New upstream version 0.52.0

[cargo.git] / vendor / crossbeam-utils / src / backoff.rs

diff --git a/vendor/crossbeam-utils/src/backoff.rs b/vendor/crossbeam-utils/src/backoff.rs
index 446755bbc7b4841ac8847cfee49cef8ff2de7894..1012f06b238a9f25fabfec6d949e6cb0ed0cd6ed 100644 (file)
--- a/vendor/crossbeam-utils/src/backoff.rs
+++ b/vendor/crossbeam-utils/src/backoff.rs
@@ -1,6 +1,6 @@
+use crate::primitive::sync::atomic;
 use core::cell::Cell;
 use core::fmt;
-use core::sync::atomic;
 
 const SPIN_LIMIT: u32 = 6;
 const YIELD_LIMIT: u32 = 10;
@@ -27,7 +27,7 @@ const YIELD_LIMIT: u32 = 10;
 ///     let backoff = Backoff::new();
 ///     loop {
 ///         let val = a.load(SeqCst);
-///         if a.compare_and_swap(val, val.wrapping_mul(b), SeqCst) == val {
+///         if a.compare_exchange(val, val.wrapping_mul(b), SeqCst, SeqCst).is_ok() {
 ///             return val;
 ///         }
 ///         backoff.spin();
@@ -72,11 +72,11 @@ const YIELD_LIMIT: u32 = 10;
 /// }
 /// ```
 ///
-/// [`is_completed`]: struct.Backoff.html#method.is_completed
-/// [`std::thread::park()`]: https://doc.rust-lang.org/std/thread/fn.park.html
-/// [`Condvar`]: https://doc.rust-lang.org/std/sync/struct.Condvar.html
-/// [`AtomicBool`]: https://doc.rust-lang.org/std/sync/atomic/struct.AtomicBool.html
-/// [`unpark()`]: https://doc.rust-lang.org/std/thread/struct.Thread.html#method.unpark
+/// [`is_completed`]: Backoff::is_completed
+/// [`std::thread::park()`]: std::thread::park
+/// [`Condvar`]: std::sync::Condvar
+/// [`AtomicBool`]: std::sync::atomic::AtomicBool
+/// [`unpark()`]: std::thread::Thread::unpark
 pub struct Backoff {
     step: Cell<u32>,
 }
@@ -131,7 +131,7 @@ impl Backoff {
     ///     let backoff = Backoff::new();
     ///     loop {
     ///         let val = a.load(SeqCst);
-    ///         if a.compare_and_swap(val, val.wrapping_mul(b), SeqCst) == val {
+    ///         if a.compare_exchange(val, val.wrapping_mul(b), SeqCst, SeqCst).is_ok() {
     ///             return val;
     ///         }
     ///         backoff.spin();
@@ -145,6 +145,9 @@ impl Backoff {
     #[inline]
     pub fn spin(&self) {
         for _ in 0..1 << self.step.get().min(SPIN_LIMIT) {
+            // TODO(taiki-e): once we bump the minimum required Rust version to 1.49+,
+            // use [`core::hint::spin_loop`] instead.
+            #[allow(deprecated)]
             atomic::spin_loop_hint();
         }
 
@@ -165,8 +168,8 @@ impl Backoff {
     /// If possible, use [`is_completed`] to check when it is advised to stop using backoff and
     /// block the current thread using a different synchronization mechanism instead.
     ///
-    /// [`spin`]: struct.Backoff.html#method.spin
-    /// [`is_completed`]: struct.Backoff.html#method.is_completed
+    /// [`spin`]: Backoff::spin
+    /// [`is_completed`]: Backoff::is_completed
     ///
     /// # Examples
     ///
@@ -200,16 +203,22 @@ impl Backoff {
     /// assert_eq!(ready.load(SeqCst), true);
     /// ```
     ///
-    /// [`AtomicBool`]: https://doc.rust-lang.org/std/sync/atomic/struct.AtomicBool.html
+    /// [`AtomicBool`]: std::sync::atomic::AtomicBool
     #[inline]
     pub fn snooze(&self) {
         if self.step.get() <= SPIN_LIMIT {
             for _ in 0..1 << self.step.get() {
+                // TODO(taiki-e): once we bump the minimum required Rust version to 1.49+,
+                // use [`core::hint::spin_loop`] instead.
+                #[allow(deprecated)]
                 atomic::spin_loop_hint();
             }
         } else {
             #[cfg(not(feature = "std"))]
             for _ in 0..1 << self.step.get() {
+                // TODO(taiki-e): once we bump the minimum required Rust version to 1.49+,
+                // use [`core::hint::spin_loop`] instead.
+                #[allow(deprecated)]
                 atomic::spin_loop_hint();
             }
 
@@ -262,22 +271,15 @@ impl Backoff {
     /// assert_eq!(ready.load(SeqCst), true);
     /// ```
     ///
-    /// [`AtomicBool`]: https://doc.rust-lang.org/std/sync/atomic/struct.AtomicBool.html
+    /// [`AtomicBool`]: std::sync::atomic::AtomicBool
     #[inline]
     pub fn is_completed(&self) -> bool {
         self.step.get() > YIELD_LIMIT
     }
-
-    #[inline]
-    #[doc(hidden)]
-    #[deprecated(note = "use `is_completed` instead")]
-    pub fn is_complete(&self) -> bool {
-        self.is_completed()
-    }
 }
 
 impl fmt::Debug for Backoff {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("Backoff")
             .field("step", &self.step)
             .field("is_completed", &self.is_completed())