diff options
Diffstat (limited to 'libcore/sync/atomic.rs')
| -rw-r--r-- | libcore/sync/atomic.rs | 1125 |
1 files changed, 459 insertions, 666 deletions
diff --git a/libcore/sync/atomic.rs b/libcore/sync/atomic.rs index e74dc08..658b131 100644 --- a/libcore/sync/atomic.rs +++ b/libcore/sync/atomic.rs @@ -26,8 +26,9 @@ //! [1]: http://llvm.org/docs/LangRef.html#memory-model-for-concurrent-operations //! //! Atomic variables are safe to share between threads (they implement `Sync`) -//! but they do not themselves provide the mechanism for sharing. The most -//! common way to share an atomic variable is to put it into an `Arc` (an +//! but they do not themselves provide the mechanism for sharing and follow the +//! [threading model](../../../std/thread/index.html#the-threading-model) of rust. +//! The most common way to share an atomic variable is to put it into an `Arc` (an //! atomically-reference-counted shared pointer). //! //! Most atomic types may be stored in static variables, initialized using @@ -48,12 +49,16 @@ //! let spinlock = Arc::new(AtomicUsize::new(1)); //! //! let spinlock_clone = spinlock.clone(); -//! thread::spawn(move|| { +//! let thread = thread::spawn(move|| { //! spinlock_clone.store(0, Ordering::SeqCst); //! }); //! //! // Wait for the other thread to release the lock //! while spinlock.load(Ordering::SeqCst) != 0 {} +//! +//! if let Err(panic) = thread.join() { +//! println!("Thread had an error: {:?}", panic); +//! } //! } //! ``` //! @@ -83,62 +88,33 @@ use default::Default; use fmt; /// A boolean type which can be safely shared between threads. +#[cfg(target_has_atomic = "8")] #[stable(feature = "rust1", since = "1.0.0")] pub struct AtomicBool { - v: UnsafeCell<usize>, + v: UnsafeCell<u8>, } +#[cfg(target_has_atomic = "8")] #[stable(feature = "rust1", since = "1.0.0")] impl Default for AtomicBool { fn default() -> Self { - Self::new(Default::default()) + Self::new(false) } } // Send is implicitly implemented for AtomicBool. +#[cfg(target_has_atomic = "8")] #[stable(feature = "rust1", since = "1.0.0")] unsafe impl Sync for AtomicBool {} -/// A signed integer type which can be safely shared between threads. -#[stable(feature = "rust1", since = "1.0.0")] -pub struct AtomicIsize { - v: UnsafeCell<isize>, -} - -#[stable(feature = "rust1", since = "1.0.0")] -impl Default for AtomicIsize { - fn default() -> Self { - Self::new(Default::default()) - } -} - -// Send is implicitly implemented for AtomicIsize. -#[stable(feature = "rust1", since = "1.0.0")] -unsafe impl Sync for AtomicIsize {} - -/// An unsigned integer type which can be safely shared between threads. -#[stable(feature = "rust1", since = "1.0.0")] -pub struct AtomicUsize { - v: UnsafeCell<usize>, -} - -#[stable(feature = "rust1", since = "1.0.0")] -impl Default for AtomicUsize { - fn default() -> Self { - Self::new(Default::default()) - } -} - -// Send is implicitly implemented for AtomicUsize. -#[stable(feature = "rust1", since = "1.0.0")] -unsafe impl Sync for AtomicUsize {} - /// A raw pointer type which can be safely shared between threads. +#[cfg(target_has_atomic = "ptr")] #[stable(feature = "rust1", since = "1.0.0")] pub struct AtomicPtr<T> { p: UnsafeCell<*mut T>, } +#[cfg(target_has_atomic = "ptr")] #[stable(feature = "rust1", since = "1.0.0")] impl<T> Default for AtomicPtr<T> { fn default() -> AtomicPtr<T> { @@ -146,8 +122,10 @@ impl<T> Default for AtomicPtr<T> { } } +#[cfg(target_has_atomic = "ptr")] #[stable(feature = "rust1", since = "1.0.0")] unsafe impl<T> Send for AtomicPtr<T> {} +#[cfg(target_has_atomic = "ptr")] #[stable(feature = "rust1", since = "1.0.0")] unsafe impl<T> Sync for AtomicPtr<T> {} @@ -169,13 +147,13 @@ pub enum Ordering { #[stable(feature = "rust1", since = "1.0.0")] Relaxed, /// When coupled with a store, all previous writes become visible - /// to another thread that performs a load with `Acquire` ordering + /// to the other threads that perform a load with `Acquire` ordering /// on the same value. #[stable(feature = "rust1", since = "1.0.0")] Release, /// When coupled with a load, all subsequent loads will see data /// written before a store with `Release` ordering on the same value - /// in another thread. + /// in other threads. #[stable(feature = "rust1", since = "1.0.0")] Acquire, /// When coupled with a load, uses `Acquire` ordering, and with a store @@ -189,18 +167,11 @@ pub enum Ordering { } /// An `AtomicBool` initialized to `false`. +#[cfg(target_has_atomic = "8")] #[stable(feature = "rust1", since = "1.0.0")] pub const ATOMIC_BOOL_INIT: AtomicBool = AtomicBool::new(false); -/// An `AtomicIsize` initialized to `0`. -#[stable(feature = "rust1", since = "1.0.0")] -pub const ATOMIC_ISIZE_INIT: AtomicIsize = AtomicIsize::new(0); -/// An `AtomicUsize` initialized to `0`. -#[stable(feature = "rust1", since = "1.0.0")] -pub const ATOMIC_USIZE_INIT: AtomicUsize = AtomicUsize::new(0); - -// NB: Needs to be -1 (0b11111111...) to make fetch_nand work correctly -const UINT_TRUE: usize = !0; +#[cfg(target_has_atomic = "8")] impl AtomicBool { /// Creates a new `AtomicBool`. /// @@ -215,7 +186,7 @@ impl AtomicBool { #[inline] #[stable(feature = "rust1", since = "1.0.0")] pub const fn new(v: bool) -> AtomicBool { - AtomicBool { v: UnsafeCell::new(-(v as isize) as usize) } + AtomicBool { v: UnsafeCell::new(v as u8) } } /// Loads a value from the bool. @@ -238,7 +209,7 @@ impl AtomicBool { #[inline] #[stable(feature = "rust1", since = "1.0.0")] pub fn load(&self, order: Ordering) -> bool { - unsafe { atomic_load(self.v.get(), order) > 0 } + unsafe { atomic_load(self.v.get(), order) != 0 } } /// Stores a value into the bool. @@ -262,9 +233,7 @@ impl AtomicBool { #[inline] #[stable(feature = "rust1", since = "1.0.0")] pub fn store(&self, val: bool, order: Ordering) { - let val = if val { UINT_TRUE } else { 0 }; - - unsafe { atomic_store(self.v.get(), val, order); } + unsafe { atomic_store(self.v.get(), val as u8, order); } } /// Stores a value into the bool, returning the old value. @@ -284,9 +253,7 @@ impl AtomicBool { #[inline] #[stable(feature = "rust1", since = "1.0.0")] pub fn swap(&self, val: bool, order: Ordering) -> bool { - let val = if val { UINT_TRUE } else { 0 }; - - unsafe { atomic_swap(self.v.get(), val, order) > 0 } + unsafe { atomic_swap(self.v.get(), val as u8, order) != 0 } } /// Stores a value into the `bool` if the current value is the same as the `current` value. @@ -332,7 +299,6 @@ impl AtomicBool { /// # Examples /// /// ``` - /// # #![feature(extended_compare_and_swap)] /// use std::sync::atomic::{AtomicBool, Ordering}; /// /// let some_bool = AtomicBool::new(true); @@ -351,18 +317,16 @@ impl AtomicBool { /// assert_eq!(some_bool.load(Ordering::Relaxed), false); /// ``` #[inline] - #[unstable(feature = "extended_compare_and_swap", reason = "recently added", issue = "31767")] + #[stable(feature = "extended_compare_and_swap", since = "1.10.0")] pub fn compare_exchange(&self, current: bool, new: bool, success: Ordering, failure: Ordering) -> Result<bool, bool> { - let current = if current { UINT_TRUE } else { 0 }; - let new = if new { UINT_TRUE } else { 0 }; - - match unsafe { atomic_compare_exchange(self.v.get(), current, new, success, failure) } { - Ok(x) => Ok(x > 0), - Err(x) => Err(x > 0), + match unsafe { atomic_compare_exchange(self.v.get(), current as u8, new as u8, + success, failure) } { + Ok(x) => Ok(x != 0), + Err(x) => Err(x != 0), } } @@ -382,7 +346,6 @@ impl AtomicBool { /// # Examples /// /// ``` - /// # #![feature(extended_compare_and_swap)] /// use std::sync::atomic::{AtomicBool, Ordering}; /// /// let val = AtomicBool::new(false); @@ -397,19 +360,16 @@ impl AtomicBool { /// } /// ``` #[inline] - #[unstable(feature = "extended_compare_and_swap", reason = "recently added", issue = "31767")] + #[stable(feature = "extended_compare_and_swap", since = "1.10.0")] pub fn compare_exchange_weak(&self, current: bool, new: bool, success: Ordering, failure: Ordering) -> Result<bool, bool> { - let current = if current { UINT_TRUE } else { 0 }; - let new = if new { UINT_TRUE } else { 0 }; - - match unsafe { atomic_compare_exchange_weak(self.v.get(), current, new, + match unsafe { atomic_compare_exchange_weak(self.v.get(), current as u8, new as u8, success, failure) } { - Ok(x) => Ok(x > 0), - Err(x) => Err(x > 0), + Ok(x) => Ok(x != 0), + Err(x) => Err(x != 0), } } @@ -440,9 +400,7 @@ impl AtomicBool { #[inline] #[stable(feature = "rust1", since = "1.0.0")] pub fn fetch_and(&self, val: bool, order: Ordering) -> bool { - let val = if val { UINT_TRUE } else { 0 }; - - unsafe { atomic_and(self.v.get(), val, order) > 0 } + unsafe { atomic_and(self.v.get(), val as u8, order) != 0 } } /// Logical "nand" with a boolean value. @@ -473,9 +431,20 @@ impl AtomicBool { #[inline] #[stable(feature = "rust1", since = "1.0.0")] pub fn fetch_nand(&self, val: bool, order: Ordering) -> bool { - let val = if val { UINT_TRUE } else { 0 }; - - unsafe { atomic_nand(self.v.get(), val, order) > 0 } + // We can't use atomic_nand here because it can result in a bool with + // an invalid value. This happens because the atomic operation is done + // with an 8-bit integer internally, which would set the upper 7 bits. + // So we just use a compare-exchange loop instead, which is what the + // intrinsic actually expands to anyways on many platforms. + let mut old = self.load(Relaxed); + loop { + let new = !(old && val); + match self.compare_exchange_weak(old, new, order, Relaxed) { + Ok(_) => break, + Err(x) => old = x, + } + } + old } /// Logical "or" with a boolean value. @@ -505,9 +474,7 @@ impl AtomicBool { #[inline] #[stable(feature = "rust1", since = "1.0.0")] pub fn fetch_or(&self, val: bool, order: Ordering) -> bool { - let val = if val { UINT_TRUE } else { 0 }; - - unsafe { atomic_or(self.v.get(), val, order) > 0 } + unsafe { atomic_or(self.v.get(), val as u8, order) != 0 } } /// Logical "xor" with a boolean value. @@ -537,563 +504,11 @@ impl AtomicBool { #[inline] #[stable(feature = "rust1", since = "1.0.0")] pub fn fetch_xor(&self, val: bool, order: Ordering) -> bool { - let val = if val { UINT_TRUE } else { 0 }; - - unsafe { atomic_xor(self.v.get(), val, order) > 0 } - } -} - -impl AtomicIsize { - /// Creates a new `AtomicIsize`. - /// - /// # Examples - /// - /// ``` - /// use std::sync::atomic::AtomicIsize; - /// - /// let atomic_forty_two = AtomicIsize::new(42); - /// ``` - #[inline] - #[stable(feature = "rust1", since = "1.0.0")] - pub const fn new(v: isize) -> AtomicIsize { - AtomicIsize {v: UnsafeCell::new(v)} - } - - /// Loads a value from the isize. - /// - /// `load` takes an `Ordering` argument which describes the memory ordering of this operation. - /// - /// # Panics - /// - /// Panics if `order` is `Release` or `AcqRel`. - /// - /// # Examples - /// - /// ``` - /// use std::sync::atomic::{AtomicIsize, Ordering}; - /// - /// let some_isize = AtomicIsize::new(5); - /// - /// assert_eq!(some_isize.load(Ordering::Relaxed), 5); - /// ``` - #[inline] - #[stable(feature = "rust1", since = "1.0.0")] - pub fn load(&self, order: Ordering) -> isize { - unsafe { atomic_load(self.v.get(), order) } - } - - /// Stores a value into the isize. - /// - /// `store` takes an `Ordering` argument which describes the memory ordering of this operation. - /// - /// # Examples - /// - /// ``` - /// use std::sync::atomic::{AtomicIsize, Ordering}; - /// - /// let some_isize = AtomicIsize::new(5); - /// - /// some_isize.store(10, Ordering::Relaxed); - /// assert_eq!(some_isize.load(Ordering::Relaxed), 10); - /// ``` - /// - /// # Panics - /// - /// Panics if `order` is `Acquire` or `AcqRel`. - #[inline] - #[stable(feature = "rust1", since = "1.0.0")] - pub fn store(&self, val: isize, order: Ordering) { - unsafe { atomic_store(self.v.get(), val, order); } - } - - /// Stores a value into the isize, returning the old value. - /// - /// `swap` takes an `Ordering` argument which describes the memory ordering of this operation. - /// - /// # Examples - /// - /// ``` - /// use std::sync::atomic::{AtomicIsize, Ordering}; - /// - /// let some_isize = AtomicIsize::new(5); - /// - /// assert_eq!(some_isize.swap(10, Ordering::Relaxed), 5); - /// ``` - #[inline] - #[stable(feature = "rust1", since = "1.0.0")] - pub fn swap(&self, val: isize, order: Ordering) -> isize { - unsafe { atomic_swap(self.v.get(), val, order) } - } - - /// Stores a value into the `isize` if the current value is the same as the `current` value. - /// - /// The return value is always the previous value. If it is equal to `current`, then the value - /// was updated. - /// - /// `compare_and_swap` also takes an `Ordering` argument which describes the memory ordering of - /// this operation. - /// - /// # Examples - /// - /// ``` - /// use std::sync::atomic::{AtomicIsize, Ordering}; - /// - /// let some_isize = AtomicIsize::new(5); - /// - /// assert_eq!(some_isize.compare_and_swap(5, 10, Ordering::Relaxed), 5); - /// assert_eq!(some_isize.load(Ordering::Relaxed), 10); - /// - /// assert_eq!(some_isize.compare_and_swap(6, 12, Ordering::Relaxed), 10); - /// assert_eq!(some_isize.load(Ordering::Relaxed), 10); - /// ``` - #[inline] - #[stable(feature = "rust1", since = "1.0.0")] - pub fn compare_and_swap(&self, current: isize, new: isize, order: Ordering) -> isize { - match self.compare_exchange(current, new, order, strongest_failure_ordering(order)) { - Ok(x) => x, - Err(x) => x, - } - } - - /// Stores a value into the `isize` if the current value is the same as the `current` value. - /// - /// The return value is a result indicating whether the new value was written and containing - /// the previous value. On success this value is guaranteed to be equal to `new`. - /// - /// `compare_exchange` takes two `Ordering` arguments to describe the memory ordering of this - /// operation. The first describes the required ordering if the operation succeeds while the - /// second describes the required ordering when the operation fails. The failure ordering can't - /// be `Release` or `AcqRel` and must be equivalent or weaker than the success ordering. - /// - /// # Examples - /// - /// ``` - /// # #![feature(extended_compare_and_swap)] - /// use std::sync::atomic::{AtomicIsize, Ordering}; - /// - /// let some_isize = AtomicIsize::new(5); - /// - /// assert_eq!(some_isize.compare_exchange(5, 10, - /// Ordering::Acquire, - /// Ordering::Relaxed), - /// Ok(5)); - /// assert_eq!(some_isize.load(Ordering::Relaxed), 10); - /// - /// assert_eq!(some_isize.compare_exchange(6, 12, - /// Ordering::SeqCst, - /// Ordering::Acquire), - /// Err(10)); - /// assert_eq!(some_isize.load(Ordering::Relaxed), 10); - /// ``` - #[inline] - #[unstable(feature = "extended_compare_and_swap", reason = "recently added", issue = "31767")] - pub fn compare_exchange(&self, - current: isize, - new: isize, - success: Ordering, - failure: Ordering) -> Result<isize, isize> { - unsafe { atomic_compare_exchange(self.v.get(), current, new, success, failure) } - } - - /// Stores a value into the `isize` if the current value is the same as the `current` value. - /// - /// Unlike `compare_exchange`, this function is allowed to spuriously fail even when the - /// comparison succeeds, which can result in more efficient code on some platforms. The - /// return value is a result indicating whether the new value was written and containing the - /// previous value. - /// - /// `compare_exchange_weak` takes two `Ordering` arguments to describe the memory - /// ordering of this operation. The first describes the required ordering if the operation - /// succeeds while the second describes the required ordering when the operation fails. The - /// failure ordering can't be `Release` or `AcqRel` and must be equivalent or weaker than the - /// success ordering. - /// - /// # Examples - /// - /// ``` - /// # #![feature(extended_compare_and_swap)] - /// use std::sync::atomic::{AtomicIsize, Ordering}; - /// - /// let val = AtomicIsize::new(4); - /// - /// let mut old = val.load(Ordering::Relaxed); - /// loop { - /// let new = old * 2; - /// match val.compare_exchange_weak(old, new, Ordering::SeqCst, Ordering::Relaxed) { - /// Ok(_) => break, - /// Err(x) => old = x, - /// } - /// } - /// ``` - #[inline] - #[unstable(feature = "extended_compare_and_swap", reason = "recently added", issue = "31767")] - pub fn compare_exchange_weak(&self, - current: isize, - new: isize, - success: Ordering, - failure: Ordering) -> Result<isize, isize> { - unsafe { atomic_compare_exchange_weak(self.v.get(), current, new, success, failure) } - } - - /// Add an isize to the current value, returning the previous value. - /// - /// # Examples - /// - /// ``` - /// use std::sync::atomic::{AtomicIsize, Ordering}; - /// - /// let foo = AtomicIsize::new(0); - /// assert_eq!(foo.fetch_add(10, Ordering::SeqCst), 0); - /// assert_eq!(foo.load(Ordering::SeqCst), 10); - /// ``` - #[inline] - #[stable(feature = "rust1", since = "1.0.0")] - pub fn fetch_add(&self, val: isize, order: Ordering) -> isize { - unsafe { atomic_add(self.v.get(), val, order) } - } - - /// Subtract an isize from the current value, returning the previous value. - /// - /// # Examples - /// - /// ``` - /// use std::sync::atomic::{AtomicIsize, Ordering}; - /// - /// let foo = AtomicIsize::new(0); - /// assert_eq!(foo.fetch_sub(10, Ordering::SeqCst), 0); - /// assert_eq!(foo.load(Ordering::SeqCst), -10); - /// ``` - #[inline] - #[stable(feature = "rust1", since = "1.0.0")] - pub fn fetch_sub(&self, val: isize, order: Ordering) -> isize { - unsafe { atomic_sub(self.v.get(), val, order) } - } - - /// Bitwise and with the current isize, returning the previous value. - /// - /// # Examples - /// - /// ``` - /// use std::sync::atomic::{AtomicIsize, Ordering}; - /// - /// let foo = AtomicIsize::new(0b101101); - /// assert_eq!(foo.fetch_and(0b110011, Ordering::SeqCst), 0b101101); - /// assert_eq!(foo.load(Ordering::SeqCst), 0b100001); - #[inline] - #[stable(feature = "rust1", since = "1.0.0")] - pub fn fetch_and(&self, val: isize, order: Ordering) -> isize { - unsafe { atomic_and(self.v.get(), val, order) } - } - - /// Bitwise or with the current isize, returning the previous value. - /// - /// # Examples - /// - /// ``` - /// use std::sync::atomic::{AtomicIsize, Ordering}; - /// - /// let foo = AtomicIsize::new(0b101101); - /// assert_eq!(foo.fetch_or(0b110011, Ordering::SeqCst), 0b101101); - /// assert_eq!(foo.load(Ordering::SeqCst), 0b111111); - #[inline] - #[stable(feature = "rust1", since = "1.0.0")] - pub fn fetch_or(&self, val: isize, order: Ordering) -> isize { - unsafe { atomic_or(self.v.get(), val, order) } - } - - /// Bitwise xor with the current isize, returning the previous value. - /// - /// # Examples - /// - /// ``` - /// use std::sync::atomic::{AtomicIsize, Ordering}; - /// - /// let foo = AtomicIsize::new(0b101101); - /// assert_eq!(foo.fetch_xor(0b110011, Ordering::SeqCst), 0b101101); - /// assert_eq!(foo.load(Ordering::SeqCst), 0b011110); - #[inline] - #[stable(feature = "rust1", since = "1.0.0")] - pub fn fetch_xor(&self, val: isize, order: Ordering) -> isize { - unsafe { atomic_xor(self.v.get(), val, order) } - } -} - -impl AtomicUsize { - /// Creates a new `AtomicUsize`. - /// - /// # Examples - /// - /// ``` - /// use std::sync::atomic::AtomicUsize; - /// - /// let atomic_forty_two = AtomicUsize::new(42); - /// ``` - #[inline] - #[stable(feature = "rust1", since = "1.0.0")] - pub const fn new(v: usize) -> AtomicUsize { - AtomicUsize { v: UnsafeCell::new(v) } - } - - /// Loads a value from the usize. - /// - /// `load` takes an `Ordering` argument which describes the memory ordering of this operation. - /// - /// # Panics - /// - /// Panics if `order` is `Release` or `AcqRel`. - /// - /// # Examples - /// - /// ``` - /// use std::sync::atomic::{AtomicUsize, Ordering}; - /// - /// let some_usize = AtomicUsize::new(5); - /// - /// assert_eq!(some_usize.load(Ordering::Relaxed), 5); - /// ``` - #[inline] - #[stable(feature = "rust1", since = "1.0.0")] - pub fn load(&self, order: Ordering) -> usize { - unsafe { atomic_load(self.v.get(), order) } - } - - /// Stores a value into the usize. - /// - /// `store` takes an `Ordering` argument which describes the memory ordering of this operation. - /// - /// # Examples - /// - /// ``` - /// use std::sync::atomic::{AtomicUsize, Ordering}; - /// - /// let some_usize = AtomicUsize::new(5); - /// - /// some_usize.store(10, Ordering::Relaxed); - /// assert_eq!(some_usize.load(Ordering::Relaxed), 10); - /// ``` - /// - /// # Panics - /// - /// Panics if `order` is `Acquire` or `AcqRel`. - #[inline] - #[stable(feature = "rust1", since = "1.0.0")] - pub fn store(&self, val: usize, order: Ordering) { - unsafe { atomic_store(self.v.get(), val, order); } - } - - /// Stores a value into the usize, returning the old value. - /// - /// `swap` takes an `Ordering` argument which describes the memory ordering of this operation. - /// - /// # Examples - /// - /// ``` - /// use std::sync::atomic::{AtomicUsize, Ordering}; - /// - /// let some_usize = AtomicUsize::new(5); - /// - /// assert_eq!(some_usize.swap(10, Ordering::Relaxed), 5); - /// assert_eq!(some_usize.load(Ordering::Relaxed), 10); - /// ``` - #[inline] - #[stable(feature = "rust1", since = "1.0.0")] - pub fn swap(&self, val: usize, order: Ordering) -> usize { - unsafe { atomic_swap(self.v.get(), val, order) } - } - - /// Stores a value into the `usize` if the current value is the same as the `current` value. - /// - /// The return value is always the previous value. If it is equal to `current`, then the value - /// was updated. - /// - /// `compare_and_swap` also takes an `Ordering` argument which describes the memory ordering of - /// this operation. - /// - /// # Examples - /// - /// ``` - /// use std::sync::atomic::{AtomicUsize, Ordering}; - /// - /// let some_usize = AtomicUsize::new(5); - /// - /// assert_eq!(some_usize.compare_and_swap(5, 10, Ordering::Relaxed), 5); - /// assert_eq!(some_usize.load(Ordering::Relaxed), 10); - /// - /// assert_eq!(some_usize.compare_and_swap(6, 12, Ordering::Relaxed), 10); - /// assert_eq!(some_usize.load(Ordering::Relaxed), 10); - /// ``` - #[inline] - #[stable(feature = "rust1", since = "1.0.0")] - pub fn compare_and_swap(&self, current: usize, new: usize, order: Ordering) -> usize { - match self.compare_exchange(current, new, order, strongest_failure_ordering(order)) { - Ok(x) => x, - Err(x) => x, - } - } - - /// Stores a value into the `usize` if the current value is the same as the `current` value. - /// - /// The return value is a result indicating whether the new value was written and containing - /// the previous value. On success this value is guaranteed to be equal to `new`. - /// - /// `compare_exchange` takes two `Ordering` arguments to describe the memory ordering of this - /// operation. The first describes the required ordering if the operation succeeds while the - /// second describes the required ordering when the operation fails. The failure ordering can't - /// be `Release` or `AcqRel` and must be equivalent or weaker than the success ordering. - /// - /// # Examples - /// - /// ``` - /// # #![feature(extended_compare_and_swap)] - /// use std::sync::atomic::{AtomicUsize, Ordering}; - /// - /// let some_isize = AtomicUsize::new(5); - /// - /// assert_eq!(some_isize.compare_exchange(5, 10, - /// Ordering::Acquire, - /// Ordering::Relaxed), - /// Ok(5)); - /// assert_eq!(some_isize.load(Ordering::Relaxed), 10); - /// - /// assert_eq!(some_isize.compare_exchange(6, 12, - /// Ordering::SeqCst, - /// Ordering::Acquire), - /// Err(10)); - /// assert_eq!(some_isize.load(Ordering::Relaxed), 10); - /// ``` - #[inline] - #[unstable(feature = "extended_compare_and_swap", reason = "recently added", issue = "31767")] - pub fn compare_exchange(&self, - current: usize, - new: usize, - success: Ordering, - failure: Ordering) -> Result<usize, usize> { - unsafe { atomic_compare_exchange(self.v.get(), current, new, success, failure) } - } - - /// Stores a value into the `usize` if the current value is the same as the `current` value. - /// - /// Unlike `compare_exchange`, this function is allowed to spuriously fail even when the - /// comparison succeeds, which can result in more efficient code on some platforms. The - /// return value is a result indicating whether the new value was written and containing the - /// previous value. - /// - /// `compare_exchange_weak` takes two `Ordering` arguments to describe the memory - /// ordering of this operation. The first describes the required ordering if the operation - /// succeeds while the second describes the required ordering when the operation fails. The - /// failure ordering can't be `Release` or `AcqRel` and must be equivalent or weaker than the - /// success ordering. - /// - /// # Examples - /// - /// ``` - /// # #![feature(extended_compare_and_swap)] - /// use std::sync::atomic::{AtomicUsize, Ordering}; - /// - /// let val = AtomicUsize::new(4); - /// - /// let mut old = val.load(Ordering::Relaxed); - /// loop { - /// let new = old * 2; - /// match val.compare_exchange_weak(old, new, Ordering::SeqCst, Ordering::Relaxed) { - /// Ok(_) => break, - /// Err(x) => old = x, - /// } - /// } - /// ``` - #[inline] - #[unstable(feature = "extended_compare_and_swap", reason = "recently added", issue = "31767")] - pub fn compare_exchange_weak(&self, - current: usize, - new: usize, - success: Ordering, - failure: Ordering) -> Result<usize, usize> { - unsafe { atomic_compare_exchange_weak(self.v.get(), current, new, success, failure) } - } - - /// Add to the current usize, returning the previous value. - /// - /// # Examples - /// - /// ``` - /// use std::sync::atomic::{AtomicUsize, Ordering}; - /// - /// let foo = AtomicUsize::new(0); - /// assert_eq!(foo.fetch_add(10, Ordering::SeqCst), 0); - /// assert_eq!(foo.load(Ordering::SeqCst), 10); - /// ``` - #[inline] - #[stable(feature = "rust1", since = "1.0.0")] - pub fn fetch_add(&self, val: usize, order: Ordering) -> usize { - unsafe { atomic_add(self.v.get(), val, order) } - } - - /// Subtract from the current usize, returning the previous value. - /// - /// # Examples - /// - /// ``` - /// use std::sync::atomic::{AtomicUsize, Ordering}; - /// - /// let foo = AtomicUsize::new(10); - /// assert_eq!(foo.fetch_sub(10, Ordering::SeqCst), 10); - /// assert_eq!(foo.load(Ordering::SeqCst), 0); - /// ``` - #[inline] - #[stable(feature = "rust1", since = "1.0.0")] - pub fn fetch_sub(&self, val: usize, order: Ordering) -> usize { - unsafe { atomic_sub(self.v.get(), val, order) } - } - - /// Bitwise and with the current usize, returning the previous value. - /// - /// # Examples - /// - /// ``` - /// use std::sync::atomic::{AtomicUsize, Ordering}; - /// - /// let foo = AtomicUsize::new(0b101101); - /// assert_eq!(foo.fetch_and(0b110011, Ordering::SeqCst), 0b101101); - /// assert_eq!(foo.load(Ordering::SeqCst), 0b100001); - #[inline] - #[stable(feature = "rust1", since = "1.0.0")] - pub fn fetch_and(&self, val: usize, order: Ordering) -> usize { - unsafe { atomic_and(self.v.get(), val, order) } - } - - /// Bitwise or with the current usize, returning the previous value. - /// - /// # Examples - /// - /// ``` - /// use std::sync::atomic::{AtomicUsize, Ordering}; - /// - /// let foo = AtomicUsize::new(0b101101); - /// assert_eq!(foo.fetch_or(0b110011, Ordering::SeqCst), 0b101101); - /// assert_eq!(foo.load(Ordering::SeqCst), 0b111111); - #[inline] - #[stable(feature = "rust1", since = "1.0.0")] - pub fn fetch_or(&self, val: usize, order: Ordering) -> usize { - unsafe { atomic_or(self.v.get(), val, order) } - } - - /// Bitwise xor with the current usize, returning the previous value. - /// - /// # Examples - /// - /// ``` - /// use std::sync::atomic::{AtomicUsize, Ordering}; - /// - /// let foo = AtomicUsize::new(0b101101); - /// assert_eq!(foo.fetch_xor(0b110011, Ordering::SeqCst), 0b101101); - /// assert_eq!(foo.load(Ordering::SeqCst), 0b011110); - #[inline] - #[stable(feature = "rust1", since = "1.0.0")] - pub fn fetch_xor(&self, val: usize, order: Ordering) -> usize { - unsafe { atomic_xor(self.v.get(), val, order) } + unsafe { atomic_xor(self.v.get(), val as u8, order) != 0 } } } +#[cfg(target_has_atomic = "ptr")] impl<T> AtomicPtr<T> { /// Creates a new `AtomicPtr`. /// @@ -1228,7 +643,6 @@ impl<T> AtomicPtr<T> { /// # Examples /// /// ``` - /// # #![feature(extended_compare_and_swap)] /// use std::sync::atomic::{AtomicPtr, Ordering}; /// /// let ptr = &mut 5; @@ -1241,7 +655,7 @@ impl<T> AtomicPtr<T> { /// Ordering::SeqCst, Ordering::Relaxed); /// ``` #[inline] - #[unstable(feature = "extended_compare_and_swap", reason = "recently added", issue = "31767")] + #[stable(feature = "extended_compare_and_swap", since = "1.10.0")] pub fn compare_exchange(&self, current: *mut T, new: *mut T, @@ -1276,7 +690,6 @@ impl<T> AtomicPtr<T> { /// # Examples /// /// ``` - /// # #![feature(extended_compare_and_swap)] /// use std::sync::atomic::{AtomicPtr, Ordering}; /// /// let some_ptr = AtomicPtr::new(&mut 5); @@ -1291,7 +704,7 @@ impl<T> AtomicPtr<T> { /// } /// ``` #[inline] - #[unstable(feature = "extended_compare_and_swap", reason = "recently added", issue = "31767")] + #[stable(feature = "extended_compare_and_swap", since = "1.10.0")] pub fn compare_exchange_weak(&self, current: *mut T, new: *mut T, @@ -1311,6 +724,403 @@ impl<T> AtomicPtr<T> { } } +macro_rules! atomic_int { + ($stable:meta, + $stable_cxchg:meta, + $stable_debug:meta, + $int_type:ident $atomic_type:ident $atomic_init:ident) => { + /// An integer type which can be safely shared between threads. + #[$stable] + pub struct $atomic_type { + v: UnsafeCell<$int_type>, + } + + /// An atomic integer initialized to `0`. + #[$stable] + pub const $atomic_init: $atomic_type = $atomic_type::new(0); + + #[$stable] + impl Default for $atomic_type { + fn default() -> Self { + Self::new(Default::default()) + } + } + + #[$stable_debug] + impl fmt::Debug for $atomic_type { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + f.debug_tuple(stringify!($atomic_type)) + .field(&self.load(Ordering::SeqCst)) + .finish() + } + } + + // Send is implicitly implemented. + #[$stable] + unsafe impl Sync for $atomic_type {} + + impl $atomic_type { + /// Creates a new atomic integer. + /// + /// # Examples + /// + /// ``` + /// use std::sync::atomic::AtomicIsize; + /// + /// let atomic_forty_two = AtomicIsize::new(42); + /// ``` + #[inline] + #[$stable] + pub const fn new(v: $int_type) -> Self { + $atomic_type {v: UnsafeCell::new(v)} + } + + /// Loads a value from the atomic integer. + /// + /// `load` takes an `Ordering` argument which describes the memory ordering of this + /// operation. + /// + /// # Panics + /// + /// Panics if `order` is `Release` or `AcqRel`. + /// + /// # Examples + /// + /// ``` + /// use std::sync::atomic::{AtomicIsize, Ordering}; + /// + /// let some_isize = AtomicIsize::new(5); + /// + /// assert_eq!(some_isize.load(Ordering::Relaxed), 5); + /// ``` + #[inline] + #[$stable] + pub fn load(&self, order: Ordering) -> $int_type { + unsafe { atomic_load(self.v.get(), order) } + } + + /// Stores a value into the atomic integer. + /// + /// `store` takes an `Ordering` argument which describes the memory ordering of this + /// operation. + /// + /// # Examples + /// + /// ``` + /// use std::sync::atomic::{AtomicIsize, Ordering}; + /// + /// let some_isize = AtomicIsize::new(5); + /// + /// some_isize.store(10, Ordering::Relaxed); + /// assert_eq!(some_isize.load(Ordering::Relaxed), 10); + /// ``` + /// + /// # Panics + /// + /// Panics if `order` is `Acquire` or `AcqRel`. + #[inline] + #[$stable] + pub fn store(&self, val: $int_type, order: Ordering) { + unsafe { atomic_store(self.v.get(), val, order); } + } + + /// Stores a value into the atomic integer, returning the old value. + /// + /// `swap` takes an `Ordering` argument which describes the memory ordering of this + /// operation. + /// + /// # Examples + /// + /// ``` + /// use std::sync::atomic::{AtomicIsize, Ordering}; + /// + /// let some_isize = AtomicIsize::new(5); + /// + /// assert_eq!(some_isize.swap(10, Ordering::Relaxed), 5); + /// ``` + #[inline] + #[$stable] + pub fn swap(&self, val: $int_type, order: Ordering) -> $int_type { + unsafe { atomic_swap(self.v.get(), val, order) } + } + + /// Stores a value into the atomic integer if the current value is the same as the + /// `current` value. + /// + /// The return value is always the previous value. If it is equal to `current`, then the + /// value was updated. + /// + /// `compare_and_swap` also takes an `Ordering` argument which describes the memory + /// ordering of this operation. + /// + /// # Examples + /// + /// ``` + /// use std::sync::atomic::{AtomicIsize, Ordering}; + /// + /// let some_isize = AtomicIsize::new(5); + /// + /// assert_eq!(some_isize.compare_and_swap(5, 10, Ordering::Relaxed), 5); + /// assert_eq!(some_isize.load(Ordering::Relaxed), 10); + /// + /// assert_eq!(some_isize.compare_and_swap(6, 12, Ordering::Relaxed), 10); + /// assert_eq!(some_isize.load(Ordering::Relaxed), 10); + /// ``` + #[inline] + #[$stable] + pub fn compare_and_swap(&self, + current: $int_type, + new: $int_type, + order: Ordering) -> $int_type { + match self.compare_exchange(current, + new, + order, + strongest_failure_ordering(order)) { + Ok(x) => x, + Err(x) => x, + } + } + + /// Stores a value into the atomic integer if the current value is the same as the + /// `current` value. + /// + /// The return value is a result indicating whether the new value was written and + /// containing the previous value. On success this value is guaranteed to be equal to + /// `new`. + /// + /// `compare_exchange` takes two `Ordering` arguments to describe the memory ordering of + /// this operation. The first describes the required ordering if the operation succeeds + /// while the second describes the required ordering when the operation fails. The + /// failure ordering can't be `Release` or `AcqRel` and must be equivalent or weaker + /// than the success ordering. + /// + /// # Examples + /// + /// ``` + /// use std::sync::atomic::{AtomicIsize, Ordering}; + /// + /// let some_isize = AtomicIsize::new(5); + /// + /// assert_eq!(some_isize.compare_exchange(5, 10, + /// Ordering::Acquire, + /// Ordering::Relaxed), + /// Ok(5)); + /// assert_eq!(some_isize.load(Ordering::Relaxed), 10); + /// + /// assert_eq!(some_isize.compare_exchange(6, 12, + /// Ordering::SeqCst, + /// Ordering::Acquire), + /// Err(10)); + /// assert_eq!(some_isize.load(Ordering::Relaxed), 10); + /// ``` + #[inline] + #[$stable_cxchg] + pub fn compare_exchange(&self, + current: $int_type, + new: $int_type, + success: Ordering, + failure: Ordering) -> Result<$int_type, $int_type> { + unsafe { atomic_compare_exchange(self.v.get(), current, new, success, failure) } + } + + /// Stores a value into the atomic integer if the current value is the same as the + /// `current` value. + /// + /// Unlike `compare_exchange`, this function is allowed to spuriously fail even when the + /// comparison succeeds, which can result in more efficient code on some platforms. The + /// return value is a result indicating whether the new value was written and containing + /// the previous value. + /// + /// `compare_exchange_weak` takes two `Ordering` arguments to describe the memory + /// ordering of this operation. The first describes the required ordering if the + /// operation succeeds while the second describes the required ordering when the + /// operation fails. The failure ordering can't be `Release` or `AcqRel` and must be + /// equivalent or weaker than the success ordering. + /// + /// # Examples + /// + /// ``` + /// use std::sync::atomic::{AtomicIsize, Ordering}; + /// + /// let val = AtomicIsize::new(4); + /// + /// let mut old = val.load(Ordering::Relaxed); + /// loop { + /// let new = old * 2; + /// match val.compare_exchange_weak(old, new, Ordering::SeqCst, Ordering::Relaxed) { + /// Ok(_) => break, + /// Err(x) => old = x, + /// } + /// } + /// ``` + #[inline] + #[$stable_cxchg] + pub fn compare_exchange_weak(&self, + current: $int_type, + new: $int_type, + success: Ordering, + failure: Ordering) -> Result<$int_type, $int_type> { + unsafe { + atomic_compare_exchange_weak(self.v.get(), current, new, success, failure) + } + } + + /// Add to the current value, returning the previous value. + /// + /// # Examples + /// + /// ``` + /// use std::sync::atomic::{AtomicIsize, Ordering}; + /// + /// let foo = AtomicIsize::new(0); + /// assert_eq!(foo.fetch_add(10, Ordering::SeqCst), 0); + /// assert_eq!(foo.load(Ordering::SeqCst), 10); + /// ``` + #[inline] + #[$stable] + pub fn fetch_add(&self, val: $int_type, order: Ordering) -> $int_type { + unsafe { atomic_add(self.v.get(), val, order) } + } + + /// Subtract from the current value, returning the previous value. + /// + /// # Examples + /// + /// ``` + /// use std::sync::atomic::{AtomicIsize, Ordering}; + /// + /// let foo = AtomicIsize::new(0); + /// assert_eq!(foo.fetch_sub(10, Ordering::SeqCst), 0); + /// assert_eq!(foo.load(Ordering::SeqCst), -10); + /// ``` + #[inline] + #[$stable] + pub fn fetch_sub(&self, val: $int_type, order: Ordering) -> $int_type { + unsafe { atomic_sub(self.v.get(), val, order) } + } + + /// Bitwise and with the current value, returning the previous value. + /// + /// # Examples + /// + /// ``` + /// use std::sync::atomic::{AtomicIsize, Ordering}; + /// + /// let foo = AtomicIsize::new(0b101101); + /// assert_eq!(foo.fetch_and(0b110011, Ordering::SeqCst), 0b101101); + /// assert_eq!(foo.load(Ordering::SeqCst), 0b100001); + #[inline] + #[$stable] + pub fn fetch_and(&self, val: $int_type, order: Ordering) -> $int_type { + unsafe { atomic_and(self.v.get(), val, order) } + } + + /// Bitwise or with the current value, returning the previous value. + /// + /// # Examples + /// + /// ``` + /// use std::sync::atomic::{AtomicIsize, Ordering}; + /// + /// let foo = AtomicIsize::new(0b101101); + /// assert_eq!(foo.fetch_or(0b110011, Ordering::SeqCst), 0b101101); + /// assert_eq!(foo.load(Ordering::SeqCst), 0b111111); + #[inline] + #[$stable] + pub fn fetch_or(&self, val: $int_type, order: Ordering) -> $int_type { + unsafe { atomic_or(self.v.get(), val, order) } + } + + /// Bitwise xor with the current value, returning the previous value. + /// + /// # Examples + /// + /// ``` + /// use std::sync::atomic::{AtomicIsize, Ordering}; + /// + /// let foo = AtomicIsize::new(0b101101); + /// assert_eq!(foo.fetch_xor(0b110011, Ordering::SeqCst), 0b101101); + /// assert_eq!(foo.load(Ordering::SeqCst), 0b011110); + #[inline] + #[$stable] + pub fn fetch_xor(&self, val: $int_type, order: Ordering) -> $int_type { + unsafe { atomic_xor(self.v.get(), val, order) } + } + } + } +} + +#[cfg(target_has_atomic = "8")] +atomic_int! { + unstable(feature = "integer_atomics", issue = "32976"), + unstable(feature = "integer_atomics", issue = "32976"), + unstable(feature = "integer_atomics", issue = "32976"), + i8 AtomicI8 ATOMIC_I8_INIT +} +#[cfg(target_has_atomic = "8")] +atomic_int! { + unstable(feature = "integer_atomics", issue = "32976"), + unstable(feature = "integer_atomics", issue = "32976"), + unstable(feature = "integer_atomics", issue = "32976"), + u8 AtomicU8 ATOMIC_U8_INIT +} +#[cfg(target_has_atomic = "16")] +atomic_int! { + unstable(feature = "integer_atomics", issue = "32976"), + unstable(feature = "integer_atomics", issue = "32976"), + unstable(feature = "integer_atomics", issue = "32976"), + i16 AtomicI16 ATOMIC_I16_INIT +} +#[cfg(target_has_atomic = "16")] +atomic_int! { + unstable(feature = "integer_atomics", issue = "32976"), + unstable(feature = "integer_atomics", issue = "32976"), + unstable(feature = "integer_atomics", issue = "32976"), + u16 AtomicU16 ATOMIC_U16_INIT +} +#[cfg(target_has_atomic = "32")] +atomic_int! { + unstable(feature = "integer_atomics", issue = "32976"), + unstable(feature = "integer_atomics", issue = "32976"), + unstable(feature = "integer_atomics", issue = "32976"), + i32 AtomicI32 ATOMIC_I32_INIT +} +#[cfg(target_has_atomic = "32")] +atomic_int! { + unstable(feature = "integer_atomics", issue = "32976"), + unstable(feature = "integer_atomics", issue = "32976"), + unstable(feature = "integer_atomics", issue = "32976"), + u32 AtomicU32 ATOMIC_U32_INIT +} +#[cfg(target_has_atomic = "64")] +atomic_int! { + unstable(feature = "integer_atomics", issue = "32976"), + unstable(feature = "integer_atomics", issue = "32976"), + unstable(feature = "integer_atomics", issue = "32976"), + i64 AtomicI64 ATOMIC_I64_INIT +} +#[cfg(target_has_atomic = "64")] +atomic_int! { + unstable(feature = "integer_atomics", issue = "32976"), + unstable(feature = "integer_atomics", issue = "32976"), + unstable(feature = "integer_atomics", issue = "32976"), + u64 AtomicU64 ATOMIC_U64_INIT +} +#[cfg(target_has_atomic = "ptr")] +atomic_int!{ + stable(feature = "rust1", since = "1.0.0"), + stable(feature = "extended_compare_and_swap", since = "1.10.0"), + stable(feature = "atomic_debug", since = "1.3.0"), + isize AtomicIsize ATOMIC_ISIZE_INIT +} +#[cfg(target_has_atomic = "ptr")] +atomic_int!{ + stable(feature = "rust1", since = "1.0.0"), + stable(feature = "extended_compare_and_swap", since = "1.10.0"), + stable(feature = "atomic_debug", since = "1.3.0"), + usize AtomicUsize ATOMIC_USIZE_INIT +} + #[inline] fn strongest_failure_ordering(order: Ordering) -> Ordering { match order { @@ -1445,18 +1255,6 @@ unsafe fn atomic_and<T>(dst: *mut T, val: T, order: Ordering) -> T { } #[inline] -unsafe fn atomic_nand<T>(dst: *mut T, val: T, order: Ordering) -> T { - match order { - Acquire => intrinsics::atomic_nand_acq(dst, val), - Release => intrinsics::atomic_nand_rel(dst, val), - AcqRel => intrinsics::atomic_nand_acqrel(dst, val), - Relaxed => intrinsics::atomic_nand_relaxed(dst, val), - SeqCst => intrinsics::atomic_nand(dst, val) - } -} - - -#[inline] unsafe fn atomic_or<T>(dst: *mut T, val: T, order: Ordering) -> T { match order { Acquire => intrinsics::atomic_or_acq(dst, val), @@ -1467,7 +1265,6 @@ unsafe fn atomic_or<T>(dst: *mut T, val: T, order: Ordering) -> T { } } - #[inline] unsafe fn atomic_xor<T>(dst: *mut T, val: T, order: Ordering) -> T { match order { @@ -1479,7 +1276,6 @@ unsafe fn atomic_xor<T>(dst: *mut T, val: T, order: Ordering) -> T { } } - /// An atomic fence. /// /// A fence 'A' which has `Release` ordering semantics, synchronizes with a @@ -1514,19 +1310,16 @@ pub fn fence(order: Ordering) { } } -macro_rules! impl_Debug { - ($($t:ident)*) => ($( - #[stable(feature = "atomic_debug", since = "1.3.0")] - impl fmt::Debug for $t { - fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { - f.debug_tuple(stringify!($t)).field(&self.load(Ordering::SeqCst)).finish() - } - } - )*); -} -impl_Debug!{ AtomicUsize AtomicIsize AtomicBool } +#[cfg(target_has_atomic = "8")] +#[stable(feature = "atomic_debug", since = "1.3.0")] +impl fmt::Debug for AtomicBool { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + f.debug_tuple("AtomicBool").field(&self.load(Ordering::SeqCst)).finish() + } +} +#[cfg(target_has_atomic = "ptr")] #[stable(feature = "atomic_debug", since = "1.3.0")] impl<T> fmt::Debug for AtomicPtr<T> { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |