How does Koin manage memory for single, factory, and scoped objects?

I’m using Koin for dependency injection in my Kotlin app and need clarification on how memory is managed for different object definitions like single, factory, and scoped.

Memory Allocation Questions:

1. How does Koin manage memory for single, factory, and scoped objects? For single, does Koin retain the object until the app closes? For factory, does it discard the object immediately after use? And for scoped, how does it handle memory when the scope ends? Garbage Collection:

2. How does Koin ensure objects are cleaned up by the garbage collector? Can this lead to memory leaks?

3. Has anyone encountered memory-related issues with Koin? Any strategies to manage memory effectively in large apps?

I can't find any deep document about this topics.

Thanks for any insights or best practices!

1. Memory Management for Different Object Definitions: Single: A single in Koin is a singleton object, meaning that it will be created only once during the application's lifecycle.

Koin retains a single instance of the object in memory throughout the lifecycle of the app, i.e., until the app closes. Once the object is created, Koin will reuse the same instance whenever it is injected. It is essentially a long-lived object.

This means Koin will hold a reference to the object for as long as the app is running (or until explicitly removed from the Koin container), so it is not discarded or garbage collected until the application shuts down.

Factory: A factory in Koin is a function that returns a new instance of an object each time it's requested.

When you define a factory in Koin, the framework creates a new instance each time the object is requested. These instances are discarded immediately after use (i.e., they are not retained in memory by Koin).

The object is typically eligible for garbage collection once it goes out of scope (when no longer referenced). Koin does not retain the object in memory after it’s no longer needed, which means it is short-lived.

Scoped: A scope in Koin allows you to define an object that lives only within a particular scope (e.g., a specific activity, fragment, or component in your app).

Objects defined in a scope will be created when the scope is created and retained until the scope is closed. When the scope ends (e.g., the activity or fragment lifecycle ends), Koin will release the object and it becomes eligible for garbage collection.

Koin will retain the object within the scope, and when the scope is closed, Koin ensures that the object is disposed of correctly. This ensures the object is not retained longer than necessary and avoids memory leaks associated with unused objects.

2. How Does Koin Ensure Objects Are Cleaned Up by the Garbage Collector? Can This Lead to Memory Leaks? Koin relies on the fact that when objects are no longer referenced, they will be automatically cleaned up by Kotlin's garbage collector (GC). For single objects, this happens when Koin itself is destroyed (e.g., at app shutdown). For factory and scoped objects, once they are no longer in use (e.g., references to them are cleared), they can be garbage collected.

Koin itself does not directly cause memory leaks, but improper handling of scopes or object references could lead to leaks. For example:

If you keep a reference to a Koin-provided object (e.g., a single or scoped object) outside of the lifecycle of the scope in which it was created (for example, keeping a reference to an activity-scoped object after the activity is destroyed), the object won't be garbage collected even if it’s no longer needed, causing a potential memory leak. Another possible issue could be if you forget to close a scope manually, causing objects within that scope to remain in memory longer than expected.