ladybird/Userland/Libraries/LibJS/Runtime/GlobalObject.h
Andreas Kling 14c57b4b7f LibJS: Remove transition avoidance & start caching prototype transitions
The way that transition avoidance (foo_without_transition) was
implemented led to shapes being unshareable and caused shape explosion
instead, precisely what we were trying to avoid.

This patch removes all the attempts to avoid transitioning shapes, and
instead *adds* transitions when changing an object's prototype.
This makes transitions flow naturally, and as a result we end up with
way fewer shape objects in real-world situations.

When we run out of big problems, we can get back to avoiding transitions
as an optimization, but for now, let's avoid ballooning our processes
with a unique shape for every object.
2021-10-01 02:59:29 +02:00

174 lines
7.1 KiB
C++

/*
* Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <LibJS/Heap/Heap.h>
#include <LibJS/Runtime/Environment.h>
#include <LibJS/Runtime/VM.h>
namespace JS {
class GlobalObject : public Object {
JS_OBJECT(GlobalObject, Object);
public:
explicit GlobalObject();
virtual void initialize_global_object();
virtual ~GlobalObject() override;
Console& console() { return *m_console; }
Shape* empty_object_shape() { return m_empty_object_shape; }
Shape* new_object_shape() { return m_new_object_shape; }
Shape* new_ordinary_function_prototype_object_shape() { return m_new_ordinary_function_prototype_object_shape; }
// Not included in JS_ENUMERATE_NATIVE_OBJECTS due to missing distinct prototype
ProxyConstructor* proxy_constructor() { return m_proxy_constructor; }
// Not included in JS_ENUMERATE_NATIVE_OBJECTS due to missing distinct constructor
GeneratorObjectPrototype* generator_object_prototype() { return m_generator_object_prototype; }
FunctionObject* array_prototype_values_function() const { return m_array_prototype_values_function; }
FunctionObject* eval_function() const { return m_eval_function; }
FunctionObject* temporal_time_zone_prototype_get_offset_nanoseconds_for_function() const { return m_temporal_time_zone_prototype_get_offset_nanoseconds_for_function; }
FunctionObject* throw_type_error_function() const { return m_throw_type_error_function; }
#define __JS_ENUMERATE(ClassName, snake_name, PrototypeName, ConstructorName, ArrayType) \
ConstructorName* snake_name##_constructor() { return m_##snake_name##_constructor; } \
Object* snake_name##_prototype() { return m_##snake_name##_prototype; }
JS_ENUMERATE_BUILTIN_TYPES
#undef __JS_ENUMERATE
#define __JS_ENUMERATE(ClassName, snake_name, PrototypeName, ConstructorName) \
Intl::ConstructorName* intl_##snake_name##_constructor() { return m_intl_##snake_name##_constructor; } \
Object* intl_##snake_name##_prototype() { return m_intl_##snake_name##_prototype; }
JS_ENUMERATE_INTL_OBJECTS
#undef __JS_ENUMERATE
#define __JS_ENUMERATE(ClassName, snake_name, PrototypeName, ConstructorName) \
Temporal::ConstructorName* temporal_##snake_name##_constructor() { return m_temporal_##snake_name##_constructor; } \
Object* temporal_##snake_name##_prototype() { return m_temporal_##snake_name##_prototype; }
JS_ENUMERATE_TEMPORAL_OBJECTS
#undef __JS_ENUMERATE
#define __JS_ENUMERATE(ClassName, snake_name) \
Object* snake_name##_prototype() { return m_##snake_name##_prototype; }
JS_ENUMERATE_ITERATOR_PROTOTYPES
#undef __JS_ENUMERATE
protected:
virtual void visit_edges(Visitor&) override;
template<typename ConstructorType>
void initialize_constructor(PropertyName const&, ConstructorType*&, Object* prototype);
template<typename ConstructorType>
void add_constructor(PropertyName const&, ConstructorType*&, Object* prototype);
private:
virtual bool is_global_object() const final { return true; }
JS_DECLARE_NATIVE_FUNCTION(gc);
JS_DECLARE_NATIVE_FUNCTION(is_nan);
JS_DECLARE_NATIVE_FUNCTION(is_finite);
JS_DECLARE_NATIVE_FUNCTION(parse_float);
JS_DECLARE_NATIVE_FUNCTION(parse_int);
JS_DECLARE_NATIVE_FUNCTION(eval);
JS_DECLARE_NATIVE_FUNCTION(encode_uri);
JS_DECLARE_NATIVE_FUNCTION(decode_uri);
JS_DECLARE_NATIVE_FUNCTION(encode_uri_component);
JS_DECLARE_NATIVE_FUNCTION(decode_uri_component);
JS_DECLARE_NATIVE_FUNCTION(escape);
JS_DECLARE_NATIVE_FUNCTION(unescape);
NonnullOwnPtr<Console> m_console;
Shape* m_empty_object_shape { nullptr };
Shape* m_new_object_shape { nullptr };
Shape* m_new_ordinary_function_prototype_object_shape { nullptr };
// Not included in JS_ENUMERATE_NATIVE_OBJECTS due to missing distinct prototype
ProxyConstructor* m_proxy_constructor { nullptr };
// Not included in JS_ENUMERATE_NATIVE_OBJECTS due to missing distinct constructor
GeneratorObjectPrototype* m_generator_object_prototype { nullptr };
FunctionObject* m_array_prototype_values_function { nullptr };
FunctionObject* m_eval_function { nullptr };
FunctionObject* m_temporal_time_zone_prototype_get_offset_nanoseconds_for_function { nullptr };
FunctionObject* m_throw_type_error_function { nullptr };
#define __JS_ENUMERATE(ClassName, snake_name, PrototypeName, ConstructorName, ArrayType) \
ConstructorName* m_##snake_name##_constructor { nullptr }; \
Object* m_##snake_name##_prototype { nullptr };
JS_ENUMERATE_BUILTIN_TYPES
#undef __JS_ENUMERATE
#define __JS_ENUMERATE(ClassName, snake_name, PrototypeName, ConstructorName) \
Intl::ConstructorName* m_intl_##snake_name##_constructor { nullptr }; \
Object* m_intl_##snake_name##_prototype { nullptr };
JS_ENUMERATE_INTL_OBJECTS
#undef __JS_ENUMERATE
#define __JS_ENUMERATE(ClassName, snake_name, PrototypeName, ConstructorName) \
Temporal::ConstructorName* m_temporal_##snake_name##_constructor { nullptr }; \
Object* m_temporal_##snake_name##_prototype { nullptr };
JS_ENUMERATE_TEMPORAL_OBJECTS
#undef __JS_ENUMERATE
#define __JS_ENUMERATE(ClassName, snake_name) \
Object* m_##snake_name##_prototype { nullptr };
JS_ENUMERATE_ITERATOR_PROTOTYPES
#undef __JS_ENUMERATE
};
template<typename ConstructorType>
inline void GlobalObject::initialize_constructor(PropertyName const& property_name, ConstructorType*& constructor, Object* prototype)
{
auto& vm = this->vm();
constructor = heap().allocate<ConstructorType>(*this, *this);
constructor->define_direct_property(vm.names.name, js_string(heap(), property_name.as_string()), Attribute::Configurable);
if (vm.exception())
return;
if (prototype) {
prototype->define_direct_property(vm.names.constructor, constructor, Attribute::Writable | Attribute::Configurable);
if (vm.exception())
return;
}
}
template<typename ConstructorType>
inline void GlobalObject::add_constructor(PropertyName const& property_name, ConstructorType*& constructor, Object* prototype)
{
// Some constructors are pre-initialized separately.
if (!constructor)
initialize_constructor(property_name, constructor, prototype);
define_direct_property(property_name, constructor, Attribute::Writable | Attribute::Configurable);
}
inline GlobalObject* Shape::global_object() const
{
return static_cast<GlobalObject*>(m_global_object);
}
template<>
inline bool Object::fast_is<GlobalObject>() const { return is_global_object(); }
template<typename... Args>
[[nodiscard]] ALWAYS_INLINE ThrowCompletionOr<Value> Value::invoke(GlobalObject& global_object, PropertyName const& property_name, Args... args)
{
if constexpr (sizeof...(Args) > 0) {
MarkedValueList arglist { global_object.vm().heap() };
(..., arglist.append(move(args)));
return invoke_internal(global_object, property_name, move(arglist));
}
return invoke_internal(global_object, property_name, Optional<MarkedValueList> {});
}
}