diff --git a/src/heap_utils.cc b/src/heap_utils.cc index e385955a5d5fce..4ba9a71673e851 100644 --- a/src/heap_utils.cc +++ b/src/heap_utils.cc @@ -474,6 +474,40 @@ void TriggerHeapSnapshot(const FunctionCallbackInfo& args) { return args.GetReturnValue().Set(filename_v); } +class PrototypeChainHas : public v8::QueryObjectPredicate { + public: + PrototypeChainHas(Local context, Local search) + : context_(context), + search_(search) {} + + // What we can do in the filter can be quite limited, but looking up + // the prototype chain is something that the inspector console API + // queryObject() does so it is supported. + bool Filter(Local object) override { + for (Local proto = object->GetPrototype(); proto->IsObject(); + proto = proto.As()->GetPrototype()) { + if (search_ == proto) return true; + } + return false; + } + + private: + Local context_; + Local search_; +}; + +void CountObjectsWithPrototype(const FunctionCallbackInfo& args) { + CHECK_EQ(args.Length(), 1); + CHECK(args[0]->IsObject()); + Local proto = args[0].As(); + Isolate* isolate = args.GetIsolate(); + Local context = isolate->GetCurrentContext(); + PrototypeChainHas prototype_chain_has(context, proto); + std::vector> out; + isolate->GetHeapProfiler()->QueryObjects(context, &prototype_chain_has, &out); + args.GetReturnValue().Set(static_cast(out.size())); +} + void Initialize(Local target, Local unused, Local context, @@ -482,12 +516,15 @@ void Initialize(Local target, SetMethod(context, target, "triggerHeapSnapshot", TriggerHeapSnapshot); SetMethod( context, target, "createHeapSnapshotStream", CreateHeapSnapshotStream); + SetMethod( + context, target, "countObjectsWithPrototype", CountObjectsWithPrototype); } void RegisterExternalReferences(ExternalReferenceRegistry* registry) { registry->Register(BuildEmbedderGraph); registry->Register(TriggerHeapSnapshot); registry->Register(CreateHeapSnapshotStream); + registry->Register(CountObjectsWithPrototype); } } // namespace heap diff --git a/test/common/gc.js b/test/common/gc.js index 9860bb191ee072..4671a5422641ca 100644 --- a/test/common/gc.js +++ b/test/common/gc.js @@ -75,7 +75,54 @@ async function runAndBreathe(fn, repeat, waitTime = 20) { } } +/** + * This requires --expose-internals. + * This function can be used to check if an object factory leaks or not by + * iterating over the heap and count objects with the specified class + * (which is checked by looking up the prototype chain). + * @param {(i: number) => number} fn The factory receiving iteration count + * and returning number of objects created. The return value should be + * precise otherwise false negatives can be produced. + * @param {Function} klass The class whose object is used to count the objects + * @param {number} count Number of iterations that this check should be done + * @param {number} waitTime Optional breathing time for GC. + */ +async function checkIfCollectableByCounting(fn, klass, count, waitTime = 20) { + const { internalBinding } = require('internal/test/binding'); + const { countObjectsWithPrototype } = internalBinding('heap_utils'); + const { prototype, name } = klass; + const initialCount = countObjectsWithPrototype(prototype); + console.log(`Initial count of ${name}: ${initialCount}`); + let totalCreated = 0; + for (let i = 0; i < count; ++i) { + const created = await fn(i); + totalCreated += created; + console.log(`#${i}: created ${created} ${name}, total ${totalCreated}`); + await wait(waitTime); // give GC some breathing room. + const currentCount = countObjectsWithPrototype(prototype); + const collected = totalCreated - (currentCount - initialCount); + console.log(`#${i}: counted ${currentCount} ${name}, collected ${collected}`); + if (collected > 0) { + console.log(`Detected ${collected} collected ${name}, finish early`); + return; + } + } + + await wait(waitTime); // give GC some breathing room. + const currentCount = countObjectsWithPrototype(prototype); + const collected = totalCreated - (currentCount - initialCount); + console.log(`Last count: counted ${currentCount} ${name}, collected ${collected}`); + // Some objects with the prototype can be collected. + if (collected > 0) { + console.log(`Detected ${collected} collected ${name}`); + return; + } + + throw new Error(`${name} cannot be collected`); +} + module.exports = { checkIfCollectable, runAndBreathe, + checkIfCollectableByCounting, };