Troels Bjerre Lund
7854b01473
This commit adds finalizers to the custom allocator. Compared to the existing solution: * The finalizer queue is replaced by an AtomicStack<ExtraObjectData>. * All objects with finalizers get meta objects attached. This was not previously the case for CleanerImpl, but is now needed to link objects together in the finalization queue. * The finalizer queue is built during SweepExtraObjects, instead of during regular sweeping. * Cleaners are executed by the finalizer thread, and no longer by a separate worker thread. Co-authored-by: Troels Lund <troels@google.com> Merge-request: KOTLIN-MR-592 Merged-by: Alexander Shabalin <alexander.shabalin@jetbrains.com>
102 lines
3.6 KiB
C++
102 lines
3.6 KiB
C++
/*
|
|
* Copyright 2010-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
|
|
* that can be found in the LICENSE file.
|
|
*/
|
|
|
|
#ifndef RUNTIME_MM_EXTRA_OBJECT_DATA_H
|
|
#define RUNTIME_MM_EXTRA_OBJECT_DATA_H
|
|
|
|
#include <atomic>
|
|
#include <cstddef>
|
|
#include <cstdint>
|
|
|
|
#include "Memory.h"
|
|
#include "TypeInfo.h"
|
|
#include "Utils.hpp"
|
|
#include "Weak.h"
|
|
|
|
namespace kotlin {
|
|
namespace mm {
|
|
|
|
// Optional data that's lazily allocated only for objects that need it.
|
|
class ExtraObjectData : private Pinned {
|
|
public:
|
|
// flags are stored as single atomic uint32, values are bit numbers in that uint32
|
|
enum Flags : uint32_t {
|
|
FLAGS_FROZEN = 0,
|
|
FLAGS_NEVER_FROZEN = 1,
|
|
FLAGS_IN_FINALIZER_QUEUE = 2,
|
|
FLAGS_FINALIZED = 3,
|
|
};
|
|
|
|
static constexpr unsigned WEAK_REF_TAG = 1;
|
|
|
|
MetaObjHeader* AsMetaObjHeader() noexcept { return reinterpret_cast<MetaObjHeader*>(this); }
|
|
static ExtraObjectData& FromMetaObjHeader(MetaObjHeader* header) noexcept { return *reinterpret_cast<ExtraObjectData*>(header); }
|
|
|
|
// Get installed `ExtraObjectData` or `nullptr`.
|
|
static ExtraObjectData* Get(const ObjHeader* object) noexcept {
|
|
return reinterpret_cast<ExtraObjectData*>(object->meta_object_or_null());
|
|
}
|
|
static ExtraObjectData& GetOrInstall(ObjHeader* object) noexcept { return FromMetaObjHeader(object->meta_object()); }
|
|
|
|
static ExtraObjectData& Install(ObjHeader* object) noexcept;
|
|
void Uninstall() noexcept;
|
|
|
|
#ifdef KONAN_OBJC_INTEROP
|
|
std::atomic<void*>& AssociatedObject() noexcept { return associatedObject_; }
|
|
#endif
|
|
bool HasAssociatedObject() noexcept;
|
|
void DetachAssociatedObject() noexcept;
|
|
|
|
bool getFlag(Flags value) noexcept { return (flags_.load() & (1u << static_cast<uint32_t>(value))) != 0; }
|
|
void setFlag(Flags value) noexcept { flags_.fetch_or(1u << static_cast<uint32_t>(value)); }
|
|
|
|
|
|
bool HasWeakReferenceCounter() noexcept { return hasPointerBits(weakReferenceCounterOrBaseObject_.load(), WEAK_REF_TAG); }
|
|
void ClearWeakReferenceCounter() noexcept;
|
|
ObjHeader* GetWeakReferenceCounter() noexcept {
|
|
auto *pointer = weakReferenceCounterOrBaseObject_.load();
|
|
if (hasPointerBits(pointer, WEAK_REF_TAG)) return clearPointerBits(pointer, WEAK_REF_TAG);
|
|
return nullptr;
|
|
}
|
|
ObjHeader* GetOrSetWeakReferenceCounter(ObjHeader* object, ObjHeader* counter) noexcept {
|
|
if (weakReferenceCounterOrBaseObject_.compare_exchange_strong(object, setPointerBits(counter, WEAK_REF_TAG))) {
|
|
return counter;
|
|
} else {
|
|
return clearPointerBits(object, WEAK_REF_TAG); // on fail current value of counter is stored to object
|
|
}
|
|
}
|
|
ObjHeader* GetBaseObject() noexcept {
|
|
auto *header = weakReferenceCounterOrBaseObject_.load();
|
|
if (hasPointerBits(header, WEAK_REF_TAG)) {
|
|
return UnsafeWeakReferenceCounterGet(clearPointerBits(header, WEAK_REF_TAG));
|
|
} else {
|
|
return header;
|
|
}
|
|
}
|
|
|
|
// info must be equal to objHeader->type_info(), but it needs to be loaded in advance to avoid data races
|
|
explicit ExtraObjectData(ObjHeader* objHeader, const TypeInfo *info) noexcept :
|
|
typeInfo_(nullptr), weakReferenceCounterOrBaseObject_(objHeader) {
|
|
atomicSetRelease(&typeInfo_, info);
|
|
}
|
|
~ExtraObjectData();
|
|
private:
|
|
// Must be first to match `TypeInfo` layout.
|
|
const TypeInfo* typeInfo_;
|
|
|
|
std::atomic<uint32_t> flags_ = 0;
|
|
|
|
#ifdef KONAN_OBJC_INTEROP
|
|
std::atomic<void*> associatedObject_ = nullptr;
|
|
#endif
|
|
|
|
std::atomic<ObjHeader*> weakReferenceCounterOrBaseObject_;
|
|
};
|
|
|
|
} // namespace mm
|
|
} // namespace kotlin
|
|
|
|
#endif // RUNTIME_MM_EXTRA_OBJECT_DATA_H
|