ReSwift: ReSwift crashes on device (but not simulator)

Help! I have been chugging along using ReSwift (on 3.0, Swift3, XCode 8.3) and now for some reason upon initialization ReSwift is crashing (when I run it on my 10.3.1/iPhone7+ thru XCode). I hate these esoteric errors and am hoping beyond hope that someone has experienced anything remotely similar.

AppDelegate has the usual declaration

let store = Store<State>(reducer: AppReducer(), state: nil)

Then my first ViewController subscribes:

override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        
        store.subscribe(self) { state in
            state.authenticationState
        }
 }

ReSwift goes through the initialization process until it gets to my AppReducer, and BAM !

Thanks everyone,

–Bill

About this issue

Original URL
State: closed
Created 7 years ago
Comments: 45 (11 by maintainers)

Most upvoted comments

Hi Guys, finally I have a clue related with this issue.

The problem occurs after memory corrupted in 32 bit devices when the struct size (substate struct size) is > ~2100 bytes.

I’ve split my substates into smaller structs, so each structs byte size in main reducer < 2000 bytes. i.e inspecting using this command in main reducer.

po MemoryLayout.size(ofValue: initialSubState)

So far with this approach, the app working fine.

ngeplurk on Mar 18, 2019

I’ve created a bug in the swift JIRA. https://bugs.swift.org/browse/SR-11093

brianmclachlin on Jul 9, 2019

What should be the approach to deal with this in ReSwift? I’m currently using a guard, so that the appReducer does not create a ton of temporary AppState objects. However, every time I create a new substate I have to add it in two spots.

guard let state = state else {
    return AppState(
        userState: userReducer(action: action, state: nil),
        profileState: profileReducer(action: action, state: nil),
        ...
    )
}

return AppState(
    userState: userReducer(action: action, state: state.userState),
    profileState: profileReducer(action: action, state: state.profileState),
    ...
)

I can deal with this for now, but I think the documentation should be updated with an approach that is less gross. Instead of a struct could the AppState be a dictionary, so we gain that copy-on-write benefit?

brianmclachlin on Jul 16, 2019