Overview › Memory Leaks

Potential Memory Leaks

96 concrete memory-leak risk patterns identified by static analysis: Handler / Runnable callbacks not cancelled, WebViews not destroyed, Coroutine Jobs not tracked, static Fragment references, listener/observer/receiver registration without unregister, and bitmap/cursor/animator resources not released.

Each finding has file path + line number; expand a row for the recommended fix.

FINDINGS

Critical

High

Medium

Distinct files

Leak patterns at a glance

Findings by leak type

Where memory pressure most likely originates

Severity distribution

Critical & High should be triaged first

What each pattern means

Pattern	Why it leaks	How to fix
HANDLER_LEAK	Anonymous `Handler`/`Runnable`/`postDelayed` retains an implicit reference to the enclosing Activity/Fragment. Pending callbacks survive destroy.	Static `Handler` + `WeakReference`, or migrate to `lifecycleScope.launch { delay() }`; always `removeCallbacksAndMessages(null)` in `onDestroyView`/`onDestroy`.
WEBVIEW	WebView holds a large native context (tab, GPU surface). Not calling `destroy()` leaks the renderer process.	`webView.destroy()` in `onDestroyView`; null out the field; never store `WebView` in a ViewModel or static.
COROUTINE_JOB	A coroutine launched from a custom `CoroutineScope` without storing the `Job` can outlive its component, holding callbacks alive.	Inside fragments, use `viewLifecycleOwner.lifecycleScope`. In helpers, accept the scope from the caller; never own one.
FRAGMENT_RETAIN	A `static` field referencing a Fragment singleton survives orientation changes and prevents the activity hierarchy from being garbage-collected.	Remove the static field; use `FragmentManager.findFragmentByTag` for lookup.
RECEIVER_NO_UNREG / OBSERVER_NO_UNREG / LISTENER_NO_UNREG	System-level callbacks (BroadcastReceiver, ContentObserver, location, sensor) keep the registrar alive until unregister.	Pair every register with an unregister in the matching teardown lifecycle method.
NETWORK_CALLBACK	Same: `ConnectivityManager.registerNetworkCallback` survives until `unregisterNetworkCallback`.	Unregister in `onDestroyView`.
ANIMATOR	`ObjectAnimator`/`ValueAnimator` held by the view system continue running and retain target views.	Track animators in a list; `cancel()` all in `onDetachedFromWindow`.
RUNNABLE	`view.postDelayed(runnable)` without `removeCallbacks` leaks the runnable + view chain.	Pair every `postDelayed` with `removeCallbacks` in `onDestroyView`.
INNER_CLASS_LEAK	A non-static inner class implicitly holds a reference to its outer class. Combined with long-lived containers (Handler, Runnable, BroadcastReceiver), this leaks the activity/fragment.	Make the inner class `static`; pass dependencies via `WeakReference`.
ADAPTER_CTX	Adapters / custom views holding a long-lived Activity context (instead of `applicationContext`) outlive the activity.	Use `@ApplicationContext` for any field-level reference where you only need to inflate.
BITMAP	Static `Bitmap` fields and undecoded `BitmapFactory.decodeResource` outputs hold native pixel buffers.	Move to instance scope; `recycle()` when no longer needed (or use Coil's lifecycle-aware loading).
RESOURCE_NO_RELEASE	`Cursor`, `MediaPlayer`, `Camera` etc. hold native resources until explicitly closed.	Use try-with-resources or `use { }`; close in matching teardown.
SUBSCRIPTION	RxJava subscriptions / Flow collections that keep references via captured state.	Use `CompositeDisposable.clear()` in onDestroy; for Flow use `repeatOnLifecycle`.

Hot files

The 5 files with the most memory-leak findings — start here.

6 findings

Costco/src/main/java/com/costco/app/android/ui/main/MainActivity.java

6 findings

Costco/src/main/java/com/costco/app/android/ui/main/MainWebViewFragment.kt

6 findings

Costco/src/main/java/com/mobeta/android/dslv/ResourceDragSortCursorAdapter.java

4 findings

Costco/src/main/java/com/costco/app/android/ui/pharmacy/PharmacyWebViewFragment.kt

4 findings

Costco/src/main/java/com/costco/app/android/ui/findastore/map/FindAStoreFragment.java

All memory-leak findings

Costco Android · Code Review Report · Generated 2026-05-07 · 238 machine-curated findings