Marked AsyncIterators as not Sendable

Author: rafaelcepeda

Sources/GRPCCore/Call/Client/Internal/RetryDelaySequence.swift

@@ -45,7 +45,7 @@ struct RetryDelaySequence: Sequence, Sendable {
   }
 
   @usableFromInline
-  struct Iterator: IteratorProtocol, Sendable {
+  struct Iterator: IteratorProtocol {
     @usableFromInline
     let policy: RetryPolicy
     @usableFromInline
@@ -99,3 +99,6 @@ struct RetryDelaySequence: Sequence, Sendable {
     }
   }
 }
+
+@available(*, unavailable)
+extension RetryDelaySequence.Iterator: Sendable {}

Sources/GRPCCore/Coding/CompressionAlgorithm.swift

@@ -107,7 +107,7 @@ extension CompressionAlgorithmSet {
       return Iterator(algorithmSet: self.algorithmSet)
     }
 
-    public struct Iterator: IteratorProtocol, Sendable {
+    public struct Iterator: IteratorProtocol {
       private let algorithmSet: CompressionAlgorithmSet
       private var iterator: IndexingIterator<[CompressionAlgorithm.Value]>
 
@@ -128,3 +128,6 @@ extension CompressionAlgorithmSet {
     }
   }
 }
+
+@available(*, unavailable)
+extension CompressionAlgorithmSet.Elements.Iterator: Sendable {}

Sources/GRPCCore/Streaming/Internal/AsyncSequenceOfOne.swift

@@ -49,7 +49,7 @@ struct AsyncSequenceOfOne<Element: Sendable, Failure: Error>: AsyncSequence, Sen
   }
 
   @usableFromInline
-  struct AsyncIterator: AsyncIteratorProtocol, Sendable {
+  struct AsyncIterator: AsyncIteratorProtocol {
     @usableFromInline
     private(set) var result: Result<Element, Failure>?
 
@@ -74,3 +74,6 @@ struct AsyncSequenceOfOne<Element: Sendable, Failure: Error>: AsyncSequence, Sen
     }
   }
 }
+
+@available(*, unavailable)
+extension AsyncSequenceOfOne.AsyncIterator: Sendable {}

Sources/GRPCCore/Streaming/Internal/BroadcastAsyncSequence.swift

@@ -89,7 +89,7 @@ struct BroadcastAsyncSequence<Element: Sendable>: Sendable, AsyncSequence {
 @available(gRPCSwift 2.0, *)
 extension BroadcastAsyncSequence {
   @usableFromInline
-  struct AsyncIterator: AsyncIteratorProtocol, Sendable {
+  struct AsyncIterator: AsyncIteratorProtocol {
     @usableFromInline
     let _storage: _BroadcastSequenceStorage<Element>
     @usableFromInline
@@ -111,6 +111,9 @@ extension BroadcastAsyncSequence {
   }
 }
 
+@available(*, unavailable)
+extension BroadcastAsyncSequence.AsyncIterator: Sendable {}
+
 // MARK: - Continuation
 
 @available(gRPCSwift 2.0, *)