void V8GCController::gcEpilogue(v8::GCType type, v8::GCCallbackFlags flags) { // FIXME: It would be nice if the GC callbacks passed the Isolate directly.... v8::Isolate* isolate = v8::Isolate::GetCurrent(); if (type == v8::kGCTypeScavenge) minorGCEpilogue(isolate); else if (type == v8::kGCTypeMarkSweepCompact) majorGCEpilogue(isolate); // Forces a Blink heap garbage collection when a garbage collection // was forced from V8. This is used for tests that force GCs from // JavaScript to verify that objects die when expected. if (flags & v8::kGCCallbackFlagForced) { // This single GC is not enough for two reasons: // (1) The GC is not precise because the GC scans on-stack pointers conservatively. // (2) One GC is not enough to break a chain of persistent handles. It's possible that // some heap allocated objects own objects that contain persistent handles // pointing to other heap allocated objects. To break the chain, we need multiple GCs. // // Regarding (1), we force a precise GC at the end of the current event loop. So if you want // to collect all garbage, you need to wait until the next event loop. // Regarding (2), it would be OK in practice to trigger only one GC per gcEpilogue, because // GCController.collectAll() forces 7 V8's GC. Heap::collectGarbage(ThreadState::HeapPointersOnStack, ThreadState::ForcedGC); // Forces a precise GC at the end of the current event loop. Heap::setForcePreciseGCForTesting(); } TRACE_EVENT_END1(TRACE_DISABLED_BY_DEFAULT("devtools.timeline"), "GCEvent", "usedHeapSizeAfter", usedHeapSize(isolate)); TRACE_EVENT_INSTANT1(TRACE_DISABLED_BY_DEFAULT("devtools.timeline"), "UpdateCounters", "data", InspectorUpdateCountersEvent::data()); }
void V8GCController::gcEpilogue(v8::GCType type, v8::GCCallbackFlags flags) { if (type == v8::kGCTypeScavenge) minorGCEpilogue(); else if (type == v8::kGCTypeMarkSweepCompact) majorGCEpilogue(); }