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Remove deprecated items
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This removes the following deprecated items:

- crossbeam-epoch:
  - `CompareAndSetError`
  - `CompareAndSetOrdering`
  - `Atomic::compare_and_set`
  - `Atomic::compare_and_set_weak`
- crossbeam-utils:
  - `AtomicCell::compare_and_swap`
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@taiki-e
taiki-e committed Jul 23, 2022
1 parent 1ea6c55 commit d3187be
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205 changes: 0 additions & 205 deletions crossbeam-epoch/src/atomic.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -13,23 +13,6 @@ use crate::guard::Guard;
use crate::primitive::sync::atomic::AtomicUsize;
use crossbeam_utils::atomic::AtomicConsume;

/// Given ordering for the success case in a compare-exchange operation, returns the strongest
/// appropriate ordering for the failure case.
#[inline]
fn strongest_failure_ordering(ord: Ordering) -> Ordering {
use self::Ordering::*;
match ord {
Relaxed | Release => Relaxed,
Acquire | AcqRel => Acquire,
_ => SeqCst,
}
}

/// The error returned on failed compare-and-set operation.
// TODO: remove in the next major version.
#[deprecated(note = "Use `CompareExchangeError` instead")]
pub type CompareAndSetError<'g, T, P> = CompareExchangeError<'g, T, P>;

/// The error returned on failed compare-and-swap operation.
pub struct CompareExchangeError<'g, T: ?Sized + Pointable, P: Pointer<T>> {
/// The value in the atomic pointer at the time of the failed operation.
Expand All @@ -48,59 +31,6 @@ impl<T, P: Pointer<T> + fmt::Debug> fmt::Debug for CompareExchangeError<'_, T, P
}
}

/// Memory orderings for compare-and-set operations.
///
/// A compare-and-set operation can have different memory orderings depending on whether it
/// succeeds or fails. This trait generalizes different ways of specifying memory orderings.
///
/// The two ways of specifying orderings for compare-and-set are:
///
/// 1. Just one `Ordering` for the success case. In case of failure, the strongest appropriate
/// ordering is chosen.
/// 2. A pair of `Ordering`s. The first one is for the success case, while the second one is
/// for the failure case.
// TODO: remove in the next major version.
#[deprecated(
note = "`compare_and_set` and `compare_and_set_weak` that use this trait are deprecated, \
use `compare_exchange` or `compare_exchange_weak instead`"
)]
pub trait CompareAndSetOrdering {
/// The ordering of the operation when it succeeds.
fn success(&self) -> Ordering;

/// The ordering of the operation when it fails.
///
/// The failure ordering can't be `Release` or `AcqRel` and must be equivalent or weaker than
/// the success ordering.
fn failure(&self) -> Ordering;
}

#[allow(deprecated)]
impl CompareAndSetOrdering for Ordering {
#[inline]
fn success(&self) -> Ordering {
*self
}

#[inline]
fn failure(&self) -> Ordering {
strongest_failure_ordering(*self)
}
}

#[allow(deprecated)]
impl CompareAndSetOrdering for (Ordering, Ordering) {
#[inline]
fn success(&self) -> Ordering {
self.0
}

#[inline]
fn failure(&self) -> Ordering {
self.1
}
}

/// Returns a bitmask containing the unused least significant bits of an aligned pointer to `T`.
#[inline]
fn low_bits<T: ?Sized + Pointable>() -> usize {
Expand Down Expand Up @@ -640,141 +570,6 @@ impl<T: ?Sized + Pointable> Atomic<T> {
Err(prev)
}

/// Stores the pointer `new` (either `Shared` or `Owned`) into the atomic pointer if the current
/// value is the same as `current`. The tag is also taken into account, so two pointers to the
/// same object, but with different tags, will not be considered equal.
///
/// The return value is a result indicating whether the new pointer was written. On success the
/// pointer that was written is returned. On failure the actual current value and `new` are
/// returned.
///
/// This method takes a [`CompareAndSetOrdering`] argument which describes the memory
/// ordering of this operation.
///
/// # Migrating to `compare_exchange`
///
/// `compare_and_set` is equivalent to `compare_exchange` with the following mapping for
/// memory orderings:
///
/// Original | Success | Failure
/// -------- | ------- | -------
/// Relaxed | Relaxed | Relaxed
/// Acquire | Acquire | Acquire
/// Release | Release | Relaxed
/// AcqRel | AcqRel | Acquire
/// SeqCst | SeqCst | SeqCst
///
/// # Examples
///
/// ```
/// # #![allow(deprecated)]
/// use crossbeam_epoch::{self as epoch, Atomic, Owned, Shared};
/// use std::sync::atomic::Ordering::SeqCst;
///
/// let a = Atomic::new(1234);
///
/// let guard = &epoch::pin();
/// let curr = a.load(SeqCst, guard);
/// let res1 = a.compare_and_set(curr, Shared::null(), SeqCst, guard);
/// let res2 = a.compare_and_set(curr, Owned::new(5678), SeqCst, guard);
/// # unsafe { drop(curr.into_owned()); } // avoid leak
/// ```
// TODO: remove in the next major version.
#[allow(deprecated)]
#[deprecated(note = "Use `compare_exchange` instead")]
pub fn compare_and_set<'g, O, P>(
&self,
current: Shared<'_, T>,
new: P,
ord: O,
guard: &'g Guard,
) -> Result<Shared<'g, T>, CompareAndSetError<'g, T, P>>
where
O: CompareAndSetOrdering,
P: Pointer<T>,
{
self.compare_exchange(current, new, ord.success(), ord.failure(), guard)
}

/// Stores the pointer `new` (either `Shared` or `Owned`) into the atomic pointer if the current
/// value is the same as `current`. The tag is also taken into account, so two pointers to the
/// same object, but with different tags, will not be considered equal.
///
/// Unlike [`compare_and_set`], this method is allowed to spuriously fail even when comparison
/// succeeds, which can result in more efficient code on some platforms. The return value is a
/// result indicating whether the new pointer was written. On success the pointer that was
/// written is returned. On failure the actual current value and `new` are returned.
///
/// This method takes a [`CompareAndSetOrdering`] argument which describes the memory
/// ordering of this operation.
///
/// [`compare_and_set`]: Atomic::compare_and_set
///
/// # Migrating to `compare_exchange_weak`
///
/// `compare_and_set_weak` is equivalent to `compare_exchange_weak` with the following mapping for
/// memory orderings:
///
/// Original | Success | Failure
/// -------- | ------- | -------
/// Relaxed | Relaxed | Relaxed
/// Acquire | Acquire | Acquire
/// Release | Release | Relaxed
/// AcqRel | AcqRel | Acquire
/// SeqCst | SeqCst | SeqCst
///
/// # Examples
///
/// ```
/// # #![allow(deprecated)]
/// use crossbeam_epoch::{self as epoch, Atomic, Owned, Shared};
/// use std::sync::atomic::Ordering::SeqCst;
///
/// let a = Atomic::new(1234);
/// let guard = &epoch::pin();
///
/// let mut new = Owned::new(5678);
/// let mut ptr = a.load(SeqCst, guard);
/// # unsafe { drop(a.load(SeqCst, guard).into_owned()); } // avoid leak
/// loop {
/// match a.compare_and_set_weak(ptr, new, SeqCst, guard) {
/// Ok(p) => {
/// ptr = p;
/// break;
/// }
/// Err(err) => {
/// ptr = err.current;
/// new = err.new;
/// }
/// }
/// }
///
/// let mut curr = a.load(SeqCst, guard);
/// loop {
/// match a.compare_and_set_weak(curr, Shared::null(), SeqCst, guard) {
/// Ok(_) => break,
/// Err(err) => curr = err.current,
/// }
/// }
/// # unsafe { drop(curr.into_owned()); } // avoid leak
/// ```
// TODO: remove in the next major version.
#[allow(deprecated)]
#[deprecated(note = "Use `compare_exchange_weak` instead")]
pub fn compare_and_set_weak<'g, O, P>(
&self,
current: Shared<'_, T>,
new: P,
ord: O,
guard: &'g Guard,
) -> Result<Shared<'g, T>, CompareAndSetError<'g, T, P>>
where
O: CompareAndSetOrdering,
P: Pointer<T>,
{
self.compare_exchange_weak(current, new, ord.success(), ord.failure(), guard)
}

/// Bitwise "and" with the current tag.
///
/// Performs a bitwise "and" operation on the current tag and the argument `val`, and sets the
Expand Down
3 changes: 0 additions & 3 deletions crossbeam-epoch/src/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -155,9 +155,6 @@ cfg_if! {
};
pub use self::collector::{Collector, LocalHandle};
pub use self::guard::{unprotected, Guard};

#[allow(deprecated)]
pub use self::atomic::{CompareAndSetError, CompareAndSetOrdering};
}
}

Expand Down
28 changes: 0 additions & 28 deletions crossbeam-utils/src/atomic/atomic_cell.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -221,34 +221,6 @@ impl<T: Copy> AtomicCell<T> {
}

impl<T: Copy + Eq> AtomicCell<T> {
/// If the current value equals `current`, stores `new` into the atomic cell.
///
/// The return value is always the previous value. If it is equal to `current`, then the value
/// was updated.
///
/// # Examples
///
/// ```
/// # #![allow(deprecated)]
/// use crossbeam_utils::atomic::AtomicCell;
///
/// let a = AtomicCell::new(1);
///
/// assert_eq!(a.compare_and_swap(2, 3), 1);
/// assert_eq!(a.load(), 1);
///
/// assert_eq!(a.compare_and_swap(1, 2), 1);
/// assert_eq!(a.load(), 2);
/// ```
// TODO: remove in the next major version.
#[deprecated(note = "Use `compare_exchange` instead")]
pub fn compare_and_swap(&self, current: T, new: T) -> T {
match self.compare_exchange(current, new) {
Ok(v) => v,
Err(v) => v,
}
}

/// If the current value equals `current`, stores `new` into the atomic cell.
///
/// The return value is a result indicating whether the new value was written and containing
Expand Down

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