The New Memory Manager Explained
How modern Kotlin/Native handles shared state.
The New Memory Manager Explained is a free Kotlin Multiplatform Academy lesson on CoddyKit — lesson 1 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Kotlin Multiplatform Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Memory on Kotlin/Native
On iOS your shared code runs as Kotlin/Native, which manages its own memory. Knowing how it works keeps your app stable.
The Old Days Were Painful
The original model froze objects so threads could share them. That freezing rule caused confusing crashes and a lot of workarounds.
Enter the New Manager
Modern Kotlin/Native ships a new memory manager that drops the freezing rule entirely. Shared objects just work across threads now.
No More InvalidMutabilityException
You no longer hit InvalidMutabilityException when touching state from another thread. Mutable objects can cross threads freely.
It Feels Like the JVM
The new model behaves much like the JVM you know from Android. The same shared Kotlin runs with familiar semantics on both.
Garbage Collection Included
A real garbage collector reclaims unused objects automatically. You write normal Kotlin and let the runtime clean up after you.
It Is the Default Now
Recent Kotlin versions enable the new manager by default, so a fresh KMP project already uses it. No special flag needed.
Coroutines Just Work
Because state is no longer frozen, coroutines can carry mutable data across dispatchers on iOS exactly like they do on Android.
launch(Dispatchers.Default) { state.count += 1 }Shared State Across Threads
You can read and write a normal object from several threads without freezing it first. The runtime handles the bookkeeping for you.
val cache = mutableMapOf<String, User>()Still Mind Concurrency
The manager removes freezing, but it does not remove race conditions. Two threads writing the same field still need coordination.
Why This Matters for You
The new manager means your shared logic ports to iOS with almost no special handling. You focus on features, not memory rules.
Quick Check
A quick check on the memory manager.
Recap
You saw how the new memory manager ends freezing, adds garbage collection, and makes shared Kotlin feel JVM-like on iOS. 🎉
Frequently asked questions
Is the “The New Memory Manager Explained” lesson free?
Yes — the full text of “The New Memory Manager Explained” is free to read here on the web, and the Kotlin Multiplatform Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Kotlin Multiplatform Academy course, upgrade to CoddyKit PRO.
What will I learn in “The New Memory Manager Explained”?
How modern Kotlin/Native handles shared state. You practise Kotlin Multiplatform Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Kotlin Multiplatform Academy?
No prior experience is required. Kotlin Multiplatform Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 1 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “The New Memory Manager Explained” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Kotlin Multiplatform Academy lesson?
Yes. Every Kotlin Multiplatform Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- The New Memory Manager Explained
- Main vs Background on iOS
- Mutable State & Race Conditions
- Debug Freezes & Threading Crashes