Snap for 8192848 from 6b4a1303bbbf49ed47f3c3a47212a81f90330b69 to tm-frc-os-statsd-release
Change-Id: I1d66788054099e837129906bcc05e976a9977798
diff --git a/.cargo_vcs_info.json b/.cargo_vcs_info.json
index e1a0b04..58935f2 100644
--- a/.cargo_vcs_info.json
+++ b/.cargo_vcs_info.json
@@ -1,5 +1,5 @@
{
"git": {
- "sha1": "86969fd7baf94312520e0b5a5f3b0861a0fd411b"
+ "sha1": "18001b819c1539c06c176c671bbe54e70b5c3d69"
}
}
diff --git a/Android.bp b/Android.bp
index cc03613..06ca975 100644
--- a/Android.bp
+++ b/Android.bp
@@ -1,4 +1,5 @@
-// This file is generated by cargo2android.py --run --device --dependencies --tests.
+// This file is generated by cargo2android.py --config cargo2android.json.
+// Do not modify this file as changes will be overridden on upgrade.
package {
default_applicable_licenses: ["external_rust_crates_lock_api_license"],
@@ -40,34 +41,17 @@
name: "liblock_api",
host_supported: true,
crate_name: "lock_api",
+ cargo_env_compat: true,
+ cargo_pkg_version: "0.4.5",
srcs: ["src/lib.rs"],
edition: "2018",
rustlibs: [
"libscopeguard",
],
-}
-
-rust_defaults {
- name: "lock_api_defaults",
- crate_name: "lock_api",
- srcs: ["src/lib.rs"],
- test_suites: ["general-tests"],
- auto_gen_config: true,
- edition: "2018",
- rustlibs: [
- "libscopeguard",
+ apex_available: [
+ "//apex_available:platform",
+ "com.android.bluetooth",
+ "com.android.virt",
],
+ min_sdk_version: "29",
}
-
-rust_test_host {
- name: "lock_api_host_test_src_lib",
- defaults: ["lock_api_defaults"],
-}
-
-rust_test {
- name: "lock_api_device_test_src_lib",
- defaults: ["lock_api_defaults"],
-}
-
-// dependent_library ["feature_list"]
-// scopeguard-1.1.0
diff --git a/Cargo.toml b/Cargo.toml
index cdc5b16..4382f30 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -3,17 +3,16 @@
# When uploading crates to the registry Cargo will automatically
# "normalize" Cargo.toml files for maximal compatibility
# with all versions of Cargo and also rewrite `path` dependencies
-# to registry (e.g., crates.io) dependencies
+# to registry (e.g., crates.io) dependencies.
#
-# If you believe there's an error in this file please file an
-# issue against the rust-lang/cargo repository. If you're
-# editing this file be aware that the upstream Cargo.toml
-# will likely look very different (and much more reasonable)
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
[package]
edition = "2018"
name = "lock_api"
-version = "0.4.2"
+version = "0.4.5"
authors = ["Amanieu d'Antras <[email protected]>"]
description = "Wrappers to create fully-featured Mutex and RwLock types. Compatible with no_std."
keywords = ["mutex", "rwlock", "lock", "no_std"]
@@ -29,9 +28,10 @@
default-features = false
[dependencies.serde]
-version = "1.0.114"
+version = "1.0.126"
optional = true
default-features = false
[features]
+arc_lock = []
nightly = []
diff --git a/Cargo.toml.orig b/Cargo.toml.orig
index 9e884a4..96ffdfc 100644
--- a/Cargo.toml.orig
+++ b/Cargo.toml.orig
@@ -1,6 +1,6 @@
[package]
name = "lock_api"
-version = "0.4.2"
+version = "0.4.5"
authors = ["Amanieu d'Antras <[email protected]>"]
description = "Wrappers to create fully-featured Mutex and RwLock types. Compatible with no_std."
license = "Apache-2.0/MIT"
@@ -16,7 +16,8 @@
# Optional dependency for supporting serde. Optional crates automatically
# create a feature with the same name as the crate, so if you need serde
# support, just pass "--features serde" when building this crate.
-serde = { version = "1.0.114", default-features = false, optional = true }
+serde = { version = "1.0.126", default-features = false, optional = true }
[features]
nightly = []
+arc_lock = []
diff --git a/METADATA b/METADATA
index a684451..ebfc44b 100644
--- a/METADATA
+++ b/METADATA
@@ -7,13 +7,13 @@
}
url {
type: ARCHIVE
- value: "https://static.crates.io/crates/lock_api/lock_api-0.4.2.crate"
+ value: "https://static.crates.io/crates/lock_api/lock_api-0.4.5.crate"
}
- version: "0.4.2"
+ version: "0.4.5"
license_type: NOTICE
last_upgrade_date {
- year: 2020
- month: 11
- day: 17
+ year: 2021
+ month: 9
+ day: 22
}
}
diff --git a/TEST_MAPPING b/TEST_MAPPING
index 738f5ec..f439cf8 100644
--- a/TEST_MAPPING
+++ b/TEST_MAPPING
@@ -1,8 +1,8 @@
-// Generated by cargo2android.py for tests in Android.bp
+// Generated by update_crate_tests.py for tests that depend on this crate.
{
- "presubmit": [
+ "imports": [
{
- "name": "lock_api_device_test_src_lib"
+ "path": "external/rust/crates/vulkano"
}
]
}
diff --git a/cargo2android.json b/cargo2android.json
new file mode 100644
index 0000000..22531ba
--- /dev/null
+++ b/cargo2android.json
@@ -0,0 +1,11 @@
+{
+ "apex-available": [
+ "//apex_available:platform",
+ "com.android.bluetooth",
+ "com.android.virt"
+ ],
+ "device": true,
+ "min-sdk-version": "29",
+ "run": true,
+ "tests": true
+}
diff --git a/src/lib.rs b/src/lib.rs
index d9097a3..c99c68b 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -79,20 +79,25 @@
//!
//! # Cargo features
//!
-//! This crate supports two cargo features:
+//! This crate supports three cargo features:
//!
//! - `owning_ref`: Allows your lock types to be used with the `owning_ref` crate.
+//! - `arc_lock`: Enables locking from an `Arc`. This enables types such as `ArcMutexGuard`. Note that this
+//! requires the `alloc` crate to be present.
//! - `nightly`: Enables nightly-only features. At the moment the only such
//! feature is `const fn` constructors for lock types.
#![no_std]
#![warn(missing_docs)]
#![warn(rust_2018_idioms)]
-#![cfg_attr(feature = "nightly", feature(const_fn))]
+#![cfg_attr(feature = "nightly", feature(const_fn_trait_bound))]
#[macro_use]
extern crate scopeguard;
+#[cfg(feature = "arc_lock")]
+extern crate alloc;
+
/// Marker type which indicates that the Guard type for a lock is `Send`.
pub struct GuardSend(());
diff --git a/src/mutex.rs b/src/mutex.rs
index aded96d..f64fc13 100644
--- a/src/mutex.rs
+++ b/src/mutex.rs
@@ -11,6 +11,13 @@
use core::mem;
use core::ops::{Deref, DerefMut};
+#[cfg(feature = "arc_lock")]
+use alloc::sync::Arc;
+#[cfg(feature = "arc_lock")]
+use core::mem::ManuallyDrop;
+#[cfg(feature = "arc_lock")]
+use core::ptr;
+
#[cfg(feature = "owning_ref")]
use owning_ref::StableAddress;
@@ -286,6 +293,45 @@
pub fn data_ptr(&self) -> *mut T {
self.data.get()
}
+
+ /// # Safety
+ ///
+ /// The lock needs to be held for the behavior of this function to be defined.
+ #[cfg(feature = "arc_lock")]
+ #[inline]
+ unsafe fn guard_arc(self: &Arc<Self>) -> ArcMutexGuard<R, T> {
+ ArcMutexGuard {
+ mutex: self.clone(),
+ marker: PhantomData,
+ }
+ }
+
+ /// Acquires a lock through an `Arc`.
+ ///
+ /// This method is similar to the `lock` method; however, it requires the `Mutex` to be inside of an `Arc`
+ /// and the resulting mutex guard has no lifetime requirements.
+ #[cfg(feature = "arc_lock")]
+ #[inline]
+ pub fn lock_arc(self: &Arc<Self>) -> ArcMutexGuard<R, T> {
+ self.raw.lock();
+ // SAFETY: the locking guarantee is upheld
+ unsafe { self.guard_arc() }
+ }
+
+ /// Attempts to acquire a lock through an `Arc`.
+ ///
+ /// This method is similar to the `try_lock` method; however, it requires the `Mutex` to be inside of an
+ /// `Arc` and the resulting mutex guard has no lifetime requirements.
+ #[cfg(feature = "arc_lock")]
+ #[inline]
+ pub fn try_lock_arc(self: &Arc<Self>) -> Option<ArcMutexGuard<R, T>> {
+ if self.raw.try_lock() {
+ // SAFETY: locking guarantee is upheld
+ Some(unsafe { self.guard_arc() })
+ } else {
+ None
+ }
+ }
}
impl<R: RawMutexFair, T: ?Sized> Mutex<R, T> {
@@ -336,6 +382,39 @@
None
}
}
+
+ /// Attempts to acquire this lock through an `Arc` until a timeout is reached.
+ ///
+ /// This method is similar to the `try_lock_for` method; however, it requires the `Mutex` to be inside of an
+ /// `Arc` and the resulting mutex guard has no lifetime requirements.
+ #[cfg(feature = "arc_lock")]
+ #[inline]
+ pub fn try_lock_arc_for(self: &Arc<Self>, timeout: R::Duration) -> Option<ArcMutexGuard<R, T>> {
+ if self.raw.try_lock_for(timeout) {
+ // SAFETY: locking guarantee is upheld
+ Some(unsafe { self.guard_arc() })
+ } else {
+ None
+ }
+ }
+
+ /// Attempts to acquire this lock through an `Arc` until a timeout is reached.
+ ///
+ /// This method is similar to the `try_lock_until` method; however, it requires the `Mutex` to be inside of
+ /// an `Arc` and the resulting mutex guard has no lifetime requirements.
+ #[cfg(feature = "arc_lock")]
+ #[inline]
+ pub fn try_lock_arc_until(
+ self: &Arc<Self>,
+ timeout: R::Instant,
+ ) -> Option<ArcMutexGuard<R, T>> {
+ if self.raw.try_lock_until(timeout) {
+ // SAFETY: locking guarantee is upheld
+ Some(unsafe { self.guard_arc() })
+ } else {
+ None
+ }
+ }
}
impl<R: RawMutex, T: ?Sized + Default> Default for Mutex<R, T> {
@@ -583,6 +662,116 @@
#[cfg(feature = "owning_ref")]
unsafe impl<'a, R: RawMutex + 'a, T: ?Sized + 'a> StableAddress for MutexGuard<'a, R, T> {}
+/// An RAII mutex guard returned by the `Arc` locking operations on `Mutex`.
+///
+/// This is similar to the `MutexGuard` struct, except instead of using a reference to unlock the `Mutex` it
+/// uses an `Arc<Mutex>`. This has several advantages, most notably that it has an `'static` lifetime.
+#[cfg(feature = "arc_lock")]
+#[must_use = "if unused the Mutex will immediately unlock"]
+pub struct ArcMutexGuard<R: RawMutex, T: ?Sized> {
+ mutex: Arc<Mutex<R, T>>,
+ marker: PhantomData<R::GuardMarker>,
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawMutex, T: ?Sized> ArcMutexGuard<R, T> {
+ /// Returns a reference to the `Mutex` this is guarding, contained in its `Arc`.
+ #[inline]
+ pub fn mutex(&self) -> &Arc<Mutex<R, T>> {
+ &self.mutex
+ }
+
+ /// Temporarily unlocks the mutex to execute the given function.
+ ///
+ /// This is safe because `&mut` guarantees that there exist no other
+ /// references to the data protected by the mutex.
+ #[inline]
+ pub fn unlocked<F, U>(s: &mut Self, f: F) -> U
+ where
+ F: FnOnce() -> U,
+ {
+ // Safety: A MutexGuard always holds the lock.
+ unsafe {
+ s.mutex.raw.unlock();
+ }
+ defer!(s.mutex.raw.lock());
+ f()
+ }
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawMutexFair, T: ?Sized> ArcMutexGuard<R, T> {
+ /// Unlocks the mutex using a fair unlock protocol.
+ ///
+ /// This is functionally identical to the `unlock_fair` method on [`MutexGuard`].
+ #[inline]
+ pub fn unlock_fair(s: Self) {
+ // Safety: A MutexGuard always holds the lock.
+ unsafe {
+ s.mutex.raw.unlock_fair();
+ }
+
+ // SAFETY: make sure the Arc gets it reference decremented
+ let mut s = ManuallyDrop::new(s);
+ unsafe { ptr::drop_in_place(&mut s.mutex) };
+ }
+
+ /// Temporarily unlocks the mutex to execute the given function.
+ ///
+ /// This is functionally identical to the `unlocked_fair` method on [`MutexGuard`].
+ #[inline]
+ pub fn unlocked_fair<F, U>(s: &mut Self, f: F) -> U
+ where
+ F: FnOnce() -> U,
+ {
+ // Safety: A MutexGuard always holds the lock.
+ unsafe {
+ s.mutex.raw.unlock_fair();
+ }
+ defer!(s.mutex.raw.lock());
+ f()
+ }
+
+ /// Temporarily yields the mutex to a waiting thread if there is one.
+ ///
+ /// This is functionally identical to the `bump` method on [`MutexGuard`].
+ #[inline]
+ pub fn bump(s: &mut Self) {
+ // Safety: A MutexGuard always holds the lock.
+ unsafe {
+ s.mutex.raw.bump();
+ }
+ }
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawMutex, T: ?Sized> Deref for ArcMutexGuard<R, T> {
+ type Target = T;
+ #[inline]
+ fn deref(&self) -> &T {
+ unsafe { &*self.mutex.data.get() }
+ }
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawMutex, T: ?Sized> DerefMut for ArcMutexGuard<R, T> {
+ #[inline]
+ fn deref_mut(&mut self) -> &mut T {
+ unsafe { &mut *self.mutex.data.get() }
+ }
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawMutex, T: ?Sized> Drop for ArcMutexGuard<R, T> {
+ #[inline]
+ fn drop(&mut self) {
+ // Safety: A MutexGuard always holds the lock.
+ unsafe {
+ self.mutex.raw.unlock();
+ }
+ }
+}
+
/// An RAII mutex guard returned by `MutexGuard::map`, which can point to a
/// subfield of the protected data.
///
diff --git a/src/remutex.rs b/src/remutex.rs
index 09833b0..8493a24 100644
--- a/src/remutex.rs
+++ b/src/remutex.rs
@@ -19,6 +19,13 @@
sync::atomic::{AtomicUsize, Ordering},
};
+#[cfg(feature = "arc_lock")]
+use alloc::sync::Arc;
+#[cfg(feature = "arc_lock")]
+use core::mem::ManuallyDrop;
+#[cfg(feature = "arc_lock")]
+use core::ptr;
+
#[cfg(feature = "owning_ref")]
use owning_ref::StableAddress;
@@ -135,6 +142,13 @@
pub fn is_locked(&self) -> bool {
self.mutex.is_locked()
}
+
+ /// Checks whether the mutex is currently held by the current thread.
+ #[inline]
+ pub fn is_owned_by_current_thread(&self) -> bool {
+ let id = self.get_thread_id.nonzero_thread_id().get();
+ self.owner.load(Ordering::Relaxed) == id
+ }
}
impl<R: RawMutexFair, G: GetThreadId> RawReentrantMutex<R, G> {
@@ -333,6 +347,12 @@
self.raw.is_locked()
}
+ /// Checks whether the mutex is currently held by the current thread.
+ #[inline]
+ pub fn is_owned_by_current_thread(&self) -> bool {
+ self.raw.is_owned_by_current_thread()
+ }
+
/// Forcibly unlocks the mutex.
///
/// This is useful when combined with `mem::forget` to hold a lock without
@@ -379,6 +399,45 @@
pub fn data_ptr(&self) -> *mut T {
self.data.get()
}
+
+ /// # Safety
+ ///
+ /// The lock must be held before calling this method.
+ #[cfg(feature = "arc_lock")]
+ #[inline]
+ unsafe fn guard_arc(self: &Arc<Self>) -> ArcReentrantMutexGuard<R, G, T> {
+ ArcReentrantMutexGuard {
+ remutex: self.clone(),
+ marker: PhantomData,
+ }
+ }
+
+ /// Acquires a reentrant mutex through an `Arc`.
+ ///
+ /// This method is similar to the `lock` method; however, it requires the `ReentrantMutex` to be inside of an
+ /// `Arc` and the resulting mutex guard has no lifetime requirements.
+ #[cfg(feature = "arc_lock")]
+ #[inline]
+ pub fn lock_arc(self: &Arc<Self>) -> ArcReentrantMutexGuard<R, G, T> {
+ self.raw.lock();
+ // SAFETY: locking guarantee is upheld
+ unsafe { self.guard_arc() }
+ }
+
+ /// Attempts to acquire a reentrant mutex through an `Arc`.
+ ///
+ /// This method is similar to the `try_lock` method; however, it requires the `ReentrantMutex` to be inside
+ /// of an `Arc` and the resulting mutex guard has no lifetime requirements.
+ #[cfg(feature = "arc_lock")]
+ #[inline]
+ pub fn try_lock_arc(self: &Arc<Self>) -> Option<ArcReentrantMutexGuard<R, G, T>> {
+ if self.raw.try_lock() {
+ // SAFETY: locking guarantee is upheld
+ Some(unsafe { self.guard_arc() })
+ } else {
+ None
+ }
+ }
}
impl<R: RawMutexFair, G: GetThreadId, T: ?Sized> ReentrantMutex<R, G, T> {
@@ -429,6 +488,36 @@
None
}
}
+
+ /// Attempts to acquire this lock until a timeout is reached, through an `Arc`.
+ ///
+ /// This method is similar to the `try_lock_for` method; however, it requires the `ReentrantMutex` to be
+ /// inside of an `Arc` and the resulting mutex guard has no lifetime requirements.
+ #[cfg(feature = "arc_lock")]
+ #[inline]
+ pub fn try_lock_arc_for(self: &Arc<Self>, timeout: R::Duration) -> Option<ArcReentrantMutexGuard<R, G, T>> {
+ if self.raw.try_lock_for(timeout) {
+ // SAFETY: locking guarantee is upheld
+ Some(unsafe { self.guard_arc() })
+ } else {
+ None
+ }
+ }
+
+ /// Attempts to acquire this lock until a timeout is reached, through an `Arc`.
+ ///
+ /// This method is similar to the `try_lock_until` method; however, it requires the `ReentrantMutex` to be
+ /// inside of an `Arc` and the resulting mutex guard has no lifetime requirements.
+ #[cfg(feature = "arc_lock")]
+ #[inline]
+ pub fn try_lock_arc_until(self: &Arc<Self>, timeout: R::Instant) -> Option<ArcReentrantMutexGuard<R, G, T>> {
+ if self.raw.try_lock_until(timeout) {
+ // SAFETY: locking guarantee is upheld
+ Some(unsafe { self.guard_arc() })
+ } else {
+ None
+ }
+ }
}
impl<R: RawMutex, G: GetThreadId, T: ?Sized + Default> Default for ReentrantMutex<R, G, T> {
@@ -647,6 +736,7 @@
s.remutex.raw.bump();
}
}
+
}
impl<'a, R: RawMutex + 'a, G: GetThreadId + 'a, T: ?Sized + 'a> Deref
@@ -693,6 +783,114 @@
{
}
+/// An RAII mutex guard returned by the `Arc` locking operations on `ReentrantMutex`.
+///
+/// This is similar to the `ReentrantMutexGuard` struct, except instead of using a reference to unlock the
+/// `Mutex` it uses an `Arc<ReentrantMutex>`. This has several advantages, most notably that it has an `'static`
+/// lifetime.
+#[cfg(feature = "arc_lock")]
+#[must_use = "if unused the ReentrantMutex will immediately unlock"]
+pub struct ArcReentrantMutexGuard<R: RawMutex, G: GetThreadId, T: ?Sized> {
+ remutex: Arc<ReentrantMutex<R, G, T>>,
+ marker: PhantomData<GuardNoSend>,
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawMutex, G: GetThreadId, T: ?Sized> ArcReentrantMutexGuard<R, G, T> {
+ /// Returns a reference to the `ReentrantMutex` this object is guarding, contained in its `Arc`.
+ pub fn remutex(s: &Self) -> &Arc<ReentrantMutex<R, G, T>> {
+ &s.remutex
+ }
+
+ /// Temporarily unlocks the mutex to execute the given function.
+ ///
+ /// This is safe because `&mut` guarantees that there exist no other
+ /// references to the data protected by the mutex.
+ #[inline]
+ pub fn unlocked<F, U>(s: &mut Self, f: F) -> U
+ where
+ F: FnOnce() -> U,
+ {
+ // Safety: A ReentrantMutexGuard always holds the lock.
+ unsafe {
+ s.remutex.raw.unlock();
+ }
+ defer!(s.remutex.raw.lock());
+ f()
+ }
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawMutexFair, G: GetThreadId, T: ?Sized>
+ ArcReentrantMutexGuard<R, G, T>
+{
+ /// Unlocks the mutex using a fair unlock protocol.
+ ///
+ /// This is functionally identical to the `unlock_fair` method on [`ReentrantMutexGuard`].
+ #[inline]
+ pub fn unlock_fair(s: Self) {
+ // Safety: A ReentrantMutexGuard always holds the lock
+ unsafe {
+ s.remutex.raw.unlock_fair();
+ }
+
+ // SAFETY: ensure that the Arc's refcount is decremented
+ let mut s = ManuallyDrop::new(s);
+ unsafe { ptr::drop_in_place(&mut s.remutex) };
+ }
+
+ /// Temporarily unlocks the mutex to execute the given function.
+ ///
+ /// This is functionally identical to the `unlocked_fair` method on [`ReentrantMutexGuard`].
+ #[inline]
+ pub fn unlocked_fair<F, U>(s: &mut Self, f: F) -> U
+ where
+ F: FnOnce() -> U,
+ {
+ // Safety: A ReentrantMutexGuard always holds the lock
+ unsafe {
+ s.remutex.raw.unlock_fair();
+ }
+ defer!(s.remutex.raw.lock());
+ f()
+ }
+
+ /// Temporarily yields the mutex to a waiting thread if there is one.
+ ///
+ /// This is functionally equivalent to the `bump` method on [`ReentrantMutexGuard`].
+ #[inline]
+ pub fn bump(s: &mut Self) {
+ // Safety: A ReentrantMutexGuard always holds the lock
+ unsafe {
+ s.remutex.raw.bump();
+ }
+ }
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawMutex, G: GetThreadId, T: ?Sized> Deref
+ for ArcReentrantMutexGuard<R, G, T>
+{
+ type Target = T;
+ #[inline]
+ fn deref(&self) -> &T {
+ unsafe { &*self.remutex.data.get() }
+ }
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawMutex, G: GetThreadId, T: ?Sized> Drop
+ for ArcReentrantMutexGuard<R, G, T>
+{
+ #[inline]
+ fn drop(&mut self) {
+ // Safety: A ReentrantMutexGuard always holds the lock.
+ unsafe {
+ self.remutex.raw.unlock();
+ }
+ }
+}
+
/// An RAII mutex guard returned by `ReentrantMutexGuard::map`, which can point to a
/// subfield of the protected data.
///
diff --git a/src/rwlock.rs b/src/rwlock.rs
index e97de98..c404934 100644
--- a/src/rwlock.rs
+++ b/src/rwlock.rs
@@ -11,6 +11,13 @@
use core::mem;
use core::ops::{Deref, DerefMut};
+#[cfg(feature = "arc_lock")]
+use alloc::sync::Arc;
+#[cfg(feature = "arc_lock")]
+use core::mem::ManuallyDrop;
+#[cfg(feature = "arc_lock")]
+use core::ptr;
+
#[cfg(feature = "owning_ref")]
use owning_ref::StableAddress;
@@ -557,6 +564,84 @@
pub fn data_ptr(&self) -> *mut T {
self.data.get()
}
+
+ /// # Safety
+ ///
+ /// The lock must be held when calling this method.
+ #[cfg(feature = "arc_lock")]
+ #[inline]
+ unsafe fn read_guard_arc(self: &Arc<Self>) -> ArcRwLockReadGuard<R, T> {
+ ArcRwLockReadGuard {
+ rwlock: self.clone(),
+ marker: PhantomData,
+ }
+ }
+
+ /// # Safety
+ ///
+ /// The lock must be held when calling this method.
+ #[cfg(feature = "arc_lock")]
+ #[inline]
+ unsafe fn write_guard_arc(self: &Arc<Self>) -> ArcRwLockWriteGuard<R, T> {
+ ArcRwLockWriteGuard {
+ rwlock: self.clone(),
+ marker: PhantomData,
+ }
+ }
+
+ /// Locks this `RwLock` with read access, through an `Arc`.
+ ///
+ /// This method is similar to the `read` method; however, it requires the `RwLock` to be inside of an `Arc`
+ /// and the resulting read guard has no lifetime requirements.
+ #[cfg(feature = "arc_lock")]
+ #[inline]
+ pub fn read_arc(self: &Arc<Self>) -> ArcRwLockReadGuard<R, T> {
+ self.raw.lock_shared();
+ // SAFETY: locking guarantee is upheld
+ unsafe { self.read_guard_arc() }
+ }
+
+ /// Attempts to lock this `RwLock` with read access, through an `Arc`.
+ ///
+ /// This method is similar to the `try_read` method; however, it requires the `RwLock` to be inside of an
+ /// `Arc` and the resulting read guard has no lifetime requirements.
+ #[cfg(feature = "arc_lock")]
+ #[inline]
+ pub fn try_read_arc(self: &Arc<Self>) -> Option<ArcRwLockReadGuard<R, T>> {
+ if self.raw.try_lock_shared() {
+ // SAFETY: locking guarantee is upheld
+ Some(unsafe { self.read_guard_arc() })
+ } else {
+ None
+ }
+ }
+
+ /// Locks this `RwLock` with write access, through an `Arc`.
+ ///
+ /// This method is similar to the `write` method; however, it requires the `RwLock` to be inside of an `Arc`
+ /// and the resulting write guard has no lifetime requirements.
+ #[cfg(feature = "arc_lock")]
+ #[inline]
+ pub fn write_arc(self: &Arc<Self>) -> ArcRwLockWriteGuard<R, T> {
+ self.raw.lock_exclusive();
+ // SAFETY: locking guarantee is upheld
+ unsafe { self.write_guard_arc() }
+ }
+
+ /// Attempts to lock this `RwLock` with writ access, through an `Arc`.
+ ///
+ /// This method is similar to the `try_write` method; however, it requires the `RwLock` to be inside of an
+ /// `Arc` and the resulting write guard has no lifetime requirements.
+ #[cfg(feature = "arc_lock")]
+ #[inline]
+ pub fn try_write_arc(self: &Arc<Self>) -> Option<ArcRwLockWriteGuard<R, T>> {
+ if self.raw.try_lock_exclusive() {
+ // SAFETY: locking guarantee is upheld
+ Some(unsafe { self.write_guard_arc() })
+ } else {
+ None
+ }
+ }
}
impl<R: RawRwLockFair, T: ?Sized> RwLock<R, T> {
@@ -657,6 +742,66 @@
None
}
}
+
+ /// Attempts to acquire this `RwLock` with read access until a timeout is reached, through an `Arc`.
+ ///
+ /// This method is similar to the `try_read_for` method; however, it requires the `RwLock` to be inside of an
+ /// `Arc` and the resulting read guard has no lifetime requirements.
+ #[cfg(feature = "arc_lock")]
+ #[inline]
+ pub fn try_read_arc_for(self: &Arc<Self>, timeout: R::Duration) -> Option<ArcRwLockReadGuard<R, T>> {
+ if self.raw.try_lock_shared_for(timeout) {
+ // SAFETY: locking guarantee is upheld
+ Some(unsafe { self.read_guard_arc() })
+ } else {
+ None
+ }
+ }
+
+ /// Attempts to acquire this `RwLock` with read access until a timeout is reached, through an `Arc`.
+ ///
+ /// This method is similar to the `try_read_until` method; however, it requires the `RwLock` to be inside of
+ /// an `Arc` and the resulting read guard has no lifetime requirements.
+ #[cfg(feature = "arc_lock")]
+ #[inline]
+ pub fn try_read_arc_until(self: &Arc<Self>, timeout: R::Instant) -> Option<ArcRwLockReadGuard<R, T>> {
+ if self.raw.try_lock_shared_until(timeout) {
+ // SAFETY: locking guarantee is upheld
+ Some(unsafe { self.read_guard_arc() })
+ } else {
+ None
+ }
+ }
+
+ /// Attempts to acquire this `RwLock` with write access until a timeout is reached, through an `Arc`.
+ ///
+ /// This method is similar to the `try_write_for` method; however, it requires the `RwLock` to be inside of
+ /// an `Arc` and the resulting write guard has no lifetime requirements.
+ #[cfg(feature = "arc_lock")]
+ #[inline]
+ pub fn try_write_arc_for(self: &Arc<Self>, timeout: R::Duration) -> Option<ArcRwLockWriteGuard<R, T>> {
+ if self.raw.try_lock_exclusive_for(timeout) {
+ // SAFETY: locking guarantee is upheld
+ Some(unsafe { self.write_guard_arc() })
+ } else {
+ None
+ }
+ }
+
+ /// Attempts to acquire this `RwLock` with read access until a timeout is reached, through an `Arc`.
+ ///
+ /// This method is similar to the `try_write_until` method; however, it requires the `RwLock` to be inside of
+ /// an `Arc` and the resulting read guard has no lifetime requirements.
+ #[cfg(feature = "arc_lock")]
+ #[inline]
+ pub fn try_write_arc_until(self: &Arc<Self>, timeout: R::Instant) -> Option<ArcRwLockWriteGuard<R, T>> {
+ if self.raw.try_lock_exclusive_until(timeout) {
+ // SAFETY: locking guarantee is upheld
+ Some(unsafe { self.write_guard_arc() })
+ } else {
+ None
+ }
+ }
}
impl<R: RawRwLockRecursive, T: ?Sized> RwLock<R, T> {
@@ -701,6 +846,33 @@
None
}
}
+
+ /// Locks this `RwLock` with shared read access, through an `Arc`.
+ ///
+ /// This method is similar to the `read_recursive` method; however, it requires the `RwLock` to be inside of
+ /// an `Arc` and the resulting read guard has no lifetime requirements.
+ #[cfg(feature = "arc_lock")]
+ #[inline]
+ pub fn read_arc_recursive(self: &Arc<Self>) -> ArcRwLockReadGuard<R, T> {
+ self.raw.lock_shared_recursive();
+ // SAFETY: locking guarantee is upheld
+ unsafe { self.read_guard_arc() }
+ }
+
+ /// Attempts to lock this `RwLock` with shared read access, through an `Arc`.
+ ///
+ /// This method is similar to the `try_read_recursive` method; however, it requires the `RwLock` to be inside
+ /// of an `Arc` and the resulting read guard has no lifetime requirements.
+ #[cfg(feature = "arc_lock")]
+ #[inline]
+ pub fn try_read_recursive_arc(self: &Arc<Self>) -> Option<ArcRwLockReadGuard<R, T>> {
+ if self.raw.try_lock_shared_recursive() {
+ // SAFETY: locking guarantee is upheld
+ Some(unsafe { self.read_guard_arc() })
+ } else {
+ None
+ }
+ }
}
impl<R: RawRwLockRecursiveTimed, T: ?Sized> RwLock<R, T> {
@@ -745,6 +917,36 @@
None
}
}
+
+ /// Attempts to lock this `RwLock` with read access until a timeout is reached, through an `Arc`.
+ ///
+ /// This method is similar to the `try_read_recursive_for` method; however, it requires the `RwLock` to be
+ /// inside of an `Arc` and the resulting read guard has no lifetime requirements.
+ #[cfg(feature = "arc_lock")]
+ #[inline]
+ pub fn try_read_arc_recursive_for(self: &Arc<Self>, timeout: R::Duration) -> Option<ArcRwLockReadGuard<R, T>> {
+ if self.raw.try_lock_shared_recursive_for(timeout) {
+ // SAFETY: locking guarantee is upheld
+ Some(unsafe { self.read_guard_arc() })
+ } else {
+ None
+ }
+ }
+
+ /// Attempts to lock this `RwLock` with read access until a timeout is reached, through an `Arc`.
+ ///
+ /// This method is similar to the `try_read_recursive_until` method; however, it requires the `RwLock` to be
+ /// inside of an `Arc` and the resulting read guard has no lifetime requirements.
+ #[cfg(feature = "arc_lock")]
+ #[inline]
+ pub fn try_read_arc_recursive_until(self: &Arc<Self>, timeout: R::Instant) -> Option<ArcRwLockReadGuard<R, T>> {
+ if self.raw.try_lock_shared_recursive_until(timeout) {
+ // SAFETY: locking guarantee is upheld
+ Some(unsafe { self.read_guard_arc() })
+ } else {
+ None
+ }
+ }
}
impl<R: RawRwLockUpgrade, T: ?Sized> RwLock<R, T> {
@@ -791,6 +993,45 @@
None
}
}
+
+ /// # Safety
+ ///
+ /// The lock must be held when calling this method.
+ #[cfg(feature = "arc_lock")]
+ #[inline]
+ unsafe fn upgradable_guard_arc(self: &Arc<Self>) -> ArcRwLockUpgradableReadGuard<R, T> {
+ ArcRwLockUpgradableReadGuard {
+ rwlock: self.clone(),
+ marker: PhantomData
+ }
+ }
+
+ /// Locks this `RwLock` with upgradable read access, through an `Arc`.
+ ///
+ /// This method is similar to the `upgradable_read` method; however, it requires the `RwLock` to be
+ /// inside of an `Arc` and the resulting read guard has no lifetime requirements.
+ #[cfg(feature = "arc_lock")]
+ #[inline]
+ pub fn upgradable_read_arc(self: &Arc<Self>) -> ArcRwLockUpgradableReadGuard<R, T> {
+ self.raw.lock_upgradable();
+ // SAFETY: locking guarantee is upheld
+ unsafe { self.upgradable_guard_arc() }
+ }
+
+ /// Attempts to lock this `RwLock` with upgradable read access, through an `Arc`.
+ ///
+ /// This method is similar to the `try_upgradable_read` method; however, it requires the `RwLock` to be
+ /// inside of an `Arc` and the resulting read guard has no lifetime requirements.
+ #[cfg(feature = "arc_lock")]
+ #[inline]
+ pub fn try_upgradable_read_arc(self: &Arc<Self>) -> Option<ArcRwLockUpgradableReadGuard<R, T>> {
+ if self.raw.try_lock_upgradable() {
+ // SAFETY: locking guarantee is upheld
+ Some(unsafe { self.upgradable_guard_arc() })
+ } else {
+ None
+ }
+ }
}
impl<R: RawRwLockUpgradeTimed, T: ?Sized> RwLock<R, T> {
@@ -831,6 +1072,42 @@
None
}
}
+
+ /// Attempts to lock this `RwLock` with upgradable access until a timeout is reached, through an `Arc`.
+ ///
+ /// This method is similar to the `try_upgradable_read_for` method; however, it requires the `RwLock` to be
+ /// inside of an `Arc` and the resulting read guard has no lifetime requirements.
+ #[cfg(feature = "arc_lock")]
+ #[inline]
+ pub fn try_upgradable_read_arc_for(
+ self: &Arc<Self>,
+ timeout: R::Duration,
+ ) -> Option<ArcRwLockUpgradableReadGuard<R, T>> {
+ if self.raw.try_lock_upgradable_for(timeout) {
+ // SAFETY: locking guarantee is upheld
+ Some(unsafe { self.upgradable_guard_arc() })
+ } else {
+ None
+ }
+ }
+
+ /// Attempts to lock this `RwLock` with upgradable access until a timeout is reached, through an `Arc`.
+ ///
+ /// This method is similar to the `try_upgradable_read_until` method; however, it requires the `RwLock` to be
+ /// inside of an `Arc` and the resulting read guard has no lifetime requirements.
+ #[cfg(feature = "arc_lock")]
+ #[inline]
+ pub fn try_upgradable_read_arc_until(
+ self: &Arc<Self>,
+ timeout: R::Instant,
+ ) -> Option<ArcRwLockUpgradableReadGuard<R, T>> {
+ if self.raw.try_lock_upgradable_until(timeout) {
+ // SAFETY: locking guarantee is upheld
+ Some(unsafe { self.upgradable_guard_arc() })
+ } else {
+ None
+ }
+ }
}
impl<R: RawRwLock, T: ?Sized + Default> Default for RwLock<R, T> {
@@ -1041,6 +1318,122 @@
#[cfg(feature = "owning_ref")]
unsafe impl<'a, R: RawRwLock + 'a, T: ?Sized + 'a> StableAddress for RwLockReadGuard<'a, R, T> {}
+/// An RAII rwlock guard returned by the `Arc` locking operations on `RwLock`.
+///
+/// This is similar to the `RwLockReadGuard` struct, except instead of using a reference to unlock the `RwLock`
+/// it uses an `Arc<RwLock>`. This has several advantages, most notably that it has an `'static` lifetime.
+#[cfg(feature = "arc_lock")]
+#[must_use = "if unused the RwLock will immediately unlock"]
+pub struct ArcRwLockReadGuard<R: RawRwLock, T: ?Sized> {
+ rwlock: Arc<RwLock<R, T>>,
+ marker: PhantomData<R::GuardMarker>,
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawRwLock, T: ?Sized> ArcRwLockReadGuard<R, T> {
+ /// Returns a reference to the rwlock, contained in its `Arc`.
+ pub fn rwlock(s: &Self) -> &Arc<RwLock<R, T>> {
+ &s.rwlock
+ }
+
+ /// Temporarily unlocks the `RwLock` to execute the given function.
+ ///
+ /// This is functionally identical to the `unlocked` method on [`RwLockReadGuard`].
+ #[inline]
+ pub fn unlocked<F, U>(s: &mut Self, f: F) -> U
+ where
+ F: FnOnce() -> U,
+ {
+ // Safety: An RwLockReadGuard always holds a shared lock.
+ unsafe {
+ s.rwlock.raw.unlock_shared();
+ }
+ defer!(s.rwlock.raw.lock_shared());
+ f()
+ }
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawRwLockFair, T: ?Sized> ArcRwLockReadGuard<R, T> {
+ /// Unlocks the `RwLock` using a fair unlock protocol.
+ ///
+ /// This is functionally identical to the `unlock_fair` method on [`RwLockReadGuard`].
+ #[inline]
+ pub fn unlock_fair(s: Self) {
+ // Safety: An RwLockReadGuard always holds a shared lock.
+ unsafe {
+ s.rwlock.raw.unlock_shared_fair();
+ }
+
+ // SAFETY: ensure the Arc has its refcount decremented
+ let mut s = ManuallyDrop::new(s);
+ unsafe { ptr::drop_in_place(&mut s.rwlock) };
+ }
+
+ /// Temporarily unlocks the `RwLock` to execute the given function.
+ ///
+ /// This is functionally identical to the `unlocked_fair` method on [`RwLockReadGuard`].
+ #[inline]
+ pub fn unlocked_fair<F, U>(s: &mut Self, f: F) -> U
+ where
+ F: FnOnce() -> U,
+ {
+ // Safety: An RwLockReadGuard always holds a shared lock.
+ unsafe {
+ s.rwlock.raw.unlock_shared_fair();
+ }
+ defer!(s.rwlock.raw.lock_shared());
+ f()
+ }
+
+ /// Temporarily yields the `RwLock` to a waiting thread if there is one.
+ ///
+ /// This is functionally identical to the `bump` method on [`RwLockReadGuard`].
+ #[inline]
+ pub fn bump(s: &mut Self) {
+ // Safety: An RwLockReadGuard always holds a shared lock.
+ unsafe {
+ s.rwlock.raw.bump_shared();
+ }
+ }
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawRwLock, T: ?Sized> Deref for ArcRwLockReadGuard<R, T> {
+ type Target = T;
+ #[inline]
+ fn deref(&self) -> &T {
+ unsafe { &*self.rwlock.data.get() }
+ }
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawRwLock, T: ?Sized> Drop for ArcRwLockReadGuard<R, T> {
+ #[inline]
+ fn drop(&mut self) {
+ // Safety: An RwLockReadGuard always holds a shared lock.
+ unsafe {
+ self.rwlock.raw.unlock_shared();
+ }
+ }
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawRwLock, T: fmt::Debug + ?Sized> fmt::Debug for ArcRwLockReadGuard<R, T> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ fmt::Debug::fmt(&**self, f)
+ }
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawRwLock, T: fmt::Display + ?Sized> fmt::Display
+ for ArcRwLockReadGuard<R, T>
+{
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ (**self).fmt(f)
+ }
+}
+
/// RAII structure used to release the exclusive write access of a lock when
/// dropped.
#[must_use = "if unused the RwLock will immediately unlock"]
@@ -1262,6 +1655,175 @@
#[cfg(feature = "owning_ref")]
unsafe impl<'a, R: RawRwLock + 'a, T: ?Sized + 'a> StableAddress for RwLockWriteGuard<'a, R, T> {}
+/// An RAII rwlock guard returned by the `Arc` locking operations on `RwLock`.
+/// This is similar to the `RwLockWriteGuard` struct, except instead of using a reference to unlock the `RwLock`
+/// it uses an `Arc<RwLock>`. This has several advantages, most notably that it has an `'static` lifetime.
+#[cfg(feature = "arc_lock")]
+#[must_use = "if unused the RwLock will immediately unlock"]
+pub struct ArcRwLockWriteGuard<R: RawRwLock, T: ?Sized> {
+ rwlock: Arc<RwLock<R, T>>,
+ marker: PhantomData<R::GuardMarker>,
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawRwLock, T: ?Sized> ArcRwLockWriteGuard<R, T> {
+ /// Returns a reference to the rwlock, contained in its `Arc`.
+ pub fn rwlock(s: &Self) -> &Arc<RwLock<R, T>> {
+ &s.rwlock
+ }
+
+ /// Temporarily unlocks the `RwLock` to execute the given function.
+ ///
+ /// This is functionally equivalent to the `unlocked` method on [`RwLockWriteGuard`].
+ #[inline]
+ pub fn unlocked<F, U>(s: &mut Self, f: F) -> U
+ where
+ F: FnOnce() -> U,
+ {
+ // Safety: An RwLockWriteGuard always holds a shared lock.
+ unsafe {
+ s.rwlock.raw.unlock_exclusive();
+ }
+ defer!(s.rwlock.raw.lock_exclusive());
+ f()
+ }
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawRwLockDowngrade, T: ?Sized> ArcRwLockWriteGuard<R, T> {
+ /// Atomically downgrades a write lock into a read lock without allowing any
+ /// writers to take exclusive access of the lock in the meantime.
+ ///
+ /// This is functionally equivalent to the `downgrade` method on [`RwLockWriteGuard`].
+ pub fn downgrade(s: Self) -> ArcRwLockReadGuard<R, T> {
+ // Safety: An RwLockWriteGuard always holds an exclusive lock.
+ unsafe {
+ s.rwlock.raw.downgrade();
+ }
+
+ // SAFETY: prevent the arc's refcount from changing using ManuallyDrop and ptr::read
+ let s = ManuallyDrop::new(s);
+ let rwlock = unsafe { ptr::read(&s.rwlock) };
+
+ ArcRwLockReadGuard {
+ rwlock,
+ marker: PhantomData,
+ }
+ }
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawRwLockUpgradeDowngrade, T: ?Sized> ArcRwLockWriteGuard<R, T> {
+ /// Atomically downgrades a write lock into an upgradable read lock without allowing any
+ /// writers to take exclusive access of the lock in the meantime.
+ ///
+ /// This is functionally identical to the `downgrade_to_upgradable` method on [`RwLockWriteGuard`].
+ pub fn downgrade_to_upgradable(s: Self) -> ArcRwLockUpgradableReadGuard<R, T> {
+ // Safety: An RwLockWriteGuard always holds an exclusive lock.
+ unsafe {
+ s.rwlock.raw.downgrade_to_upgradable();
+ }
+
+ // SAFETY: same as above
+ let s = ManuallyDrop::new(s);
+ let rwlock = unsafe { ptr::read(&s.rwlock) };
+
+ ArcRwLockUpgradableReadGuard {
+ rwlock,
+ marker: PhantomData,
+ }
+ }
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawRwLockFair, T: ?Sized> ArcRwLockWriteGuard<R, T> {
+ /// Unlocks the `RwLock` using a fair unlock protocol.
+ ///
+ /// This is functionally equivalent to the `unlock_fair` method on [`RwLockWriteGuard`].
+ #[inline]
+ pub fn unlock_fair(s: Self) {
+ // Safety: An RwLockWriteGuard always holds an exclusive lock.
+ unsafe {
+ s.rwlock.raw.unlock_exclusive_fair();
+ }
+
+ // SAFETY: prevent the Arc from leaking memory
+ let mut s = ManuallyDrop::new(s);
+ unsafe { ptr::drop_in_place(&mut s.rwlock) };
+ }
+
+ /// Temporarily unlocks the `RwLock` to execute the given function.
+ ///
+ /// This is functionally equivalent to the `unlocked_fair` method on [`RwLockWriteGuard`].
+ #[inline]
+ pub fn unlocked_fair<F, U>(s: &mut Self, f: F) -> U
+ where
+ F: FnOnce() -> U,
+ {
+ // Safety: An RwLockWriteGuard always holds an exclusive lock.
+ unsafe {
+ s.rwlock.raw.unlock_exclusive_fair();
+ }
+ defer!(s.rwlock.raw.lock_exclusive());
+ f()
+ }
+
+ /// Temporarily yields the `RwLock` to a waiting thread if there is one.
+ ///
+ /// This method is functionally equivalent to the `bump` method on [`RwLockWriteGuard`].
+ #[inline]
+ pub fn bump(s: &mut Self) {
+ // Safety: An RwLockWriteGuard always holds an exclusive lock.
+ unsafe {
+ s.rwlock.raw.bump_exclusive();
+ }
+ }
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawRwLock, T: ?Sized> Deref for ArcRwLockWriteGuard<R, T> {
+ type Target = T;
+ #[inline]
+ fn deref(&self) -> &T {
+ unsafe { &*self.rwlock.data.get() }
+ }
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawRwLock, T: ?Sized> DerefMut for ArcRwLockWriteGuard<R, T> {
+ #[inline]
+ fn deref_mut(&mut self) -> &mut T {
+ unsafe { &mut *self.rwlock.data.get() }
+ }
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawRwLock, T: ?Sized> Drop for ArcRwLockWriteGuard<R, T> {
+ #[inline]
+ fn drop(&mut self) {
+ // Safety: An RwLockWriteGuard always holds an exclusive lock.
+ unsafe {
+ self.rwlock.raw.unlock_exclusive();
+ }
+ }
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawRwLock, T: fmt::Debug + ?Sized> fmt::Debug for ArcRwLockWriteGuard<R, T> {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ fmt::Debug::fmt(&**self, f)
+ }
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawRwLock, T: fmt::Display + ?Sized> fmt::Display
+ for ArcRwLockWriteGuard<R, T>
+{
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ (**self).fmt(f)
+ }
+}
+
/// RAII structure used to release the upgradable read access of a lock when
/// dropped.
#[must_use = "if unused the RwLock will immediately unlock"]
@@ -1495,6 +2057,241 @@
{
}
+/// An RAII rwlock guard returned by the `Arc` locking operations on `RwLock`.
+/// This is similar to the `RwLockUpgradableReadGuard` struct, except instead of using a reference to unlock the
+/// `RwLock` it uses an `Arc<RwLock>`. This has several advantages, most notably that it has an `'static`
+/// lifetime.
+#[cfg(feature = "arc_lock")]
+#[must_use = "if unused the RwLock will immediately unlock"]
+pub struct ArcRwLockUpgradableReadGuard<R: RawRwLockUpgrade, T: ?Sized> {
+ rwlock: Arc<RwLock<R, T>>,
+ marker: PhantomData<R::GuardMarker>,
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawRwLockUpgrade , T: ?Sized> ArcRwLockUpgradableReadGuard<R, T> {
+ /// Returns a reference to the rwlock, contained in its original `Arc`.
+ pub fn rwlock(s: &Self) -> &Arc<RwLock<R, T>> {
+ &s.rwlock
+ }
+
+ /// Temporarily unlocks the `RwLock` to execute the given function.
+ ///
+ /// This is functionally identical to the `unlocked` method on [`RwLockUpgradableReadGuard`].
+ #[inline]
+ pub fn unlocked<F, U>(s: &mut Self, f: F) -> U
+ where
+ F: FnOnce() -> U,
+ {
+ // Safety: An RwLockUpgradableReadGuard always holds an upgradable lock.
+ unsafe {
+ s.rwlock.raw.unlock_upgradable();
+ }
+ defer!(s.rwlock.raw.lock_upgradable());
+ f()
+ }
+
+ /// Atomically upgrades an upgradable read lock lock into a exclusive write lock,
+ /// blocking the current thread until it can be acquired.
+ pub fn upgrade(s: Self) -> ArcRwLockWriteGuard<R, T> {
+ // Safety: An RwLockUpgradableReadGuard always holds an upgradable lock.
+ unsafe {
+ s.rwlock.raw.upgrade();
+ }
+
+ // SAFETY: avoid incrementing or decrementing the refcount using ManuallyDrop and reading the Arc out
+ // of the struct
+ let s = ManuallyDrop::new(s);
+ let rwlock = unsafe { ptr::read(&s.rwlock) };
+
+ ArcRwLockWriteGuard {
+ rwlock,
+ marker: PhantomData,
+ }
+ }
+
+ /// Tries to atomically upgrade an upgradable read lock into a exclusive write lock.
+ ///
+ /// If the access could not be granted at this time, then the current guard is returned.
+ pub fn try_upgrade(s: Self) -> Result<ArcRwLockWriteGuard<R, T>, Self> {
+ // Safety: An RwLockUpgradableReadGuard always holds an upgradable lock.
+ if unsafe { s.rwlock.raw.try_upgrade() } {
+ // SAFETY: same as above
+ let s = ManuallyDrop::new(s);
+ let rwlock = unsafe { ptr::read(&s.rwlock) };
+
+ Ok(ArcRwLockWriteGuard {
+ rwlock,
+ marker: PhantomData,
+ })
+ } else {
+ Err(s)
+ }
+ }
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawRwLockUpgradeFair, T: ?Sized> ArcRwLockUpgradableReadGuard<R, T> {
+ /// Unlocks the `RwLock` using a fair unlock protocol.
+ ///
+ /// This is functionally identical to the `unlock_fair` method on [`RwLockUpgradableReadGuard`].
+ #[inline]
+ pub fn unlock_fair(s: Self) {
+ // Safety: An RwLockUpgradableReadGuard always holds an upgradable lock.
+ unsafe {
+ s.rwlock.raw.unlock_upgradable_fair();
+ }
+
+ // SAFETY: make sure we decrement the refcount properly
+ let mut s = ManuallyDrop::new(s);
+ unsafe { ptr::drop_in_place(&mut s.rwlock) };
+ }
+
+ /// Temporarily unlocks the `RwLock` to execute the given function.
+ ///
+ /// This is functionally equivalent to the `unlocked_fair` method on [`RwLockUpgradableReadGuard`].
+ #[inline]
+ pub fn unlocked_fair<F, U>(s: &mut Self, f: F) -> U
+ where
+ F: FnOnce() -> U,
+ {
+ // Safety: An RwLockUpgradableReadGuard always holds an upgradable lock.
+ unsafe {
+ s.rwlock.raw.unlock_upgradable_fair();
+ }
+ defer!(s.rwlock.raw.lock_upgradable());
+ f()
+ }
+
+ /// Temporarily yields the `RwLock` to a waiting thread if there is one.
+ ///
+ /// This method is functionally equivalent to calling `bump` on [`RwLockUpgradableReadGuard`].
+ #[inline]
+ pub fn bump(s: &mut Self) {
+ // Safety: An RwLockUpgradableReadGuard always holds an upgradable lock.
+ unsafe {
+ s.rwlock.raw.bump_upgradable();
+ }
+ }
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawRwLockUpgradeDowngrade, T: ?Sized> ArcRwLockUpgradableReadGuard<R, T> {
+ /// Atomically downgrades an upgradable read lock lock into a shared read lock
+ /// without allowing any writers to take exclusive access of the lock in the
+ /// meantime.
+ ///
+ /// Note that if there are any writers currently waiting to take the lock
+ /// then other readers may not be able to acquire the lock even if it was
+ /// downgraded.
+ pub fn downgrade(s: Self) -> ArcRwLockReadGuard<R, T> {
+ // Safety: An RwLockUpgradableReadGuard always holds an upgradable lock.
+ unsafe {
+ s.rwlock.raw.downgrade_upgradable();
+ }
+
+ // SAFETY: use ManuallyDrop and ptr::read to ensure the refcount is not changed
+ let s = ManuallyDrop::new(s);
+ let rwlock = unsafe { ptr::read(&s.rwlock) };
+
+ ArcRwLockReadGuard {
+ rwlock,
+ marker: PhantomData,
+ }
+ }
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawRwLockUpgradeTimed, T: ?Sized> ArcRwLockUpgradableReadGuard<R, T> {
+ /// Tries to atomically upgrade an upgradable read lock into a exclusive
+ /// write lock, until a timeout is reached.
+ ///
+ /// If the access could not be granted before the timeout expires, then
+ /// the current guard is returned.
+ pub fn try_upgrade_for(
+ s: Self,
+ timeout: R::Duration,
+ ) -> Result<ArcRwLockWriteGuard<R, T>, Self> {
+ // Safety: An RwLockUpgradableReadGuard always holds an upgradable lock.
+ if unsafe { s.rwlock.raw.try_upgrade_for(timeout) } {
+ // SAFETY: same as above
+ let s = ManuallyDrop::new(s);
+ let rwlock = unsafe { ptr::read(&s.rwlock) };
+
+ Ok(ArcRwLockWriteGuard {
+ rwlock,
+ marker: PhantomData,
+ })
+ } else {
+ Err(s)
+ }
+ }
+
+ /// Tries to atomically upgrade an upgradable read lock into a exclusive
+ /// write lock, until a timeout is reached.
+ ///
+ /// If the access could not be granted before the timeout expires, then
+ /// the current guard is returned.
+ #[inline]
+ pub fn try_upgrade_until(
+ s: Self,
+ timeout: R::Instant,
+ ) -> Result<ArcRwLockWriteGuard<R, T>, Self> {
+ // Safety: An RwLockUpgradableReadGuard always holds an upgradable lock.
+ if unsafe { s.rwlock.raw.try_upgrade_until(timeout) } {
+ // SAFETY: same as above
+ let s = ManuallyDrop::new(s);
+ let rwlock = unsafe { ptr::read(&s.rwlock) };
+
+ Ok(ArcRwLockWriteGuard {
+ rwlock,
+ marker: PhantomData,
+ })
+ } else {
+ Err(s)
+ }
+ }
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawRwLockUpgrade, T: ?Sized> Deref for ArcRwLockUpgradableReadGuard<R, T> {
+ type Target = T;
+ #[inline]
+ fn deref(&self) -> &T {
+ unsafe { &*self.rwlock.data.get() }
+ }
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawRwLockUpgrade, T: ?Sized> Drop for ArcRwLockUpgradableReadGuard<R, T> {
+ #[inline]
+ fn drop(&mut self) {
+ // Safety: An RwLockUpgradableReadGuard always holds an upgradable lock.
+ unsafe {
+ self.rwlock.raw.unlock_upgradable();
+ }
+ }
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawRwLockUpgrade, T: fmt::Debug + ?Sized> fmt::Debug
+ for ArcRwLockUpgradableReadGuard<R, T>
+{
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ fmt::Debug::fmt(&**self, f)
+ }
+}
+
+#[cfg(feature = "arc_lock")]
+impl<R: RawRwLockUpgrade, T: fmt::Display + ?Sized> fmt::Display
+ for ArcRwLockUpgradableReadGuard<R, T>
+{
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ (**self).fmt(f)
+ }
+}
+
+
/// An RAII read lock guard returned by `RwLockReadGuard::map`, which can point to a
/// subfield of the protected data.
///
