qiurui
/
qtdeclarative
mirror of https://github.com/qt/qtdeclarative.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Cleanup JS stack allocations 

Avoid double writes to the stack, and use scope.alloc() for
most allocations on the stack.

Change-Id: I8b89273c1b6796d955fc8eeb72c67cff208ef786
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>
This commit is contained in:
Lars Knoll 2018-05-25 09:03:51 +02:00
parent 9ff4c5c216
commit 6cbc287c06
8 changed files with 65 additions and 30 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
src/qml/jsruntime/qv4context.cpp
View File

@ -110,7 +110,7 @@ Heap::CallContext *ExecutionContext::newCallContext(CppStackFrame *frame)
uint nLocals = compiledFunction->nLocals;
c->locals.size = nLocals;
c->locals.alloc = localsAndFormals;
// memory allocated from the JS heap is 0 initialized, so check if undefined is 0
// memory allocated from the JS heap is 0 initialized, so check if empty is 0
Q_ASSERT(Primitive::undefinedValue().asReturnedValue() == 0);
Value *args = c->locals.values + nLocals;

1
src/qml/jsruntime/qv4engine.cpp
View File

@ -193,6 +193,7 @@ ExecutionEngine::ExecutionEngine(QJSEngine *jsEngine)
}
exceptionValue = jsAlloca(1);
*exceptionValue = Encode::undefined();
globalObject = static_cast<Object *>(jsAlloca(1));
jsObjects = jsAlloca(NJSObjects);
typedArrayPrototype = static_cast<Object *>(jsAlloca(NTypedArrayTypes));

2
src/qml/jsruntime/qv4engine_p.h
View File

@ -142,8 +142,6 @@ public:
QML_NEARLY_ALWAYS_INLINE Value *jsAlloca(int nValues) {
Value *ptr = jsStackTop;
jsStackTop = ptr + nValues;
for (int i = 0; i < nValues; ++i)
ptr[i] = Primitive::undefinedValue();
return ptr;
}

2
src/qml/jsruntime/qv4functionobject.cpp
View File

@ -344,7 +344,7 @@ ReturnedValue FunctionPrototype::method_apply(const QV4::FunctionObject *b, cons
uint len = arr->getLength();
Scope scope(v4);
Value *arguments = v4->jsAlloca(len);
Value *arguments = scope.alloc(len);
if (len) {
if (ArgumentsObject::isNonStrictArgumentsObject(arr) && !arr->cast<ArgumentsObject>()->fullyCreated()) {
QV4::ArgumentsObject *a = arr->cast<ArgumentsObject>();

5
src/qml/jsruntime/qv4jscall_p.h
View File

@ -67,7 +67,7 @@ struct JSCallData {
if (thisObject)
this->thisObject = const_cast<Value *>(thisObject);
else
this->thisObject = scope.alloc(1);
this->thisObject = scope.alloc();
if (argv)
this->args = const_cast<Value *>(argv);
else
@ -80,8 +80,7 @@ struct JSCallData {
CallData *callData(const FunctionObject *f = nullptr) const {
int size = int(offsetof(QV4::CallData, args)/sizeof(QV4::Value)) + argc;
CallData *ptr = reinterpret_cast<CallData *>(scope.engine->jsStackTop);
scope.engine->jsStackTop += size;
CallData *ptr = reinterpret_cast<CallData *>(scope.alloc<Scope::Uninitialized>(size));
ptr->function = Encode::undefined();
ptr->context = Encode::undefined();
ptr->accumulator = Encode::undefined();

4
src/qml/jsruntime/qv4objectiterator_p.h
View File

@ -92,8 +92,8 @@ struct Q_QML_EXPORT ObjectIterator: ObjectIteratorData
ObjectIterator(Scope &scope, const Object *o, uint flags)
{
engine = scope.engine;
object = scope.alloc(1);
current = scope.alloc(1);
object = scope.alloc();
current = scope.alloc();
arrayNode = nullptr;
arrayIndex = 0;
memberIndex = 0;

73
src/qml/jsruntime/qv4scopedvalue_p.h
View File

@ -117,8 +117,45 @@ struct Scope {
engine->jsStackTop = mark;
}
QML_NEARLY_ALWAYS_INLINE Value *alloc(int nValues) const {
return engine->jsAlloca(nValues);
enum AllocMode {
Undefined,
Empty,
/* Be careful when using Uninitialized, the stack has to be fully initialized before calling into the memory manager again */
Uninitialized
};
template <AllocMode mode = Undefined>
QML_NEARLY_ALWAYS_INLINE Value *alloc(int nValues) const
{
Value *ptr = engine->jsAlloca(nValues);
switch (mode) {
case Undefined:
for (int i = 0; i < nValues; ++i)
ptr[i] = Primitive::undefinedValue();
break;
case Empty:
for (int i = 0; i < nValues; ++i)
ptr[i] = Primitive::emptyValue();
break;
case Uninitialized:
break;
}
return ptr;
}
template <AllocMode mode = Undefined>
QML_NEARLY_ALWAYS_INLINE Value *alloc() const
{
Value *ptr = engine->jsAlloca(1);
switch (mode) {
case Undefined:
*ptr = Primitive::undefinedValue();
break;
case Empty:
*ptr = Primitive::emptyValue();
break;
case Uninitialized:
break;
}
return ptr;
}
bool hasException() const {
@ -136,31 +173,31 @@ struct ScopedValue
{
ScopedValue(const Scope &scope)
{
ptr = scope.engine->jsStackTop++;
ptr = scope.alloc<Scope::Uninitialized>();
ptr->setRawValue(0);
}
ScopedValue(const Scope &scope, const Value &v)
{
ptr = scope.engine->jsStackTop++;
ptr = scope.alloc<Scope::Uninitialized>();
*ptr = v;
}
ScopedValue(const Scope &scope, Heap::Base *o)
{
ptr = scope.engine->jsStackTop++;
ptr = scope.alloc<Scope::Uninitialized>();
ptr->setM(o);
}
ScopedValue(const Scope &scope, Managed *m)
{
ptr = scope.engine->jsStackTop++;
ptr = scope.alloc<Scope::Uninitialized>();
ptr->setRawValue(m->asReturnedValue());
}
ScopedValue(const Scope &scope, const ReturnedValue &v)
{
ptr = scope.engine->jsStackTop++;
ptr = scope.alloc<Scope::Uninitialized>();
ptr->setRawValue(v);
}
@ -214,66 +251,66 @@ struct Scoped
QML_NEARLY_ALWAYS_INLINE Scoped(const Scope &scope)
{
ptr = scope.engine->jsAlloca(1);
ptr = scope.alloc<Scope::Undefined>();
}
QML_NEARLY_ALWAYS_INLINE Scoped(const Scope &scope, const Value &v)
{
ptr = scope.engine->jsAlloca(1);
ptr = scope.alloc<Scope::Uninitialized>();
setPointer(v.as<T>());
}
QML_NEARLY_ALWAYS_INLINE Scoped(const Scope &scope, Heap::Base *o)
{
Value v;
v = o;
ptr = scope.engine->jsAlloca(1);
ptr = scope.alloc<Scope::Uninitialized>();
setPointer(v.as<T>());
}
QML_NEARLY_ALWAYS_INLINE Scoped(const Scope &scope, const ScopedValue &v)
{
ptr = scope.engine->jsAlloca(1);
ptr = scope.alloc<Scope::Uninitialized>();
setPointer(v.ptr->as<T>());
}
QML_NEARLY_ALWAYS_INLINE Scoped(const Scope &scope, const Value &v, ConvertType)
{
ptr = scope.engine->jsAlloca(1);
ptr = scope.alloc<Scope::Uninitialized>();
ptr->setRawValue(value_convert<T>(scope.engine, v));
}
QML_NEARLY_ALWAYS_INLINE Scoped(const Scope &scope, const Value *v)
{
ptr = scope.engine->jsAlloca(1);
ptr = scope.alloc<Scope::Uninitialized>();
setPointer(v ? v->as<T>() : nullptr);
}
QML_NEARLY_ALWAYS_INLINE Scoped(const Scope &scope, T *t)
{
ptr = scope.engine->jsAlloca(1);
ptr = scope.alloc<Scope::Uninitialized>();
setPointer(t);
}
QML_NEARLY_ALWAYS_INLINE Scoped(const Scope &scope, const T *t)
{
ptr = scope.engine->jsAlloca(1);
ptr = scope.alloc<Scope::Uninitialized>();
setPointer(t);
}
QML_NEARLY_ALWAYS_INLINE Scoped(const Scope &scope, typename T::Data *t)
{
ptr = scope.engine->jsAlloca(1);
ptr = scope.alloc<Scope::Uninitialized>();
*ptr = t;
}
QML_NEARLY_ALWAYS_INLINE Scoped(const Scope &scope, const ReturnedValue &v)
{
ptr = scope.engine->jsAlloca(1);
ptr = scope.alloc<Scope::Uninitialized>();
setPointer(QV4::Value::fromReturnedValue(v).as<T>());
}
QML_NEARLY_ALWAYS_INLINE Scoped(const Scope &scope, const ReturnedValue &v, ConvertType)
{
ptr = scope.engine->jsAlloca(1);
ptr = scope.alloc<Scope::Uninitialized>();
ptr->setRawValue(value_convert<T>(scope.engine, QV4::Value::fromReturnedValue(v)));
}

6
src/qml/qml/qqmlobjectcreator.cpp
View File

@ -252,7 +252,7 @@ bool QQmlObjectCreator::populateDeferredProperties(QObject *instance, QQmlData::
Q_ASSERT(!sharedState->allJavaScriptObjects);
sharedState->allJavaScriptObjects = valueScope.alloc(compilationUnit->totalObjectCount);
QV4::QmlContext *qmlContext = static_cast<QV4::QmlContext *>(valueScope.alloc(1));
QV4::QmlContext *qmlContext = static_cast<QV4::QmlContext *>(valueScope.alloc());
qSwap(_qmlContext, qmlContext);
@ -312,7 +312,7 @@ bool QQmlObjectCreator::populateDeferredBinding(const QQmlProperty &qmlProperty,
if (!sharedState->allJavaScriptObjects)
sharedState->allJavaScriptObjects = valueScope.alloc(compilationUnit->totalObjectCount);
QV4::QmlContext *qmlContext = static_cast<QV4::QmlContext *>(valueScope.alloc(1));
QV4::QmlContext *qmlContext = static_cast<QV4::QmlContext *>(valueScope.alloc());
qSwap(_qmlContext, qmlContext);
@ -1292,7 +1292,7 @@ QObject *QQmlObjectCreator::createInstance(int index, QObject *parent, bool isCo
++sharedState->allJavaScriptObjects;
QV4::Scope valueScope(v4);
QV4::QmlContext *qmlContext = static_cast<QV4::QmlContext *>(valueScope.alloc(1));
QV4::QmlContext *qmlContext = static_cast<QV4::QmlContext *>(valueScope.alloc());
qSwap(_qmlContext, qmlContext);