/*
* Copyright (C) 2017 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.
*/
#include "var_handle.h"
#include "array-inl.h"
#include "art_field-inl.h"
#include "base/casts.h"
#include "class-inl.h"
#include "class_linker.h"
#include "class_root.h"
#include "intrinsics_enum.h"
#include "jni/jni_internal.h"
#include "jvalue-inl.h"
#include "method_handles-inl.h"
#include "method_type-inl.h"
#include "object_array-alloc-inl.h"
#include "obj_ptr-inl.h"
#include "well_known_classes.h"
namespace art {
namespace mirror {
static constexpr bool kTransactionActive = true;
static constexpr bool kTransactionInactive = !kTransactionActive;
namespace {
struct VarHandleAccessorToAccessModeEntry {
const char* method_name;
VarHandle::AccessMode access_mode;
// Binary predicate function for finding access_mode by
// method_name. The access_mode field is ignored.
static bool CompareName(const VarHandleAccessorToAccessModeEntry& lhs,
const VarHandleAccessorToAccessModeEntry& rhs) {
return strcmp(lhs.method_name, rhs.method_name) < 0;
}
};
// Map of VarHandle accessor method names to access mode values. The list is alpha-sorted to support
// binary search. For the usage scenario - lookups in the verifier - a linear scan would likely
// suffice since we expect VarHandles to be a lesser encountered class. We could use a std::hashmap
// here and this would be easier to maintain if new values are added here. However, this entails
// CPU cycles initializing the structure on every execution and uses O(N) more memory for
// intermediate nodes and makes that memory dirty. Compile-time magic using constexpr is possible
// here, but that's a tax when this code is recompiled.
const VarHandleAccessorToAccessModeEntry kAccessorToAccessMode[VarHandle::kNumberOfAccessModes] = {
{ "compareAndExchange", VarHandle::AccessMode::kCompareAndExchange },
{ "compareAndExchangeAcquire", VarHandle::AccessMode::kCompareAndExchangeAcquire },
{ "compareAndExchangeRelease", VarHandle::AccessMode::kCompareAndExchangeRelease },
{ "compareAndSet", VarHandle::AccessMode::kCompareAndSet },
{ "get", VarHandle::AccessMode::kGet },
{ "getAcquire", VarHandle::AccessMode::kGetAcquire },
{ "getAndAdd", VarHandle::AccessMode::kGetAndAdd },
{ "getAndAddAcquire", VarHandle::AccessMode::kGetAndAddAcquire },
{ "getAndAddRelease", VarHandle::AccessMode::kGetAndAddRelease },
{ "getAndBitwiseAnd", VarHandle::AccessMode::kGetAndBitwiseAnd },
{ "getAndBitwiseAndAcquire", VarHandle::AccessMode::kGetAndBitwiseAndAcquire },
{ "getAndBitwiseAndRelease", VarHandle::AccessMode::kGetAndBitwiseAndRelease },
{ "getAndBitwiseOr", VarHandle::AccessMode::kGetAndBitwiseOr },
{ "getAndBitwiseOrAcquire", VarHandle::AccessMode::kGetAndBitwiseOrAcquire },
{ "getAndBitwiseOrRelease", VarHandle::AccessMode::kGetAndBitwiseOrRelease },
{ "getAndBitwiseXor", VarHandle::AccessMode::kGetAndBitwiseXor },
{ "getAndBitwiseXorAcquire", VarHandle::AccessMode::kGetAndBitwiseXorAcquire },
{ "getAndBitwiseXorRelease", VarHandle::AccessMode::kGetAndBitwiseXorRelease },
{ "getAndSet", VarHandle::AccessMode::kGetAndSet },
{ "getAndSetAcquire", VarHandle::AccessMode::kGetAndSetAcquire },
{ "getAndSetRelease", VarHandle::AccessMode::kGetAndSetRelease },
{ "getOpaque", VarHandle::AccessMode::kGetOpaque },
{ "getVolatile", VarHandle::AccessMode::kGetVolatile },
{ "set", VarHandle::AccessMode::kSet },
{ "setOpaque", VarHandle::AccessMode::kSetOpaque },
{ "setRelease", VarHandle::AccessMode::kSetRelease },
{ "setVolatile", VarHandle::AccessMode::kSetVolatile },
{ "weakCompareAndSet", VarHandle::AccessMode::kWeakCompareAndSet },
{ "weakCompareAndSetAcquire", VarHandle::AccessMode::kWeakCompareAndSetAcquire },
{ "weakCompareAndSetPlain", VarHandle::AccessMode::kWeakCompareAndSetPlain },
{ "weakCompareAndSetRelease", VarHandle::AccessMode::kWeakCompareAndSetRelease },
};
// Enumeration for describing the parameter and return types of an AccessMode.
enum class AccessModeTemplate : uint32_t {
kGet, // T Op(C0..CN)
kSet, // void Op(C0..CN, T)
kCompareAndSet, // boolean Op(C0..CN, T, T)
kCompareAndExchange, // T Op(C0..CN, T, T)
kGetAndUpdate, // T Op(C0..CN, T)
};
// Look up the AccessModeTemplate for a given VarHandle
// AccessMode. This simplifies finding the correct signature for a
// VarHandle accessor method.
AccessModeTemplate GetAccessModeTemplate(VarHandle::AccessMode access_mode) {
switch (access_mode) {
case VarHandle::AccessMode::kGet:
return AccessModeTemplate::kGet;
case VarHandle::AccessMode::kSet:
return AccessModeTemplate::kSet;
case VarHandle::AccessMode::kGetVolatile:
return AccessModeTemplate::kGet;
case VarHandle::AccessMode::kSetVolatile:
return AccessModeTemplate::kSet;
case VarHandle::AccessMode::kGetAcquire:
return AccessModeTemplate::kGet;
case VarHandle::AccessMode::kSetRelease:
return AccessModeTemplate::kSet;
case VarHandle::AccessMode::kGetOpaque:
return AccessModeTemplate::kGet;
case VarHandle::AccessMode::kSetOpaque:
return AccessModeTemplate::kSet;
case VarHandle::AccessMode::kCompareAndSet:
return AccessModeTemplate::kCompareAndSet;
case VarHandle::AccessMode::kCompareAndExchange:
return AccessModeTemplate::kCompareAndExchange;
case VarHandle::AccessMode::kCompareAndExchangeAcquire:
return AccessModeTemplate::kCompareAndExchange;
case VarHandle::AccessMode::kCompareAndExchangeRelease:
return AccessModeTemplate::kCompareAndExchange;
case VarHandle::AccessMode::kWeakCompareAndSetPlain:
return AccessModeTemplate::kCompareAndSet;
case VarHandle::AccessMode::kWeakCompareAndSet:
return AccessModeTemplate::kCompareAndSet;
case VarHandle::AccessMode::kWeakCompareAndSetAcquire:
return AccessModeTemplate::kCompareAndSet;
case VarHandle::AccessMode::kWeakCompareAndSetRelease:
return AccessModeTemplate::kCompareAndSet;
case VarHandle::AccessMode::kGetAndSet:
return AccessModeTemplate::kGetAndUpdate;
case VarHandle::AccessMode::kGetAndSetAcquire:
return AccessModeTemplate::kGetAndUpdate;
case VarHandle::AccessMode::kGetAndSetRelease:
return AccessModeTemplate::kGetAndUpdate;
case VarHandle::AccessMode::kGetAndAdd:
return AccessModeTemplate::kGetAndUpdate;
case VarHandle::AccessMode::kGetAndAddAcquire:
return AccessModeTemplate::kGetAndUpdate;
case VarHandle::AccessMode::kGetAndAddRelease:
return AccessModeTemplate::kGetAndUpdate;
case VarHandle::AccessMode::kGetAndBitwiseOr:
return AccessModeTemplate::kGetAndUpdate;
case VarHandle::AccessMode::kGetAndBitwiseOrRelease:
return AccessModeTemplate::kGetAndUpdate;
case VarHandle::AccessMode::kGetAndBitwiseOrAcquire:
return AccessModeTemplate::kGetAndUpdate;
case VarHandle::AccessMode::kGetAndBitwiseAnd:
return AccessModeTemplate::kGetAndUpdate;
case VarHandle::AccessMode::kGetAndBitwiseAndRelease:
return AccessModeTemplate::kGetAndUpdate;
case VarHandle::AccessMode::kGetAndBitwiseAndAcquire:
return AccessModeTemplate::kGetAndUpdate;
case VarHandle::AccessMode::kGetAndBitwiseXor:
return AccessModeTemplate::kGetAndUpdate;
case VarHandle::AccessMode::kGetAndBitwiseXorRelease:
return AccessModeTemplate::kGetAndUpdate;
case VarHandle::AccessMode::kGetAndBitwiseXorAcquire:
return AccessModeTemplate::kGetAndUpdate;
}
}
int32_t GetNumberOfVarTypeParameters(AccessModeTemplate access_mode_template) {
switch (access_mode_template) {
case AccessModeTemplate::kGet:
return 0;
case AccessModeTemplate::kSet:
case AccessModeTemplate::kGetAndUpdate:
return 1;
case AccessModeTemplate::kCompareAndSet:
case AccessModeTemplate::kCompareAndExchange:
return 2;
}
UNREACHABLE();
}
// Returns the number of parameters associated with an
// AccessModeTemplate and the supplied coordinate types.
int32_t GetNumberOfParameters(AccessModeTemplate access_mode_template,
ObjPtr<Class> coordinateType0,
ObjPtr<Class> coordinateType1) {
int32_t count = 0;
if (!coordinateType0.IsNull()) {
count++;
if (!coordinateType1.IsNull()) {
count++;
}
}
return count + GetNumberOfVarTypeParameters(access_mode_template);
}
void ThrowNullPointerExceptionForCoordinate() REQUIRES_SHARED(Locks::mutator_lock_) {
ThrowNullPointerException("Attempt to access memory on a null object");
}
bool CheckElementIndex(Primitive::Type type,
int32_t relative_index,
int32_t start,
int32_t limit) REQUIRES_SHARED(Locks::mutator_lock_) {
int64_t index = start + relative_index;
int64_t max_index = limit - Primitive::ComponentSize(type);
if (index < start || index > max_index) {
ThrowIndexOutOfBoundsException(index, limit - start);
return false;
}
return true;
}
bool CheckElementIndex(Primitive::Type type, int32_t index, int32_t range_limit)
REQUIRES_SHARED(Locks::mutator_lock_) {
return CheckElementIndex(type, index, 0, range_limit);
}
// Returns true if access_mode only entails a memory read. False if
// access_mode may write to memory.
bool IsReadOnlyAccessMode(VarHandle::AccessMode access_mode) {
AccessModeTemplate access_mode_template = GetAccessModeTemplate(access_mode);
return access_mode_template == AccessModeTemplate::kGet;
}
// Writes the parameter types associated with the AccessModeTemplate
// into an array. The parameter types are derived from the specified
// variable type and coordinate types. Returns the number of
// parameters written.
int32_t BuildParameterArray(ObjPtr<Class> (¶meters)[VarHandle::kMaxAccessorParameters],
AccessModeTemplate access_mode_template,
ObjPtr<Class> varType,
ObjPtr<Class> coordinateType0,
ObjPtr<Class> coordinateType1)
REQUIRES_SHARED(Locks::mutator_lock_) {
DCHECK(varType != nullptr);
int32_t index = 0;
if (!coordinateType0.IsNull()) {
parameters[index++] = coordinateType0;
if (!coordinateType1.IsNull()) {
parameters[index++] = coordinateType1;
}
} else {
DCHECK(coordinateType1.IsNull());
}
switch (access_mode_template) {
case AccessModeTemplate::kCompareAndExchange:
case AccessModeTemplate::kCompareAndSet:
parameters[index++] = varType;
parameters[index++] = varType;
return index;
case AccessModeTemplate::kGet:
return index;
case AccessModeTemplate::kGetAndUpdate:
case AccessModeTemplate::kSet:
parameters[index++] = varType;
return index;
}
return -1;
}
// Returns the return type associated with an AccessModeTemplate based
// on the template and the variable type specified.
static ObjPtr<Class> GetReturnType(AccessModeTemplate access_mode_template, ObjPtr<Class> varType)
REQUIRES_SHARED(Locks::mutator_lock_) {
DCHECK(varType != nullptr);
switch (access_mode_template) {
case AccessModeTemplate::kCompareAndSet:
return GetClassRoot(ClassRoot::kPrimitiveBoolean);
case AccessModeTemplate::kCompareAndExchange:
case AccessModeTemplate::kGet:
case AccessModeTemplate::kGetAndUpdate:
return varType;
case AccessModeTemplate::kSet:
return GetClassRoot(ClassRoot::kPrimitiveVoid);
}
return nullptr;
}
// Method to insert a read barrier for accessors to reference fields.
inline void ReadBarrierForVarHandleAccess(ObjPtr<Object> obj, MemberOffset field_offset)
REQUIRES_SHARED(Locks::mutator_lock_) {
if (kUseReadBarrier) {
// We need to ensure that the reference stored in the field is a to-space one before attempting
// the CompareAndSet/CompareAndExchange/Exchange operation otherwise it will fail incorrectly
// if obj is in the process of being moved.
uint8_t* raw_field_addr = reinterpret_cast<uint8_t*>(obj.Ptr()) + field_offset.SizeValue();
auto field_addr = reinterpret_cast<mirror::HeapReference<mirror::Object>*>(raw_field_addr);
// Note that the read barrier load does NOT need to be volatile.
static constexpr bool kIsVolatile = false;
static constexpr bool kAlwaysUpdateField = true;
ReadBarrier::Barrier<mirror::Object, kIsVolatile, kWithReadBarrier, kAlwaysUpdateField>(
obj.Ptr(),
MemberOffset(field_offset),
field_addr);
}
}
inline MemberOffset GetMemberOffset(jfieldID field_id) REQUIRES_SHARED(Locks::mutator_lock_) {
ArtField* const field = jni::DecodeArtField(field_id);
return field->GetOffset();
}
//
// Helper methods for storing results from atomic operations into
// JValue instances.
//
inline void StoreResult(uint8_t value, JValue* result) {
result->SetZ(value);
}
inline void StoreResult(int8_t value, JValue* result) {
result->SetB(value);
}
inline void StoreResult(uint16_t value, JValue* result) {
result->SetC(value);
}
inline void StoreResult(int16_t value, JValue* result) {
result->SetS(value);
}
inline void StoreResult(int32_t value, JValue* result) {
result->SetI(value);
}
inline void StoreResult(int64_t value, JValue* result) {
result->SetJ(value);
}
inline void StoreResult(float value, JValue* result) {
result->SetF(value);
}
inline void StoreResult(double value, JValue* result) {
result->SetD(value);
}
inline void StoreResult(ObjPtr<Object> value, JValue* result)
REQUIRES_SHARED(Locks::mutator_lock_) {
result->SetL(value);
}
//
// Helper class for byte-swapping value that has been stored in a JValue.
//
template <typename T>
class JValueByteSwapper final {
public:
static void ByteSwap(JValue* value);
static void MaybeByteSwap(bool byte_swap, JValue* value) {
if (byte_swap) {
ByteSwap(value);
}
}
};
template <>
void JValueByteSwapper<uint16_t>::ByteSwap(JValue* value) {
value->SetC(BSWAP(value->GetC()));
}
template <>
void JValueByteSwapper<int16_t>::ByteSwap(JValue* value) {
value->SetS(BSWAP(value->GetS()));
}
template <>
void JValueByteSwapper<int32_t>::ByteSwap(JValue* value) {
value->SetI(BSWAP(value->GetI()));
}
template <>
void JValueByteSwapper<int64_t>::ByteSwap(JValue* value) {
value->SetJ(BSWAP(value->GetJ()));
}
//
// Accessor implementations, shared across all VarHandle types.
//
template <typename T, std::memory_order MO>
class AtomicGetAccessor : public Object::Accessor<T> {
public:
explicit AtomicGetAccessor(JValue* result) : result_(result) {}
void Access(T* addr) override {
std::atomic<T>* atom = reinterpret_cast<std::atomic<T>*>(addr);
StoreResult(atom->load(MO), result_);
}
private:
JValue* result_;
};
template <typename T, std::memory_order MO>
class AtomicSetAccessor : public Object::Accessor<T> {
public:
explicit AtomicSetAccessor(T new_value) : new_value_(new_value) {}
void Access(T* addr) override {
std::atomic<T>* atom = reinterpret_cast<std::atomic<T>*>(addr);
atom->store(new_value_, MO);
}
private:
T new_value_;
};
template <typename T> using GetAccessor = AtomicGetAccessor<T, std::memory_order_relaxed>;
template <typename T> using SetAccessor = AtomicSetAccessor<T, std::memory_order_relaxed>;
template <typename T>
using GetVolatileAccessor = AtomicGetAccessor<T, std::memory_order_seq_cst>;
template <typename T>
using SetVolatileAccessor = AtomicSetAccessor<T, std::memory_order_seq_cst>;
template <typename T, std::memory_order MOS, std::memory_order MOF>
class AtomicStrongCompareAndSetAccessor : public Object::Accessor<T> {
public:
AtomicStrongCompareAndSetAccessor(T expected_value, T desired_value, JValue* result)
: expected_value_(expected_value), desired_value_(desired_value), result_(result) {}
void Access(T* addr) override {
std::atomic<T>* atom = reinterpret_cast<std::atomic<T>*>(addr);
bool success = atom->compare_exchange_strong(expected_value_, desired_value_, MOS, MOF);
StoreResult(success ? JNI_TRUE : JNI_FALSE, result_);
}
private:
T expected_value_;
T desired_value_;
JValue* result_;
};
template<typename T>
using CompareAndSetAccessor =
AtomicStrongCompareAndSetAccessor<T, std::memory_order_seq_cst, std::memory_order_seq_cst>;
template <typename T, std::memory_order MOS, std::memory_order MOF>
class AtomicStrongCompareAndExchangeAccessor : public Object::Accessor<T> {
public:
AtomicStrongCompareAndExchangeAccessor(T expected_value, T desired_value, JValue* result)
: expected_value_(expected_value), desired_value_(desired_value), result_(result) {}
void Access(T* addr) override {
std::atomic<T>* atom = reinterpret_cast<std::atomic<T>*>(addr);
atom->compare_exchange_strong(expected_value_, desired_value_, MOS, MOF);
StoreResult(expected_value_, result_);
}
private:
T expected_value_;
T desired_value_;
JValue* result_;
};
template <typename T>
using CompareAndExchangeAccessor =
AtomicStrongCompareAndExchangeAccessor<T, std::memory_order_seq_cst, std::memory_order_seq_cst>;
template <typename T, std::memory_order MOS, std::memory_order MOF>
class AtomicWeakCompareAndSetAccessor : public Object::Accessor<T> {
public:
AtomicWeakCompareAndSetAccessor(T expected_value, T desired_value, JValue* result)
: expected_value_(expected_value), desired_value_(desired_value), result_(result) {}
void Access(T* addr) override {
std::atomic<T>* atom = reinterpret_cast<std::atomic<T>*>(addr);
bool success = atom->compare_exchange_weak(expected_value_, desired_value_, MOS, MOF);
StoreResult(success ? JNI_TRUE : JNI_FALSE, result_);
}
private:
T expected_value_;
T desired_value_;
JValue* result_;
};
template <typename T>
using WeakCompareAndSetAccessor =
AtomicWeakCompareAndSetAccessor<T, std::memory_order_seq_cst, std::memory_order_seq_cst>;
template <typename T, std::memory_order MO>
class AtomicGetAndSetAccessor : public Object::Accessor<T> {
public:
AtomicGetAndSetAccessor(T new_value, JValue* result) : new_value_(new_value), result_(result) {}
void Access(T* addr) override {
std::atomic<T>* atom = reinterpret_cast<std::atomic<T>*>(addr);
T old_value = atom->exchange(new_value_, MO);
StoreResult(old_value, result_);
}
private:
T new_value_;
JValue* result_;
};
template <typename T>
using GetAndSetAccessor = AtomicGetAndSetAccessor<T, std::memory_order_seq_cst>;
template <typename T, bool kIsFloat, std::memory_order MO>
class AtomicGetAndAddOperator {
public:
static T Apply(T* addr, T addend) {
std::atomic<T>* atom = reinterpret_cast<std::atomic<T>*>(addr);
return atom->fetch_add(addend, MO);
}
};
template <typename T, std::memory_order MO>
class AtomicGetAndAddOperator<T, /* kIsFloat */ true, MO> {
public:
static T Apply(T* addr, T addend) {
// c++11 does not have std::atomic<T>::fetch_and_add for floating
// point types, so we effect one with a compare and swap.
std::atomic<T>* atom = reinterpret_cast<std::atomic<T>*>(addr);
T old_value = atom->load(std::memory_order_relaxed);
T new_value;
do {
new_value = old_value + addend;
} while (!atom->compare_exchange_weak(old_value, new_value, MO, std::memory_order_relaxed));
return old_value;
}
};
template <typename T, std::memory_order MO>
class AtomicGetAndAddAccessor : public Object::Accessor<T> {
public:
AtomicGetAndAddAccessor(T addend, JValue* result) : addend_(addend), result_(result) {}
void Access(T* addr) override {
constexpr bool kIsFloatingPoint = std::is_floating_point<T>::value;
T old_value = AtomicGetAndAddOperator<T, kIsFloatingPoint, MO>::Apply(addr, addend_);
StoreResult(old_value, result_);
}
private:
T addend_;
JValue* result_;
};
template <typename T>
using GetAndAddAccessor = AtomicGetAndAddAccessor<T, std::memory_order_seq_cst>;
// Accessor specifically for memory views where the caller can specify
// the byte-ordering. Addition only works outside of the byte-swapped
// memory view because of the direction of carries.
template <typename T, std::memory_order MO>
class AtomicGetAndAddWithByteSwapAccessor : public Object::Accessor<T> {
public:
AtomicGetAndAddWithByteSwapAccessor(T value, JValue* result) : value_(value), result_(result) {}
void Access(T* addr) override {
std::atomic<T>* const atom = reinterpret_cast<std::atomic<T>*>(addr);
T current_value = atom->load(std::memory_order_relaxed);
T sum;
do {
sum = BSWAP(current_value) + value_;
// NB current_value is a pass-by-reference argument in the call to
// atomic<T>::compare_exchange_weak().
} while (!atom->compare_exchange_weak(current_value,
BSWAP(sum),
MO,
std::memory_order_relaxed));
StoreResult(BSWAP(current_value), result_);
}
private:
T value_;
JValue* result_;
};
template <typename T>
using GetAndAddWithByteSwapAccessor =
AtomicGetAndAddWithByteSwapAccessor<T, std::memory_order_seq_cst>;
template <typename T, std::memory_order MO>
class AtomicGetAndBitwiseOrAccessor : public Object::Accessor<T> {
public:
AtomicGetAndBitwiseOrAccessor(T value, JValue* result) : value_(value), result_(result) {}
void Access(T* addr) override {
std::atomic<T>* atom = reinterpret_cast<std::atomic<T>*>(addr);
T old_value = atom->fetch_or(value_, MO);
StoreResult(old_value, result_);
}
private:
T value_;
JValue* result_;
};
template <typename T>
using GetAndBitwiseOrAccessor = AtomicGetAndBitwiseOrAccessor<T, std::memory_order_seq_cst>;
template <typename T, std::memory_order MO>
class AtomicGetAndBitwiseAndAccessor : public Object::Accessor<T> {
public:
AtomicGetAndBitwiseAndAccessor(T value, JValue* result) : value_(value), result_(result) {}
void Access(T* addr) override {
std::atomic<T>* atom = reinterpret_cast<std::atomic<T>*>(addr);
T old_value = atom->fetch_and(value_, MO);
StoreResult(old_value, result_);
}
private:
T value_;
JValue* result_;
};
template <typename T>
using GetAndBitwiseAndAccessor =
AtomicGetAndBitwiseAndAccessor<T, std::memory_order_seq_cst>;
template <typename T, std::memory_order MO>
class AtomicGetAndBitwiseXorAccessor : public Object::Accessor<T> {
public:
AtomicGetAndBitwiseXorAccessor(T value, JValue* result) : value_(value), result_(result) {}
void Access(T* addr) override {
std::atomic<T>* atom = reinterpret_cast<std::atomic<T>*>(addr);
T old_value = atom->fetch_xor(value_, MO);
StoreResult(old_value, result_);
}
private:
T value_;
JValue* result_;
};
template <typename T>
using GetAndBitwiseXorAccessor = AtomicGetAndBitwiseXorAccessor<T, std::memory_order_seq_cst>;
//
// Unreachable access modes.
//
NO_RETURN void UnreachableAccessMode(const char* access_mode, const char* type_name) {
LOG(FATAL) << "Unreachable access mode :" << access_mode << " for type " << type_name;
UNREACHABLE();
}
#define UNREACHABLE_ACCESS_MODE(ACCESS_MODE, TYPE) \
template<> void ACCESS_MODE ## Accessor<TYPE>::Access(TYPE*) { \
UnreachableAccessMode(#ACCESS_MODE, #TYPE); \
}
// The boolean primitive type is not numeric (boolean == std::uint8_t).
UNREACHABLE_ACCESS_MODE(GetAndAdd, uint8_t)
// The floating point types do not support bitwise operations.
UNREACHABLE_ACCESS_MODE(GetAndBitwiseOr, float)
UNREACHABLE_ACCESS_MODE(GetAndBitwiseAnd, float)
UNREACHABLE_ACCESS_MODE(GetAndBitwiseXor, float)
UNREACHABLE_ACCESS_MODE(GetAndBitwiseOr, double)
UNREACHABLE_ACCESS_MODE(GetAndBitwiseAnd, double)
UNREACHABLE_ACCESS_MODE(GetAndBitwiseXor, double)
// A helper class for object field accesses for floats and
// doubles. The object interface deals with Field32 and Field64. The
// former is used for both integers and floats, the latter for longs
// and doubles. This class provides the necessary coercion.
template <typename T, typename U>
class TypeAdaptorAccessor : public Object::Accessor<T> {
public:
explicit TypeAdaptorAccessor(Object::Accessor<U>* inner_accessor)
: inner_accessor_(inner_accessor) {}
void Access(T* addr) override {
static_assert(sizeof(T) == sizeof(U), "bad conversion");
inner_accessor_->Access(reinterpret_cast<U*>(addr));
}
private:
Object::Accessor<U>* inner_accessor_;
};
template <typename T>
class FieldAccessViaAccessor {
public:
using Accessor = Object::Accessor<T>;
// Apply an Accessor to get a field in an object.
static void Get(ObjPtr<Object> obj,
MemberOffset field_offset,
Accessor* accessor)
REQUIRES_SHARED(Locks::mutator_lock_) {
obj->GetPrimitiveFieldViaAccessor(field_offset, accessor);
}
// Apply an Accessor to update a field in an object.
static void Update(ObjPtr<Object> obj,
MemberOffset field_offset,
Accessor* accessor)
REQUIRES_SHARED(Locks::mutator_lock_);
};
template <>
inline void FieldAccessViaAccessor<float>::Get(ObjPtr<Object> obj,
MemberOffset field_offset,
Accessor* accessor)
REQUIRES_SHARED(Locks::mutator_lock_) {
TypeAdaptorAccessor<int32_t, float> float_to_int_accessor(accessor);
obj->GetPrimitiveFieldViaAccessor(field_offset, &float_to_int_accessor);
}
template <>
inline void FieldAccessViaAccessor<double>::Get(ObjPtr<Object> obj,
MemberOffset field_offset,
Accessor* accessor)
REQUIRES_SHARED(Locks::mutator_lock_) {
TypeAdaptorAccessor<int64_t, double> double_to_int_accessor(accessor);
obj->GetPrimitiveFieldViaAccessor(field_offset, &double_to_int_accessor);
}
template <>
void FieldAccessViaAccessor<uint8_t>::Update(ObjPtr<Object> obj,
MemberOffset field_offset,
Accessor* accessor)
REQUIRES_SHARED(Locks::mutator_lock_) {
if (Runtime::Current()->IsActiveTransaction()) {
obj->UpdateFieldBooleanViaAccessor<kTransactionActive>(field_offset, accessor);
} else {
obj->UpdateFieldBooleanViaAccessor<kTransactionInactive>(field_offset, accessor);
}
}
template <>
void FieldAccessViaAccessor<int8_t>::Update(ObjPtr<Object> obj,
MemberOffset field_offset,
Accessor* accessor)
REQUIRES_SHARED(Locks::mutator_lock_) {
if (Runtime::Current()->IsActiveTransaction()) {
obj->UpdateFieldByteViaAccessor<kTransactionActive>(field_offset, accessor);
} else {
obj->UpdateFieldByteViaAccessor<kTransactionInactive>(field_offset, accessor);
}
}
template <>
void FieldAccessViaAccessor<uint16_t>::Update(ObjPtr<Object> obj,
MemberOffset field_offset,
Accessor* accessor)
REQUIRES_SHARED(Locks::mutator_lock_) {
if (Runtime::Current()->IsActiveTransaction()) {
obj->UpdateFieldCharViaAccessor<kTransactionActive>(field_offset, accessor);
} else {
obj->UpdateFieldCharViaAccessor<kTransactionInactive>(field_offset, accessor);
}
}
template <>
void FieldAccessViaAccessor<int16_t>::Update(ObjPtr<Object> obj,
MemberOffset field_offset,
Accessor* accessor)
REQUIRES_SHARED(Locks::mutator_lock_) {
if (Runtime::Current()->IsActiveTransaction()) {
obj->UpdateFieldShortViaAccessor<kTransactionActive>(field_offset, accessor);
} else {
obj->UpdateFieldShortViaAccessor<kTransactionInactive>(field_offset, accessor);
}
}
template <>
void FieldAccessViaAccessor<int32_t>::Update(ObjPtr<Object> obj,
MemberOffset field_offset,
Accessor* accessor)
REQUIRES_SHARED(Locks::mutator_lock_) {
if (Runtime::Current()->IsActiveTransaction()) {
obj->UpdateField32ViaAccessor<kTransactionActive>(field_offset, accessor);
} else {
obj->UpdateField32ViaAccessor<kTransactionInactive>(field_offset, accessor);
}
}
template <>
void FieldAccessViaAccessor<int64_t>::Update(ObjPtr<Object> obj,
MemberOffset field_offset,
Accessor* accessor)
REQUIRES_SHARED(Locks::mutator_lock_) {
if (Runtime::Current()->IsActiveTransaction()) {
obj->UpdateField64ViaAccessor<kTransactionActive>(field_offset, accessor);
} else {
obj->UpdateField64ViaAccessor<kTransactionInactive>(field_offset, accessor);
}
}
template <>
void FieldAccessViaAccessor<float>::Update(ObjPtr<Object> obj,
MemberOffset field_offset,
Accessor* accessor)
REQUIRES_SHARED(Locks::mutator_lock_) {
TypeAdaptorAccessor<int32_t, float> float_to_int_accessor(accessor);
if (Runtime::Current()->IsActiveTransaction()) {
obj->UpdateField32ViaAccessor<kTransactionActive>(field_offset, &float_to_int_accessor);
} else {
obj->UpdateField32ViaAccessor<kTransactionInactive>(field_offset, &float_to_int_accessor);
}
}
template <>
void FieldAccessViaAccessor<double>::Update(ObjPtr<Object> obj,
MemberOffset field_offset,
Accessor* accessor)
REQUIRES_SHARED(Locks::mutator_lock_) {
TypeAdaptorAccessor<int64_t, double> double_to_int_accessor(accessor);
if (Runtime::Current()->IsActiveTransaction()) {
obj->UpdateField64ViaAccessor<kTransactionActive>(field_offset, &double_to_int_accessor);
} else {
obj->UpdateField64ViaAccessor<kTransactionInactive>(field_offset, &double_to_int_accessor);
}
}
// Helper class that gets values from a shadow frame with appropriate type coercion.
template <typename T>
class ValueGetter {
public:
static T Get(ShadowFrameGetter* getter) REQUIRES_SHARED(Locks::mutator_lock_) {
static_assert(sizeof(T) <= sizeof(uint32_t), "Bad size");
uint32_t raw_value = getter->Get();
return static_cast<T>(raw_value);
}
};
template <>
int64_t ValueGetter<int64_t>::Get(ShadowFrameGetter* getter) {
return getter->GetLong();
}
template <>
float ValueGetter<float>::Get(ShadowFrameGetter* getter) {
uint32_t raw_value = getter->Get();
return *reinterpret_cast<float*>(&raw_value);
}
template <>
double ValueGetter<double>::Get(ShadowFrameGetter* getter) {
int64_t raw_value = getter->GetLong();
return *reinterpret_cast<double*>(&raw_value);
}
template <>
ObjPtr<Object> ValueGetter<ObjPtr<Object>>::Get(ShadowFrameGetter* getter) {
return getter->GetReference();
}
// Class for accessing fields of Object instances
template <typename T>
class FieldAccessor {
public:
static bool Dispatch(VarHandle::AccessMode access_mode,
ObjPtr<Object> obj,
MemberOffset field_offset,
ShadowFrameGetter* getter,
JValue* result)
REQUIRES_SHARED(Locks::mutator_lock_);
};
// Dispatch implementation for primitive fields.
template <typename T>
bool FieldAccessor<T>::Dispatch(VarHandle::AccessMode access_mode,
ObjPtr<Object> obj,
MemberOffset field_offset,
ShadowFrameGetter* getter,
JValue* result) {
switch (access_mode) {
case VarHandle::AccessMode::kGet: {
GetAccessor<T> accessor(result);
FieldAccessViaAccessor<T>::Get(obj, field_offset, &accessor);
break;
}
case VarHandle::AccessMode::kSet: {
T new_value = ValueGetter<T>::Get(getter);
SetAccessor<T> accessor(new_value);
FieldAccessViaAccessor<T>::Update(obj, field_offset, &accessor);
break;
}
case VarHandle::AccessMode::kGetAcquire:
case VarHandle::AccessMode::kGetOpaque:
case VarHandle::AccessMode::kGetVolatile: {
GetVolatileAccessor<T> accessor(result);
FieldAccessViaAccessor<T>::Get(obj, field_offset, &accessor);
break;
}
case VarHandle::AccessMode::kSetOpaque:
case VarHandle::AccessMode::kSetRelease:
case VarHandle::AccessMode::kSetVolatile: {
T new_value = ValueGetter<T>::Get(getter);
SetVolatileAccessor<T> accessor(new_value);
FieldAccessViaAccessor<T>::Update(obj, field_offset, &accessor);
break;
}
case VarHandle::AccessMode::kCompareAndSet: {
T expected_value = ValueGetter<T>::Get(getter);
T desired_value = ValueGetter<T>::Get(getter);
CompareAndSetAccessor<T> accessor(expected_value, desired_value, result);
FieldAccessViaAccessor<T>::Update(obj, field_offset, &accessor);
break;
}
case VarHandle::AccessMode::kCompareAndExchange:
case VarHandle::AccessMode::kCompareAndExchangeAcquire:
case VarHandle::AccessMode::kCompareAndExchangeRelease: {
T expected_value = ValueGetter<T>::Get(getter);
T desired_value = ValueGetter<T>::Get(getter);
CompareAndExchangeAccessor<T> accessor(expected_value, desired_value, result);
FieldAccessViaAccessor<T>::Update(obj, field_offset, &accessor);
break;
}
case VarHandle::AccessMode::kWeakCompareAndSet:
case VarHandle::AccessMode::kWeakCompareAndSetAcquire:
case VarHandle::AccessMode::kWeakCompareAndSetPlain:
case VarHandle::AccessMode::kWeakCompareAndSetRelease: {
T expected_value = ValueGetter<T>::Get(getter);
T desired_value = ValueGetter<T>::Get(getter);
WeakCompareAndSetAccessor<T> accessor(expected_value, desired_value, result);
FieldAccessViaAccessor<T>::Update(obj, field_offset, &accessor);
break;
}
case VarHandle::AccessMode::kGetAndSet:
case VarHandle::AccessMode::kGetAndSetAcquire:
case VarHandle::AccessMode::kGetAndSetRelease: {
T new_value = ValueGetter<T>::Get(getter);
GetAndSetAccessor<T> accessor(new_value, result);
FieldAccessViaAccessor<T>::Update(obj, field_offset, &accessor);
break;
}
case VarHandle::AccessMode::kGetAndAdd:
case VarHandle::AccessMode::kGetAndAddAcquire:
case VarHandle::AccessMode::kGetAndAddRelease: {
T value = ValueGetter<T>::Get(getter);
GetAndAddAccessor<T> accessor(value, result);
FieldAccessViaAccessor<T>::Update(obj, field_offset, &accessor);
break;
}
case VarHandle::AccessMode::kGetAndBitwiseOr:
case VarHandle::AccessMode::kGetAndBitwiseOrAcquire:
case VarHandle::AccessMode::kGetAndBitwiseOrRelease: {
T value = ValueGetter<T>::Get(getter);
GetAndBitwiseOrAccessor<T> accessor(value, result);
FieldAccessViaAccessor<T>::Update(obj, field_offset, &accessor);
break;
}
case VarHandle::AccessMode::kGetAndBitwiseAnd:
case VarHandle::AccessMode::kGetAndBitwiseAndAcquire:
case VarHandle::AccessMode::kGetAndBitwiseAndRelease: {
T value = ValueGetter<T>::Get(getter);
GetAndBitwiseAndAccessor<T> accessor(value, result);
FieldAccessViaAccessor<T>::Update(obj, field_offset, &accessor);
break;
}
case VarHandle::AccessMode::kGetAndBitwiseXor:
case VarHandle::AccessMode::kGetAndBitwiseXorAcquire:
case VarHandle::AccessMode::kGetAndBitwiseXorRelease: {
T value = ValueGetter<T>::Get(getter);
GetAndBitwiseXorAccessor<T> accessor(value, result);
FieldAccessViaAccessor<T>::Update(obj, field_offset, &accessor);
break;
}
}
return true;
}
// Dispatch implementation for reference fields.
template <>
bool FieldAccessor<ObjPtr<Object>>::Dispatch(VarHandle::AccessMode access_mode,
ObjPtr<Object> obj,
MemberOffset field_offset,
ShadowFrameGetter* getter,
JValue* result)
REQUIRES_SHARED(Locks::mutator_lock_) {
// To keep things simple, use the minimum strongest existing
// field accessor for Object fields. This may be the most
// straightforward strategy in general for the interpreter.
switch (access_mode) {
case VarHandle::AccessMode::kGet: {
StoreResult(obj->GetFieldObject<Object>(field_offset), result);
break;
}
case VarHandle::AccessMode::kSet: {
ObjPtr<Object> new_value = ValueGetter<ObjPtr<Object>>::Get(getter);
if (Runtime::Current()->IsActiveTransaction()) {
obj->SetFieldObject<kTransactionActive>(field_offset, new_value);
} else {
obj->SetFieldObject<kTransactionInactive>(field_offset, new_value);
}
break;
}
case VarHandle::AccessMode::kGetAcquire:
case VarHandle::AccessMode::kGetOpaque:
case VarHandle::AccessMode::kGetVolatile: {
StoreResult(obj->GetFieldObjectVolatile<Object>(field_offset), result);
break;
}
case VarHandle::AccessMode::kSetOpaque:
case VarHandle::AccessMode::kSetRelease:
case VarHandle::AccessMode::kSetVolatile: {
ObjPtr<Object> new_value = ValueGetter<ObjPtr<Object>>::Get(getter);
if (Runtime::Current()->IsActiveTransaction()) {
obj->SetFieldObjectVolatile<kTransactionActive>(field_offset, new_value);
} else {
obj->SetFieldObjectVolatile<kTransactionInactive>(field_offset, new_value);
}
break;
}
case VarHandle::AccessMode::kCompareAndSet: {
ReadBarrierForVarHandleAccess(obj, field_offset);
ObjPtr<Object> expected_value = ValueGetter<ObjPtr<Object>>::Get(getter);
ObjPtr<Object> desired_value = ValueGetter<ObjPtr<Object>>::Get(getter);
bool cas_result;
if (Runtime::Current()->IsActiveTransaction()) {
cas_result = obj->CasFieldObject<kTransactionActive>(field_offset,
expected_value,
desired_value,
CASMode::kStrong,
std::memory_order_seq_cst);
} else {
cas_result = obj->CasFieldObject<kTransactionInactive>(field_offset,
expected_value,
desired_value,
CASMode::kStrong,
std::memory_order_seq_cst);
}
StoreResult(static_cast<uint8_t>(cas_result), result);
break;
}
case VarHandle::AccessMode::kWeakCompareAndSet:
case VarHandle::AccessMode::kWeakCompareAndSetAcquire:
case VarHandle::AccessMode::kWeakCompareAndSetPlain:
case VarHandle::AccessMode::kWeakCompareAndSetRelease: {
ReadBarrierForVarHandleAccess(obj, field_offset);
ObjPtr<Object> expected_value = ValueGetter<ObjPtr<Object>>::Get(getter);
ObjPtr<Object> desired_value = ValueGetter<ObjPtr<Object>>::Get(getter);
bool cas_result;
if (Runtime::Current()->IsActiveTransaction()) {
cas_result = obj->CasFieldObject<kTransactionActive>(field_offset,
expected_value,
desired_value,
CASMode::kWeak,
std::memory_order_seq_cst);
} else {
cas_result = obj->CasFieldObject<kTransactionInactive>(
field_offset,
expected_value,
desired_value,
CASMode::kWeak,
std::memory_order_seq_cst);
}
StoreResult(static_cast<uint8_t>(cas_result), result);
break;
}
case VarHandle::AccessMode::kCompareAndExchange:
case VarHandle::AccessMode::kCompareAndExchangeAcquire:
case VarHandle::AccessMode::kCompareAndExchangeRelease: {
ReadBarrierForVarHandleAccess(obj, field_offset);
ObjPtr<Object> expected_value = ValueGetter<ObjPtr<Object>>::Get(getter);
ObjPtr<Object> desired_value = ValueGetter<ObjPtr<Object>>::Get(getter);
ObjPtr<Object> witness_value;
if (Runtime::Current()->IsActiveTransaction()) {
witness_value = obj->CompareAndExchangeFieldObject<kTransactionActive>(field_offset,
expected_value,
desired_value);
} else {
witness_value = obj->CompareAndExchangeFieldObject<kTransactionInactive>(field_offset,
expected_value,
desired_value);
}
StoreResult(witness_value, result);
break;
}
case VarHandle::AccessMode::kGetAndSet:
case VarHandle::AccessMode::kGetAndSetAcquire:
case VarHandle::AccessMode::kGetAndSetRelease: {
ReadBarrierForVarHandleAccess(obj, field_offset);
ObjPtr<Object> new_value = ValueGetter<ObjPtr<Object>>::Get(getter);
ObjPtr<Object> old_value;
if (Runtime::Current()->IsActiveTransaction()) {
old_value = obj->ExchangeFieldObject<kTransactionActive>(field_offset, new_value);
} else {
old_value = obj->ExchangeFieldObject<kTransactionInactive>(field_offset, new_value);
}
StoreResult(old_value, result);
break;
}
case VarHandle::AccessMode::kGetAndAdd:
case VarHandle::AccessMode::kGetAndAddAcquire:
case VarHandle::AccessMode::kGetAndAddRelease:
case VarHandle::AccessMode::kGetAndBitwiseOr:
case VarHandle::AccessMode::kGetAndBitwiseOrAcquire:
case VarHandle::AccessMode::kGetAndBitwiseOrRelease:
case VarHandle::AccessMode::kGetAndBitwiseAnd:
case VarHandle::AccessMode::kGetAndBitwiseAndAcquire:
case VarHandle::AccessMode::kGetAndBitwiseAndRelease:
case VarHandle::AccessMode::kGetAndBitwiseXor:
case VarHandle::AccessMode::kGetAndBitwiseXorAcquire:
case VarHandle::AccessMode::kGetAndBitwiseXorRelease: {
size_t index = static_cast<size_t>(access_mode);
const char* access_mode_name = kAccessorToAccessMode[index].method_name;
UnreachableAccessMode(access_mode_name, "Object");
}
}
return true;
}
// Class for accessing primitive array elements.
template <typename T>
class PrimitiveArrayElementAccessor {
public:
static T* GetElementAddress(ObjPtr<Array> target_array, int target_element)
REQUIRES_SHARED(Locks::mutator_lock_) {
auto primitive_array = ObjPtr<PrimitiveArray<T>>::DownCast(target_array);
DCHECK(primitive_array->CheckIsValidIndex(target_element));
return &primitive_array->GetData()[target_element];
}
static bool Dispatch(VarHandle::AccessMode access_mode,
ObjPtr<Array> target_array,
int target_element,
ShadowFrameGetter* getter,
JValue* result)
REQUIRES_SHARED(Locks::mutator_lock_) {
T* element_address = GetElementAddress(target_array, target_element);
switch (access_mode) {
case VarHandle::AccessMode::kGet: {
GetAccessor<T> accessor(result);
accessor.Access(element_address);
break;
}
case VarHandle::AccessMode::kSet: {
T new_value = ValueGetter<T>::Get(getter);
SetAccessor<T> accessor(new_value);
accessor.Access(element_address);
break;
}
case VarHandle::AccessMode::kGetAcquire:
case VarHandle::AccessMode::kGetOpaque:
case VarHandle::AccessMode::kGetVolatile: {
GetVolatileAccessor<T> accessor(result);
accessor.Access(element_address);
break;
}
case VarHandle::AccessMode::kSetOpaque:
case VarHandle::AccessMode::kSetRelease:
case VarHandle::AccessMode::kSetVolatile: {
T new_value = ValueGetter<T>::Get(getter);
SetVolatileAccessor<T> accessor(new_value);
accessor.Access(element_address);
break;
}
case VarHandle::AccessMode::kCompareAndSet: {
T expected_value = ValueGetter<T>::Get(getter);
T desired_value = ValueGetter<T>::Get(getter);
CompareAndSetAccessor<T> accessor(expected_value, desired_value, result);
accessor.Access(element_address);
break;
}
case VarHandle::AccessMode::kCompareAndExchange:
case VarHandle::AccessMode::kCompareAndExchangeAcquire:
case VarHandle::AccessMode::kCompareAndExchangeRelease: {
T expected_value = ValueGetter<T>::Get(getter);
T desired_value = ValueGetter<T>::Get(getter);
CompareAndExchangeAccessor<T> accessor(expected_value, desired_value, result);
accessor.Access(element_address);
break;
}
case VarHandle::AccessMode::kWeakCompareAndSet:
case VarHandle::AccessMode::kWeakCompareAndSetAcquire:
case VarHandle::AccessMode::kWeakCompareAndSetPlain:
case VarHandle::AccessMode::kWeakCompareAndSetRelease: {
T expected_value = ValueGetter<T>::Get(getter);
T desired_value = ValueGetter<T>::Get(getter);
WeakCompareAndSetAccessor<T> accessor(expected_value, desired_value, result);
accessor.Access(element_address);
break;
}
case VarHandle::AccessMode::kGetAndSet:
case VarHandle::AccessMode::kGetAndSetAcquire:
case VarHandle::AccessMode::kGetAndSetRelease: {
T new_value = ValueGetter<T>::Get(getter);
GetAndSetAccessor<T> accessor(new_value, result);
accessor.Access(element_address);
break;
}
case VarHandle::AccessMode::kGetAndAdd:
case VarHandle::AccessMode::kGetAndAddAcquire:
case VarHandle::AccessMode::kGetAndAddRelease: {
T value = ValueGetter<T>::Get(getter);
GetAndAddAccessor<T> accessor(value, result);
accessor.Access(element_address);
break;
}
case VarHandle::AccessMode::kGetAndBitwiseOr:
case VarHandle::AccessMode::kGetAndBitwiseOrAcquire:
case VarHandle::AccessMode::kGetAndBitwiseOrRelease: {
T value = ValueGetter<T>::Get(getter);
GetAndBitwiseOrAccessor<T> accessor(value, result);
accessor.Access(element_address);
break;
}
case VarHandle::AccessMode::kGetAndBitwiseAnd:
case VarHandle::AccessMode::kGetAndBitwiseAndAcquire:
case VarHandle::AccessMode::kGetAndBitwiseAndRelease: {
T value = ValueGetter<T>::Get(getter);
GetAndBitwiseAndAccessor<T> accessor(value, result);
accessor.Access(element_address);
break;
}
case VarHandle::AccessMode::kGetAndBitwiseXor:
case VarHandle::AccessMode::kGetAndBitwiseXorAcquire:
case VarHandle::AccessMode::kGetAndBitwiseXorRelease: {
T value = ValueGetter<T>::Get(getter);
GetAndBitwiseXorAccessor<T> accessor(value, result);
accessor.Access(element_address);
break;
}
}
return true;
}
};
// Class for accessing primitive array elements.
template <typename T>
class ByteArrayViewAccessor {
public:
static inline bool IsAccessAligned(int8_t* data, int data_index) {
static_assert(IsPowerOfTwo(sizeof(T)), "unexpected size");
static_assert(std::is_arithmetic<T>::value, "unexpected type");
uintptr_t alignment_mask = sizeof(T) - 1;
uintptr_t address = reinterpret_cast<uintptr_t>(data + data_index);
return (address & alignment_mask) == 0;
}
static inline void MaybeByteSwap(bool byte_swap, T* const value) {
if (byte_swap) {
*value = BSWAP(*value);
}
}
static bool Dispatch(const VarHandle::AccessMode access_mode,
int8_t* const data,
const int data_index,
const bool byte_swap,
ShadowFrameGetter* const getter,
JValue* const result)
REQUIRES_SHARED(Locks::mutator_lock_) {
const bool is_aligned = IsAccessAligned(data, data_index);
if (!is_aligned) {
switch (access_mode) {
case VarHandle::AccessMode::kGet: {
T value;
memcpy(&value, data + data_index, sizeof(T));
MaybeByteSwap(byte_swap, &value);
StoreResult(value, result);
return true;
}
case VarHandle::AccessMode::kSet: {
T new_value = ValueGetter<T>::Get(getter);
MaybeByteSwap(byte_swap, &new_value);
memcpy(data + data_index, &new_value, sizeof(T));
return true;
}
default:
// No other access modes support unaligned access.
ThrowIllegalStateException("Unaligned access not supported");
return false;
}
}
T* const element_address = reinterpret_cast<T*>(data + data_index);
CHECK(IsAccessAligned(reinterpret_cast<int8_t*>(element_address), 0));
switch (access_mode) {
case VarHandle::AccessMode::kGet: {
GetAccessor<T> accessor(result);
accessor.Access(element_address);
JValueByteSwapper<T>::MaybeByteSwap(byte_swap, result);
break;
}
case VarHandle::AccessMode::kSet: {
T new_value = ValueGetter<T>::Get(getter);
MaybeByteSwap(byte_swap, &new_value);
SetAccessor<T> accessor(new_value);
accessor.Access(element_address);
break;
}
case VarHandle::AccessMode::kGetAcquire:
case VarHandle::AccessMode::kGetOpaque:
case VarHandle::AccessMode::kGetVolatile: {
GetVolatileAccessor<T> accessor(result);
accessor.Access(element_address);
JValueByteSwapper<T>::MaybeByteSwap(byte_swap, result);
break;
}
case VarHandle::AccessMode::kSetOpaque:
case VarHandle::AccessMode::kSetRelease:
case VarHandle::AccessMode::kSetVolatile: {
T new_value = ValueGetter<T>::Get(getter);
MaybeByteSwap(byte_swap, &new_value);
SetVolatileAccessor<T> accessor(new_value);
accessor.Access(element_address);
break;
}
case VarHandle::AccessMode::kCompareAndSet: {
T expected_value = ValueGetter<T>::Get(getter);
T desired_value = ValueGetter<T>::Get(getter);
MaybeByteSwap(byte_swap, &expected_value);
MaybeByteSwap(byte_swap, &desired_value);
CompareAndSetAccessor<T> accessor(expected_value, desired_value, result);
accessor.Access(element_address);
break;
}
case VarHandle::AccessMode::kCompareAndExchange:
case VarHandle::AccessMode::kCompareAndExchangeAcquire:
case VarHandle::AccessMode::kCompareAndExchangeRelease: {
T expected_value = ValueGetter<T>::Get(getter);
T desired_value = ValueGetter<T>::Get(getter);
MaybeByteSwap(byte_swap, &expected_value);
MaybeByteSwap(byte_swap, &desired_value);
CompareAndExchangeAccessor<T> accessor(expected_value, desired_value, result);
accessor.Access(element_address);
JValueByteSwapper<T>::MaybeByteSwap(byte_swap, result);
break;
}
case VarHandle::AccessMode::kWeakCompareAndSet:
case VarHandle::AccessMode::kWeakCompareAndSetAcquire:
case VarHandle::AccessMode::kWeakCompareAndSetPlain:
case VarHandle::AccessMode::kWeakCompareAndSetRelease: {
T expected_value = ValueGetter<T>::Get(getter);
T desired_value = ValueGetter<T>::Get(getter);
MaybeByteSwap(byte_swap, &expected_value);
MaybeByteSwap(byte_swap, &desired_value);
WeakCompareAndSetAccessor<T> accessor(expected_value, desired_value, result);
accessor.Access(element_address);
break;
}
case VarHandle::AccessMode::kGetAndSet:
case VarHandle::AccessMode::kGetAndSetAcquire:
case VarHandle::AccessMode::kGetAndSetRelease: {
T new_value = ValueGetter<T>::Get(getter);
MaybeByteSwap(byte_swap, &new_value);
GetAndSetAccessor<T> accessor(new_value, result);
accessor.Access(element_address);
JValueByteSwapper<T>::MaybeByteSwap(byte_swap, result);
break;
}
case VarHandle::AccessMode::kGetAndAdd:
case VarHandle::AccessMode::kGetAndAddAcquire:
case VarHandle::AccessMode::kGetAndAddRelease: {
T value = ValueGetter<T>::Get(getter);
if (byte_swap) {
GetAndAddWithByteSwapAccessor<T> accessor(value, result);
accessor.Access(element_address);
} else {
GetAndAddAccessor<T> accessor(value, result);
accessor.Access(element_address);
}
break;
}
case VarHandle::AccessMode::kGetAndBitwiseOr:
case VarHandle::AccessMode::kGetAndBitwiseOrAcquire:
case VarHandle::AccessMode::kGetAndBitwiseOrRelease: {
T value = ValueGetter<T>::Get(getter);
MaybeByteSwap(byte_swap, &value);
GetAndBitwiseOrAccessor<T> accessor(value, result);
accessor.Access(element_address);
JValueByteSwapper<T>::MaybeByteSwap(byte_swap, result);
break;
}
case VarHandle::AccessMode::kGetAndBitwiseAnd:
case VarHandle::AccessMode::kGetAndBitwiseAndAcquire:
case VarHandle::AccessMode::kGetAndBitwiseAndRelease: {
T value = ValueGetter<T>::Get(getter);
MaybeByteSwap(byte_swap, &value);
GetAndBitwiseAndAccessor<T> accessor(value, result);
accessor.Access(element_address);
JValueByteSwapper<T>::MaybeByteSwap(byte_swap, result);
break;
}
case VarHandle::AccessMode::kGetAndBitwiseXor:
case VarHandle::AccessMode::kGetAndBitwiseXorAcquire:
case VarHandle::AccessMode::kGetAndBitwiseXorRelease: {
T value = ValueGetter<T>::Get(getter);
MaybeByteSwap(byte_swap, &value);
GetAndBitwiseXorAccessor<T> accessor(value, result);
accessor.Access(element_address);
JValueByteSwapper<T>::MaybeByteSwap(byte_swap, result);
break;
}
}
return true;
}
};
} // namespace
ObjPtr<Class> VarHandle::GetVarType() {
return GetFieldObject<Class>(VarTypeOffset());
}
ObjPtr<Class> VarHandle::GetCoordinateType0() {
return GetFieldObject<Class>(CoordinateType0Offset());
}
ObjPtr<Class> VarHandle::GetCoordinateType1() {
return GetFieldObject<Class>(CoordinateType1Offset());
}
int32_t VarHandle::GetAccessModesBitMask() {
return GetField32(AccessModesBitMaskOffset());
}
VarHandle::MatchKind VarHandle::GetMethodTypeMatchForAccessMode(AccessMode access_mode,
ObjPtr<MethodType> method_type) {
MatchKind match = MatchKind::kExact;
ObjPtr<VarHandle> vh = this;
ObjPtr<Class> var_type = vh->GetVarType();
ObjPtr<Class> mt_rtype = method_type->GetRType();
AccessModeTemplate access_mode_template = GetAccessModeTemplate(access_mode);
// Check return type first. If the return type of the method
// of the VarHandle is immaterial.
if (mt_rtype->GetPrimitiveType() != Primitive::Type::kPrimVoid) {
ObjPtr<Class> vh_rtype = GetReturnType(access_mode_template, var_type);
if (vh_rtype != mt_rtype) {
if (!IsReturnTypeConvertible(vh_rtype, mt_rtype)) {
return MatchKind::kNone;
}
match = MatchKind::kWithConversions;
}
}
// Check the number of parameters matches.
ObjPtr<Class> vh_ptypes[VarHandle::kMaxAccessorParameters];
const int32_t vh_ptypes_count = BuildParameterArray(vh_ptypes,
access_mode_template,
var_type,
GetCoordinateType0(),
GetCoordinateType1());
if (vh_ptypes_count != method_type->GetPTypes()->GetLength()) {
return MatchKind::kNone;
}
// Check the parameter types are compatible.
ObjPtr<ObjectArray<Class>> mt_ptypes = method_type->GetPTypes();
for (int32_t i = 0; i < vh_ptypes_count; ++i) {
if (mt_ptypes->Get(i) == vh_ptypes[i]) {
continue;
}
if (!IsParameterTypeConvertible(mt_ptypes->Get(i), vh_ptypes[i])) {
return MatchKind::kNone;
}
match = MatchKind::kWithConversions;
}
return match;
}
bool VarHandle::IsInvokerMethodTypeCompatible(AccessMode access_mode,
ObjPtr<MethodType> method_type) {
StackHandleScope<3> hs(Thread::Current());
Handle<Class> mt_rtype(hs.NewHandle(method_type->GetRType()));
Handle<VarHandle> vh(hs.NewHandle(this));
Handle<Class> var_type(hs.NewHandle(vh->GetVarType()));
AccessModeTemplate access_mode_template = GetAccessModeTemplate(access_mode);
// Check return type first.
if (mt_rtype->GetPrimitiveType() == Primitive::Type::kPrimVoid) {
// The result of the operation will be discarded. The return type
// of the VarHandle is immaterial.
} else {
ObjPtr<Class> vh_rtype(GetReturnType(access_mode_template, var_type.Get()));
if (!IsReturnTypeConvertible(vh_rtype, mt_rtype.Get())) {
return false;
}
}
// Check the number of parameters matches (ignoring the VarHandle parameter).
static const int32_t kVarHandleParameters = 1;
ObjPtr<Class> vh_ptypes[VarHandle::kMaxAccessorParameters];
const int32_t vh_ptypes_count = BuildParameterArray(vh_ptypes,
access_mode_template,
var_type.Get(),
GetCoordinateType0(),
GetCoordinateType1());
if (vh_ptypes_count != method_type->GetPTypes()->GetLength() - kVarHandleParameters) {
return false;
}
// Check the parameter types are compatible (ignoring the VarHandle parameter).
ObjPtr<ObjectArray<Class>> mt_ptypes = method_type->GetPTypes();
for (int32_t i = 0; i < vh_ptypes_count; ++i) {
if (!IsParameterTypeConvertible(mt_ptypes->Get(i + kVarHandleParameters), vh_ptypes[i])) {
return false;
}
}
return true;
}
ObjPtr<MethodType> VarHandle::GetMethodTypeForAccessMode(Thread* self,
ObjPtr<VarHandle> var_handle,
AccessMode access_mode) {
// This is a static method as the var_handle might be moved by the GC during it's execution.
AccessModeTemplate access_mode_template = GetAccessModeTemplate(access_mode);
StackHandleScope<3> hs(self);
Handle<VarHandle> vh = hs.NewHandle(var_handle);
Handle<Class> rtype = hs.NewHandle(GetReturnType(access_mode_template, vh->GetVarType()));
const int32_t ptypes_count = GetNumberOfParameters(access_mode_template,
vh->GetCoordinateType0(),
vh->GetCoordinateType1());
ObjPtr<Class> array_of_class = GetClassRoot<ObjectArray<Class>>();
Handle<ObjectArray<Class>> ptypes =
hs.NewHandle(ObjectArray<Class>::Alloc(Thread::Current(), array_of_class, ptypes_count));
if (ptypes == nullptr) {
return nullptr;
}
ObjPtr<Class> ptypes_array[VarHandle::kMaxAccessorParameters];
BuildParameterArray(ptypes_array,
access_mode_template,
vh->GetVarType(),
vh->GetCoordinateType0(),
vh->GetCoordinateType1());
for (int32_t i = 0; i < ptypes_count; ++i) {
ptypes->Set(i, ptypes_array[i]);
}
return MethodType::Create(self, rtype, ptypes);
}
ObjPtr<MethodType> VarHandle::GetMethodTypeForAccessMode(Thread* self, AccessMode access_mode) {
return GetMethodTypeForAccessMode(self, this, access_mode);
}
std::string VarHandle::PrettyDescriptorForAccessMode(AccessMode access_mode) {
// Effect MethodType::PrettyDescriptor() without first creating a method type first.
std::ostringstream oss;
oss << '(';
AccessModeTemplate access_mode_template = GetAccessModeTemplate(access_mode);
ObjPtr<Class> var_type = GetVarType();
ObjPtr<Class> ctypes[2] = { GetCoordinateType0(), GetCoordinateType1() };
const int32_t ptypes_count = GetNumberOfParameters(access_mode_template, ctypes[0], ctypes[1]);
int32_t ptypes_done = 0;
for (ObjPtr<Class> ctype : ctypes) {
if (!ctype.IsNull()) {
if (ptypes_done != 0) {
oss << ", ";
}
oss << ctype->PrettyDescriptor();;
ptypes_done++;
}
}
while (ptypes_done != ptypes_count) {
if (ptypes_done != 0) {
oss << ", ";
}
oss << var_type->PrettyDescriptor();
ptypes_done++;
}
ObjPtr<Class> rtype = GetReturnType(access_mode_template, var_type);
oss << ')' << rtype->PrettyDescriptor();
return oss.str();
}
bool VarHandle::Access(AccessMode access_mode,
ShadowFrame* shadow_frame,
const InstructionOperands* const operands,
JValue* result) {
ObjPtr<ObjectArray<Class>> class_roots = Runtime::Current()->GetClassLinker()->GetClassRoots();
ObjPtr<Class> klass = GetClass();
if (klass == GetClassRoot<FieldVarHandle>(class_roots)) {
auto vh = reinterpret_cast<FieldVarHandle*>(this);
return vh->Access(access_mode, shadow_frame, operands, result);
} else if (klass == GetClassRoot<ArrayElementVarHandle>(class_roots)) {
auto vh = reinterpret_cast<ArrayElementVarHandle*>(this);
return vh->Access(access_mode, shadow_frame, operands, result);
} else if (klass == GetClassRoot<ByteArrayViewVarHandle>(class_roots)) {
auto vh = reinterpret_cast<ByteArrayViewVarHandle*>(this);
return vh->Access(access_mode, shadow_frame, operands, result);
} else if (klass == GetClassRoot<ByteBufferViewVarHandle>(class_roots)) {
auto vh = reinterpret_cast<ByteBufferViewVarHandle*>(this);
return vh->Access(access_mode, shadow_frame, operands, result);
} else {
LOG(FATAL) << "Unknown varhandle kind";
UNREACHABLE();
}
}
const char* VarHandle::GetReturnTypeDescriptor(const char* accessor_name) {
AccessMode access_mode;
if (!GetAccessModeByMethodName(accessor_name, &access_mode)) {
return nullptr;
}
AccessModeTemplate access_mode_template = GetAccessModeTemplate(access_mode);
switch (access_mode_template) {
case AccessModeTemplate::kGet:
case AccessModeTemplate::kCompareAndExchange:
case AccessModeTemplate::kGetAndUpdate:
return "Ljava/lang/Object;";
case AccessModeTemplate::kCompareAndSet:
return "Z";
case AccessModeTemplate::kSet:
return "V";
}
}
VarHandle::AccessMode VarHandle::GetAccessModeByIntrinsic(Intrinsics intrinsic) {
#define VAR_HANDLE_ACCESS_MODE(V) \
V(CompareAndExchange) \
V(CompareAndExchangeAcquire) \
V(CompareAndExchangeRelease) \
V(CompareAndSet) \
V(Get) \
V(GetAcquire) \
V(GetAndAdd) \
V(GetAndAddAcquire) \
V(GetAndAddRelease) \
V(GetAndBitwiseAnd) \
V(GetAndBitwiseAndAcquire) \
V(GetAndBitwiseAndRelease) \
V(GetAndBitwiseOr) \
V(GetAndBitwiseOrAcquire) \
V(GetAndBitwiseOrRelease) \
V(GetAndBitwiseXor) \
V(GetAndBitwiseXorAcquire) \
V(GetAndBitwiseXorRelease) \
V(GetAndSet) \
V(GetAndSetAcquire) \
V(GetAndSetRelease) \
V(GetOpaque) \
V(GetVolatile) \
V(Set) \
V(SetOpaque) \
V(SetRelease) \
V(SetVolatile) \
V(WeakCompareAndSet) \
V(WeakCompareAndSetAcquire) \
V(WeakCompareAndSetPlain) \
V(WeakCompareAndSetRelease)
switch (intrinsic) {
#define INTRINSIC_CASE(Name) \
case Intrinsics::kVarHandle ## Name: \
return VarHandle::AccessMode::k ## Name;
VAR_HANDLE_ACCESS_MODE(INTRINSIC_CASE)
#undef INTRINSIC_CASE
#undef VAR_HANDLE_ACCESS_MODE
default:
break;
}
LOG(FATAL) << "Unknown VarHandle instrinsic: " << static_cast<int>(intrinsic);
UNREACHABLE();
}
bool VarHandle::GetAccessModeByMethodName(const char* method_name, AccessMode* access_mode) {
if (method_name == nullptr) {
return false;
}
VarHandleAccessorToAccessModeEntry target = { method_name, /*dummy*/VarHandle::AccessMode::kGet };
auto last = std::cend(kAccessorToAccessMode);
auto it = std::lower_bound(std::cbegin(kAccessorToAccessMode),
last,
target,
VarHandleAccessorToAccessModeEntry::CompareName);
if (it == last || strcmp(it->method_name, method_name) != 0) {
return false;
}
*access_mode = it->access_mode;
return true;
}
ArtField* FieldVarHandle::GetField() {
return reinterpret_cast64<ArtField*>(GetField64(ArtFieldOffset()));
}
bool FieldVarHandle::Access(AccessMode access_mode,
ShadowFrame* shadow_frame,
const InstructionOperands* const operands,
JValue* result) {
ShadowFrameGetter getter(*shadow_frame, operands);
ArtField* field = GetField();
ObjPtr<Object> obj;
if (field->IsStatic()) {
DCHECK_LE(operands->GetNumberOfOperands(),
2u * (Primitive::Is64BitType(GetVarType()->GetPrimitiveType()) ? 2u : 1u));
obj = field->GetDeclaringClass();
} else {
DCHECK_GE(operands->GetNumberOfOperands(), 1u);
DCHECK_LE(operands->GetNumberOfOperands(),
1u + 2u * (Primitive::Is64BitType(GetVarType()->GetPrimitiveType()) ? 2u : 1u));
obj = getter.GetReference();
if (obj.IsNull()) {
ThrowNullPointerExceptionForCoordinate();
return false;
}
}
DCHECK(!obj.IsNull());
const MemberOffset offset = field->GetOffset();
const Primitive::Type primitive_type = GetVarType()->GetPrimitiveType();
switch (primitive_type) {
case Primitive::Type::kPrimNot:
return FieldAccessor<ObjPtr<Object>>::Dispatch(access_mode, obj, offset, &getter, result);
case Primitive::kPrimBoolean:
return FieldAccessor<uint8_t>::Dispatch(access_mode, obj, offset, &getter, result);
case Primitive::kPrimByte:
return FieldAccessor<int8_t>::Dispatch(access_mode, obj, offset, &getter, result);
case Primitive::kPrimChar:
return FieldAccessor<uint16_t>::Dispatch(access_mode, obj, offset, &getter, result);
case Primitive::kPrimShort:
return FieldAccessor<int16_t>::Dispatch(access_mode, obj, offset, &getter, result);
case Primitive::kPrimInt:
return FieldAccessor<int32_t>::Dispatch(access_mode, obj, offset, &getter, result);
case Primitive::kPrimFloat:
return FieldAccessor<float>::Dispatch(access_mode, obj, offset, &getter, result);
case Primitive::kPrimLong:
return FieldAccessor<int64_t>::Dispatch(access_mode, obj, offset, &getter, result);
case Primitive::kPrimDouble:
return FieldAccessor<double>::Dispatch(access_mode, obj, offset, &getter, result);
case Primitive::kPrimVoid:
break;
}
LOG(FATAL) << "Unreachable: Unexpected primitive " << primitive_type;
UNREACHABLE();
}
bool ArrayElementVarHandle::Access(AccessMode access_mode,
ShadowFrame* shadow_frame,
const InstructionOperands* const operands,
JValue* result) {
ShadowFrameGetter getter(*shadow_frame, operands);
// The target array is the first co-ordinate type preceeding var type arguments.
ObjPtr<Object> raw_array(getter.GetReference());
if (raw_array == nullptr) {
ThrowNullPointerExceptionForCoordinate();
return false;
}
ObjPtr<Array> target_array(raw_array->AsArray());
// The target array element is the second co-ordinate type preceeding var type arguments.
const int target_element = getter.Get();
if (!target_array->CheckIsValidIndex(target_element)) {
DCHECK(Thread::Current()->IsExceptionPending());
return false;
}
const Primitive::Type primitive_type = GetVarType()->GetPrimitiveType();
switch (primitive_type) {
case Primitive::Type::kPrimNot: {
MemberOffset target_element_offset =
target_array->AsObjectArray<Object>()->OffsetOfElement(target_element);
return FieldAccessor<ObjPtr<Object>>::Dispatch(access_mode,
target_array,
target_element_offset,
&getter,
result);
}
case Primitive::Type::kPrimBoolean:
return PrimitiveArrayElementAccessor<uint8_t>::Dispatch(access_mode,
target_array,
target_element,
&getter,
result);
case Primitive::Type::kPrimByte:
return PrimitiveArrayElementAccessor<int8_t>::Dispatch(access_mode,
target_array,
target_element,
&getter,
result);
case Primitive::Type::kPrimChar:
return PrimitiveArrayElementAccessor<uint16_t>::Dispatch(access_mode,
target_array,
target_element,
&getter,
result);
case Primitive::Type::kPrimShort:
return PrimitiveArrayElementAccessor<int16_t>::Dispatch(access_mode,
target_array,
target_element,
&getter,
result);
case Primitive::Type::kPrimInt:
return PrimitiveArrayElementAccessor<int32_t>::Dispatch(access_mode,
target_array,
target_element,
&getter,
result);
case Primitive::Type::kPrimLong:
return PrimitiveArrayElementAccessor<int64_t>::Dispatch(access_mode,
target_array,
target_element,
&getter,
result);
case Primitive::Type::kPrimFloat:
return PrimitiveArrayElementAccessor<float>::Dispatch(access_mode,
target_array,
target_element,
&getter,
result);
case Primitive::Type::kPrimDouble:
return PrimitiveArrayElementAccessor<double>::Dispatch(access_mode,
target_array,
target_element,
&getter,
result);
case Primitive::Type::kPrimVoid:
break;
}
LOG(FATAL) << "Unreachable: Unexpected primitive " << primitive_type;
UNREACHABLE();
}
bool ByteArrayViewVarHandle::GetNativeByteOrder() {
return GetFieldBoolean(NativeByteOrderOffset());
}
bool ByteArrayViewVarHandle::Access(AccessMode access_mode,
ShadowFrame* shadow_frame,
const InstructionOperands* const operands,
JValue* result) {
ShadowFrameGetter getter(*shadow_frame, operands);
// The byte array is the first co-ordinate type preceeding var type arguments.
ObjPtr<Object> raw_byte_array(getter.GetReference());
if (raw_byte_array == nullptr) {
ThrowNullPointerExceptionForCoordinate();
return false;
}
ObjPtr<ByteArray> byte_array(raw_byte_array->AsByteArray());
// The offset in the byte array element is the second co-ordinate type.
const int32_t data_offset = getter.Get();
// Bounds check requested access.
const Primitive::Type primitive_type = GetVarType()->GetPrimitiveType();
if (!CheckElementIndex(primitive_type, data_offset, byte_array->GetLength())) {
return false;
}
int8_t* const data = byte_array->GetData();
bool byte_swap = !GetNativeByteOrder();
switch (primitive_type) {
case Primitive::Type::kPrimNot:
case Primitive::kPrimBoolean:
case Primitive::kPrimByte:
case Primitive::kPrimVoid:
// These are not supported for byte array views and not instantiable.
break;
case Primitive::kPrimChar:
return ByteArrayViewAccessor<uint16_t>::Dispatch(access_mode,
data,
data_offset,
byte_swap,
&getter,
result);
case Primitive::kPrimShort:
return ByteArrayViewAccessor<int16_t>::Dispatch(access_mode,
data,
data_offset,
byte_swap,
&getter,
result);
case Primitive::kPrimInt:
return ByteArrayViewAccessor<int32_t>::Dispatch(access_mode,
data,
data_offset,
byte_swap,
&getter,
result);
case Primitive::kPrimFloat:
// Treated as a bitwise representation. See javadoc comments for
// java.lang.invoke.MethodHandles.byteArrayViewVarHandle().
return ByteArrayViewAccessor<int32_t>::Dispatch(access_mode,
data,
data_offset,
byte_swap,
&getter,
result);
case Primitive::kPrimLong:
return ByteArrayViewAccessor<int64_t>::Dispatch(access_mode,
data,
data_offset,
byte_swap,
&getter,
result);
case Primitive::kPrimDouble:
// Treated as a bitwise representation. See javadoc comments for
// java.lang.invoke.MethodHandles.byteArrayViewVarHandle().
return ByteArrayViewAccessor<int64_t>::Dispatch(access_mode,
data,
data_offset,
byte_swap,
&getter,
result);
}
LOG(FATAL) << "Unreachable: Unexpected primitive " << primitive_type;
UNREACHABLE();
}
bool ByteBufferViewVarHandle::GetNativeByteOrder() {
return GetFieldBoolean(NativeByteOrderOffset());
}
bool ByteBufferViewVarHandle::Access(AccessMode access_mode,
ShadowFrame* shadow_frame,
const InstructionOperands* const operands,
JValue* result) {
ShadowFrameGetter getter(*shadow_frame, operands);
// The byte buffer is the first co-ordinate argument preceeding var type arguments.
ObjPtr<Object> byte_buffer(getter.GetReference());
if (byte_buffer == nullptr) {
ThrowNullPointerExceptionForCoordinate();
return false;
}
// The byte index for access is the second co-ordinate
// argument. This is relative to the offset field of the ByteBuffer.
const int32_t byte_index = getter.Get();
// Check access_mode is compatible with ByteBuffer's read-only property.
bool is_read_only = byte_buffer->GetFieldBoolean(
GetMemberOffset(WellKnownClasses::java_nio_ByteBuffer_isReadOnly));
if (is_read_only && !IsReadOnlyAccessMode(access_mode)) {
ThrowReadOnlyBufferException();
return false;
}
// The native_address is only set for ByteBuffer instances backed by native memory.
const int64_t native_address =
byte_buffer->GetField64(GetMemberOffset(WellKnownClasses::java_nio_ByteBuffer_address));
// Determine offset and limit for accesses.
int32_t byte_buffer_offset;
if (native_address == 0L) {
// Accessing a heap allocated byte buffer.
byte_buffer_offset = byte_buffer->GetField32(
GetMemberOffset(WellKnownClasses::java_nio_ByteBuffer_offset));
} else {
// Accessing direct memory.
byte_buffer_offset = 0;
}
const int32_t byte_buffer_limit = byte_buffer->GetField32(
GetMemberOffset(WellKnownClasses::java_nio_ByteBuffer_limit));
const Primitive::Type primitive_type = GetVarType()->GetPrimitiveType();
if (!CheckElementIndex(primitive_type, byte_index, byte_buffer_offset, byte_buffer_limit)) {
return false;
}
const int32_t checked_offset32 = byte_buffer_offset + byte_index;
int8_t* data;
if (native_address == 0) {
ObjPtr<ByteArray> heap_byte_array = byte_buffer->GetFieldObject<ByteArray>(
GetMemberOffset(WellKnownClasses::java_nio_ByteBuffer_hb));
data = heap_byte_array->GetData();
} else {
data = reinterpret_cast<int8_t*>(static_cast<uint32_t>(native_address));
}
bool byte_swap = !GetNativeByteOrder();
switch (primitive_type) {
case Primitive::kPrimChar:
return ByteArrayViewAccessor<uint16_t>::Dispatch(access_mode,
data,
checked_offset32,
byte_swap,
&getter,
result);
case Primitive::kPrimShort:
return ByteArrayViewAccessor<int16_t>::Dispatch(access_mode,
data,
checked_offset32,
byte_swap,
&getter,
result);
case Primitive::kPrimInt:
return ByteArrayViewAccessor<int32_t>::Dispatch(access_mode,
data,
checked_offset32,
byte_swap,
&getter,
result);
case Primitive::kPrimFloat:
// Treated as a bitwise representation. See javadoc comments for
// java.lang.invoke.MethodHandles.byteArrayViewVarHandle().
return ByteArrayViewAccessor<int32_t>::Dispatch(access_mode,
data,
checked_offset32,
byte_swap,
&getter,
result);
case Primitive::kPrimLong:
return ByteArrayViewAccessor<int64_t>::Dispatch(access_mode,
data,
checked_offset32,
byte_swap,
&getter,
result);
case Primitive::kPrimDouble:
// Treated as a bitwise representation. See javadoc comments for
// java.lang.invoke.MethodHandles.byteArrayViewVarHandle().
return ByteArrayViewAccessor<int64_t>::Dispatch(access_mode,
data,
checked_offset32,
byte_swap,
&getter,
result);
case Primitive::Type::kPrimNot:
case Primitive::kPrimBoolean:
case Primitive::kPrimByte:
case Primitive::kPrimVoid:
// These are not supported for byte array views and not instantiable.
break;
}
LOG(FATAL) << "Unreachable: Unexpected primitive " << primitive_type;
UNREACHABLE();
}
} // namespace mirror
} // namespace art