+++ /dev/null
-// Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-//! Atomic types
-//!
-//! Atomic types provide primitive shared-memory communication between
-//! threads, and are the building blocks of other concurrent
-//! types.
-//!
-//! This module defines atomic versions of a select number of primitive
-//! types, including `AtomicBool`, `AtomicInt`, `AtomicUint`, and `AtomicOption`.
-//! Atomic types present operations that, when used correctly, synchronize
-//! updates between threads.
-//!
-//! Each method takes an `Ordering` which represents the strength of
-//! the memory barrier for that operation. These orderings are the
-//! same as [C++11 atomic orderings][1].
-//!
-//! [1]: http://gcc.gnu.org/wiki/Atomic/GCCMM/AtomicSync
-//!
-//! Atomic variables are safe to share between threads (they implement `Share`)
-//! 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
-//! atomically-reference-counted shared pointer).
-//!
-//! Most atomic types may be stored in static variables, initialized using
-//! the provided static initializers like `INIT_ATOMIC_BOOL`. Atomic statics
-//! are often used for lazy global initialization.
-//!
-//!
-//! # Examples
-//!
-//! A simple spinlock:
-//!
-//! ```ignore
-//! # // FIXME: Needs PR #12430
-//! extern crate sync;
-//!
-//! use sync::Arc;
-//! use std::sync::atomics::{AtomicUint, SeqCst};
-//! use std::task::deschedule;
-//!
-//! fn main() {
-//! let spinlock = Arc::new(AtomicUint::new(1));
-//!
-//! let spinlock_clone = spinlock.clone();
-//! spawn(proc() {
-//! spinlock_clone.store(0, SeqCst);
-//! });
-//!
-//! // Wait for the other task to release the lock
-//! while spinlock.load(SeqCst) != 0 {
-//! // Since tasks may not be preemptive (if they are green threads)
-//! // yield to the scheduler to let the other task run. Low level
-//! // concurrent code needs to take into account Rust's two threading
-//! // models.
-//! deschedule();
-//! }
-//! }
-//! ```
-//!
-//! Transferring a heap object with `AtomicOption`:
-//!
-//! ```ignore
-//! # // FIXME: Needs PR #12430
-//! extern crate sync;
-//!
-//! use sync::Arc;
-//! use std::sync::atomics::{AtomicOption, SeqCst};
-//!
-//! fn main() {
-//! struct BigObject;
-//!
-//! let shared_big_object = Arc::new(AtomicOption::empty());
-//!
-//! let shared_big_object_clone = shared_big_object.clone();
-//! spawn(proc() {
-//! let unwrapped_big_object = shared_big_object_clone.take(SeqCst);
-//! if unwrapped_big_object.is_some() {
-//! println!("got a big object from another task");
-//! } else {
-//! println!("other task hasn't sent big object yet");
-//! }
-//! });
-//!
-//! shared_big_object.swap(~BigObject, SeqCst);
-//! }
-//! ```
-//!
-//! Keep a global count of live tasks:
-//!
-//! ```
-//! use std::sync::atomics::{AtomicUint, SeqCst, INIT_ATOMIC_UINT};
-//!
-//! static mut GLOBAL_TASK_COUNT: AtomicUint = INIT_ATOMIC_UINT;
-//!
-//! unsafe {
-//! let old_task_count = GLOBAL_TASK_COUNT.fetch_add(1, SeqCst);
-//! println!("live tasks: {}", old_task_count + 1);
-//! }
-//! ```
-
-#[allow(missing_doc)];
-
-use intrinsics;
-use cast;
-use std::kinds::marker;
-use option::{Option,Some,None};
-use ops::Drop;
-use ty::Unsafe;
-
-/// An atomic boolean type.
-pub struct AtomicBool {
- priv v: Unsafe<uint>,
- priv nopod: marker::NoPod
-}
-
-/// A signed atomic integer type, supporting basic atomic arithmetic operations
-pub struct AtomicInt {
- priv v: Unsafe<int>,
- priv nopod: marker::NoPod
-}
-
-/// An unsigned atomic integer type, supporting basic atomic arithmetic operations
-pub struct AtomicUint {
- priv v: Unsafe<uint>,
- priv nopod: marker::NoPod
-}
-
-/// An unsigned atomic integer type that is forced to be 64-bits. This does not
-/// support all operations.
-pub struct AtomicU64 {
- priv v: Unsafe<u64>,
- priv nopod: marker::NoPod
-}
-
-/// An unsafe atomic pointer. Only supports basic atomic operations
-pub struct AtomicPtr<T> {
- priv p: Unsafe<uint>,
- priv nopod: marker::NoPod
-}
-
-/// An atomic, nullable unique pointer
-///
-/// This can be used as the concurrency primitive for operations that transfer
-/// owned heap objects across tasks.
-#[unsafe_no_drop_flag]
-pub struct AtomicOption<T> {
- priv p: Unsafe<uint>,
-}
-
-/// Atomic memory orderings
-///
-/// Memory orderings limit the ways that both the compiler and CPU may reorder
-/// instructions around atomic operations. At its most restrictive,
-/// "sequentially consistent" atomics allow neither reads nor writes
-/// to be moved either before or after the atomic operation; on the other end
-/// "relaxed" atomics allow all reorderings.
-///
-/// Rust's memory orderings are the same as in C++[1].
-///
-/// [1]: http://gcc.gnu.org/wiki/Atomic/GCCMM/AtomicSync
-pub enum Ordering {
- /// No ordering constraints, only atomic operations
- Relaxed,
- /// When coupled with a store, all previous writes become visible
- /// to another thread that performs a load with `Acquire` ordering
- /// on the same value
- 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
- Acquire,
- /// When coupled with a load, uses `Acquire` ordering, and with a store
- /// `Release` ordering
- AcqRel,
- /// Like `AcqRel` with the additional guarantee that all threads see all
- /// sequentially consistent operations in the same order.
- SeqCst
-}
-
-/// An `AtomicBool` initialized to `false`
-pub static INIT_ATOMIC_BOOL : AtomicBool = AtomicBool { v: Unsafe{value: 0,
- marker1: marker::InvariantType},
- nopod: marker::NoPod };
-/// An `AtomicInt` initialized to `0`
-pub static INIT_ATOMIC_INT : AtomicInt = AtomicInt { v: Unsafe{value: 0,
- marker1: marker::InvariantType},
- nopod: marker::NoPod };
-/// An `AtomicUint` initialized to `0`
-pub static INIT_ATOMIC_UINT : AtomicUint = AtomicUint { v: Unsafe{value: 0,
- marker1: marker::InvariantType},
- nopod: marker::NoPod };
-/// An `AtomicU64` initialized to `0`
-pub static INIT_ATOMIC_U64 : AtomicU64 = AtomicU64 { v: Unsafe{value: 0,
- marker1: marker::InvariantType},
- nopod: marker::NoPod };
-
-
-// NB: Needs to be -1 (0b11111111...) to make fetch_nand work correctly
-static UINT_TRUE: uint = -1;
-
-impl AtomicBool {
- /// Create a new `AtomicBool`
- pub fn new(v: bool) -> AtomicBool {
- let val = if v { UINT_TRUE } else { 0 };
- AtomicBool { v: Unsafe::new(val), nopod: marker::NoPod }
- }
-
- /// Load the value
- #[inline]
- pub fn load(&self, order: Ordering) -> bool {
- unsafe { atomic_load(&*self.v.get(), order) > 0 }
- }
-
- /// Store the value
- #[inline]
- pub fn store(&mut self, val: bool, order: Ordering) {
- let val = if val { UINT_TRUE } else { 0 };
-
- unsafe { atomic_store(&mut *self.v.get(), val, order); }
- }
-
- /// Store a value, returning the old value
- #[inline]
- pub fn swap(&mut self, val: bool, order: Ordering) -> bool {
- let val = if val { UINT_TRUE } else { 0 };
-
- unsafe { atomic_swap(&mut *self.v.get(), val, order) > 0 }
- }
-
- /// If the current value is the same as expected, store a new value
- ///
- /// Compare the current value with `old`; if they are the same then
- /// replace the current value with `new`. Return the previous value.
- /// If the return value is equal to `old` then the value was updated.
- ///
- /// # Examples
- ///
- /// ```ignore
- /// # // FIXME: Needs PR #12430
- /// extern crate sync;
- ///
- /// use sync::Arc;
- /// use std::sync::atomics::{AtomicBool, SeqCst};
- ///
- /// fn main() {
- /// let spinlock = Arc::new(AtomicBool::new(false));
- /// let spinlock_clone = spin_lock.clone();
- ///
- /// spawn(proc() {
- /// with_lock(&spinlock, || println!("task 1 in lock"));
- /// });
- ///
- /// spawn(proc() {
- /// with_lock(&spinlock_clone, || println!("task 2 in lock"));
- /// });
- /// }
- ///
- /// fn with_lock(spinlock: &Arc<AtomicBool>, f: || -> ()) {
- /// // CAS loop until we are able to replace `false` with `true`
- /// while spinlock.compare_and_swap(false, true, SeqCst) == false {
- /// // Since tasks may not be preemptive (if they are green threads)
- /// // yield to the scheduler to let the other task run. Low level
- /// // concurrent code needs to take into account Rust's two threading
- /// // models.
- /// deschedule();
- /// }
- ///
- /// // Now we have the spinlock
- /// f();
- ///
- /// // Release the lock
- /// spinlock.store(false);
- /// }
- /// ```
- #[inline]
- pub fn compare_and_swap(&mut self, old: bool, new: bool, order: Ordering) -> bool {
- let old = if old { UINT_TRUE } else { 0 };
- let new = if new { UINT_TRUE } else { 0 };
-
- unsafe { atomic_compare_and_swap(&mut *self.v.get(), old, new, order) > 0 }
- }
-
- /// A logical "and" operation
- ///
- /// Performs a logical "and" operation on the current value and the
- /// argument `val`, and sets the new value to the result.
- /// Returns the previous value.
- ///
- /// # Examples
- ///
- /// ```
- /// use std::sync::atomics::{AtomicBool, SeqCst};
- ///
- /// let mut foo = AtomicBool::new(true);
- /// assert_eq!(true, foo.fetch_and(false, SeqCst));
- /// assert_eq!(false, foo.load(SeqCst));
- ///
- /// let mut foo = AtomicBool::new(true);
- /// assert_eq!(true, foo.fetch_and(true, SeqCst));
- /// assert_eq!(true, foo.load(SeqCst));
- ///
- /// let mut foo = AtomicBool::new(false);
- /// assert_eq!(false, foo.fetch_and(false, SeqCst));
- /// assert_eq!(false, foo.load(SeqCst));
- /// ```
- #[inline]
- pub fn fetch_and(&mut self, val: bool, order: Ordering) -> bool {
- let val = if val { UINT_TRUE } else { 0 };
-
- unsafe { atomic_and(&mut *self.v.get(), val, order) > 0 }
- }
-
- /// A logical "nand" operation
- ///
- /// Performs a logical "nand" operation on the current value and the
- /// argument `val`, and sets the new value to the result.
- /// Returns the previous value.
- ///
- /// # Examples
- ///
- /// ```
- /// use std::sync::atomics::{AtomicBool, SeqCst};
- ///
- /// let mut foo = AtomicBool::new(true);
- /// assert_eq!(true, foo.fetch_nand(false, SeqCst));
- /// assert_eq!(true, foo.load(SeqCst));
- ///
- /// let mut foo = AtomicBool::new(true);
- /// assert_eq!(true, foo.fetch_nand(true, SeqCst));
- /// assert_eq!(0, foo.load(SeqCst) as int);
- /// assert_eq!(false, foo.load(SeqCst));
- ///
- /// let mut foo = AtomicBool::new(false);
- /// assert_eq!(false, foo.fetch_nand(false, SeqCst));
- /// assert_eq!(true, foo.load(SeqCst));
- /// ```
- #[inline]
- pub fn fetch_nand(&mut self, val: bool, order: Ordering) -> bool {
- let val = if val { UINT_TRUE } else { 0 };
-
- unsafe { atomic_nand(&mut *self.v.get(), val, order) > 0 }
- }
-
- /// A logical "or" operation
- ///
- /// Performs a logical "or" operation on the current value and the
- /// argument `val`, and sets the new value to the result.
- /// Returns the previous value.
- ///
- /// # Examples
- ///
- /// ```
- /// use std::sync::atomics::{AtomicBool, SeqCst};
- ///
- /// let mut foo = AtomicBool::new(true);
- /// assert_eq!(true, foo.fetch_or(false, SeqCst));
- /// assert_eq!(true, foo.load(SeqCst));
- ///
- /// let mut foo = AtomicBool::new(true);
- /// assert_eq!(true, foo.fetch_or(true, SeqCst));
- /// assert_eq!(true, foo.load(SeqCst));
- ///
- /// let mut foo = AtomicBool::new(false);
- /// assert_eq!(false, foo.fetch_or(false, SeqCst));
- /// assert_eq!(false, foo.load(SeqCst));
- /// ```
- #[inline]
- pub fn fetch_or(&mut self, val: bool, order: Ordering) -> bool {
- let val = if val { UINT_TRUE } else { 0 };
-
- unsafe { atomic_or(&mut *self.v.get(), val, order) > 0 }
- }
-
- /// A logical "xor" operation
- ///
- /// Performs a logical "xor" operation on the current value and the
- /// argument `val`, and sets the new value to the result.
- /// Returns the previous value.
- ///
- /// # Examples
- ///
- /// ```
- /// use std::sync::atomics::{AtomicBool, SeqCst};
- ///
- /// let mut foo = AtomicBool::new(true);
- /// assert_eq!(true, foo.fetch_xor(false, SeqCst));
- /// assert_eq!(true, foo.load(SeqCst));
- ///
- /// let mut foo = AtomicBool::new(true);
- /// assert_eq!(true, foo.fetch_xor(true, SeqCst));
- /// assert_eq!(false, foo.load(SeqCst));
- ///
- /// let mut foo = AtomicBool::new(false);
- /// assert_eq!(false, foo.fetch_xor(false, SeqCst));
- /// assert_eq!(false, foo.load(SeqCst));
- /// ```
- #[inline]
- pub fn fetch_xor(&mut self, val: bool, order: Ordering) -> bool {
- let val = if val { UINT_TRUE } else { 0 };
-
- unsafe { atomic_xor(&mut *self.v.get(), val, order) > 0 }
- }
-}
-
-impl AtomicInt {
- /// Create a new `AtomicInt`
- pub fn new(v: int) -> AtomicInt {
- AtomicInt {v: Unsafe::new(v), nopod: marker::NoPod}
- }
-
- /// Load the value
- #[inline]
- pub fn load(&self, order: Ordering) -> int {
- unsafe { atomic_load(&*self.v.get(), order) }
- }
-
- /// Store the value
- #[inline]
- pub fn store(&mut self, val: int, order: Ordering) {
- unsafe { atomic_store(&mut *self.v.get(), val, order); }
- }
-
- /// Store a value, returning the old value
- #[inline]
- pub fn swap(&mut self, val: int, order: Ordering) -> int {
- unsafe { atomic_swap(&mut *self.v.get(), val, order) }
- }
-
- /// If the current value is the same as expected, store a new value
- ///
- /// Compare the current value with `old`; if they are the same then
- /// replace the current value with `new`. Return the previous value.
- /// If the return value is equal to `old` then the value was updated.
- #[inline]
- pub fn compare_and_swap(&mut self, old: int, new: int, order: Ordering) -> int {
- unsafe { atomic_compare_and_swap(&mut *self.v.get(), old, new, order) }
- }
-
- /// Add to the current value, returning the previous
- ///
- /// # Examples
- ///
- /// ```
- /// use std::sync::atomics::{AtomicInt, SeqCst};
- ///
- /// let mut foo = AtomicInt::new(0);
- /// assert_eq!(0, foo.fetch_add(10, SeqCst));
- /// assert_eq!(10, foo.load(SeqCst));
- /// ```
- #[inline]
- pub fn fetch_add(&mut self, val: int, order: Ordering) -> int {
- unsafe { atomic_add(&mut *self.v.get(), val, order) }
- }
-
- /// Subtract from the current value, returning the previous
- ///
- /// # Examples
- ///
- /// ```
- /// use std::sync::atomics::{AtomicInt, SeqCst};
- ///
- /// let mut foo = AtomicInt::new(0);
- /// assert_eq!(0, foo.fetch_sub(10, SeqCst));
- /// assert_eq!(-10, foo.load(SeqCst));
- /// ```
- #[inline]
- pub fn fetch_sub(&mut self, val: int, order: Ordering) -> int {
- unsafe { atomic_sub(&mut *self.v.get(), val, order) }
- }
-}
-
-// temporary workaround
-// it causes link failure on MIPS target
-// libgcc doesn't implement 64-bit atomic operations for MIPS32
-#[cfg(not(target_arch = "mips"))]
-impl AtomicU64 {
- pub fn new(v: u64) -> AtomicU64 {
- AtomicU64 { v: Unsafe::new(v), nopod: marker::NoPod }
- }
-
- #[inline]
- pub fn load(&self, order: Ordering) -> u64 {
- unsafe { atomic_load(&*self.v.get(), order) }
- }
-
- #[inline]
- pub fn store(&mut self, val: u64, order: Ordering) {
- unsafe { atomic_store(&mut *self.v.get(), val, order); }
- }
-
- #[inline]
- pub fn swap(&mut self, val: u64, order: Ordering) -> u64 {
- unsafe { atomic_swap(&mut *self.v.get(), val, order) }
- }
-
- #[inline]
- pub fn compare_and_swap(&mut self, old: u64, new: u64, order: Ordering) -> u64 {
- unsafe { atomic_compare_and_swap(&mut *self.v.get(), old, new, order) }
- }
-
- #[inline]
- pub fn fetch_add(&mut self, val: u64, order: Ordering) -> u64 {
- unsafe { atomic_add(&mut *self.v.get(), val, order) }
- }
-
- #[inline]
- pub fn fetch_sub(&mut self, val: u64, order: Ordering) -> u64 {
- unsafe { atomic_sub(&mut *self.v.get(), val, order) }
- }
-}
-
-impl AtomicUint {
- /// Create a new `AtomicUint`
- pub fn new(v: uint) -> AtomicUint {
- AtomicUint { v: Unsafe::new(v), nopod: marker::NoPod }
- }
-
- /// Load the value
- #[inline]
- pub fn load(&self, order: Ordering) -> uint {
- unsafe { atomic_load(&*self.v.get(), order) }
- }
-
- /// Store the value
- #[inline]
- pub fn store(&mut self, val: uint, order: Ordering) {
- unsafe { atomic_store(&mut *self.v.get(), val, order); }
- }
-
- /// Store a value, returning the old value
- #[inline]
- pub fn swap(&mut self, val: uint, order: Ordering) -> uint {
- unsafe { atomic_swap(&mut *self.v.get(), val, order) }
- }
-
- /// If the current value is the same as expected, store a new value
- ///
- /// Compare the current value with `old`; if they are the same then
- /// replace the current value with `new`. Return the previous value.
- /// If the return value is equal to `old` then the value was updated.
- #[inline]
- pub fn compare_and_swap(&mut self, old: uint, new: uint, order: Ordering) -> uint {
- unsafe { atomic_compare_and_swap(&mut *self.v.get(), old, new, order) }
- }
-
- /// Add to the current value, returning the previous
- ///
- /// # Examples
- ///
- /// ```
- /// use std::sync::atomics::{AtomicUint, SeqCst};
- ///
- /// let mut foo = AtomicUint::new(0);
- /// assert_eq!(0, foo.fetch_add(10, SeqCst));
- /// assert_eq!(10, foo.load(SeqCst));
- /// ```
- #[inline]
- pub fn fetch_add(&mut self, val: uint, order: Ordering) -> uint {
- unsafe { atomic_add(&mut *self.v.get(), val, order) }
- }
-
- /// Subtract from the current value, returning the previous
- ///
- /// # Examples
- ///
- /// ```
- /// use std::sync::atomics::{AtomicUint, SeqCst};
- ///
- /// let mut foo = AtomicUint::new(10);
- /// assert_eq!(10, foo.fetch_sub(10, SeqCst));
- /// assert_eq!(0, foo.load(SeqCst));
- /// ```
- #[inline]
- pub fn fetch_sub(&mut self, val: uint, order: Ordering) -> uint {
- unsafe { atomic_sub(&mut *self.v.get(), val, order) }
- }
-}
-
-impl<T> AtomicPtr<T> {
- /// Create a new `AtomicPtr`
- pub fn new(p: *mut T) -> AtomicPtr<T> {
- AtomicPtr { p: Unsafe::new(p as uint), nopod: marker::NoPod }
- }
-
- /// Load the value
- #[inline]
- pub fn load(&self, order: Ordering) -> *mut T {
- unsafe {
- atomic_load(&*self.p.get(), order) as *mut T
- }
- }
-
- /// Store the value
- #[inline]
- pub fn store(&mut self, ptr: *mut T, order: Ordering) {
- unsafe { atomic_store(&mut *self.p.get(), ptr as uint, order); }
- }
-
- /// Store a value, returning the old value
- #[inline]
- pub fn swap(&mut self, ptr: *mut T, order: Ordering) -> *mut T {
- unsafe { atomic_swap(&mut *self.p.get(), ptr as uint, order) as *mut T }
- }
-
- /// If the current value is the same as expected, store a new value
- ///
- /// Compare the current value with `old`; if they are the same then
- /// replace the current value with `new`. Return the previous value.
- /// If the return value is equal to `old` then the value was updated.
- #[inline]
- pub fn compare_and_swap(&mut self, old: *mut T, new: *mut T, order: Ordering) -> *mut T {
- unsafe {
- atomic_compare_and_swap(&mut *self.p.get(), old as uint,
- new as uint, order) as *mut T
- }
- }
-}
-
-impl<T> AtomicOption<T> {
- /// Create a new `AtomicOption`
- pub fn new(p: ~T) -> AtomicOption<T> {
- unsafe { AtomicOption { p: Unsafe::new(cast::transmute(p)) } }
- }
-
- /// Create a new `AtomicOption` that doesn't contain a value
- pub fn empty() -> AtomicOption<T> { AtomicOption { p: Unsafe::new(0) } }
-
- /// Store a value, returning the old value
- #[inline]
- pub fn swap(&mut self, val: ~T, order: Ordering) -> Option<~T> {
- unsafe {
- let val = cast::transmute(val);
-
- let p = atomic_swap(&mut *self.p.get(), val, order);
- if p as uint == 0 {
- None
- } else {
- Some(cast::transmute(p))
- }
- }
- }
-
- /// Remove the value, leaving the `AtomicOption` empty.
- #[inline]
- pub fn take(&mut self, order: Ordering) -> Option<~T> {
- unsafe { self.swap(cast::transmute(0), order) }
- }
-
- /// Replace an empty value with a non-empty value.
- ///
- /// Succeeds if the option is `None` and returns `None` if so. If
- /// the option was already `Some`, returns `Some` of the rejected
- /// value.
- #[inline]
- pub fn fill(&mut self, val: ~T, order: Ordering) -> Option<~T> {
- unsafe {
- let val = cast::transmute(val);
- let expected = cast::transmute(0);
- let oldval = atomic_compare_and_swap(&mut *self.p.get(), expected, val, order);
- if oldval == expected {
- None
- } else {
- Some(cast::transmute(val))
- }
- }
- }
-
- /// Returns `true` if the `AtomicOption` is empty.
- ///
- /// Be careful: The caller must have some external method of ensuring the
- /// result does not get invalidated by another task after this returns.
- #[inline]
- pub fn is_empty(&mut self, order: Ordering) -> bool {
- unsafe { atomic_load(&*self.p.get(), order) as uint == 0 }
- }
-}
-
-#[unsafe_destructor]
-impl<T> Drop for AtomicOption<T> {
- fn drop(&mut self) {
- let _ = self.take(SeqCst);
- }
-}
-
-#[inline]
-pub unsafe fn atomic_store<T>(dst: &mut T, val: T, order:Ordering) {
- match order {
- Release => intrinsics::atomic_store_rel(dst, val),
- Relaxed => intrinsics::atomic_store_relaxed(dst, val),
- _ => intrinsics::atomic_store(dst, val)
- }
-}
-
-#[inline]
-pub unsafe fn atomic_load<T>(dst: &T, order:Ordering) -> T {
- match order {
- Acquire => intrinsics::atomic_load_acq(dst),
- Relaxed => intrinsics::atomic_load_relaxed(dst),
- _ => intrinsics::atomic_load(dst)
- }
-}
-
-#[inline]
-pub unsafe fn atomic_swap<T>(dst: &mut T, val: T, order: Ordering) -> T {
- match order {
- Acquire => intrinsics::atomic_xchg_acq(dst, val),
- Release => intrinsics::atomic_xchg_rel(dst, val),
- AcqRel => intrinsics::atomic_xchg_acqrel(dst, val),
- Relaxed => intrinsics::atomic_xchg_relaxed(dst, val),
- _ => intrinsics::atomic_xchg(dst, val)
- }
-}
-
-/// Returns the old value (like __sync_fetch_and_add).
-#[inline]
-pub unsafe fn atomic_add<T>(dst: &mut T, val: T, order: Ordering) -> T {
- match order {
- Acquire => intrinsics::atomic_xadd_acq(dst, val),
- Release => intrinsics::atomic_xadd_rel(dst, val),
- AcqRel => intrinsics::atomic_xadd_acqrel(dst, val),
- Relaxed => intrinsics::atomic_xadd_relaxed(dst, val),
- _ => intrinsics::atomic_xadd(dst, val)
- }
-}
-
-/// Returns the old value (like __sync_fetch_and_sub).
-#[inline]
-pub unsafe fn atomic_sub<T>(dst: &mut T, val: T, order: Ordering) -> T {
- match order {
- Acquire => intrinsics::atomic_xsub_acq(dst, val),
- Release => intrinsics::atomic_xsub_rel(dst, val),
- AcqRel => intrinsics::atomic_xsub_acqrel(dst, val),
- Relaxed => intrinsics::atomic_xsub_relaxed(dst, val),
- _ => intrinsics::atomic_xsub(dst, val)
- }
-}
-
-#[inline]
-pub unsafe fn atomic_compare_and_swap<T>(dst:&mut T, old:T, new:T, order: Ordering) -> T {
- match order {
- Acquire => intrinsics::atomic_cxchg_acq(dst, old, new),
- Release => intrinsics::atomic_cxchg_rel(dst, old, new),
- AcqRel => intrinsics::atomic_cxchg_acqrel(dst, old, new),
- Relaxed => intrinsics::atomic_cxchg_relaxed(dst, old, new),
- _ => intrinsics::atomic_cxchg(dst, old, new),
- }
-}
-
-#[inline]
-pub unsafe fn atomic_and<T>(dst: &mut T, val: T, order: Ordering) -> T {
- match order {
- Acquire => intrinsics::atomic_and_acq(dst, val),
- Release => intrinsics::atomic_and_rel(dst, val),
- AcqRel => intrinsics::atomic_and_acqrel(dst, val),
- Relaxed => intrinsics::atomic_and_relaxed(dst, val),
- _ => intrinsics::atomic_and(dst, val)
- }
-}
-
-#[inline]
-pub 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),
- _ => intrinsics::atomic_nand(dst, val)
- }
-}
-
-
-#[inline]
-pub unsafe fn atomic_or<T>(dst: &mut T, val: T, order: Ordering) -> T {
- match order {
- Acquire => intrinsics::atomic_or_acq(dst, val),
- Release => intrinsics::atomic_or_rel(dst, val),
- AcqRel => intrinsics::atomic_or_acqrel(dst, val),
- Relaxed => intrinsics::atomic_or_relaxed(dst, val),
- _ => intrinsics::atomic_or(dst, val)
- }
-}
-
-
-#[inline]
-pub unsafe fn atomic_xor<T>(dst: &mut T, val: T, order: Ordering) -> T {
- match order {
- Acquire => intrinsics::atomic_xor_acq(dst, val),
- Release => intrinsics::atomic_xor_rel(dst, val),
- AcqRel => intrinsics::atomic_xor_acqrel(dst, val),
- Relaxed => intrinsics::atomic_xor_relaxed(dst, val),
- _ => intrinsics::atomic_xor(dst, val)
- }
-}
-
-
-/// An atomic fence.
-///
-/// A fence 'A' which has `Release` ordering semantics, synchronizes with a
-/// fence 'B' with (at least) `Acquire` semantics, if and only if there exists
-/// atomic operations X and Y, both operating on some atomic object 'M' such
-/// that A is sequenced before X, Y is synchronized before B and Y observers
-/// the change to M. This provides a happens-before dependence between A and B.
-///
-/// Atomic operations with `Release` or `Acquire` semantics can also synchronize
-/// with a fence.
-///
-/// A fence with has `SeqCst` ordering, in addition to having both `Acquire` and
-/// `Release` semantics, participates in the global program order of the other
-/// `SeqCst` operations and/or fences.
-///
-/// Accepts `Acquire`, `Release`, `AcqRel` and `SeqCst` orderings.
-///
-/// # Failure
-///
-/// Fails if `order` is `Relaxed`
-#[inline]
-pub fn fence(order: Ordering) {
- unsafe {
- match order {
- Acquire => intrinsics::atomic_fence_acq(),
- Release => intrinsics::atomic_fence_rel(),
- AcqRel => intrinsics::atomic_fence_acqrel(),
- SeqCst => intrinsics::atomic_fence(),
- Relaxed => fail!("there is no such thing as a relaxed fence")
- }
- }
-}
-
-#[cfg(test)]
-mod test {
- use option::*;
- use super::*;
-
- #[test]
- fn bool_() {
- let mut a = AtomicBool::new(false);
- assert_eq!(a.compare_and_swap(false, true, SeqCst), false);
- assert_eq!(a.compare_and_swap(false, true, SeqCst), true);
-
- a.store(false, SeqCst);
- assert_eq!(a.compare_and_swap(false, true, SeqCst), false);
- }
-
- #[test]
- fn option_empty() {
- let mut option: AtomicOption<()> = AtomicOption::empty();
- assert!(option.is_empty(SeqCst));
- }
-
- #[test]
- fn option_swap() {
- let mut p = AtomicOption::new(~1);
- let a = ~2;
-
- let b = p.swap(a, SeqCst);
-
- assert_eq!(b, Some(~1));
- assert_eq!(p.take(SeqCst), Some(~2));
- }
-
- #[test]
- fn option_take() {
- let mut p = AtomicOption::new(~1);
-
- assert_eq!(p.take(SeqCst), Some(~1));
- assert_eq!(p.take(SeqCst), None);
-
- let p2 = ~2;
- p.swap(p2, SeqCst);
-
- assert_eq!(p.take(SeqCst), Some(~2));
- }
-
- #[test]
- fn option_fill() {
- let mut p = AtomicOption::new(~1);
- assert!(p.fill(~2, SeqCst).is_some()); // should fail; shouldn't leak!
- assert_eq!(p.take(SeqCst), Some(~1));
-
- assert!(p.fill(~2, SeqCst).is_none()); // shouldn't fail
- assert_eq!(p.take(SeqCst), Some(~2));
- }
-
- #[test]
- fn bool_and() {
- let mut a = AtomicBool::new(true);
- assert_eq!(a.fetch_and(false, SeqCst),true);
- assert_eq!(a.load(SeqCst),false);
- }
-
- static mut S_BOOL : AtomicBool = INIT_ATOMIC_BOOL;
- static mut S_INT : AtomicInt = INIT_ATOMIC_INT;
- static mut S_UINT : AtomicUint = INIT_ATOMIC_UINT;
-
- #[test]
- fn static_init() {
- unsafe {
- assert!(!S_BOOL.load(SeqCst));
- assert!(S_INT.load(SeqCst) == 0);
- assert!(S_UINT.load(SeqCst) == 0);
- }
- }
-
- #[test]
- fn different_sizes() {
- unsafe {
- let mut slot = 0u16;
- assert_eq!(super::atomic_swap(&mut slot, 1, SeqCst), 0);
-
- let mut slot = 0u8;
- assert_eq!(super::atomic_compare_and_swap(&mut slot, 1, 2, SeqCst), 0);
-
- let mut slot = 0u32;
- assert_eq!(super::atomic_load(&mut slot, SeqCst), 0);
-
- let mut slot = 0u64;
- super::atomic_store(&mut slot, 2, SeqCst);
- }
- }
-}
-
projects / rust.git / commitdiff