fix: release ObjectManager's JS handles and JNI weak refs at teardown - #2008
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📝 WalkthroughWalkthroughThe PR adds ChangesRuntime wrapper teardown
Estimated code review effort: 3 (Moderate) | ~20 minutes Merge Risk: ⚪ Minimal · up to The PR adds explicit teardown cleanup for JavaScript handles and JNI weak references; no actionable merge-blocking risk remains based on the supplied evidence. Possibly related issues
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ObjectManager had no destructor at all. `delete m_objectManager` ran the implicit one, which destroyed the containers and abandoned everything they pointed at. The expensive part is the JNI weak global refs. m_cache holds one per entry, up to its capacity of 1000, and LRUCache only ever ran its evict callback under capacity pressure or explicit invalidation -- never at destruction, since it had no destructor either. So a worker that touched Java objects abandoned its whole cache when it died. ART's weak-global table is bounded, so this is not merely a leak: enough worker cycles exhaust it and ART aborts. The JS side leaked too. Every linked object owns a Persistent<Object>, a JSInstanceInfo and an ObjectWeakCallbackState, freed only from the GC finalizer -- and V8 does not run weak callbacks when an isolate is disposed. In the default `none` marking mode the finalizer additionally re-arms SetWeak while the Java counterpart is alive, so those wrappers are deliberately retained and are therefore all still live at teardown. Split across the two windows teardown actually has: - ReleaseAllRegistered(), called from DestroyRuntime while the isolate is alive and locked: clears each wrapper's JsInfo internal field before freeing the JSInstanceInfo it points at, resets and deletes the Persistent, and releases m_poJsWrapperFunc. - ~ObjectManager, reached from ~Runtime once the isolate is gone and while the thread is still attached to the JVM: clears the LRU cache, which now evicts through the callback. It touches no v8 handle. That ordering is not incidental: Persistent::Reset() after Isolate::Dispose writes into a freed handle table, and the JNI eviction has to happen before ~Runtime drops the com.tns.Runtime global ref, which ObjectManager calls through. m_idToObject now maps to ObjectWeakCallbackState* rather than the bare Persistent*. The state was created and handed to SetWeak but stored nowhere, so teardown had no way to reach it or the JSInstanceInfo. That also lets ReleaseJSInstance free the state, which it never did.
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In `@test-app/runtime/src/main/cpp/ObjectManager.cpp`:
- Around line 473-488: Update the null-JSInstanceInfo path in
JSObjectFinalizer() to erase the corresponding m_idToObject entry before
deleting callbackState, and delete its owned JSInstanceInfo there as well.
Preserve the existing bulk teardown behavior in DestroyRuntime while ensuring no
stale map entry can reference freed state.
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test-app/runtime/src/main/cpp/LRUCache.htest-app/runtime/src/main/cpp/ObjectManager.cpptest-app/runtime/src/main/cpp/ObjectManager.htest-app/runtime/src/main/cpp/Runtime.cpp
…dropped ReleaseNativeCounterpart frees the JSInstanceInfo and clears the JsInfo internal field but leaves the m_idToObject entry in place. The finalizer that later collects the wrapper then takes its "no JSInstanceInfo" branch, which freed the callback state without unregistering it, so the map was left pointing at freed memory -- and the teardown sweep added here would free it a second time. The finalizer now unregisters via an id carried on the callback state, and ReleaseNativeCounterpart clears the state's back-pointer to the JSInstanceInfo it frees.
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…p robustness (#2013) * fix: runtime lifetime — deferred leaks, cross-isolate sharing, startup robustness Works through the tracking issue left by #2006/#2008, minus the HMRSupport item (handled separately). Startup: - Main-runtime election and the once-per-process V8 initialization now happen in one critical section, so two concurrent bootstraps cannot both elect themselves and overwrite Runtime::platform / s_mainEventLoop. A runtime that loses the election waits for the main runtime to publish the metadata tree it reads, instead of relying on call ordering. - A native initialization that throws after Isolate::New is unwound through the existing two teardown windows rather than left half-built; the Runtime itself is freed instead of leaking with its isolate still in the caches. Leaks: - MetadataNodeCache now owns every callback payload handed to V8 as External or FunctionTemplate data (MethodCallbackData, FieldCallbackData, PropertyCallbackData, TypeMetadata, ExtendedClassCallbackData). V8 finalizes none of them, so they leaked on every GC. An arena, because the same MethodCallbackData is shared between a prototype method, CtorCacheData and derived classes. - ModuleInternal::m_loadedModules is released at teardown, deduplicated by pointer (a module is cached under two keys), and a failed load no longer leaks its module handle. - The JS error handed to Java as jsValueAddress is now an id into a per-runtime table instead of a raw Persistent* Java could never free. The entry is dropped when the error is converted back, when the throwable is collected, or with the runtime — this was the only leak that grew inside a live runtime. Cross-isolate sharing: - MetadataNode's three process-wide node caches are guarded. The lock covers map access only and is dropped around the metadata reader. - MetadataReader's node vector, value-buffer bump allocator, type-name cache and memoized node types are guarded by a reentrant lock that can be released to zero mid-section, so it is never held across the Java call that resolves an unknown type (ART class loading, and dex generation on the .extend() path). GetNodeById is bounds-checked. Also makes IsolateDisposer.h's two namespace-scope definitions inline (ODR). * refactor: move isolate-bound objects into RuntimeState `isolateBoundObjects_` was a process-wide Isolate*-keyed map behind a mutex -- the same shape RuntimeState exists to remove -- and it held exactly one object per runtime: Timers. Timers now lives in RuntimeState like every other per-runtime subsystem, so the map, its mutex and the unique_void_ptr machinery are deleted rather than made inline, which resolves the ODR item by removing the definitions. disposeIsolate stays for the two builtin-layer hooks. Timers is consequently destroyed at m_state->Clear() instead of inside disposeIsolate. ~Timers -> Destroy() touches only its own task map, the event loop and the tasks' Java token peers -- nothing torn down in between -- and both the isolate and JNI are still alive at Clear(), which is what resetting the task handles and deleting the token global refs require. * refactor: move the builtin layer's isolate state into RuntimeState BuiltinLoader kept two Isolate*-keyed process-wide maps (isolateToPrimordials, isolateToBuiltinRequire) and NsBuiltinModules a third (isolateToRealm), each behind its own mutex -- the same shape RuntimeState exists to remove. The primordials lookup runs on every builtin call, so that one took a lock on a hot path to reach state that was never actually shared. All three become per-runtime state: a BuiltinRealm holding the two handles as v8::Globals, and RealmState, which was already a per-runtime struct with a destructor. Reaching either is now an isolate data-slot read plus a vector index, and both are released with the runtime while its isolate is alive. GetRealm can now return null (the runtime has begun tearing down), so its four callers degrade rather than resurrect state teardown already released; Instantiate keeps its contract of leaving an exception pending. With nothing left to release per isolate, disposeIsolate and IsolateDisposer are deleted along with the DestroyRuntime call site. RealmState and the BuiltinLoader handles are consequently destroyed at m_state->Clear() instead; neither destructor runs JS or touches anything torn down in between, and ~RealmState only deletes v8::Persistents, which never call into V8. * fix: unique JS error handle ids, and diagnose bad metadata node ids Two review findings on this branch. The JS error handle id was minted from a per-runtime counter, so every runtime produced 1, 2, 3... A throwable converted back to JS on a runtime other than the one that created it would then find an unrelated entry under the same id and consume it, instead of missing and falling back to rebuilding the error from the Java throwable. Ids are now unique process-wide, which is what makes the table lookup itself the ownership check. GetNodeById's new bounds check turned an out-of-range read into a nullptr its callers still dereferenced. It now logs the offending id, ReadTypeName and the array-element lookup in GetNodeType throw a NativeScriptException naming the problem, and GetBaseClassNode returns null -- which every caller already treats as "no base class". The assert it relied on was a no-op in release, where the bounds check was missing entirely. Also asserts the ownership precondition in StateMutex::Unlock and ReleaseAll: an unmatched unlock would wrap depth_ and hold the mutex forever, and a non-owner ReleaseAll would drop another thread's lock mid-section.
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Problem
ObjectManagerhas no destructor.delete m_objectManagerruns the implicit one, which destroys the containers and abandons everything they point at.The expensive part: JNI weak global refs
m_cache(anLRUCache<int, jweak>, capacity 1000) holds one JNI weak global ref per entry.LRUCacheruns its evict callback only under capacity pressure or explicit invalidation — never at destruction, because it had no destructor either. So a worker that touched Java objects abandons its entire cache when it dies.ART's weak-global table is bounded (~51200 entries), so this is not merely a leak: enough worker cycles exhaust it and ART aborts with
weak global reference table overflow.The JS side
Every linked object owns a
Persistent<Object>, aJSInstanceInfoand anObjectWeakCallbackState, freed only from the GC finalizer — and V8 does not run weak callbacks when an isolate is disposed.It is worse than "some survive". In the default
nonemarking mode (AppConfig.java),JSObjectFinalizerre-armsSetWeakwhenever the Java counterpart is still alive, so those wrappers are deliberately retained and are therefore all still live at teardown.Fix
Split across the two windows teardown actually has:
ReleaseAllRegistered()DestroyRuntimeJsInfointernal field before freeing theJSInstanceInfoit points at, resets + deletes thePersistent, releasesm_poJsWrapperFunc~ObjectManager~RuntimeThat ordering is not incidental:
Persistent::Reset()afterIsolate::Dispose()writes into a freed handle table, so the V8 phase must be inDestroyRuntime.~Runtimedrops thecom.tns.Runtimeglobal ref (added in fix: isolate/runtime lifetime — worker startup race, teardown use-after-free, and leaks #2006), becauseObjectManagercalls Java through that same object.Supporting changes
m_idToObjectnow maps toObjectWeakCallbackState*rather than the barePersistent*. The state was created and handed toSetWeakbut stored nowhere, so teardown had no way to reach it — or theJSInstanceInfo— at all. 7 use sites.LRUCache::clear()— evicts every entry through the callback. Without it the cache cannot release what it owns.ReleaseJSInstancenow frees the callback state, which it never did (a smaller pre-existing leak on the same path).Testing
Full suite green, and the crash-loop harness from #2006 (SIGSEGV handler temporarily disabled so faults are fatal and tombstoned, not part of this PR) — result posted below once the 20-run loop finishes.
Notes for review
full-marking paths (ReleaseRegularObjects,MakeRegularObjectsWeak) are untouched. Worth knowing: three ofObjectManager's declared methods —MakeRegularObjectsWeak,MakeImplObjectsWeak,CheckWeakObjectsAreAlive— have no definition anywhere in the tree and are called from nowhere. They are not part of this fix, but they are why "something else already drains these maps" is not true.NativeScriptException::m_javascriptException, whose raw pointer is handed to Java as ajlong, so fixing it changes a cross-language ownership contract. (~MetadataNodeCachewas completed in fix: isolate/runtime lifetime — worker startup race, teardown use-after-free, and leaks #2006, where that destructor lives.)Summary by CodeRabbit