diff options
| author | Ulf Hermann <ulf.hermann@qt.io> | 2022-07-25 13:50:10 +0200 |
|---|---|---|
| committer | Ulf Hermann <ulf.hermann@qt.io> | 2022-08-03 08:32:33 +0200 |
| commit | 0b9fa18dfefc06f542bd0c98b7e41fa14aa0c2cf (patch) | |
| tree | 5b61c47556699c04c4dfca8168061d1d6cc48d64 /src/qml/jsruntime/qv4object.cpp | |
| parent | d8db6e9484884f9d93ef584e63e695ae0322fc8f (diff) | |
V4: Mark InternalClass parents when running GC
We need to preserve them as they notify us about protoId related
changes. In order to avoid wasting heap space in case many properties
are added and removed from the same object, we put a mechanism in place
to rebuild the InternalClass hierarchy if many redundant transitions are
detected.
Amends commit 69d76d59cec0dcff4c52eef24e779fbef14beeca.
Pick-to: 5.15 6.2 6.3 6.4
Fixes: QTBUG-91687
Task-number: QTBUG-58559
Change-Id: I3238931b5919ed2b98059e0b7f928334284ce7bf
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Diffstat (limited to 'src/qml/jsruntime/qv4object.cpp')
| -rw-r--r-- | src/qml/jsruntime/qv4object.cpp | 59 |
1 files changed, 47 insertions, 12 deletions
diff --git a/src/qml/jsruntime/qv4object.cpp b/src/qml/jsruntime/qv4object.cpp index 4325af836d..aec04b167d 100644 --- a/src/qml/jsruntime/qv4object.cpp +++ b/src/qml/jsruntime/qv4object.cpp @@ -25,17 +25,52 @@ DEFINE_OBJECT_VTABLE(Object); void Object::setInternalClass(Heap::InternalClass *ic) { - d()->internalClass.set(engine(), ic); - if (ic->isUsedAsProto) - ic->updateProtoUsage(d()); Q_ASSERT(ic && ic->vtable); - uint nInline = d()->vtable()->nInlineProperties; - if (ic->size <= nInline) - return; - bool hasMD = d()->memberData != nullptr; - uint requiredSize = ic->size - nInline; - if (!(hasMD && requiredSize) || (hasMD && d()->memberData->values.size < requiredSize)) - d()->memberData.set(ic->engine, MemberData::allocate(ic->engine, requiredSize, d()->memberData)); + Heap::Object *p = d(); + + if (ic->numRedundantTransitions < p->internalClass.get()->numRedundantTransitions) { + // IC was rebuilt. The indices are different now. We need to move everything. + + Scope scope(engine()); + + // We allocate before setting the new IC. Protect it from GC. + Scoped<InternalClass> newIC(scope, ic); + + // Pick the members of the old IC that are still valid in the new IC. + // Order them by index in memberData (or inline data). + Scoped<MemberData> newMembers(scope, MemberData::allocate(scope.engine, ic->size)); + for (uint i = 0; i < ic->size; ++i) + newMembers->set(scope.engine, i, get(ic->nameMap.at(i))); + + p->internalClass.set(scope.engine, ic); + const uint nInline = p->vtable()->nInlineProperties; + + if (ic->size > nInline) + p->memberData.set(scope.engine, MemberData::allocate(ic->engine, ic->size - nInline)); + else + p->memberData.set(scope.engine, nullptr); + + const auto &memberValues = newMembers->d()->values; + for (uint i = 0; i < ic->size; ++i) + setProperty(i, memberValues[i]); + } else { + // The old indices are still the same. No need to move any values. + // We may need to re-allocate, though. + + p->internalClass.set(ic->engine, ic); + const uint nInline = p->vtable()->nInlineProperties; + if (ic->size > nInline) { + const uint requiredSize = ic->size - nInline; + if ((p->memberData ? p->memberData->values.size : 0) < requiredSize) { + p->memberData.set(ic->engine, MemberData::allocate( + ic->engine, requiredSize, p->memberData)); + } + } + } + + if (ic->isUsedAsProto()) + ic->updateProtoUsage(p); + } void Object::getProperty(const InternalClassEntry &entry, Property *p) const @@ -922,7 +957,7 @@ bool Object::virtualDefineOwnProperty(Managed *m, PropertyKey id, const Property bool Object::virtualIsExtensible(const Managed *m) { - return m->d()->internalClass->extensible; + return m->d()->internalClass->isExtensible(); } bool Object::virtualPreventExtensions(Managed *m) @@ -946,7 +981,7 @@ bool Object::virtualSetPrototypeOf(Managed *m, const Object *proto) Heap::Object *protod = proto ? proto->d() : nullptr; if (current == protod) return true; - if (!o->internalClass()->extensible) + if (!o->internalClass()->isExtensible()) return false; Heap::Object *p = protod; while (p) { |