318 lines
18 KiB
Swift
318 lines
18 KiB
Swift
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This source file is part of the SwiftNIO open source project
|
|
//
|
|
// Copyright (c) 2017-2018 Apple Inc. and the SwiftNIO project authors
|
|
// Licensed under Apache License v2.0
|
|
//
|
|
// See LICENSE.txt for license information
|
|
// See CONTRIBUTORS.txt for the list of SwiftNIO project authors
|
|
//
|
|
// SPDX-License-Identifier: Apache-2.0
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
import CNIOAtomics
|
|
|
|
/// The protocol that all types that can be made atomic must conform to.
|
|
///
|
|
/// **Do not add conformance to this protocol for arbitrary types**. Only a small range
|
|
/// of types have appropriate atomic operations supported by the CPU, and those types
|
|
/// already have conformances implemented.
|
|
public protocol NIOAtomicPrimitive {
|
|
associatedtype AtomicWrapper
|
|
static var nio_atomic_create_with_existing_storage: (UnsafeMutablePointer<AtomicWrapper>, Self) -> Void { get }
|
|
static var nio_atomic_compare_and_exchange: (UnsafeMutablePointer<AtomicWrapper>, Self, Self) -> Bool { get }
|
|
static var nio_atomic_add: (UnsafeMutablePointer<AtomicWrapper>, Self) -> Self { get }
|
|
static var nio_atomic_sub: (UnsafeMutablePointer<AtomicWrapper>, Self) -> Self { get }
|
|
static var nio_atomic_exchange: (UnsafeMutablePointer<AtomicWrapper>, Self) -> Self { get }
|
|
static var nio_atomic_load: (UnsafeMutablePointer<AtomicWrapper>) -> Self { get }
|
|
static var nio_atomic_store: (UnsafeMutablePointer<AtomicWrapper>, Self) -> Void { get }
|
|
}
|
|
|
|
extension Bool: NIOAtomicPrimitive {
|
|
public typealias AtomicWrapper = catmc_nio_atomic__Bool
|
|
public static let nio_atomic_create_with_existing_storage = catmc_nio_atomic__Bool_create_with_existing_storage
|
|
public static let nio_atomic_compare_and_exchange = catmc_nio_atomic__Bool_compare_and_exchange
|
|
public static let nio_atomic_add = catmc_nio_atomic__Bool_add
|
|
public static let nio_atomic_sub = catmc_nio_atomic__Bool_sub
|
|
public static let nio_atomic_exchange = catmc_nio_atomic__Bool_exchange
|
|
public static let nio_atomic_load = catmc_nio_atomic__Bool_load
|
|
public static let nio_atomic_store = catmc_nio_atomic__Bool_store
|
|
}
|
|
|
|
extension Int8: NIOAtomicPrimitive {
|
|
public typealias AtomicWrapper = catmc_nio_atomic_int_least8_t
|
|
public static let nio_atomic_create_with_existing_storage = catmc_nio_atomic_int_least8_t_create_with_existing_storage
|
|
public static let nio_atomic_compare_and_exchange = catmc_nio_atomic_int_least8_t_compare_and_exchange
|
|
public static let nio_atomic_add = catmc_nio_atomic_int_least8_t_add
|
|
public static let nio_atomic_sub = catmc_nio_atomic_int_least8_t_sub
|
|
public static let nio_atomic_exchange = catmc_nio_atomic_int_least8_t_exchange
|
|
public static let nio_atomic_load = catmc_nio_atomic_int_least8_t_load
|
|
public static let nio_atomic_store = catmc_nio_atomic_int_least8_t_store
|
|
}
|
|
|
|
extension UInt8: NIOAtomicPrimitive {
|
|
public typealias AtomicWrapper = catmc_nio_atomic_uint_least8_t
|
|
public static let nio_atomic_create_with_existing_storage = catmc_nio_atomic_uint_least8_t_create_with_existing_storage
|
|
public static let nio_atomic_compare_and_exchange = catmc_nio_atomic_uint_least8_t_compare_and_exchange
|
|
public static let nio_atomic_add = catmc_nio_atomic_uint_least8_t_add
|
|
public static let nio_atomic_sub = catmc_nio_atomic_uint_least8_t_sub
|
|
public static let nio_atomic_exchange = catmc_nio_atomic_uint_least8_t_exchange
|
|
public static let nio_atomic_load = catmc_nio_atomic_uint_least8_t_load
|
|
public static let nio_atomic_store = catmc_nio_atomic_uint_least8_t_store
|
|
}
|
|
|
|
extension Int16: NIOAtomicPrimitive {
|
|
public typealias AtomicWrapper = catmc_nio_atomic_int_least16_t
|
|
public static let nio_atomic_create_with_existing_storage = catmc_nio_atomic_int_least16_t_create_with_existing_storage
|
|
public static let nio_atomic_compare_and_exchange = catmc_nio_atomic_int_least16_t_compare_and_exchange
|
|
public static let nio_atomic_add = catmc_nio_atomic_int_least16_t_add
|
|
public static let nio_atomic_sub = catmc_nio_atomic_int_least16_t_sub
|
|
public static let nio_atomic_exchange = catmc_nio_atomic_int_least16_t_exchange
|
|
public static let nio_atomic_load = catmc_nio_atomic_int_least16_t_load
|
|
public static let nio_atomic_store = catmc_nio_atomic_int_least16_t_store
|
|
}
|
|
|
|
extension UInt16: NIOAtomicPrimitive {
|
|
public typealias AtomicWrapper = catmc_nio_atomic_uint_least16_t
|
|
public static let nio_atomic_create_with_existing_storage = catmc_nio_atomic_uint_least16_t_create_with_existing_storage
|
|
public static let nio_atomic_compare_and_exchange = catmc_nio_atomic_uint_least16_t_compare_and_exchange
|
|
public static let nio_atomic_add = catmc_nio_atomic_uint_least16_t_add
|
|
public static let nio_atomic_sub = catmc_nio_atomic_uint_least16_t_sub
|
|
public static let nio_atomic_exchange = catmc_nio_atomic_uint_least16_t_exchange
|
|
public static let nio_atomic_load = catmc_nio_atomic_uint_least16_t_load
|
|
public static let nio_atomic_store = catmc_nio_atomic_uint_least16_t_store
|
|
}
|
|
|
|
extension Int32: NIOAtomicPrimitive {
|
|
public typealias AtomicWrapper = catmc_nio_atomic_int_least32_t
|
|
public static let nio_atomic_create_with_existing_storage = catmc_nio_atomic_int_least32_t_create_with_existing_storage
|
|
public static let nio_atomic_compare_and_exchange = catmc_nio_atomic_int_least32_t_compare_and_exchange
|
|
public static let nio_atomic_add = catmc_nio_atomic_int_least32_t_add
|
|
public static let nio_atomic_sub = catmc_nio_atomic_int_least32_t_sub
|
|
public static let nio_atomic_exchange = catmc_nio_atomic_int_least32_t_exchange
|
|
public static let nio_atomic_load = catmc_nio_atomic_int_least32_t_load
|
|
public static let nio_atomic_store = catmc_nio_atomic_int_least32_t_store
|
|
}
|
|
|
|
extension UInt32: NIOAtomicPrimitive {
|
|
public typealias AtomicWrapper = catmc_nio_atomic_uint_least32_t
|
|
public static let nio_atomic_create_with_existing_storage = catmc_nio_atomic_uint_least32_t_create_with_existing_storage
|
|
public static let nio_atomic_compare_and_exchange = catmc_nio_atomic_uint_least32_t_compare_and_exchange
|
|
public static let nio_atomic_add = catmc_nio_atomic_uint_least32_t_add
|
|
public static let nio_atomic_sub = catmc_nio_atomic_uint_least32_t_sub
|
|
public static let nio_atomic_exchange = catmc_nio_atomic_uint_least32_t_exchange
|
|
public static let nio_atomic_load = catmc_nio_atomic_uint_least32_t_load
|
|
public static let nio_atomic_store = catmc_nio_atomic_uint_least32_t_store
|
|
}
|
|
|
|
extension Int64: NIOAtomicPrimitive {
|
|
public typealias AtomicWrapper = catmc_nio_atomic_long_long
|
|
public static let nio_atomic_create_with_existing_storage = catmc_nio_atomic_long_long_create_with_existing_storage
|
|
public static let nio_atomic_compare_and_exchange = catmc_nio_atomic_long_long_compare_and_exchange
|
|
public static let nio_atomic_add = catmc_nio_atomic_long_long_add
|
|
public static let nio_atomic_sub = catmc_nio_atomic_long_long_sub
|
|
public static let nio_atomic_exchange = catmc_nio_atomic_long_long_exchange
|
|
public static let nio_atomic_load = catmc_nio_atomic_long_long_load
|
|
public static let nio_atomic_store = catmc_nio_atomic_long_long_store
|
|
}
|
|
|
|
extension UInt64: NIOAtomicPrimitive {
|
|
public typealias AtomicWrapper = catmc_nio_atomic_unsigned_long_long
|
|
public static let nio_atomic_create_with_existing_storage = catmc_nio_atomic_unsigned_long_long_create_with_existing_storage
|
|
public static let nio_atomic_compare_and_exchange = catmc_nio_atomic_unsigned_long_long_compare_and_exchange
|
|
public static let nio_atomic_add = catmc_nio_atomic_unsigned_long_long_add
|
|
public static let nio_atomic_sub = catmc_nio_atomic_unsigned_long_long_sub
|
|
public static let nio_atomic_exchange = catmc_nio_atomic_unsigned_long_long_exchange
|
|
public static let nio_atomic_load = catmc_nio_atomic_unsigned_long_long_load
|
|
public static let nio_atomic_store = catmc_nio_atomic_unsigned_long_long_store
|
|
}
|
|
|
|
#if os(Windows)
|
|
extension Int: NIOAtomicPrimitive {
|
|
public typealias AtomicWrapper = catmc_nio_atomic_intptr_t
|
|
public static let nio_atomic_create_with_existing_storage = catmc_nio_atomic_intptr_t_create_with_existing_storage
|
|
public static let nio_atomic_compare_and_exchange = catmc_nio_atomic_intptr_t_compare_and_exchange
|
|
public static let nio_atomic_add = catmc_nio_atomic_intptr_t_add
|
|
public static let nio_atomic_sub = catmc_nio_atomic_intptr_t_sub
|
|
public static let nio_atomic_exchange = catmc_nio_atomic_intptr_t_exchange
|
|
public static let nio_atomic_load = catmc_nio_atomic_intptr_t_load
|
|
public static let nio_atomic_store = catmc_nio_atomic_intptr_t_store
|
|
}
|
|
|
|
extension UInt: NIOAtomicPrimitive {
|
|
public typealias AtomicWrapper = catmc_nio_atomic_uintptr_t
|
|
public static let nio_atomic_create_with_existing_storage = catmc_nio_atomic_uintptr_t_create_with_existing_storage
|
|
public static let nio_atomic_compare_and_exchange = catmc_nio_atomic_uintptr_t_compare_and_exchange
|
|
public static let nio_atomic_add = catmc_nio_atomic_uintptr_t_add
|
|
public static let nio_atomic_sub = catmc_nio_atomic_uintptr_t_sub
|
|
public static let nio_atomic_exchange = catmc_nio_atomic_uintptr_t_exchange
|
|
public static let nio_atomic_load = catmc_nio_atomic_uintptr_t_load
|
|
public static let nio_atomic_store = catmc_nio_atomic_uintptr_t_store
|
|
}
|
|
#else
|
|
extension Int: NIOAtomicPrimitive {
|
|
public typealias AtomicWrapper = catmc_nio_atomic_long
|
|
public static let nio_atomic_create_with_existing_storage = catmc_nio_atomic_long_create_with_existing_storage
|
|
public static let nio_atomic_compare_and_exchange = catmc_nio_atomic_long_compare_and_exchange
|
|
public static let nio_atomic_add = catmc_nio_atomic_long_add
|
|
public static let nio_atomic_sub = catmc_nio_atomic_long_sub
|
|
public static let nio_atomic_exchange = catmc_nio_atomic_long_exchange
|
|
public static let nio_atomic_load = catmc_nio_atomic_long_load
|
|
public static let nio_atomic_store = catmc_nio_atomic_long_store
|
|
}
|
|
|
|
extension UInt: NIOAtomicPrimitive {
|
|
public typealias AtomicWrapper = catmc_nio_atomic_unsigned_long
|
|
public static let nio_atomic_create_with_existing_storage = catmc_nio_atomic_unsigned_long_create_with_existing_storage
|
|
public static let nio_atomic_compare_and_exchange = catmc_nio_atomic_unsigned_long_compare_and_exchange
|
|
public static let nio_atomic_add = catmc_nio_atomic_unsigned_long_add
|
|
public static let nio_atomic_sub = catmc_nio_atomic_unsigned_long_sub
|
|
public static let nio_atomic_exchange = catmc_nio_atomic_unsigned_long_exchange
|
|
public static let nio_atomic_load = catmc_nio_atomic_unsigned_long_load
|
|
public static let nio_atomic_store = catmc_nio_atomic_unsigned_long_store
|
|
}
|
|
#endif
|
|
|
|
/// An encapsulation of an atomic primitive object.
|
|
///
|
|
/// Atomic objects support a wide range of atomic operations:
|
|
///
|
|
/// - Compare and swap
|
|
/// - Add
|
|
/// - Subtract
|
|
/// - Exchange
|
|
/// - Load current value
|
|
/// - Store current value
|
|
///
|
|
/// Atomic primitives are useful when building constructs that need to
|
|
/// communicate or cooperate across multiple threads. In the case of
|
|
/// SwiftNIO this usually involves communicating across multiple event loops.
|
|
///
|
|
/// By necessity, all atomic values are references: after all, it makes no
|
|
/// sense to talk about managing an atomic value when each time it's modified
|
|
/// the thread that modified it gets a local copy!
|
|
@available(*, deprecated, message:"please use ManagedAtomic from https://github.com/apple/swift-atomics instead")
|
|
public final class NIOAtomic<T: NIOAtomicPrimitive> {
|
|
@usableFromInline
|
|
typealias Manager = ManagedBufferPointer<Void, T.AtomicWrapper>
|
|
|
|
/// Create an atomic object with `value`
|
|
@inlinable
|
|
public static func makeAtomic(value: T) -> NIOAtomic {
|
|
let manager = Manager(bufferClass: self, minimumCapacity: 1) { _, _ in }
|
|
manager.withUnsafeMutablePointerToElements {
|
|
T.nio_atomic_create_with_existing_storage($0, value)
|
|
}
|
|
return manager.buffer as! NIOAtomic<T>
|
|
}
|
|
|
|
/// Atomically compares the value against `expected` and, if they are equal,
|
|
/// replaces the value with `desired`.
|
|
///
|
|
/// This implementation conforms to C11's `atomic_compare_exchange_strong`. This
|
|
/// means that the compare-and-swap will always succeed if `expected` is equal to
|
|
/// value. Additionally, it uses a *sequentially consistent ordering*. For more
|
|
/// details on atomic memory models, check the documentation for C11's
|
|
/// `stdatomic.h`.
|
|
///
|
|
/// - Parameter expected: The value that this object must currently hold for the
|
|
/// compare-and-swap to succeed.
|
|
/// - Parameter desired: The new value that this object will hold if the compare
|
|
/// succeeds.
|
|
/// - Returns: `True` if the exchange occurred, or `False` if `expected` did not
|
|
/// match the current value and so no exchange occurred.
|
|
@inlinable
|
|
public func compareAndExchange(expected: T, desired: T) -> Bool {
|
|
return Manager(unsafeBufferObject: self).withUnsafeMutablePointerToElements {
|
|
return T.nio_atomic_compare_and_exchange($0, expected, desired)
|
|
}
|
|
}
|
|
|
|
/// Atomically adds `rhs` to this object.
|
|
///
|
|
/// This implementation uses a *relaxed* memory ordering. This guarantees nothing
|
|
/// more than that this operation is atomic: there is no guarantee that any other
|
|
/// event will be ordered before or after this one.
|
|
///
|
|
/// - Parameter rhs: The value to add to this object.
|
|
/// - Returns: The previous value of this object, before the addition occurred.
|
|
@inlinable
|
|
@discardableResult
|
|
public func add(_ rhs: T) -> T {
|
|
return Manager(unsafeBufferObject: self).withUnsafeMutablePointerToElements {
|
|
return T.nio_atomic_add($0, rhs)
|
|
}
|
|
}
|
|
|
|
/// Atomically subtracts `rhs` from this object.
|
|
///
|
|
/// This implementation uses a *relaxed* memory ordering. This guarantees nothing
|
|
/// more than that this operation is atomic: there is no guarantee that any other
|
|
/// event will be ordered before or after this one.
|
|
///
|
|
/// - Parameter rhs: The value to subtract from this object.
|
|
/// - Returns: The previous value of this object, before the subtraction occurred.
|
|
@inlinable
|
|
@discardableResult
|
|
public func sub(_ rhs: T) -> T {
|
|
return Manager(unsafeBufferObject: self).withUnsafeMutablePointerToElements {
|
|
return T.nio_atomic_sub($0, rhs)
|
|
}
|
|
}
|
|
|
|
/// Atomically exchanges `value` for the current value of this object.
|
|
///
|
|
/// This implementation uses a *relaxed* memory ordering. This guarantees nothing
|
|
/// more than that this operation is atomic: there is no guarantee that any other
|
|
/// event will be ordered before or after this one.
|
|
///
|
|
/// - Parameter value: The new value to set this object to.
|
|
/// - Returns: The value previously held by this object.
|
|
@inlinable
|
|
public func exchange(with value: T) -> T {
|
|
return Manager(unsafeBufferObject: self).withUnsafeMutablePointerToElements {
|
|
return T.nio_atomic_exchange($0, value)
|
|
}
|
|
}
|
|
|
|
/// Atomically loads and returns the value of this object.
|
|
///
|
|
/// This implementation uses a *relaxed* memory ordering. This guarantees nothing
|
|
/// more than that this operation is atomic: there is no guarantee that any other
|
|
/// event will be ordered before or after this one.
|
|
///
|
|
/// - Returns: The value of this object
|
|
@inlinable
|
|
public func load() -> T {
|
|
return Manager(unsafeBufferObject: self).withUnsafeMutablePointerToElements {
|
|
return T.nio_atomic_load($0)
|
|
}
|
|
}
|
|
|
|
/// Atomically replaces the value of this object with `value`.
|
|
///
|
|
/// This implementation uses a *relaxed* memory ordering. This guarantees nothing
|
|
/// more than that this operation is atomic: there is no guarantee that any other
|
|
/// event will be ordered before or after this one.
|
|
///
|
|
/// - Parameter value: The new value to set the object to.
|
|
@inlinable
|
|
public func store(_ value: T) -> Void {
|
|
return Manager(unsafeBufferObject: self).withUnsafeMutablePointerToElements {
|
|
return T.nio_atomic_store($0, value)
|
|
}
|
|
}
|
|
|
|
deinit {
|
|
Manager(unsafeBufferObject: self).withUnsafeMutablePointers { headerPtr, elementsPtr in
|
|
elementsPtr.deinitialize(count: 1)
|
|
headerPtr.deinitialize(count: 1)
|
|
}
|
|
}
|
|
}
|
|
|
|
@available(*, deprecated)
|
|
extension NIOAtomic: Sendable {}
|