I have enabled runtime concurrency warnings to check for future problems concerning concurrency: Build Setting / Other Swift Flags:
-Xfrontend -warn-concurrency -Xfrontend -enable-actor-data-race-checks
When trying to call the async form of PHPhotoLibrary.shared().performChanges{}
I get the following runtime warning: warning: data race detected: @MainActor function at ... was not called on the main thread
in the line containing performChanges.
My sample code inside a default Xcode multi platform app template is as follows:
import SwiftUI
import Photos
@MainActor
class FotoChanger{
func addFotos() async throws{
await PHPhotoLibrary.requestAuthorization(for: .addOnly)
try! await PHPhotoLibrary.shared().performChanges{
let data = NSDataAsset(name: "Swift")!.data
let creationRequest = PHAssetCreationRequest.forAsset()
creationRequest.addResource(with: .photo, data: data, options: PHAssetResourceCreationOptions())
}
}
}
struct ContentView: View {
var body: some View {
ProgressView()
.task{
try! await FotoChanger().addFotos()
}
}
}
You would have to have a Swift data asset inside the asset catalog to run the above code, but the error can even be recreated if the data is invalid.
But what am I doing wrong? I have not found a way to run perform changes, the block or whatever causes the error on the main thread.
PS: This is only test code to show the problem, don't mind the forced unwraps.