128 lines
4 KiB
C++
128 lines
4 KiB
C++
/*
|
|
* Copyright (C) 2014 The Android Open Source Project
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*/
|
|
|
|
#ifndef ART_RUNTIME_MIRROR_OBJECT_REFERENCE_H_
|
|
#define ART_RUNTIME_MIRROR_OBJECT_REFERENCE_H_
|
|
|
|
#include "base/mutex.h" // For Locks::mutator_lock_.
|
|
#include "globals.h"
|
|
#include "obj_ptr.h"
|
|
|
|
namespace art {
|
|
namespace mirror {
|
|
|
|
class Object;
|
|
|
|
// Classes shared with the managed side of the world need to be packed so that they don't have
|
|
// extra platform specific padding.
|
|
#define MANAGED PACKED(4)
|
|
|
|
// Value type representing a reference to a mirror::Object of type MirrorType.
|
|
template<bool kPoisonReferences, class MirrorType>
|
|
class MANAGED ObjectReference {
|
|
public:
|
|
MirrorType* AsMirrorPtr() const REQUIRES_SHARED(Locks::mutator_lock_) {
|
|
return UnCompress();
|
|
}
|
|
|
|
void Assign(MirrorType* other) REQUIRES_SHARED(Locks::mutator_lock_) {
|
|
reference_ = Compress(other);
|
|
}
|
|
|
|
void Assign(ObjPtr<MirrorType> ptr)
|
|
REQUIRES_SHARED(Locks::mutator_lock_);
|
|
|
|
void Clear() {
|
|
reference_ = 0;
|
|
DCHECK(IsNull());
|
|
}
|
|
|
|
bool IsNull() const {
|
|
return reference_ == 0;
|
|
}
|
|
|
|
uint32_t AsVRegValue() const {
|
|
return reference_;
|
|
}
|
|
|
|
protected:
|
|
explicit ObjectReference(MirrorType* mirror_ptr)
|
|
REQUIRES_SHARED(Locks::mutator_lock_)
|
|
: reference_(Compress(mirror_ptr)) {
|
|
}
|
|
|
|
// Compress reference to its bit representation.
|
|
static uint32_t Compress(MirrorType* mirror_ptr) REQUIRES_SHARED(Locks::mutator_lock_) {
|
|
uintptr_t as_bits = reinterpret_cast<uintptr_t>(mirror_ptr);
|
|
return static_cast<uint32_t>(kPoisonReferences ? -as_bits : as_bits);
|
|
}
|
|
|
|
// Uncompress an encoded reference from its bit representation.
|
|
MirrorType* UnCompress() const REQUIRES_SHARED(Locks::mutator_lock_) {
|
|
uintptr_t as_bits = kPoisonReferences ? -reference_ : reference_;
|
|
return reinterpret_cast<MirrorType*>(as_bits);
|
|
}
|
|
|
|
friend class Object;
|
|
|
|
// The encoded reference to a mirror::Object.
|
|
uint32_t reference_;
|
|
};
|
|
|
|
// References between objects within the managed heap.
|
|
template<class MirrorType>
|
|
class MANAGED HeapReference : public ObjectReference<kPoisonHeapReferences, MirrorType> {
|
|
public:
|
|
static HeapReference<MirrorType> FromMirrorPtr(MirrorType* mirror_ptr)
|
|
REQUIRES_SHARED(Locks::mutator_lock_) {
|
|
return HeapReference<MirrorType>(mirror_ptr);
|
|
}
|
|
|
|
static HeapReference<MirrorType> FromObjPtr(ObjPtr<MirrorType> ptr)
|
|
REQUIRES_SHARED(Locks::mutator_lock_);
|
|
|
|
bool CasWeakRelaxed(MirrorType* old_ptr, MirrorType* new_ptr)
|
|
REQUIRES_SHARED(Locks::mutator_lock_);
|
|
|
|
private:
|
|
explicit HeapReference(MirrorType* mirror_ptr) REQUIRES_SHARED(Locks::mutator_lock_)
|
|
: ObjectReference<kPoisonHeapReferences, MirrorType>(mirror_ptr) {}
|
|
};
|
|
|
|
static_assert(sizeof(mirror::HeapReference<mirror::Object>) == kHeapReferenceSize,
|
|
"heap reference size does not match");
|
|
|
|
// Standard compressed reference used in the runtime. Used for StackReference and GC roots.
|
|
template<class MirrorType>
|
|
class MANAGED CompressedReference : public mirror::ObjectReference<false, MirrorType> {
|
|
public:
|
|
CompressedReference<MirrorType>() REQUIRES_SHARED(Locks::mutator_lock_)
|
|
: mirror::ObjectReference<false, MirrorType>(nullptr) {}
|
|
|
|
static CompressedReference<MirrorType> FromMirrorPtr(MirrorType* p)
|
|
REQUIRES_SHARED(Locks::mutator_lock_) {
|
|
return CompressedReference<MirrorType>(p);
|
|
}
|
|
|
|
private:
|
|
explicit CompressedReference(MirrorType* p) REQUIRES_SHARED(Locks::mutator_lock_)
|
|
: mirror::ObjectReference<false, MirrorType>(p) {}
|
|
};
|
|
|
|
} // namespace mirror
|
|
} // namespace art
|
|
|
|
#endif // ART_RUNTIME_MIRROR_OBJECT_REFERENCE_H_
|