blob: 6756c7b3682f62c133db8b05b1f740ce25bf1f2e [file] [log] [blame]
/*
* 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.
*/
#include "transaction.h"
#include <android-base/logging.h>
#include "aot_class_linker.h"
#include "base/mutex-inl.h"
#include "base/stl_util.h"
#include "gc/accounting/card_table-inl.h"
#include "gc/heap.h"
#include "gc_root-inl.h"
#include "intern_table.h"
#include "mirror/class-inl.h"
#include "mirror/dex_cache-inl.h"
#include "mirror/object-inl.h"
#include "mirror/object_array-inl.h"
#include "obj_ptr-inl.h"
#include "runtime.h"
#include <list>
namespace art {
// TODO: remove (only used for debugging purpose).
static constexpr bool kEnableTransactionStats = false;
Transaction::Transaction(bool strict, mirror::Class* root)
: log_lock_("transaction log lock", kTransactionLogLock),
aborted_(false),
rolling_back_(false),
heap_(Runtime::Current()->GetHeap()),
strict_(strict),
root_(root) {
DCHECK(Runtime::Current()->IsAotCompiler());
}
Transaction::~Transaction() {
if (kEnableTransactionStats) {
MutexLock mu(Thread::Current(), log_lock_);
size_t objects_count = object_logs_.size();
size_t field_values_count = 0;
for (const auto& it : object_logs_) {
field_values_count += it.second.Size();
}
size_t array_count = array_logs_.size();
size_t array_values_count = 0;
for (const auto& it : array_logs_) {
array_values_count += it.second.Size();
}
size_t intern_string_count = intern_string_logs_.size();
size_t resolve_string_count = resolve_string_logs_.size();
LOG(INFO) << "Transaction::~Transaction"
<< ": objects_count=" << objects_count
<< ", field_values_count=" << field_values_count
<< ", array_count=" << array_count
<< ", array_values_count=" << array_values_count
<< ", intern_string_count=" << intern_string_count
<< ", resolve_string_count=" << resolve_string_count;
}
}
void Transaction::Abort(const std::string& abort_message) {
MutexLock mu(Thread::Current(), log_lock_);
// We may abort more than once if the exception thrown at the time of the
// previous abort has been caught during execution of a class initializer.
// We just keep the message of the first abort because it will cause the
// transaction to be rolled back anyway.
if (!aborted_) {
aborted_ = true;
abort_message_ = abort_message;
}
}
void Transaction::ThrowAbortError(Thread* self, const std::string* abort_message) {
const bool rethrow = (abort_message == nullptr);
if (kIsDebugBuild && rethrow) {
CHECK(IsAborted()) << "Rethrow " << Transaction::kAbortExceptionDescriptor
<< " while transaction is not aborted";
}
if (rethrow) {
// Rethrow an exception with the earlier abort message stored in the transaction.
self->ThrowNewWrappedException(Transaction::kAbortExceptionSignature,
GetAbortMessage().c_str());
} else {
// Throw an exception with the given abort message.
self->ThrowNewWrappedException(Transaction::kAbortExceptionSignature,
abort_message->c_str());
}
}
bool Transaction::IsAborted() {
MutexLock mu(Thread::Current(), log_lock_);
return aborted_;
}
bool Transaction::IsRollingBack() {
return rolling_back_;
}
const std::string& Transaction::GetAbortMessage() {
MutexLock mu(Thread::Current(), log_lock_);
return abort_message_;
}
bool Transaction::WriteConstraint(Thread* self, ObjPtr<mirror::Object> obj) {
DCHECK(obj != nullptr);
MutexLock mu(self, log_lock_);
// Prevent changes in boot image spaces for app or boot image extension.
// For boot image there are no boot image spaces and this condition evaluates to false.
if (heap_->ObjectIsInBootImageSpace(obj)) {
return true;
}
// For apps, also prevent writing to other classes.
return IsStrict() &&
obj->IsClass() && // no constraint updating instances or arrays
obj != root_; // modifying other classes' static field, fail
}
bool Transaction::WriteValueConstraint(Thread* self, ObjPtr<mirror::Object> value) {
if (value == nullptr) {
return false; // We can always store null values.
}
gc::Heap* heap = Runtime::Current()->GetHeap();
MutexLock mu(self, log_lock_);
if (IsStrict()) {
// TODO: Should we restrict writes the same way as for boot image extension?
return false;
} else if (heap->GetBootImageSpaces().empty()) {
return false; // No constraints for boot image.
} else {
// Boot image extension.
ObjPtr<mirror::Class> klass = value->IsClass() ? value->AsClass() : value->GetClass();
return !AotClassLinker::CanReferenceInBootImageExtension(klass, heap);
}
}
bool Transaction::ReadConstraint(Thread* self, ObjPtr<mirror::Object> obj) {
// Read constraints are checked only for static field reads as there are
// no constraints on reading instance fields and array elements.
DCHECK(obj->IsClass());
MutexLock mu(self, log_lock_);
if (IsStrict()) {
return obj != root_; // fail if not self-updating
} else {
// For boot image and boot image extension, allow reading any field.
return false;
}
}
void Transaction::RecordWriteFieldBoolean(mirror::Object* obj,
MemberOffset field_offset,
uint8_t value,
bool is_volatile) {
DCHECK(obj != nullptr);
MutexLock mu(Thread::Current(), log_lock_);
ObjectLog& object_log = object_logs_[obj];
object_log.LogBooleanValue(field_offset, value, is_volatile);
}
void Transaction::RecordWriteFieldByte(mirror::Object* obj,
MemberOffset field_offset,
int8_t value,
bool is_volatile) {
DCHECK(obj != nullptr);
MutexLock mu(Thread::Current(), log_lock_);
ObjectLog& object_log = object_logs_[obj];
object_log.LogByteValue(field_offset, value, is_volatile);
}
void Transaction::RecordWriteFieldChar(mirror::Object* obj,
MemberOffset field_offset,
uint16_t value,
bool is_volatile) {
DCHECK(obj != nullptr);
MutexLock mu(Thread::Current(), log_lock_);
ObjectLog& object_log = object_logs_[obj];
object_log.LogCharValue(field_offset, value, is_volatile);
}
void Transaction::RecordWriteFieldShort(mirror::Object* obj,
MemberOffset field_offset,
int16_t value,
bool is_volatile) {
DCHECK(obj != nullptr);
MutexLock mu(Thread::Current(), log_lock_);
ObjectLog& object_log = object_logs_[obj];
object_log.LogShortValue(field_offset, value, is_volatile);
}
void Transaction::RecordWriteField32(mirror::Object* obj,
MemberOffset field_offset,
uint32_t value,
bool is_volatile) {
DCHECK(obj != nullptr);
MutexLock mu(Thread::Current(), log_lock_);
ObjectLog& object_log = object_logs_[obj];
object_log.Log32BitsValue(field_offset, value, is_volatile);
}
void Transaction::RecordWriteField64(mirror::Object* obj,
MemberOffset field_offset,
uint64_t value,
bool is_volatile) {
DCHECK(obj != nullptr);
MutexLock mu(Thread::Current(), log_lock_);
ObjectLog& object_log = object_logs_[obj];
object_log.Log64BitsValue(field_offset, value, is_volatile);
}
void Transaction::RecordWriteFieldReference(mirror::Object* obj,
MemberOffset field_offset,
mirror::Object* value,
bool is_volatile) {
DCHECK(obj != nullptr);
MutexLock mu(Thread::Current(), log_lock_);
ObjectLog& object_log = object_logs_[obj];
object_log.LogReferenceValue(field_offset, value, is_volatile);
}
void Transaction::RecordWriteArray(mirror::Array* array, size_t index, uint64_t value) {
DCHECK(array != nullptr);
DCHECK(array->IsArrayInstance());
DCHECK(!array->IsObjectArray());
MutexLock mu(Thread::Current(), log_lock_);
auto it = array_logs_.find(array);
if (it == array_logs_.end()) {
ArrayLog log;
it = array_logs_.emplace(array, std::move(log)).first;
}
it->second.LogValue(index, value);
}
void Transaction::RecordResolveString(ObjPtr<mirror::DexCache> dex_cache,
dex::StringIndex string_idx) {
DCHECK(dex_cache != nullptr);
DCHECK_LT(string_idx.index_, dex_cache->GetDexFile()->NumStringIds());
MutexLock mu(Thread::Current(), log_lock_);
resolve_string_logs_.emplace_back(dex_cache, string_idx);
}
void Transaction::RecordStrongStringInsertion(ObjPtr<mirror::String> s) {
InternStringLog log(s, InternStringLog::kStrongString, InternStringLog::kInsert);
LogInternedString(std::move(log));
}
void Transaction::RecordWeakStringInsertion(ObjPtr<mirror::String> s) {
InternStringLog log(s, InternStringLog::kWeakString, InternStringLog::kInsert);
LogInternedString(std::move(log));
}
void Transaction::RecordStrongStringRemoval(ObjPtr<mirror::String> s) {
InternStringLog log(s, InternStringLog::kStrongString, InternStringLog::kRemove);
LogInternedString(std::move(log));
}
void Transaction::RecordWeakStringRemoval(ObjPtr<mirror::String> s) {
InternStringLog log(s, InternStringLog::kWeakString, InternStringLog::kRemove);
LogInternedString(std::move(log));
}
void Transaction::LogInternedString(InternStringLog&& log) {
Locks::intern_table_lock_->AssertExclusiveHeld(Thread::Current());
MutexLock mu(Thread::Current(), log_lock_);
intern_string_logs_.push_front(std::move(log));
}
void Transaction::Rollback() {
Thread* self = Thread::Current();
self->AssertNoPendingException();
MutexLock mu1(self, *Locks::intern_table_lock_);
MutexLock mu2(self, log_lock_);
rolling_back_ = true;
CHECK(!Runtime::Current()->IsActiveTransaction());
UndoObjectModifications();
UndoArrayModifications();
UndoInternStringTableModifications();
UndoResolveStringModifications();
rolling_back_ = false;
}
void Transaction::UndoObjectModifications() {
// TODO we may not need to restore objects allocated during this transaction. Or we could directly
// remove them from the heap.
for (const auto& it : object_logs_) {
it.second.Undo(it.first);
}
object_logs_.clear();
}
void Transaction::UndoArrayModifications() {
// TODO we may not need to restore array allocated during this transaction. Or we could directly
// remove them from the heap.
for (const auto& it : array_logs_) {
it.second.Undo(it.first);
}
array_logs_.clear();
}
void Transaction::UndoInternStringTableModifications() {
InternTable* const intern_table = Runtime::Current()->GetInternTable();
// We want to undo each operation from the most recent to the oldest. List has been filled so the
// most recent operation is at list begin so just have to iterate over it.
for (const InternStringLog& string_log : intern_string_logs_) {
string_log.Undo(intern_table);
}
intern_string_logs_.clear();
}
void Transaction::UndoResolveStringModifications() {
for (ResolveStringLog& string_log : resolve_string_logs_) {
string_log.Undo();
}
resolve_string_logs_.clear();
}
void Transaction::VisitRoots(RootVisitor* visitor) {
MutexLock mu(Thread::Current(), log_lock_);
visitor->VisitRoot(reinterpret_cast<mirror::Object**>(&root_), RootInfo(kRootUnknown));
VisitObjectLogs(visitor);
VisitArrayLogs(visitor);
VisitInternStringLogs(visitor);
VisitResolveStringLogs(visitor);
}
void Transaction::VisitObjectLogs(RootVisitor* visitor) {
// List of moving roots.
using ObjectPair = std::pair<mirror::Object*, mirror::Object*>;
std::list<ObjectPair> moving_roots;
// Visit roots.
for (auto& it : object_logs_) {
it.second.VisitRoots(visitor);
mirror::Object* old_root = it.first;
mirror::Object* new_root = old_root;
visitor->VisitRoot(&new_root, RootInfo(kRootUnknown));
if (new_root != old_root) {
moving_roots.push_back(std::make_pair(old_root, new_root));
}
}
// Update object logs with moving roots.
for (const ObjectPair& pair : moving_roots) {
mirror::Object* old_root = pair.first;
mirror::Object* new_root = pair.second;
auto old_root_it = object_logs_.find(old_root);
CHECK(old_root_it != object_logs_.end());
CHECK(object_logs_.find(new_root) == object_logs_.end());
object_logs_.emplace(new_root, std::move(old_root_it->second));
object_logs_.erase(old_root_it);
}
}
void Transaction::VisitArrayLogs(RootVisitor* visitor) {
// List of moving roots.
using ArrayPair = std::pair<mirror::Array*, mirror::Array*>;
std::list<ArrayPair> moving_roots;
for (auto& it : array_logs_) {
mirror::Array* old_root = it.first;
CHECK(!old_root->IsObjectArray());
mirror::Array* new_root = old_root;
visitor->VisitRoot(reinterpret_cast<mirror::Object**>(&new_root), RootInfo(kRootUnknown));
if (new_root != old_root) {
moving_roots.push_back(std::make_pair(old_root, new_root));
}
}
// Update array logs with moving roots.
for (const ArrayPair& pair : moving_roots) {
mirror::Array* old_root = pair.first;
mirror::Array* new_root = pair.second;
auto old_root_it = array_logs_.find(old_root);
CHECK(old_root_it != array_logs_.end());
CHECK(array_logs_.find(new_root) == array_logs_.end());
array_logs_.emplace(new_root, std::move(old_root_it->second));
array_logs_.erase(old_root_it);
}
}
void Transaction::VisitInternStringLogs(RootVisitor* visitor) {
for (InternStringLog& log : intern_string_logs_) {
log.VisitRoots(visitor);
}
}
void Transaction::VisitResolveStringLogs(RootVisitor* visitor) {
for (ResolveStringLog& log : resolve_string_logs_) {
log.VisitRoots(visitor);
}
}
void Transaction::ObjectLog::LogBooleanValue(MemberOffset offset, uint8_t value, bool is_volatile) {
LogValue(ObjectLog::kBoolean, offset, value, is_volatile);
}
void Transaction::ObjectLog::LogByteValue(MemberOffset offset, int8_t value, bool is_volatile) {
LogValue(ObjectLog::kByte, offset, value, is_volatile);
}
void Transaction::ObjectLog::LogCharValue(MemberOffset offset, uint16_t value, bool is_volatile) {
LogValue(ObjectLog::kChar, offset, value, is_volatile);
}
void Transaction::ObjectLog::LogShortValue(MemberOffset offset, int16_t value, bool is_volatile) {
LogValue(ObjectLog::kShort, offset, value, is_volatile);
}
void Transaction::ObjectLog::Log32BitsValue(MemberOffset offset, uint32_t value, bool is_volatile) {
LogValue(ObjectLog::k32Bits, offset, value, is_volatile);
}
void Transaction::ObjectLog::Log64BitsValue(MemberOffset offset, uint64_t value, bool is_volatile) {
LogValue(ObjectLog::k64Bits, offset, value, is_volatile);
}
void Transaction::ObjectLog::LogReferenceValue(MemberOffset offset,
mirror::Object* obj,
bool is_volatile) {
LogValue(ObjectLog::kReference, offset, reinterpret_cast<uintptr_t>(obj), is_volatile);
}
void Transaction::ObjectLog::LogValue(ObjectLog::FieldValueKind kind,
MemberOffset offset,
uint64_t value,
bool is_volatile) {
auto it = field_values_.find(offset.Uint32Value());
if (it == field_values_.end()) {
ObjectLog::FieldValue field_value;
field_value.value = value;
field_value.is_volatile = is_volatile;
field_value.kind = kind;
field_values_.emplace(offset.Uint32Value(), std::move(field_value));
}
}
void Transaction::ObjectLog::Undo(mirror::Object* obj) const {
for (auto& it : field_values_) {
// Garbage collector needs to access object's class and array's length. So we don't rollback
// these values.
MemberOffset field_offset(it.first);
if (field_offset.Uint32Value() == mirror::Class::ClassOffset().Uint32Value()) {
// Skip Object::class field.
continue;
}
if (obj->IsArrayInstance() &&
field_offset.Uint32Value() == mirror::Array::LengthOffset().Uint32Value()) {
// Skip Array::length field.
continue;
}
const FieldValue& field_value = it.second;
UndoFieldWrite(obj, field_offset, field_value);
}
}
void Transaction::ObjectLog::UndoFieldWrite(mirror::Object* obj,
MemberOffset field_offset,
const FieldValue& field_value) const {
// TODO We may want to abort a transaction while still being in transaction mode. In this case,
// we'd need to disable the check.
constexpr bool kCheckTransaction = false;
switch (field_value.kind) {
case kBoolean:
if (UNLIKELY(field_value.is_volatile)) {
obj->SetFieldBooleanVolatile<false, kCheckTransaction>(
field_offset,
field_value.value);
} else {
obj->SetFieldBoolean<false, kCheckTransaction>(
field_offset,
field_value.value);
}
break;
case kByte:
if (UNLIKELY(field_value.is_volatile)) {
obj->SetFieldByteVolatile<false, kCheckTransaction>(
field_offset,
static_cast<int8_t>(field_value.value));
} else {
obj->SetFieldByte<false, kCheckTransaction>(
field_offset,
static_cast<int8_t>(field_value.value));
}
break;
case kChar:
if (UNLIKELY(field_value.is_volatile)) {
obj->SetFieldCharVolatile<false, kCheckTransaction>(
field_offset,
static_cast<uint16_t>(field_value.value));
} else {
obj->SetFieldChar<false, kCheckTransaction>(
field_offset,
static_cast<uint16_t>(field_value.value));
}
break;
case kShort:
if (UNLIKELY(field_value.is_volatile)) {
obj->SetFieldShortVolatile<false, kCheckTransaction>(
field_offset,
static_cast<int16_t>(field_value.value));
} else {
obj->SetFieldShort<false, kCheckTransaction>(
field_offset,
static_cast<int16_t>(field_value.value));
}
break;
case k32Bits:
if (UNLIKELY(field_value.is_volatile)) {
obj->SetField32Volatile<false, kCheckTransaction>(
field_offset,
static_cast<uint32_t>(field_value.value));
} else {
obj->SetField32<false, kCheckTransaction>(
field_offset,
static_cast<uint32_t>(field_value.value));
}
break;
case k64Bits:
if (UNLIKELY(field_value.is_volatile)) {
obj->SetField64Volatile<false, kCheckTransaction>(field_offset, field_value.value);
} else {
obj->SetField64<false, kCheckTransaction>(field_offset, field_value.value);
}
break;
case kReference:
if (UNLIKELY(field_value.is_volatile)) {
obj->SetFieldObjectVolatile<false, kCheckTransaction>(
field_offset,
reinterpret_cast<mirror::Object*>(field_value.value));
} else {
obj->SetFieldObject<false, kCheckTransaction>(
field_offset,
reinterpret_cast<mirror::Object*>(field_value.value));
}
break;
default:
LOG(FATAL) << "Unknown value kind " << static_cast<int>(field_value.kind);
UNREACHABLE();
}
}
void Transaction::ObjectLog::VisitRoots(RootVisitor* visitor) {
for (auto& it : field_values_) {
FieldValue& field_value = it.second;
if (field_value.kind == ObjectLog::kReference) {
visitor->VisitRootIfNonNull(reinterpret_cast<mirror::Object**>(&field_value.value),
RootInfo(kRootUnknown));
}
}
}
void Transaction::InternStringLog::Undo(InternTable* intern_table) const {
DCHECK(intern_table != nullptr);
switch (string_op_) {
case InternStringLog::kInsert: {
switch (string_kind_) {
case InternStringLog::kStrongString:
intern_table->RemoveStrongFromTransaction(str_.Read());
break;
case InternStringLog::kWeakString:
intern_table->RemoveWeakFromTransaction(str_.Read());
break;
default:
LOG(FATAL) << "Unknown interned string kind";
UNREACHABLE();
}
break;
}
case InternStringLog::kRemove: {
switch (string_kind_) {
case InternStringLog::kStrongString:
intern_table->InsertStrongFromTransaction(str_.Read());
break;
case InternStringLog::kWeakString:
intern_table->InsertWeakFromTransaction(str_.Read());
break;
default:
LOG(FATAL) << "Unknown interned string kind";
UNREACHABLE();
}
break;
}
default:
LOG(FATAL) << "Unknown interned string op";
UNREACHABLE();
}
}
void Transaction::InternStringLog::VisitRoots(RootVisitor* visitor) {
str_.VisitRoot(visitor, RootInfo(kRootInternedString));
}
void Transaction::ResolveStringLog::Undo() const {
dex_cache_.Read()->ClearString(string_idx_);
}
Transaction::ResolveStringLog::ResolveStringLog(ObjPtr<mirror::DexCache> dex_cache,
dex::StringIndex string_idx)
: dex_cache_(dex_cache),
string_idx_(string_idx) {
DCHECK(dex_cache != nullptr);
DCHECK_LT(string_idx_.index_, dex_cache->GetDexFile()->NumStringIds());
}
void Transaction::ResolveStringLog::VisitRoots(RootVisitor* visitor) {
dex_cache_.VisitRoot(visitor, RootInfo(kRootVMInternal));
}
Transaction::InternStringLog::InternStringLog(ObjPtr<mirror::String> s,
StringKind kind,
StringOp op)
: str_(s),
string_kind_(kind),
string_op_(op) {
DCHECK(s != nullptr);
}
void Transaction::ArrayLog::LogValue(size_t index, uint64_t value) {
auto it = array_values_.find(index);
if (it == array_values_.end()) {
array_values_.insert(std::make_pair(index, value));
}
}
void Transaction::ArrayLog::Undo(mirror::Array* array) const {
DCHECK(array != nullptr);
DCHECK(array->IsArrayInstance());
Primitive::Type type = array->GetClass()->GetComponentType()->GetPrimitiveType();
for (auto it : array_values_) {
UndoArrayWrite(array, type, it.first, it.second);
}
}
void Transaction::ArrayLog::UndoArrayWrite(mirror::Array* array,
Primitive::Type array_type,
size_t index,
uint64_t value) const {
// TODO We may want to abort a transaction while still being in transaction mode. In this case,
// we'd need to disable the check.
constexpr bool kCheckTransaction = false;
switch (array_type) {
case Primitive::kPrimBoolean:
array->AsBooleanArray()->SetWithoutChecks<false, kCheckTransaction>(
index, static_cast<uint8_t>(value));
break;
case Primitive::kPrimByte:
array->AsByteArray()->SetWithoutChecks<false, kCheckTransaction>(
index, static_cast<int8_t>(value));
break;
case Primitive::kPrimChar:
array->AsCharArray()->SetWithoutChecks<false, kCheckTransaction>(
index, static_cast<uint16_t>(value));
break;
case Primitive::kPrimShort:
array->AsShortArray()->SetWithoutChecks<false, kCheckTransaction>(
index, static_cast<int16_t>(value));
break;
case Primitive::kPrimInt:
array->AsIntArray()->SetWithoutChecks<false, kCheckTransaction>(
index, static_cast<int32_t>(value));
break;
case Primitive::kPrimFloat:
array->AsFloatArray()->SetWithoutChecks<false, kCheckTransaction>(
index, static_cast<float>(value));
break;
case Primitive::kPrimLong:
array->AsLongArray()->SetWithoutChecks<false, kCheckTransaction>(
index, static_cast<int64_t>(value));
break;
case Primitive::kPrimDouble:
array->AsDoubleArray()->SetWithoutChecks<false, kCheckTransaction>(
index, static_cast<double>(value));
break;
case Primitive::kPrimNot:
LOG(FATAL) << "ObjectArray should be treated as Object";
UNREACHABLE();
default:
LOG(FATAL) << "Unsupported type " << array_type;
UNREACHABLE();
}
}
} // namespace art