AtomicInt.swift.gyb

//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//

// NOTE: older runtimes had Swift._stdlib_AtomicInt as the ObjC name.
// The two must coexist, so it was renamed. The old name must not be
// used in the new runtime. _TtCs18__stdlib_AtomicInt is the mangled
// name for Swift.__stdlib_AtomicInt
@available(swift, deprecated: 4.2, obsoleted: 5.0)
@_objcRuntimeName(_TtCs18__stdlib_AtomicInt)
public final class _stdlib_AtomicInt {
  internal var _value: Int

  internal var _valuePtr: UnsafeMutablePointer<Int> {
    return _getUnsafePointerToStoredProperties(self).assumingMemoryBound(
      to: Int.self)
  }

  public init(_ value: Int = 0) {
    _value = value
  }

  public func store(_ desired: Int) {
    return _swift_stdlib_atomicStoreInt(object: _valuePtr, desired: desired)
  }

  public func load() -> Int {
    return _swift_stdlib_atomicLoadInt(object: _valuePtr)
  }

% for operation_name, operation in [ ('Add', '+'), ('And', '&'), ('Or', '|'), ('Xor', '^') ]:
  @discardableResult
  public func fetchAnd${operation_name}(_ operand: Int) -> Int {
    return _swift_stdlib_atomicFetch${operation_name}Int(
      object: _valuePtr,
      operand: operand)
  }

  public func ${operation_name.lower()}AndFetch(_ operand: Int) -> Int {
    return fetchAnd${operation_name}(operand) ${operation} operand
  }
% end

  public func compareExchange(expected: inout Int, desired: Int) -> Bool {
    var expectedVar = expected
    let result = _swift_stdlib_atomicCompareExchangeStrongInt(
      object: _valuePtr,
      expected: &expectedVar,
      desired: desired)
    expected = expectedVar
    return result
  }
}

@available(*, unavailable)
extension _stdlib_AtomicInt: Sendable {}

@usableFromInline // used by SwiftPrivate._stdlib_AtomicInt
internal func _swift_stdlib_atomicCompareExchangeStrongInt(
  object target: UnsafeMutablePointer<Int>,
  expected: UnsafeMutablePointer<Int>,
  desired: Int) -> Bool {
#if _pointerBitWidth(_64)
  let (oldValue, won) = Builtin.cmpxchg_seqcst_seqcst_Int64(
    target._rawValue, expected.pointee._value, desired._value)
#elseif _pointerBitWidth(_32)
  let (oldValue, won) = Builtin.cmpxchg_seqcst_seqcst_Int32(
    target._rawValue, expected.pointee._value, desired._value)
#else
#error("Unknown platform")
#endif
  expected.pointee._value = oldValue
  return Bool(won)
}


// FIXME: ideally it should not be here, at the very least not public, but
// @usableFromInline internal to be used by SwiftPrivate._stdlib_AtomicInt
public // Existing uses outside stdlib
func _swift_stdlib_atomicLoadInt(
  object target: UnsafeMutablePointer<Int>) -> Int {
#if _pointerBitWidth(_64)
  let value = Builtin.atomicload_seqcst_Int64(target._rawValue)
  return Int(value)
#elseif _pointerBitWidth(_32)
  let value = Builtin.atomicload_seqcst_Int32(target._rawValue)
  return Int(value)
#else
#error("Unknown platform")
#endif
}

@usableFromInline // used by SwiftPrivate._stdlib_AtomicInt
internal func _swift_stdlib_atomicStoreInt(
  object target: UnsafeMutablePointer<Int>,
  desired: Int) {
#if _pointerBitWidth(_64)
  Builtin.atomicstore_seqcst_Int64(target._rawValue, desired._value)
#elseif _pointerBitWidth(_32)
  Builtin.atomicstore_seqcst_Int32(target._rawValue, desired._value)
#else
#error("Unknown platform")
#endif
}

% for operation in ['Add', 'And', 'Or', 'Xor']:
// Warning: no overflow checking.
// FIXME: ideally it should not be here, at the very least not public, but
// @usableFromInline internal to be used by SwiftPrivate._stdlib_AtomicInt
public // Existing uses outside stdlib
func _swift_stdlib_atomicFetch${operation}Int(
  object target: UnsafeMutablePointer<Int>,
  operand: Int) -> Int {
  let rawTarget = UnsafeMutableRawPointer(target)
#if _pointerBitWidth(_64)
  let value = _swift_stdlib_atomicFetch${operation}Int64(
    object: rawTarget.assumingMemoryBound(to: Int64.self),
    operand: Int64(operand))
#elseif _pointerBitWidth(_32)
  let value = _swift_stdlib_atomicFetch${operation}Int32(
    object: rawTarget.assumingMemoryBound(to: Int32.self),
    operand: Int32(operand))
#else
#error("Unknown platform")
#endif
  return Int(value)
}

%   for bits in [ 32, 64 ]:

// Warning: no overflow checking.
@usableFromInline // used by SwiftPrivate._stdlib_AtomicInt
internal func _swift_stdlib_atomicFetch${operation}Int${bits}(
  object target: UnsafeMutablePointer<Int${bits}>,
  operand: Int${bits}) -> Int${bits} {

  let value = Builtin.atomicrmw_${operation.lower()}_seqcst_Int${bits}(
    target._rawValue, operand._value)

  return Int${bits}(value)
}

%   end

% end