
|
||||
fn deref_mut(&mut self) -> &mut T {
|
||||
// SAFETY: the conditions of `RwLockWriteGuard::new` were satisfied when the original guard
|
||||
// was created, and have been upheld throughout `map` and/or `try_map`.
|
||||
unsafe { self.data.as_mut() }
|
||||
}
|
||||
}
|
||||
|
||||
#[stable(feature = "rust1", since = "1.0.0")]
|
||||
impl<T: ?Sized> Drop for RwLockReadGuard<'_, T> {
|
||||
fn drop(&mut self) {
|
||||
|
|
@ -605,3 +727,310 @@ impl<T: ?Sized> Drop for RwLockWriteGuard<'_, T> {
|
|||
}
|
||||
}
|
||||
}
|
||||
|
||||
#[unstable(feature = "mapped_lock_guards", issue = "117108")]
|
||||
impl<T: ?Sized> Drop for MappedRwLockReadGuard<'_, T> {
|
||||
fn drop(&mut self) {
|
||||
// SAFETY: the conditions of `RwLockReadGuard::new` were satisfied when the original guard
|
||||
// was created, and have been upheld throughout `map` and/or `try_map`.
|
||||
unsafe {
|
||||
self.inner_lock.read_unlock();
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
#[unstable(feature = "mapped_lock_guards", issue = "117108")]
|
||||
impl<T: ?Sized> Drop for MappedRwLockWriteGuard<'_, T> {
|
||||
fn drop(&mut self) {
|
||||
self.poison_flag.done(&self.poison);
|
||||
// SAFETY: the conditions of `RwLockWriteGuard::new` were satisfied when the original guard
|
||||
// was created, and have been upheld throughout `map` and/or `try_map`.
|
||||
unsafe {
|
||||
self.inner_lock.write_unlock();
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T: ?Sized> RwLockReadGuard<'a, T> {
|
||||
/// Makes a [`MappedRwLockReadGuard`] for a component of the borrowed data, e.g.
|
||||
/// an enum variant.
|
||||
///
|
||||
/// The `RwLock` is already locked for reading, so this cannot fail.
|
||||
///
|
||||
/// This is an associated function that needs to be used as
|
||||
/// `RwLockReadGuard::map(...)`. A method would interfere with methods of
|
||||
/// the same name on the contents of the `RwLockReadGuard` used through
|
||||
/// `Deref`.
|
||||
///
|
||||
/// # Panics
|
||||
///
|
||||
/// If the closure panics, the guard will be dropped (unlocked) and the RwLock will not be poisoned.
|
||||
#[unstable(feature = "mapped_lock_guards", issue = "117108")]
|
||||
pub fn map<U, F>(orig: Self, f: F) -> MappedRwLockReadGuard<'a, U>
|
||||
where
|
||||
F: FnOnce(&T) -> &U,
|
||||
U: ?Sized,
|
||||
{
|
||||
// SAFETY: the conditions of `RwLockReadGuard::new` were satisfied when the original guard
|
||||
// was created, and have been upheld throughout `map` and/or `try_map`.
|
||||
// The signature of the closure guarantees that it will not "leak" the lifetime of the reference
|
||||
// passed to it. If the closure panics, the guard will be dropped.
|
||||
let data = NonNull::from(f(unsafe { orig.data.as_ref() }));
|
||||
let orig = ManuallyDrop::new(orig);
|
||||
MappedRwLockReadGuard { data, inner_lock: &orig.inner_lock }
|
||||
}
|
||||
|
||||
/// Makes a [`MappedRwLockReadGuard`] for a component of the borrowed data. The
|
||||
/// original guard is returned as an `Err(...)` if the closure returns
|
||||
/// `None`.
|
||||
///
|
||||
/// The `RwLock` is already locked for reading, so this cannot fail.
|
||||
///
|
||||
/// This is an associated function that needs to be used as
|
||||
/// `RwLockReadGuard::try_map(...)`. A method would interfere with methods
|
||||
/// of the same name on the contents of the `RwLockReadGuard` used through
|
||||
/// `Deref`.
|
||||
///
|
||||
/// # Panics
|
||||
///
|
||||
/// If the closure panics, the guard will be dropped (unlocked) and the RwLock will not be poisoned.
|
||||
#[doc(alias = "filter_map")]
|
||||
#[unstable(feature = "mapped_lock_guards", issue = "117108")]
|
||||
pub fn try_map<U, F>(orig: Self, f: F) -> Result<MappedRwLockReadGuard<'a, U>, Self>
|
||||
where
|
||||
F: FnOnce(&T) -> Option<&U>,
|
||||
U: ?Sized,
|
||||
{
|
||||
// SAFETY: the conditions of `RwLockReadGuard::new` were satisfied when the original guard
|
||||
// was created, and have been upheld throughout `map` and/or `try_map`.
|
||||
// The signature of the closure guarantees that it will not "leak" the lifetime of the reference
|
||||
// passed to it. If the closure panics, the guard will be dropped.
|
||||
match f(unsafe { orig.data.as_ref() }) {
|
||||
Some(data) => {
|
||||
let data = NonNull::from(data);
|
||||
let orig = ManuallyDrop::new(orig);
|
||||
Ok(MappedRwLockReadGuard { data, inner_lock: &orig.inner_lock })
|
||||
}
|
||||
None => Err(orig),
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T: ?Sized> MappedRwLockReadGuard<'a, T> {
|
||||
/// Makes a [`MappedRwLockReadGuard`] for a component of the borrowed data,
|
||||
/// e.g. an enum variant.
|
||||
///
|
||||
/// The `RwLock` is already locked for reading, so this cannot fail.
|
||||
///
|
||||
/// This is an associated function that needs to be used as
|
||||
/// `MappedRwLockReadGuard::map(...)`. A method would interfere with
|
||||
/// methods of the same name on the contents of the `MappedRwLockReadGuard`
|
||||
/// used through `Deref`.
|
||||
///
|
||||
/// # Panics
|
||||
///
|
||||
/// If the closure panics, the guard will be dropped (unlocked) and the RwLock will not be poisoned.
|
||||
#[unstable(feature = "mapped_lock_guards", issue = "117108")]
|
||||
pub fn map<U, F>(orig: Self, f: F) -> MappedRwLockReadGuard<'a, U>
|
||||
where
|
||||
F: FnOnce(&T) -> &U,
|
||||
U: ?Sized,
|
||||
{
|
||||
// SAFETY: the conditions of `RwLockReadGuard::new` were satisfied when the original guard
|
||||
// was created, and have been upheld throughout `map` and/or `try_map`.
|
||||
// The signature of the closure guarantees that it will not "leak" the lifetime of the reference
|
||||
// passed to it. If the closure panics, the guard will be dropped.
|
||||
let data = NonNull::from(f(unsafe { orig.data.as_ref() }));
|
||||
let orig = ManuallyDrop::new(orig);
|
||||
MappedRwLockReadGuard { data, inner_lock: &orig.inner_lock }
|
||||
}
|
||||
|
||||
/// Makes a [`MappedRwLockReadGuard`] for a component of the borrowed data.
|
||||
/// The original guard is returned as an `Err(...)` if the closure returns
|
||||
/// `None`.
|
||||
///
|
||||
/// The `RwLock` is already locked for reading, so this cannot fail.
|
||||
///
|
||||
/// This is an associated function that needs to be used as
|
||||
/// `MappedRwLockReadGuard::try_map(...)`. A method would interfere with
|
||||
/// methods of the same name on the contents of the `MappedRwLockReadGuard`
|
||||
/// used through `Deref`.
|
||||
///
|
||||
/// # Panics
|
||||
///
|
||||
/// If the closure panics, the guard will be dropped (unlocked) and the RwLock will not be poisoned.
|
||||
#[doc(alias = "filter_map")]
|
||||
#[unstable(feature = "mapped_lock_guards", issue = "117108")]
|
||||
pub fn try_map<U, F>(orig: Self, f: F) -> Result<MappedRwLockReadGuard<'a, U>, Self>
|
||||
where
|
||||
F: FnOnce(&T) -> Option<&U>,
|
||||
U: ?Sized,
|
||||
{
|
||||
// SAFETY: the conditions of `RwLockReadGuard::new` were satisfied when the original guard
|
||||
// was created, and have been upheld throughout `map` and/or `try_map`.
|
||||
// The signature of the closure guarantees that it will not "leak" the lifetime of the reference
|
||||
// passed to it. If the closure panics, the guard will be dropped.
|
||||
match f(unsafe { orig.data.as_ref() }) {
|
||||
Some(data) => {
|
||||
let data = NonNull::from(data);
|
||||
let orig = ManuallyDrop::new(orig);
|
||||
Ok(MappedRwLockReadGuard { data, inner_lock: &orig.inner_lock })
|
||||
}
|
||||
None => Err(orig),
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T: ?Sized> RwLockWriteGuard<'a, T> {
|
||||
/// Makes a [`MappedRwLockWriteGuard`] for a component of the borrowed data, e.g.
|
||||
/// an enum variant.
|
||||
///
|
||||
/// The `RwLock` is already locked for writing, so this cannot fail.
|
||||
///
|
||||
/// This is an associated function that needs to be used as
|
||||
/// `RwLockWriteGuard::map(...)`. A method would interfere with methods of
|
||||
/// the same name on the contents of the `RwLockWriteGuard` used through
|
||||
/// `Deref`.
|
||||
///
|
||||
/// # Panics
|
||||
///
|
||||
/// If the closure panics, the guard will be dropped (unlocked) and the RwLock will be poisoned.
|
||||
#[unstable(feature = "mapped_lock_guards", issue = "117108")]
|
||||
pub fn map<U, F>(orig: Self, f: F) -> MappedRwLockWriteGuard<'a, U>
|
||||
where
|
||||
F: FnOnce(&mut T) -> &mut U,
|
||||
U: ?Sized,
|
||||
{
|
||||
// SAFETY: the conditions of `RwLockWriteGuard::new` were satisfied when the original guard
|
||||
// was created, and have been upheld throughout `map` and/or `try_map`.
|
||||
// The signature of the closure guarantees that it will not "leak" the lifetime of the reference
|
||||
// passed to it. If the closure panics, the guard will be dropped.
|
||||
let data = NonNull::from(f(unsafe { &mut *orig.lock.data.get() }));
|
||||
let orig = ManuallyDrop::new(orig);
|
||||
MappedRwLockWriteGuard {
|
||||
data,
|
||||
inner_lock: &orig.lock.inner,
|
||||
poison_flag: &orig.lock.poison,
|
||||
poison: orig.poison.clone(),
|
||||
_variance: PhantomData,
|
||||
}
|
||||
}
|
||||
|
||||
/// Makes a [`MappedRwLockWriteGuard`] for a component of the borrowed data. The
|
||||
/// original guard is returned as an `Err(...)` if the closure returns
|
||||
/// `None`.
|
||||
///
|
||||
/// The `RwLock` is already locked for writing, so this cannot fail.
|
||||
///
|
||||
/// This is an associated function that needs to be used as
|
||||
/// `RwLockWriteGuard::try_map(...)`. A method would interfere with methods
|
||||
/// of the same name on the contents of the `RwLockWriteGuard` used through
|
||||
/// `Deref`.
|
||||
///
|
||||
/// # Panics
|
||||
///
|
||||
/// If the closure panics, the guard will be dropped (unlocked) and the RwLock will be poisoned.
|
||||
#[doc(alias = "filter_map")]
|
||||
#[unstable(feature = "mapped_lock_guards", issue = "117108")]
|
||||
pub fn try_map<U, F>(orig: Self, f: F) -> Result<MappedRwLockWriteGuard<'a, U>, Self>
|
||||
where
|
||||
F: FnOnce(&mut T) -> Option<&mut U>,
|
||||
U: ?Sized,
|
||||
{
|
||||
// SAFETY: the conditions of `RwLockWriteGuard::new` were satisfied when the original guard
|
||||
// was created, and have been upheld throughout `map` and/or `try_map`.
|
||||
// The signature of the closure guarantees that it will not "leak" the lifetime of the reference
|
||||
// passed to it. If the closure panics, the guard will be dropped.
|
||||
match f(unsafe { &mut *orig.lock.data.get() }) {
|
||||
Some(data) => {
|
||||
let data = NonNull::from(data);
|
||||
let orig = ManuallyDrop::new(orig);
|
||||
Ok(MappedRwLockWriteGuard {
|
||||
data,
|
||||
inner_lock: &orig.lock.inner,
|
||||
poison_flag: &orig.lock.poison,
|
||||
poison: orig.poison.clone(),
|
||||
_variance: PhantomData,
|
||||
})
|
||||
}
|
||||
None => Err(orig),
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T: ?Sized> MappedRwLockWriteGuard<'a, T> {
|
||||
/// Makes a [`MappedRwLockWriteGuard`] for a component of the borrowed data,
|
||||
/// e.g. an enum variant.
|
||||
///
|
||||
/// The `RwLock` is already locked for writing, so this cannot fail.
|
||||
///
|
||||
/// This is an associated function that needs to be used as
|
||||
/// `MappedRwLockWriteGuard::map(...)`. A method would interfere with
|
||||
/// methods of the same name on the contents of the `MappedRwLockWriteGuard`
|
||||
/// used through `Deref`.
|
||||
///
|
||||
/// # Panics
|
||||
///
|
||||
/// If the closure panics, the guard will be dropped (unlocked) and the RwLock will be poisoned.
|
||||
#[unstable(feature = "mapped_lock_guards", issue = "117108")]
|
||||
pub fn map<U, F>(mut orig: Self, f: F) -> MappedRwLockWriteGuard<'a, U>
|
||||
where
|
||||
F: FnOnce(&mut T) -> &mut U,
|
||||
U: ?Sized,
|
||||
{
|
||||
// SAFETY: the conditions of `RwLockWriteGuard::new` were satisfied when the original guard
|
||||
// was created, and have been upheld throughout `map` and/or `try_map`.
|
||||
// The signature of the closure guarantees that it will not "leak" the lifetime of the reference
|
||||
// passed to it. If the closure panics, the guard will be dropped.
|
||||
let data = NonNull::from(f(unsafe { orig.data.as_mut() }));
|
||||
let orig = ManuallyDrop::new(orig);
|
||||
MappedRwLockWriteGuard {
|
||||
data,
|
||||
inner_lock: orig.inner_lock,
|
||||
poison_flag: orig.poison_flag,
|
||||
poison: orig.poison.clone(),
|
||||
_variance: PhantomData,
|
||||
}
|
||||
}
|
||||
|
||||
/// Makes a [`MappedRwLockWriteGuard`] for a component of the borrowed data.
|
||||
/// The original guard is returned as an `Err(...)` if the closure returns
|
||||
/// `None`.
|
||||
///
|
||||
/// The `RwLock` is already locked for writing, so this cannot fail.
|
||||
///
|
||||
/// This is an associated function that needs to be used as
|
||||
/// `MappedRwLockWriteGuard::try_map(...)`. A method would interfere with
|
||||
/// methods of the same name on the contents of the `MappedRwLockWriteGuard`
|
||||
/// used through `Deref`.
|
||||
///
|
||||
/// # Panics
|
||||
///
|
||||
/// If the closure panics, the guard will be dropped (unlocked) and the RwLock will be poisoned.
|
||||
#[doc(alias = "filter_map")]
|
||||
#[unstable(feature = "mapped_lock_guards", issue = "117108")]
|
||||
pub fn try_map<U, F>(mut orig: Self, f: F) -> Result<MappedRwLockWriteGuard<'a, U>, Self>
|
||||
where
|
||||
F: FnOnce(&mut T) -> Option<&mut U>,
|
||||
U: ?Sized,
|
||||
{
|
||||
// SAFETY: the conditions of `RwLockWriteGuard::new` were satisfied when the original guard
|
||||
// was created, and have been upheld throughout `map` and/or `try_map`.
|
||||
// The signature of the closure guarantees that it will not "leak" the lifetime of the reference
|
||||
// passed to it. If the closure panics, the guard will be dropped.
|
||||
match f(unsafe { orig.data.as_mut() }) {
|
||||
Some(data) => {
|
||||
let data = NonNull::from(data);
|
||||
let orig = ManuallyDrop::new(orig);
|
||||
Ok(MappedRwLockWriteGuard {
|
||||
data,
|
||||
inner_lock: orig.inner_lock,
|
||||
poison_flag: orig.poison_flag,
|
||||
poison: orig.poison.clone(),
|
||||
_variance: PhantomData,
|
||||
})
|
||||
}
|
||||
None => Err(orig),
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
|
|||
|
|
@ -1,6 +1,9 @@
|
|||
use crate::sync::atomic::{AtomicUsize, Ordering};
|
||||
use crate::sync::mpsc::channel;
|
||||
use crate::sync::{Arc, RwLock, RwLockReadGuard, TryLockError};
|
||||
use crate::sync::{
|
||||
Arc, MappedRwLockReadGuard, MappedRwLockWriteGuard, RwLock, RwLockReadGuard, RwLockWriteGuard,
|
||||
TryLockError,
|
||||
};
|
||||
use crate::thread;
|
||||
use rand::Rng;
|
||||
|
||||
|
|
@ -55,6 +58,19 @@ fn test_rw_arc_poison_wr() {
|
|||
assert!(arc.read().is_err());
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_rw_arc_poison_mapped_w_r() {
|
||||
let arc = Arc::new(RwLock::new(1));
|
||||
let arc2 = arc.clone();
|
||||
let _: Result<(), _> = thread::spawn(move || {
|
||||
let lock = arc2.write().unwrap();
|
||||
let _lock = RwLockWriteGuard::map(lock, |val| val);
|
||||
panic!();
|
||||
})
|
||||
.join();
|
||||
assert!(arc.read().is_err());
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_rw_arc_poison_ww() {
|
||||
let arc = Arc::new(RwLock::new(1));
|
||||
|
|
@ -69,6 +85,20 @@ fn test_rw_arc_poison_ww() {
|
|||
assert!(arc.is_poisoned());
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_rw_arc_poison_mapped_w_w() {
|
||||
let arc = Arc::new(RwLock::new(1));
|
||||
let arc2 = arc.clone();
|
||||
let _: Result<(), _> = thread::spawn(move || {
|
||||
let lock = arc2.write().unwrap();
|
||||
let _lock = RwLockWriteGuard::map(lock, |val| val);
|
||||
panic!();
|
||||
})
|
||||
.join();
|
||||
assert!(arc.write().is_err());
|
||||
assert!(arc.is_poisoned());
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_rw_arc_no_poison_rr() {
|
||||
let arc = Arc::new(RwLock::new(1));
|
||||
|
|
@ -81,6 +111,21 @@ fn test_rw_arc_no_poison_rr() {
|
|||
let lock = arc.read().unwrap();
|
||||
assert_eq!(*lock, 1);
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_rw_arc_no_poison_mapped_r_r() {
|
||||
let arc = Arc::new(RwLock::new(1));
|
||||
let arc2 = arc.clone();
|
||||
let _: Result<(), _> = thread::spawn(move || {
|
||||
let lock = arc2.read().unwrap();
|
||||
let _lock = RwLockReadGuard::map(lock, |val| val);
|
||||
panic!();
|
||||
})
|
||||
.join();
|
||||
let lock = arc.read().unwrap();
|
||||
assert_eq!(*lock, 1);
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_rw_arc_no_poison_rw() {
|
||||
let arc = Arc::new(RwLock::new(1));
|
||||
|
|
@ -94,6 +139,20 @@ fn test_rw_arc_no_poison_rw() {
|
|||
assert_eq!(*lock, 1);
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_rw_arc_no_poison_mapped_r_w() {
|
||||
let arc = Arc::new(RwLock::new(1));
|
||||
let arc2 = arc.clone();
|
||||
let _: Result<(), _> = thread::spawn(move || {
|
||||
let lock = arc2.read().unwrap();
|
||||
let _lock = RwLockReadGuard::map(lock, |val| val);
|
||||
panic!();
|
||||
})
|
||||
.join();
|
||||
let lock = arc.write().unwrap();
|
||||
assert_eq!(*lock, 1);
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_rw_arc() {
|
||||
let arc = Arc::new(RwLock::new(0));
|
||||
|
|
@ -179,6 +238,16 @@ fn test_rwlock_try_write() {
|
|||
}
|
||||
|
||||
drop(read_guard);
|
||||
let mapped_read_guard = RwLockReadGuard::map(lock.read().unwrap(), |_| &());
|
||||
|
||||
let write_result = lock.try_write();
|
||||
match write_result {
|
||||
Err(TryLockError::WouldBlock) => (),
|
||||
Ok(_) => assert!(false, "try_write should not succeed while mapped_read_guard is in scope"),
|
||||
Err(_) => assert!(false, "unexpected error"),
|
||||
}
|
||||
|
||||
drop(mapped_read_guard);
|
||||
}
|
||||
|
||||
#[test]
|
||||
|
|
@ -257,3 +326,173 @@ fn test_read_guard_covariance() {
|
|||
}
|
||||
drop(lock);
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_mapped_read_guard_covariance() {
|
||||
fn do_stuff<'a>(_: MappedRwLockReadGuard<'_, &'a i32>, _: &'a i32) {}
|
||||
let j: i32 = 5;
|
||||
let lock = RwLock::new((&j, &j));
|
||||
{
|
||||
let i = 6;
|
||||
let guard = lock.read().unwrap();
|
||||
let guard = RwLockReadGuard::map(guard, |(val, _val)| val);
|
||||
do_stuff(guard, &i);
|
||||
}
|
||||
drop(lock);
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_mapping_mapped_guard() {
|
||||
let arr = [0; 4];
|
||||
let mut lock = RwLock::new(arr);
|
||||
let guard = lock.write().unwrap();
|
||||
let guard = RwLockWriteGuard::map(guard, |arr| &mut arr[..2]);
|
||||
let mut guard = MappedRwLockWriteGuard::map(guard, |slice| &mut slice[1..]);
|
||||
assert_eq!(guard.len(), 1);
|
||||
guard[0] = 42;
|
||||
drop(guard);
|
||||
assert_eq!(*lock.get_mut().unwrap(), [0, 42, 0, 0]);
|
||||
|
||||
let guard = lock.read().unwrap();
|
||||
let guard = RwLockReadGuard::map(guard, |arr| &arr[..2]);
|
||||
let guard = MappedRwLockReadGuard::map(guard, |slice| &slice[1..]);
|
||||
assert_eq!(*guard, [42]);
|
||||
drop(guard);
|
||||
assert_eq!(*lock.get_mut().unwrap(), [0, 42, 0, 0]);
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn panic_while_mapping_read_unlocked_no_poison() {
|
||||
let lock = RwLock::new(());
|
||||
|
||||
let _ = crate::panic::catch_unwind(|| {
|
||||
let guard = lock.read().unwrap();
|
||||
let _guard = RwLockReadGuard::map::<(), _>(guard, |_| panic!());
|
||||
});
|
||||
|
||||
match lock.try_write() {
|
||||
Ok(_) => {}
|
||||
Err(TryLockError::WouldBlock) => {
|
||||
panic!("panicking in a RwLockReadGuard::map closure should release the read lock")
|
||||
}
|
||||
Err(TryLockError::Poisoned(_)) => {
|
||||
panic!("panicking in a RwLockReadGuard::map closure should not poison the RwLock")
|
||||
}
|
||||
}
|
||||
|
||||
let _ = crate::panic::catch_unwind(|| {
|
||||
let guard = lock.read().unwrap();
|
||||
let _guard = RwLockReadGuard::try_map::<(), _>(guard, |_| panic!());
|
||||
});
|
||||
|
||||
match lock.try_write() {
|
||||
Ok(_) => {}
|
||||
Err(TryLockError::WouldBlock) => {
|
||||
panic!("panicking in a RwLockReadGuard::try_map closure should release the read lock")
|
||||
}
|
||||
Err(TryLockError::Poisoned(_)) => {
|
||||
panic!("panicking in a RwLockReadGuard::try_map closure should not poison the RwLock")
|
||||
}
|
||||
}
|
||||
|
||||
let _ = crate::panic::catch_unwind(|| {
|
||||
let guard = lock.read().unwrap();
|
||||
let guard = RwLockReadGuard::map::<(), _>(guard, |val| val);
|
||||
let _guard = MappedRwLockReadGuard::map::<(), _>(guard, |_| panic!());
|
||||
});
|
||||
|
||||
match lock.try_write() {
|
||||
Ok(_) => {}
|
||||
Err(TryLockError::WouldBlock) => {
|
||||
panic!("panicking in a MappedRwLockReadGuard::map closure should release the read lock")
|
||||
}
|
||||
Err(TryLockError::Poisoned(_)) => {
|
||||
panic!("panicking in a MappedRwLockReadGuard::map closure should not poison the RwLock")
|
||||
}
|
||||
}
|
||||
|
||||
let _ = crate::panic::catch_unwind(|| {
|
||||
let guard = lock.read().unwrap();
|
||||
let guard = RwLockReadGuard::map::<(), _>(guard, |val| val);
|
||||
let _guard = MappedRwLockReadGuard::try_map::<(), _>(guard, |_| panic!());
|
||||
});
|
||||
|
||||
match lock.try_write() {
|
||||
Ok(_) => {}
|
||||
Err(TryLockError::WouldBlock) => panic!(
|
||||
"panicking in a MappedRwLockReadGuard::try_map closure should release the read lock"
|
||||
),
|
||||
Err(TryLockError::Poisoned(_)) => panic!(
|
||||
"panicking in a MappedRwLockReadGuard::try_map closure should not poison the RwLock"
|
||||
),
|
||||
}
|
||||
|
||||
drop(lock);
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn panic_while_mapping_write_unlocked_poison() {
|
||||
let lock = RwLock::new(());
|
||||
|
||||
let _ = crate::panic::catch_unwind(|| {
|
||||
let guard = lock.write().unwrap();
|
||||
let _guard = RwLockWriteGuard::map::<(), _>(guard, |_| panic!());
|
||||
});
|
||||
|
||||
match lock.try_write() {
|
||||
Ok(_) => panic!("panicking in a RwLockWriteGuard::map closure should poison the RwLock"),
|
||||
Err(TryLockError::WouldBlock) => {
|
||||
panic!("panicking in a RwLockWriteGuard::map closure should release the write lock")
|
||||
}
|
||||
Err(TryLockError::Poisoned(_)) => {}
|
||||
}
|
||||
|
||||
let _ = crate::panic::catch_unwind(|| {
|
||||
let guard = lock.write().unwrap();
|
||||
let _guard = RwLockWriteGuard::try_map::<(), _>(guard, |_| panic!());
|
||||
});
|
||||
|
||||
match lock.try_write() {
|
||||
Ok(_) => {
|
||||
panic!("panicking in a RwLockWriteGuard::try_map closure should poison the RwLock")
|
||||
}
|
||||
Err(TryLockError::WouldBlock) => {
|
||||
panic!("panicking in a RwLockWriteGuard::try_map closure should release the write lock")
|
||||
}
|
||||
Err(TryLockError::Poisoned(_)) => {}
|
||||
}
|
||||
|
||||
let _ = crate::panic::catch_unwind(|| {
|
||||
let guard = lock.write().unwrap();
|
||||
let guard = RwLockWriteGuard::map::<(), _>(guard, |val| val);
|
||||
let _guard = MappedRwLockWriteGuard::map::<(), _>(guard, |_| panic!());
|
||||
});
|
||||
|
||||
match lock.try_write() {
|
||||
Ok(_) => {
|
||||
panic!("panicking in a MappedRwLockWriteGuard::map closure should poison the RwLock")
|
||||
}
|
||||
Err(TryLockError::WouldBlock) => panic!(
|
||||
"panicking in a MappedRwLockWriteGuard::map closure should release the write lock"
|
||||
),
|
||||
Err(TryLockError::Poisoned(_)) => {}
|
||||
}
|
||||
|
||||
let _ = crate::panic::catch_unwind(|| {
|
||||
let guard = lock.write().unwrap();
|
||||
let guard = RwLockWriteGuard::map::<(), _>(guard, |val| val);
|
||||
let _guard = MappedRwLockWriteGuard::try_map::<(), _>(guard, |_| panic!());
|
||||
});
|
||||
|
||||
match lock.try_write() {
|
||||
Ok(_) => panic!(
|
||||
"panicking in a MappedRwLockWriteGuard::try_map closure should poison the RwLock"
|
||||
),
|
||||
Err(TryLockError::WouldBlock) => panic!(
|
||||
"panicking in a MappedRwLockWriteGuard::try_map closure should release the write lock"
|
||||
),
|
||||
Err(TryLockError::Poisoned(_)) => {}
|
||||
}
|
||||
|
||||
drop(lock);
|
||||
}
|
||||
|
|
|
|||
Loading…
Add table
Reference in a new issue