Art: Verification of X took Y ms

Question

I've got a warning in my logcat:

W/art: Verification of void com.myapp.LoginFragment$override.lambda$logIn$5(com.myapp.LoginFragment, java.lang.Throwable) took 217.578ms

Here's the code:

subscription = viewModel.logIn()
            .observeOn(AndroidSchedulers.mainThread())
            .subscribe(
               this::showStudioSelection,
               error -> {
                    ErrorResponse errorResponse = ErrorResponseFactory.create(error);

                    if (errorResponse.code() == ApiResult.BAD_REQUEST) {
                       Snackbar.make(getView(), R.string.login_bad_credentials, Snackbar.LENGTH_LONG)
                            .setAction(android.R.string.ok, v -> {})
                            .show();
                    } else {
                        Snackbar.make(getView(), "Unknown error " + errorResponse.code(), Snackbar.LENGTH_LONG)
                            .setAction(android.R.string.ok, v -> {})
                            .show();
                    }
                    viewModel.updateLoginButtonState();
                 }
            );

220ms is quite a lot (and I feel like I'm noticing a lag on startup of that Fragment).

I'm using RxJava and retrolambda, but this is not the only spot where this message pops up so I don't think it's directly related.

How can I influence the verification time? Is it even worth it?

It seems like it has something to do with cyclomatic complexity, since I could get rid of the waring by removing the Snackbar.make calls in the if with some more dry code:

String errorMessage;
if (errorResponse.code() == ApiResult.BAD_REQUEST) {
    errorMessage = getString(R.string.login_bad_credentials);
} else {
    errorMessage = "Unknown error " + errorResponse.code();
}

Cunning

Answer 1

It looks like this is part of the 'backwards compatibility' requirement for the newer ART runtime. That is, apps built against DALVIK need to be able to run on ART as well.

If you run a DVM app on an ART system, you'll see this message the first time it runs when dex2oat converts the application. If you build the application targeting ART, the app will no longer be able to run on DVM, but the OAT conversion will happen during installation and is not seen at runtime.

Source: The Art of Art note this is part one of a three part investigation of ART and you may need to check parts two and three

Tweedy

I am seeing this message every time the app runs, not just the first time. I see the message, kill the app, start it again, and see the message again. – Axolotl

Did you happen to ever find a resolution for this? I'm getting this when running an android app using bazel. It doesn't happen when I build the same project using gradle. – Incandesce

It's just a warning. Annoying but not an issue. – Helenhelena

In my case verification of one of my methods took 900+ ms - it's an issue, when you need to show your app asap. – Pockmark

@David O'Meara It's not just a warning. This useless verification takes a lot of time. Annoyance IS an issue. – Aught

Answer 2

For anyone in year 2020 and beyond looking for the solution -- Android 11 has the following setting in the Developer options:

It's ON by default. Turn it OFF to get rid of the annoying delays every time app is launched when debugging.

Summertree

And reinstall an application. – Leonard

this answer should be marked as the accepted. – Forefinger

I upvoted before trying - turns out this solution for my app leads to an instant native crash after splash screen with message "null pointer dereference". Better not mark this as accepted. Can only run the app in debugger with the verify flag enabled. – Astrix

How will I be able to disable it in a Firebase test lab device? Need a solution to disable it via compiler args or something – Clisthenes