Fix sync issues for dependency container access

[ianrumac]

Changes in this pull request

Checklist

• All unit tests pass.
• All UI tests pass.
• Demo project builds and runs.
• I added/updated tests or detailed why my change isn't tested.
• I added an entry to the CHANGELOG.md for any breaking changes, enhancements, or bug fixes.
• I have run ktlint in the main directory and fixed any issues.
• I have updated the SDK documentation as well as the online docs.
• I have reviewed the contributing guide

Greptile Summary

This PR fixes an AB-BA deadlock (tracked as SW-5092 / expo-superwall#194) that caused ANR in React Native by removing the synchronized(this) block from the dependencyContainer getter and replacing it with @Volatile on the backing field. The lock was unnecessary for the write-once field and created a deadlock cycle with the SynchronizedLazyImpl monitor on the entitlements lazy property. A new regression test is included that arms the exact interleaving that previously deadlocked and asserts both threads complete within a tight timeout.

Confidence Score: 4/5

Safe to merge — the fix is mechanically correct and well-tested; only a minor test-coverage gap remains.

The core change (replacing synchronized getter with @Volatile) is the right tool for a write-once field and correctly breaks the lock cycle. The regression test is well-designed and will catch regressions. The only finding is a P2: the subscriptionStatus lazy (same deadlock surface) is not covered by the test.

superwall/src/test/java/com/superwall/sdk/SuperwallConfigureDeadlockTest.kt — consider extending the test to cover the subscriptionStatus lazy property.

Important Files Changed

Filename	Overview
superwall/src/main/java/com/superwall/sdk/Superwall.kt	Replaces synchronized(this) getter for _dependencyContainer with a @Volatile field — correct fix for the AB-BA deadlock; also includes minor ktlint-driven indentation reformatting.
superwall/src/test/java/com/superwall/sdk/SuperwallConfigureDeadlockTest.kt	New regression guard that precisely arms the AB-BA deadlock interleaving; correctly detects if the lazy initializer re-enters the singleton monitor, though subscriptionStatus lazy is not also exercised.
CHANGELOG.md	Adds 2.7.13 entry documenting the ANR/deadlock fix.
version.env	Bumps version from 2.7.12 to 2.7.13.

Sequence Diagram

sequenceDiagram
    participant X as worker-1 (setup)
    participant Y as worker-2 (lazy init)
    Note over X,Y: BEFORE fix — AB-BA deadlock
    X->>X: synchronized(Superwall) → Lock A acquired
    Y->>Y: SynchronizedLazyImpl.getValue → Lock B acquired
    X-->>Y: needs Lock B (entitlements lazy)
    Y-->>X: needs Lock A (old synchronized getter)
    Note over X,Y: ❌ Deadlock — both threads blocked

    Note over X,Y: AFTER fix
    X->>X: synchronized(Superwall) → Lock A acquired
    Y->>Y: SynchronizedLazyImpl.getValue → Lock B acquired
    Y->>Y: volatile read of _dependencyContainer (no lock)
    Y->>Y: lazy initialized → Lock B released
    X->>X: reads entitlements (lazy already warm) → Lock A released
    Note over X,Y: ✅ Both threads complete

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Prompt To Fix All With AI

Fix the following 1 code review issue. Work through them one at a time, proposing concise fixes.

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### Issue 1 of 1
superwall/src/test/java/com/superwall/sdk/SuperwallConfigureDeadlockTest.kt:73-78
**`subscriptionStatus` lazy not covered by deadlock guard**

The `subscriptionStatus` property has the exact same AB-BA deadlock exposure as `entitlements` — its initializer is `by lazy { dependencyContainer.entitlements.status }`, which also calls through the `dependencyContainer` getter. The fix resolves both lazies simultaneously, but the regression guard only exercises `sw.entitlements`. A deadlock reintroduced specifically into the `subscriptionStatus` path (e.g., by wrapping its initializer in `synchronized`) would go undetected.

Consider adding a parallel read of `sw.subscriptionStatus` alongside `sw.entitlements` in Thread Y so both lazies are covered by the same test.

_{Reviews (1): Last reviewed commit: "Merge branch 'develop' into ir/fix/sync-..." | Re-trigger Greptile}

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