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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef GPU_OBJECT_MODEL_H_
#define GPU_OBJECT_MODEL_H_
#include "nsWrapperCache.h"
#include "nsString.h"
class nsIGlobalObject;
namespace mozilla::webgpu {
class WebGPUChild;
template <typename T>
class ChildOf {
protected:
explicit ChildOf(T* const parent);
virtual ~ChildOf();
RefPtr<T> mParent;
public:
nsIGlobalObject* GetParentObject() const;
};
/// Most WebGPU DOM objects inherit from this class.
///
/// mValid should only be used in the destruction steps in Cleanup() to check
/// whether they have already run. This is because the destruction steps can be
/// triggered by either the object's destructor or the cycle collector
/// attempting to break a cycle. As a result, all methods accessible from JS can
/// assume that mValid is true.
///
/// Similarly, pointers to the device and the IPDL actor (bridge) can be assumed
/// to be non-null whenever the object is accessible from JS but not during
/// cleanup as they might have been snatched by cycle collection.
///
/// The general pattern is that all objects should implement Cleanup more or
/// less the same way. Cleanup should be the only function sending the
/// corresponding Drop message and cleanup should *never* be called by anything
/// other than the object destructor or the cycle collector.
///
/// These rules guarantee that:
/// - The Drop message is called only once and that no other IPC message
/// referring
/// to the same object is send after Drop.
/// - Any method outside of the destruction sequence can assume the pointers are
/// non-null. They only have to check that the IPDL actor can send messages
/// using `WebGPUChild::CanSend()`.
class ObjectBase : public nsWrapperCache {
protected:
virtual ~ObjectBase() = default;
/// False during the destruction sequence of the object.
bool mValid = true;
public:
void GetLabel(nsAString& aValue) const;
void SetLabel(const nsAString& aLabel);
auto CLabel() const { return NS_ConvertUTF16toUTF8(mLabel); }
protected:
// Object label, initialized from GPUObjectDescriptorBase.label.
nsString mLabel;
};
} // namespace mozilla::webgpu
#define GPU_DECL_JS_WRAP(T) \
JSObject* WrapObject(JSContext* cx, JS::Handle<JSObject*> givenProto) \
override;
#define GPU_DECL_CYCLE_COLLECTION(T) \
NS_DECL_CYCLE_COLLECTION_NATIVE_WRAPPERCACHE_CLASS(T) \
NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(T)
#define GPU_IMPL_JS_WRAP(T) \
JSObject* T::WrapObject(JSContext* cx, JS::Handle<JSObject*> givenProto) { \
return dom::GPU##T##_Binding::Wrap(cx, this, givenProto); \
}
// Note: we don't use `NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE` directly
// because there is a custom action we need to always do.
#define GPU_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(T, ...) \
NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_CLASS(T) \
NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(T) \
tmp->Cleanup(); \
NS_IMPL_CYCLE_COLLECTION_UNLINK(__VA_ARGS__) \
NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER \
NS_IMPL_CYCLE_COLLECTION_UNLINK_END \
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(T) \
NS_IMPL_CYCLE_COLLECTION_TRAVERSE(__VA_ARGS__) \
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
#define GPU_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_WEAK_PTR(T, ...) \
NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_CLASS(T) \
NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(T) \
tmp->Cleanup(); \
NS_IMPL_CYCLE_COLLECTION_UNLINK(__VA_ARGS__) \
NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER \
NS_IMPL_CYCLE_COLLECTION_UNLINK_WEAK_PTR \
NS_IMPL_CYCLE_COLLECTION_UNLINK_END \
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(T) \
NS_IMPL_CYCLE_COLLECTION_TRAVERSE(__VA_ARGS__) \
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
#define GPU_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_INHERITED(T, P, ...) \
NS_IMPL_CYCLE_COLLECTION_CLASS(T) \
NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(T, P) \
tmp->Cleanup(); \
NS_IMPL_CYCLE_COLLECTION_UNLINK(__VA_ARGS__) \
NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER \
NS_IMPL_CYCLE_COLLECTION_UNLINK_WEAK_PTR \
NS_IMPL_CYCLE_COLLECTION_UNLINK_END \
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(T, P) \
NS_IMPL_CYCLE_COLLECTION_TRAVERSE(__VA_ARGS__) \
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
#define GPU_IMPL_CYCLE_COLLECTION(T, ...) \
GPU_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(T, __VA_ARGS__)
template <typename T>
void ImplCycleCollectionTraverse(nsCycleCollectionTraversalCallback& callback,
nsTArray<RefPtr<const T>>& field,
const char* name, uint32_t flags) {
for (auto& element : field) {
CycleCollectionNoteChild(callback, const_cast<T*>(element.get()), name,
flags);
}
}
template <typename T>
void ImplCycleCollectionUnlink(nsTArray<RefPtr<const T>>& field) {
for (auto& element : field) {
ImplCycleCollectionUnlink(element);
}
field.Clear();
}
#endif // GPU_OBJECT_MODEL_H_