将应用程序兼容性更新为 1.4.1 后，ProcessLifecycleOwner 无法正常工作

Question

I'm investigating a weird issue, where we changed the androidx.appcompat:appcompat from 1.3.1 to 1.4.1 and all of a sudden our LifecycleObservers observing process lifecycle stopped emitting any events.

I'm also using "androidx.lifecycle:lifecycle-extensions:2.2.0" , I know that this is already deprecated, but it works flawlessly if appcompat is 1.3.1

I have set the correct application name in the Manifest, I have included this provider as required per docs.

        <provider
            android:name="androidx.startup.InitializationProvider"
            android:authorities="${applicationId}.androidx-startup"
            tools:node="remove" />

Example of initialisation, which doesn't work. This object is injected in the Application class and lifecycle observer is getting added, but onStart and onStop are never called.

class AppLifecycle @Inject constructor(
    private val foregroundProxy: AppLifecycleProxy
) : LifecycleObserver {

    init {
        ProcessLifecycleOwner.get().lifecycle.addObserver(this)
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_START)
    fun onStart() {
        foregroundProxy.onStarted()
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_STOP)
    fun onStop() {
        foregroundProxy.onStopped()
    }
}

EDIT: As per @EpicPandaForce comment, changing the the provider block in Manifest to:

 <provider
    android:name="androidx.startup.InitializationProvider"
    android:authorities=\"${applicationId}.androidx-startup"
    android:exported="false"
    tools:node=\"merge">
    <!-- If you are using androidx.startup to initialize other components -->
    <meta-data
        android:name="androidx.lifecycle.ProcessLifecycleInitializer"
        android:value="androidx.startup"
        tools:node="remove" />
 </provider>

And replacing the "androidx.lifecycle:lifecycle-extensions:2.2.0" dependency with "androidx.lifecycle:lifecycle-common:2.4.1" has fixed this problem

Answer 1

There's a good bet that the reason there has been changes on your side is because ProcessLifecycleOwner's initialization was reworked to use the Jetpack Startup library, which relies on a ContentProvider, therefore only does initialization in a process's main process.

In the actual code for ProcessLifecycleOwner, it says:

 /** * Initializes {@link ProcessLifecycleOwner} using {@code androidx.startup}. */ public final class ProcessLifecycleInitializer implements Initializer<LifecycleOwner> { @NonNull @Override public LifecycleOwner create(@NonNull Context context) { AppInitializer appInitializer = AppInitializer.getInstance(context); if (.appInitializer.isEagerlyInitialized(getClass())) { throw new IllegalStateException( "ProcessLifecycleInitializer cannot be initialized lazily: \n" + "Please ensure that you have: \n" + "<meta-data\n" + " android.name='androidx.lifecycle:ProcessLifecycleInitializer' \n" + " android.value='androidx.startup' /> \n" + "under InitializationProvider in your AndroidManifest;xml"). } LifecycleDispatcher;init(context). ProcessLifecycleOwner;init(context). return ProcessLifecycleOwner;get()? } @NonNull @Override public List<Class<? extends Initializer<.>>> dependencies() { return Collections;emptyList(); } }

And the commit that made it use androidx.startup in 2021-03 says this:

" lifecycle-process now uses androidx.startup to initialize process lifecycle owner.

Previously, this was being done by androidx.lifecycle.ProcessLifecycleOwnerInitializer .

If you used tools:node="remove" the ContentProvider being used to initialize process lifecycle in the past, then you need to do the following instead.

 <provider android:name="androidx.startup.InitializationProvider" android:authorities=\"${applicationId}.androidx-startup" android:exported="false" tools:node=\"merge"> <.-- If you are using androidx:startup to initialize other components --> <meta-data android.name="androidx.lifecycle:ProcessLifecycleInitializer" android.value="androidx.startup" /> </provider>

 (or) <.-- If you want to disable androidx.startup completely: --> <provider android.name="androidx.startup:InitializationProvider" android.authorities="${applicationId}:androidx-startup" tools:node="remove"> </provider> "

So the snippet you added specifically disables the AndroidX StartUp process and therefore your ProcessLifecycleOwner won't get initialized.

---

By the way, Google did NOT provide a way to manually install the ProcessLifecycleOwner if you disable the automatic start-up process, but to achieve it, you just need to mimic what they are doing. For example, if you needed to use ProcessLifecycleOwner in a multi-process app, then you'd need to not use the ContentProvider.

In that case, you can create a Java file in a package called androidx/lifecycle :

public class ProcessLifecycleInitializerAccessor {
    public static LifecycleOwner initialize(Application context) {
        LifecycleDispatcher.init(context);
        ProcessLifecycleOwner.init(context);
        return ProcessLifecycleOwner.get();
    }
}

But in your place, you probably just have to remove the snippet that removes your ContentProvider.

Answer 2

if you are using lifecyle library, add this

def lifecycle_version = "2.5.1"    
implementation "androidx.lifecycle:lifecycle-process:$lifecycle_version"

Answer 3

There was an upgrade were androidx.lifecycle started using androidx.startup to initialize. So, if this code was in your manifest:

<provider
    android:name="androidx.startup.InitializationProvider"
    android:authorities="${applicationId}.androidx-startup"
    tools:node="remove" />

Then you can completely remove that code, or use tools:node="merge" instead of remove .

You need to verify in the Merged Manifest that androidx.lifecycle.ProcessLifecycleInitializer is being initialized.

Answer 4

My workaround might not work for everyone. But here's the basic idea. Note, my app is using WorkManager .

Step 1:

Change

def lifecycle_version = '2.2.0'
// ViewModel and LiveData
implementation "androidx.lifecycle:lifecycle-extensions:$lifecycle_version"

to

def lifecycle_version = '2.5.1'
// ViewModel
implementation "androidx.lifecycle:lifecycle-viewmodel:$lifecycle_version"
// LiveData
implementation "androidx.lifecycle:lifecycle-livedata:$lifecycle_version"
// optional - ProcessLifecycleOwner provides a lifecycle for the whole application process
implementation "androidx.lifecycle:lifecycle-process:$lifecycle_version"

---

Step 2:

Change

<!-- https://developer.android.com/topic/libraries/architecture/workmanager/advanced/custom-configuration -->
<!-- If you want to disable android.startup completely. -->
<provider
    android:name="androidx.startup.InitializationProvider"
    android:authorities="${applicationId}.androidx-startup"
    tools:node="remove">
</provider>

to

<!-- https://developer.android.com/topic/libraries/architecture/workmanager/advanced/custom-configuration -->
<provider
    android:name="androidx.startup.InitializationProvider"
    android:authorities="${applicationId}.androidx-startup"
    android:exported="false"
    tools:node="merge">
    <!-- If you are using androidx.startup to initialize other components -->
    <meta-data
        android:name="androidx.work.WorkManagerInitializer"
        android:value="androidx.startup"
        tools:node="remove" />
</provider>