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d8f7f20c4b
The goal of doing this is to reduce the amount of boilerplate and repeated code w.r.t. Continuation. Having just added `resume()` in four places, I got the sense that there was a lot of common code that was being duplicated. I removed the Throwing variants of these types (they can be expressed as Continuation<T, E:Error> instead of ThrowingContinuation<E>) and I broke out a significant amount of common code between CheckedContinuation and UnsafeContinuation into an implementation-only protocol to avoid repeating it. D.R.Y. This change resolves rdar://74154769.
113 lines
3.1 KiB
Swift
113 lines
3.1 KiB
Swift
//===----------------------------------------------------------------------===//
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//
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2020 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See https://swift.org/LICENSE.txt for license information
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// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
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//
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//===----------------------------------------------------------------------===//
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import Swift
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@_implementationOnly import _SwiftConcurrencyShims
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/// A partial task is a unit of scheduleable work.
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@frozen
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public struct PartialAsyncTask {
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private var context: Builtin.Job
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public func run() { }
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}
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@frozen
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public struct UnsafeContinuation<T, E: Error>: _Continuation {
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@usableFromInline internal var context: Builtin.RawUnsafeContinuation
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@_alwaysEmitIntoClient
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internal init(_ context: Builtin.RawUnsafeContinuation) {
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self.context = context
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}
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@usableFromInline
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@_silgen_name("swift_continuation_resume")
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internal func _resume(returning value: __owned T)
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@_alwaysEmitIntoClient
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public func resume(returning value: __owned T) where E == Never {
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self._resume(returning: value)
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}
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@usableFromInline
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@_silgen_name("swift_continuation_throwingResume")
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internal func _resume(returningToThrowingFunction: __owned T)
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@_alwaysEmitIntoClient
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public func resume(returning value: __owned T) {
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self._resume(returningToThrowingFunction: value)
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}
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@usableFromInline
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@_silgen_name("swift_continuation_throwingResumeWithError")
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internal func _resume(throwing: __owned Error)
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@_alwaysEmitIntoClient
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public func resume(throwing error: __owned E) {
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self._resume(throwing: error)
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}
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}
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#if _runtime(_ObjC)
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// Intrinsics used by SILGen to resume or fail continuations.
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@_alwaysEmitIntoClient
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internal func _resumeUnsafeContinuation<T>(
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_ continuation: UnsafeContinuation<T, Never>,
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_ value: __owned T
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) {
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continuation.resume(returning: value)
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}
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@_alwaysEmitIntoClient
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internal func _resumeUnsafeThrowingContinuation<T>(
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_ continuation: UnsafeContinuation<T, Error>,
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_ value: __owned T
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) {
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continuation.resume(returning: value)
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}
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@_alwaysEmitIntoClient
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internal func _resumeUnsafeThrowingContinuationWithError<T>(
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_ continuation: UnsafeContinuation<T, Error>,
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_ error: __owned Error
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) {
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continuation.resume(throwing: error)
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}
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#endif
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/// The operation functions must resume the continuation *exactly once*.
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///
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/// The continuation will not begin executing until the operation function returns.
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@_alwaysEmitIntoClient
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public func withUnsafeContinuation<T>(
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_ fn: (UnsafeContinuation<T, Never>) -> Void
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) async -> T {
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return await Builtin.withUnsafeContinuation {
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fn(UnsafeContinuation<T, Never>($0))
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}
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}
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/// The operation functions must resume the continuation *exactly once*.
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///
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/// The continuation will not begin executing until the operation function returns.
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@_alwaysEmitIntoClient
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public func withUnsafeThrowingContinuation<T>(
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_ fn: (UnsafeContinuation<T, Error>) -> Void
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) async throws -> T {
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return try await Builtin.withUnsafeThrowingContinuation {
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fn(UnsafeContinuation<T, Error>($0))
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}
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}
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