mirror of
https://github.com/google/app-check
synced 2026-11-10 22:05:53 +05:45
c7eb17e554
Signed-off-by: Nick Cooke <36927374+ncooke3@users.noreply.github.com> Co-authored-by: Nick Cooke <36927374+ncooke3@users.noreply.github.com> Co-authored-by: Nick Cooke <nickcooke@google.com>
54 lines
1.9 KiB
Swift
54 lines
1.9 KiB
Swift
// Copyright 2026 Google LLC
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
import Foundation
|
|
|
|
/// A wrapper around `CheckedContinuation` that ensures it is resumed exactly once.
|
|
/// If the underlying completion block is invoked multiple times (e.g. by a misbehaving
|
|
/// third-party provider), subsequent resumes are safely ignored instead of trapping.
|
|
/// Note: Like `CheckedContinuation`, this does not enforce that a resume is ever
|
|
/// called. If the underlying block never invokes the handler, the awaiting task will hang.
|
|
public final class SafeContinuation<T: Sendable, E: Error>: @unchecked Sendable {
|
|
private var continuation: CheckedContinuation<T, E>?
|
|
private let lock = NSLock()
|
|
|
|
init(_ continuation: CheckedContinuation<T, E>) {
|
|
self.continuation = continuation
|
|
}
|
|
|
|
public func resume(returning value: T) {
|
|
lock.lock()
|
|
let cont = continuation
|
|
continuation = nil
|
|
lock.unlock()
|
|
cont?.resume(returning: value)
|
|
}
|
|
|
|
public func resume(throwing error: E) {
|
|
lock.lock()
|
|
let cont = continuation
|
|
continuation = nil
|
|
lock.unlock()
|
|
cont?.resume(throwing: error)
|
|
}
|
|
}
|
|
|
|
public func withSafeCheckedThrowingContinuation<T: Sendable>(_ body: (SafeContinuation<T, Error>)
|
|
-> Void) async throws -> T {
|
|
return try await withCheckedThrowingContinuation { continuation in
|
|
let safeContinuation = SafeContinuation(continuation)
|
|
body(safeContinuation)
|
|
}
|
|
}
|