/*
* Copyright (C) 2011 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 "image_writer.h"
#include <sys/stat.h>
#include <memory>
#include <numeric>
#include <vector>
#include "art_field-inl.h"
#include "art_method-inl.h"
#include "base/logging.h"
#include "base/unix_file/fd_file.h"
#include "class_linker-inl.h"
#include "compiled_method.h"
#include "dex_file-inl.h"
#include "driver/compiler_driver.h"
#include "elf_file.h"
#include "elf_utils.h"
#include "elf_writer.h"
#include "gc/accounting/card_table-inl.h"
#include "gc/accounting/heap_bitmap.h"
#include "gc/accounting/space_bitmap-inl.h"
#include "gc/heap.h"
#include "gc/space/large_object_space.h"
#include "gc/space/space-inl.h"
#include "globals.h"
#include "image.h"
#include "intern_table.h"
#include "linear_alloc.h"
#include "lock_word.h"
#include "mirror/abstract_method.h"
#include "mirror/array-inl.h"
#include "mirror/class-inl.h"
#include "mirror/class_loader.h"
#include "mirror/dex_cache-inl.h"
#include "mirror/method.h"
#include "mirror/object-inl.h"
#include "mirror/object_array-inl.h"
#include "mirror/string-inl.h"
#include "oat.h"
#include "oat_file.h"
#include "runtime.h"
#include "scoped_thread_state_change.h"
#include "handle_scope-inl.h"
#include "utils/dex_cache_arrays_layout-inl.h"
using ::art::mirror::Class;
using ::art::mirror::DexCache;
using ::art::mirror::Object;
using ::art::mirror::ObjectArray;
using ::art::mirror::String;
namespace art {
// Separate objects into multiple bins to optimize dirty memory use.
static constexpr bool kBinObjects = true;
static constexpr bool kComputeEagerResolvedStrings = false;
static void CheckNoDexObjectsCallback(Object* obj, void* arg ATTRIBUTE_UNUSED)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
Class* klass = obj->GetClass();
CHECK_NE(PrettyClass(klass), "com.android.dex.Dex");
}
static void CheckNoDexObjects() {
ScopedObjectAccess soa(Thread::Current());
Runtime::Current()->GetHeap()->VisitObjects(CheckNoDexObjectsCallback, nullptr);
}
bool ImageWriter::PrepareImageAddressSpace() {
target_ptr_size_ = InstructionSetPointerSize(compiler_driver_.GetInstructionSet());
{
Thread::Current()->TransitionFromSuspendedToRunnable();
PruneNonImageClasses(); // Remove junk
ComputeLazyFieldsForImageClasses(); // Add useful information
// Calling this can in theory fill in some resolved strings. However, in practice it seems to
// never resolve any.
if (kComputeEagerResolvedStrings) {
ComputeEagerResolvedStrings();
}
Thread::Current()->TransitionFromRunnableToSuspended(kNative);
}
gc::Heap* heap = Runtime::Current()->GetHeap();
heap->CollectGarbage(false); // Remove garbage.
// Dex caches must not have their dex fields set in the image. These are memory buffers of mapped
// dex files.
//
// We may open them in the unstarted-runtime code for class metadata. Their fields should all be
// reset in PruneNonImageClasses and the objects reclaimed in the GC. Make sure that's actually
// true.
if (kIsDebugBuild) {
CheckNoDexObjects();
}
if (kIsDebugBuild) {
ScopedObjectAccess soa(Thread::Current());
CheckNonImageClassesRemoved();
}
Thread::Current()->TransitionFromSuspendedToRunnable();
CalculateNewObjectOffsets();
Thread::Current()->TransitionFromRunnableToSuspended(kNative);
// This needs to happen after CalculateNewObjectOffsets since it relies on intern_table_bytes_ and
// bin size sums being calculated.
if (!AllocMemory()) {
return false;
}
return true;
}
bool ImageWriter::Write(const std::string& image_filename,
const std::string& oat_filename,
const std::string& oat_location) {
CHECK(!image_filename.empty());
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
std::unique_ptr<File> oat_file(OS::OpenFileReadWrite(oat_filename.c_str()));
if (oat_file.get() == nullptr) {
PLOG(ERROR) << "Failed to open oat file " << oat_filename << " for " << oat_location;
return false;
}
std::string error_msg;
oat_file_ = OatFile::OpenReadable(oat_file.get(), oat_location, nullptr, &error_msg);
if (oat_file_ == nullptr) {
PLOG(ERROR) << "Failed to open writable oat file " << oat_filename << " for " << oat_location
<< ": " << error_msg;
oat_file->Erase();
return false;
}
CHECK_EQ(class_linker->RegisterOatFile(oat_file_), oat_file_);
interpreter_to_interpreter_bridge_offset_ =
oat_file_->GetOatHeader().GetInterpreterToInterpreterBridgeOffset();
interpreter_to_compiled_code_bridge_offset_ =
oat_file_->GetOatHeader().GetInterpreterToCompiledCodeBridgeOffset();
jni_dlsym_lookup_offset_ = oat_file_->GetOatHeader().GetJniDlsymLookupOffset();
quick_generic_jni_trampoline_offset_ =
oat_file_->GetOatHeader().GetQuickGenericJniTrampolineOffset();
quick_imt_conflict_trampoline_offset_ =
oat_file_->GetOatHeader().GetQuickImtConflictTrampolineOffset();
quick_resolution_trampoline_offset_ =
oat_file_->GetOatHeader().GetQuickResolutionTrampolineOffset();
quick_to_interpreter_bridge_offset_ =
oat_file_->GetOatHeader().GetQuickToInterpreterBridgeOffset();
size_t oat_loaded_size = 0;
size_t oat_data_offset = 0;
ElfWriter::GetOatElfInformation(oat_file.get(), &oat_loaded_size, &oat_data_offset);
Thread::Current()->TransitionFromSuspendedToRunnable();
CreateHeader(oat_loaded_size, oat_data_offset);
CopyAndFixupNativeData();
// TODO: heap validation can't handle these fix up passes.
Runtime::Current()->GetHeap()->DisableObjectValidation();
CopyAndFixupObjects();
Thread::Current()->TransitionFromRunnableToSuspended(kNative);
SetOatChecksumFromElfFile(oat_file.get());
if (oat_file->FlushCloseOrErase() != 0) {
LOG(ERROR) << "Failed to flush and close oat file " << oat_filename << " for " << oat_location;
return false;
}
std::unique_ptr<File> image_file(OS::CreateEmptyFile(image_filename.c_str()));
ImageHeader* image_header = reinterpret_cast<ImageHeader*>(image_->Begin());
if (image_file.get() == nullptr) {
LOG(ERROR) << "Failed to open image file " << image_filename;
return false;
}
if (fchmod(image_file->Fd(), 0644) != 0) {
PLOG(ERROR) << "Failed to make image file world readable: " << image_filename;
image_file->Erase();
return EXIT_FAILURE;
}
// Write out the image + fields + methods.
const auto write_count = image_header->GetImageSize();
if (!image_file->WriteFully(image_->Begin(), write_count)) {
PLOG(ERROR) << "Failed to write image file " << image_filename;
image_file->Erase();
return false;
}
// Write out the image bitmap at the page aligned start of the image end.
const ImageSection& bitmap_section = image_header->GetImageSection(ImageHeader::kSectionImageBitmap);
CHECK_ALIGNED(bitmap_section.Offset(), kPageSize);
if (!image_file->Write(reinterpret_cast<char*>(image_bitmap_->Begin()),
bitmap_section.Size(), bitmap_section.Offset())) {
PLOG(ERROR) << "Failed to write image file " << image_filename;
image_file->Erase();
return false;
}
CHECK_EQ(bitmap_section.End(), static_cast<size_t>(image_file->GetLength()));
if (image_file->FlushCloseOrErase() != 0) {
PLOG(ERROR) << "Failed to flush and close image file " << image_filename;
return false;
}
return true;
}
void ImageWriter::SetImageOffset(mirror::Object* object, size_t offset) {
DCHECK(object != nullptr);
DCHECK_NE(offset, 0U);
// The object is already deflated from when we set the bin slot. Just overwrite the lock word.
object->SetLockWord(LockWord::FromForwardingAddress(offset), false);
DCHECK_EQ(object->GetLockWord(false).ReadBarrierState(), 0u);
DCHECK(IsImageOffsetAssigned(object));
}
void ImageWriter::UpdateImageOffset(mirror::Object* obj, uintptr_t offset) {
DCHECK(IsImageOffsetAssigned(obj)) << obj << " " << offset;
obj->SetLockWord(LockWord::FromForwardingAddress(offset), false);
DCHECK_EQ(obj->GetLockWord(false).ReadBarrierState(), 0u);
}
void ImageWriter::AssignImageOffset(mirror::Object* object, ImageWriter::BinSlot bin_slot) {
DCHECK(object != nullptr);
DCHECK_NE(image_objects_offset_begin_, 0u);
size_t previous_bin_sizes = bin_slot_previous_sizes_[bin_slot.GetBin()];
size_t new_offset = image_objects_offset_begin_ + previous_bin_sizes + bin_slot.GetIndex();
DCHECK_ALIGNED(new_offset, kObjectAlignment);
SetImageOffset(object, new_offset);
DCHECK_LT(new_offset, image_end_);
}
bool ImageWriter::IsImageOffsetAssigned(mirror::Object* object) const {
// Will also return true if the bin slot was assigned since we are reusing the lock word.
DCHECK(object != nullptr);
return object->GetLockWord(false).GetState() == LockWord::kForwardingAddress;
}
size_t ImageWriter::GetImageOffset(mirror::Object* object) const {
DCHECK(object != nullptr);
DCHECK(IsImageOffsetAssigned(object));
LockWord lock_word = object->GetLockWord(false);
size_t offset = lock_word.ForwardingAddress();
DCHECK_LT(offset, image_end_);
return offset;
}
void ImageWriter::SetImageBinSlot(mirror::Object* object, BinSlot bin_slot) {
DCHECK(object != nullptr);
DCHECK(!IsImageOffsetAssigned(object));
DCHECK(!IsImageBinSlotAssigned(object));
// Before we stomp over the lock word, save the hash code for later.
Monitor::Deflate(Thread::Current(), object);;
LockWord lw(object->GetLockWord(false));
switch (lw.GetState()) {
case LockWord::kFatLocked: {
LOG(FATAL) << "Fat locked object " << object << " found during object copy";
break;
}
case LockWord::kThinLocked: {
LOG(FATAL) << "Thin locked object " << object << " found during object copy";
break;
}
case LockWord::kUnlocked:
// No hash, don't need to save it.
break;
case LockWord::kHashCode:
DCHECK(saved_hashcode_map_.find(object) == saved_hashcode_map_.end());
saved_hashcode_map_.emplace(object, lw.GetHashCode());
break;
default:
LOG(FATAL) << "Unreachable.";
UNREACHABLE();
}
object->SetLockWord(LockWord::FromForwardingAddress(bin_slot.Uint32Value()), false);
DCHECK_EQ(object->GetLockWord(false).ReadBarrierState(), 0u);
DCHECK(IsImageBinSlotAssigned(object));
}
void ImageWriter::PrepareDexCacheArraySlots() {
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
ReaderMutexLock mu(Thread::Current(), *class_linker->DexLock());
size_t dex_cache_count = class_linker->GetDexCacheCount();
uint32_t size = 0u;
for (size_t idx = 0; idx < dex_cache_count; ++idx) {
DexCache* dex_cache = class_linker->GetDexCache(idx);
const DexFile* dex_file = dex_cache->GetDexFile();
dex_cache_array_starts_.Put(dex_file, size);
DexCacheArraysLayout layout(target_ptr_size_, dex_file);
DCHECK(layout.Valid());
auto types_size = layout.TypesSize(dex_file->NumTypeIds());
auto methods_size = layout.MethodsSize(dex_file->NumMethodIds());
auto fields_size = layout.FieldsSize(dex_file->NumFieldIds());
auto strings_size = layout.StringsSize(dex_file->NumStringIds());
dex_cache_array_indexes_.Put(
dex_cache->GetResolvedTypes(),
DexCacheArrayLocation {size + layout.TypesOffset(), types_size, kBinRegular});
dex_cache_array_indexes_.Put(
dex_cache->GetResolvedMethods(),
DexCacheArrayLocation {size + layout.MethodsOffset(), methods_size, kBinArtMethodClean});
AddMethodPointerArray(dex_cache->GetResolvedMethods());
dex_cache_array_indexes_.Put(
dex_cache->GetResolvedFields(),
DexCacheArrayLocation {size + layout.FieldsOffset(), fields_size, kBinArtField});
pointer_arrays_.emplace(dex_cache->GetResolvedFields(), kBinArtField);
dex_cache_array_indexes_.Put(
dex_cache->GetStrings(),
DexCacheArrayLocation {size + layout.StringsOffset(), strings_size, kBinRegular});
size += layout.Size();
CHECK_EQ(layout.Size(), types_size + methods_size + fields_size + strings_size);
}
// Set the slot size early to avoid DCHECK() failures in IsImageBinSlotAssigned()
// when AssignImageBinSlot() assigns their indexes out or order.
bin_slot_sizes_[kBinDexCacheArray] = size;
}
void ImageWriter::AddMethodPointerArray(mirror::PointerArray* arr) {
DCHECK(arr != nullptr);
if (kIsDebugBuild) {
for (size_t i = 0, len = arr->GetLength(); i < len; i++) {
auto* method = arr->GetElementPtrSize<ArtMethod*>(i, target_ptr_size_);
if (method != nullptr && !method->IsRuntimeMethod()) {
auto* klass = method->GetDeclaringClass();
CHECK(klass == nullptr || IsImageClass(klass)) << PrettyClass(klass)
<< " should be an image class";
}
}
}
// kBinArtMethodClean picked arbitrarily, just required to differentiate between ArtFields and
// ArtMethods.
pointer_arrays_.emplace(arr, kBinArtMethodClean);
}
void ImageWriter::AssignImageBinSlot(mirror::Object* object) {
DCHECK(object != nullptr);
size_t object_size = object->SizeOf();
// The magic happens here. We segregate objects into different bins based
// on how likely they are to get dirty at runtime.
//
// Likely-to-dirty objects get packed together into the same bin so that
// at runtime their page dirtiness ratio (how many dirty objects a page has) is
// maximized.
//
// This means more pages will stay either clean or shared dirty (with zygote) and
// the app will use less of its own (private) memory.
Bin bin = kBinRegular;
size_t current_offset = 0u;
if (kBinObjects) {
//
// Changing the bin of an object is purely a memory-use tuning.
// It has no change on runtime correctness.
//
// Memory analysis has determined that the following types of objects get dirtied
// the most:
//
// * Dex cache arrays are stored in a special bin. The arrays for each dex cache have
// a fixed layout which helps improve generated code (using PC-relative addressing),
// so we pre-calculate their offsets separately in PrepareDexCacheArraySlots().
// Since these arrays are huge, most pages do not overlap other objects and it's not
// really important where they are for the clean/dirty separation. Due to their
// special PC-relative addressing, we arbitrarily keep them at the beginning.
// * Class'es which are verified [their clinit runs only at runtime]
// - classes in general [because their static fields get overwritten]
// - initialized classes with all-final statics are unlikely to be ever dirty,
// so bin them separately
// * Art Methods that are:
// - native [their native entry point is not looked up until runtime]
// - have declaring classes that aren't initialized
// [their interpreter/quick entry points are trampolines until the class
// becomes initialized]
//
// We also assume the following objects get dirtied either never or extremely rarely:
// * Strings (they are immutable)
// * Art methods that aren't native and have initialized declared classes
//
// We assume that "regular" bin objects are highly unlikely to become dirtied,
// so packing them together will not result in a noticeably tighter dirty-to-clean ratio.
//
if (object->IsClass()) {
bin = kBinClassVerified;
mirror::Class* klass = object->AsClass();
// Add non-embedded vtable to the pointer array table if there is one.
auto* vtable = klass->GetVTable();
if (vtable != nullptr) {
AddMethodPointerArray(vtable);
}
auto* iftable = klass->GetIfTable();
if (iftable != nullptr) {
for (int32_t i = 0; i < klass->GetIfTableCount(); ++i) {
if (iftable->GetMethodArrayCount(i) > 0) {
AddMethodPointerArray(iftable->GetMethodArray(i));
}
}
}
if (klass->GetStatus() == Class::kStatusInitialized) {
bin = kBinClassInitialized;
// If the class's static fields are all final, put it into a separate bin
// since it's very likely it will stay clean.
uint32_t num_static_fields = klass->NumStaticFields();
if (num_static_fields == 0) {
bin = kBinClassInitializedFinalStatics;
} else {
// Maybe all the statics are final?
bool all_final = true;
for (uint32_t i = 0; i < num_static_fields; ++i) {
ArtField* field = klass->GetStaticField(i);
if (!field->IsFinal()) {
all_final = false;
break;
}
}
if (all_final) {
bin = kBinClassInitializedFinalStatics;
}
}
}
} else if (object->GetClass<kVerifyNone>()->IsStringClass()) {
bin = kBinString; // Strings are almost always immutable (except for object header).
} else if (object->IsArrayInstance()) {
mirror::Class* klass = object->GetClass<kVerifyNone>();
if (klass->IsObjectArrayClass() || klass->IsIntArrayClass() || klass->IsLongArrayClass()) {
auto it = dex_cache_array_indexes_.find(object);
if (it != dex_cache_array_indexes_.end()) {
bin = kBinDexCacheArray;
// Use prepared offset defined by the DexCacheLayout.
current_offset = it->second.offset_;
// Override incase of cross compilation.
object_size = it->second.length_;
} // else bin = kBinRegular
}
} // else bin = kBinRegular
}
size_t offset_delta = RoundUp(object_size, kObjectAlignment); // 64-bit alignment
if (bin != kBinDexCacheArray) {
DCHECK(dex_cache_array_indexes_.find(object) == dex_cache_array_indexes_.end()) << object;
current_offset = bin_slot_sizes_[bin]; // How many bytes the current bin is at (aligned).
// Move the current bin size up to accomodate the object we just assigned a bin slot.
bin_slot_sizes_[bin] += offset_delta;
}
BinSlot new_bin_slot(bin, current_offset);
SetImageBinSlot(object, new_bin_slot);
++bin_slot_count_[bin];
// Grow the image closer to the end by the object we just assigned.
image_end_ += offset_delta;
}
bool ImageWriter::WillMethodBeDirty(ArtMethod* m) const {
if (m->IsNative()) {
return true;
}
mirror::Class* declaring_class = m->GetDeclaringClass();
// Initialized is highly unlikely to dirty since there's no entry points to mutate.
return declaring_class == nullptr || declaring_class->GetStatus() != Class::kStatusInitialized;
}
bool ImageWriter::IsImageBinSlotAssigned(mirror::Object* object) const {
DCHECK(object != nullptr);
// We always stash the bin slot into a lockword, in the 'forwarding address' state.
// If it's in some other state, then we haven't yet assigned an image bin slot.
if (object->GetLockWord(false).GetState() != LockWord::kForwardingAddress) {
return false;
} else if (kIsDebugBuild) {
LockWord lock_word = object->GetLockWord(false);
size_t offset = lock_word.ForwardingAddress();
BinSlot bin_slot(offset);
DCHECK_LT(bin_slot.GetIndex(), bin_slot_sizes_[bin_slot.GetBin()])
<< "bin slot offset should not exceed the size of that bin";
}
return true;
}
ImageWriter::BinSlot ImageWriter::GetImageBinSlot(mirror::Object* object) const {
DCHECK(object != nullptr);
DCHECK(IsImageBinSlotAssigned(object));
LockWord lock_word = object->GetLockWord(false);
size_t offset = lock_word.ForwardingAddress(); // TODO: ForwardingAddress should be uint32_t
DCHECK_LE(offset, std::numeric_limits<uint32_t>::max());
BinSlot bin_slot(static_cast<uint32_t>(offset));
DCHECK_LT(bin_slot.GetIndex(), bin_slot_sizes_[bin_slot.GetBin()]);
return bin_slot;
}
bool ImageWriter::AllocMemory() {
const size_t length = RoundUp(image_objects_offset_begin_ + GetBinSizeSum() + intern_table_bytes_,
kPageSize);
std::string error_msg;
image_.reset(MemMap::MapAnonymous("image writer image", nullptr, length, PROT_READ | PROT_WRITE,
false, false, &error_msg));
if (UNLIKELY(image_.get() == nullptr)) {
LOG(ERROR) << "Failed to allocate memory for image file generation: " << error_msg;
return false;
}
// Create the image bitmap, only needs to cover mirror object section which is up to image_end_.
CHECK_LE(image_end_, length);
image_bitmap_.reset(gc::accounting::ContinuousSpaceBitmap::Create(
"image bitmap", image_->Begin(), RoundUp(image_end_, kPageSize)));
if (image_bitmap_.get() == nullptr) {
LOG(ERROR) << "Failed to allocate memory for image bitmap";
return false;
}
return true;
}
void ImageWriter::ComputeLazyFieldsForImageClasses() {
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
class_linker->VisitClassesWithoutClassesLock(ComputeLazyFieldsForClassesVisitor, nullptr);
}
bool ImageWriter::ComputeLazyFieldsForClassesVisitor(Class* c, void* /*arg*/) {
Thread* self = Thread::Current();
StackHandleScope<1> hs(self);
mirror::Class::ComputeName(hs.NewHandle(c));
return true;
}
void ImageWriter::ComputeEagerResolvedStringsCallback(Object* obj, void* arg ATTRIBUTE_UNUSED) {
if (!obj->GetClass()->IsStringClass()) {
return;
}
mirror::String* string = obj->AsString();
const uint16_t* utf16_string = string->GetValue();
size_t utf16_length = static_cast<size_t>(string->GetLength());
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
ReaderMutexLock mu(Thread::Current(), *class_linker->DexLock());
size_t dex_cache_count = class_linker->GetDexCacheCount();
for (size_t i = 0; i < dex_cache_count; ++i) {
DexCache* dex_cache = class_linker->GetDexCache(i);
const DexFile& dex_file = *dex_cache->GetDexFile();
const DexFile::StringId* string_id;
if (UNLIKELY(utf16_length == 0)) {
string_id = dex_file.FindStringId("");
} else {
string_id = dex_file.FindStringId(utf16_string, utf16_length);
}
if (string_id != nullptr) {
// This string occurs in this dex file, assign the dex cache entry.
uint32_t string_idx = dex_file.GetIndexForStringId(*string_id);
if (dex_cache->GetResolvedString(string_idx) == nullptr) {
dex_cache->SetResolvedString(string_idx, string);
}
}
}
}
void ImageWriter::ComputeEagerResolvedStrings() {
Runtime::Current()->GetHeap()->VisitObjects(ComputeEagerResolvedStringsCallback, this);
}
bool ImageWriter::IsImageClass(Class* klass) {
if (klass == nullptr) {
return false;
}
std::string temp;
return compiler_driver_.IsImageClass(klass->GetDescriptor(&temp));
}
struct NonImageClasses {
ImageWriter* image_writer;
std::set<std::string>* non_image_classes;
};
void ImageWriter::PruneNonImageClasses() {
if (compiler_driver_.GetImageClasses() == nullptr) {
return;
}
Runtime* runtime = Runtime::Current();
ClassLinker* class_linker = runtime->GetClassLinker();
Thread* self = Thread::Current();
// Make a list of classes we would like to prune.
std::set<std::string> non_image_classes;
NonImageClasses context;
context.image_writer = this;
context.non_image_classes = &non_image_classes;
class_linker->VisitClasses(NonImageClassesVisitor, &context);
// Remove the undesired classes from the class roots.
for (const std::string& it : non_image_classes) {
bool result = class_linker->RemoveClass(it.c_str(), nullptr);
DCHECK(result);
}
// Clear references to removed classes from the DexCaches.
const ArtMethod* resolution_method = runtime->GetResolutionMethod();
size_t dex_cache_count;
{
ReaderMutexLock mu(self, *class_linker->DexLock());
dex_cache_count = class_linker->GetDexCacheCount();
}
for (size_t idx = 0; idx < dex_cache_count; ++idx) {
DexCache* dex_cache;
{
ReaderMutexLock mu(self, *class_linker->DexLock());
dex_cache = class_linker->GetDexCache(idx);
}
for (size_t i = 0; i < dex_cache->NumResolvedTypes(); i++) {
Class* klass = dex_cache->GetResolvedType(i);
if (klass != nullptr && !IsImageClass(klass)) {
dex_cache->SetResolvedType(i, nullptr);
}
}
auto* resolved_methods = down_cast<mirror::PointerArray*>(dex_cache->GetResolvedMethods());
for (size_t i = 0, len = resolved_methods->GetLength(); i < len; i++) {
auto* method = resolved_methods->GetElementPtrSize<ArtMethod*>(i, target_ptr_size_);
if (method != nullptr) {
auto* declaring_class = method->GetDeclaringClass();
// Miranda methods may be held live by a class which was not an image class but have a
// declaring class which is an image class. Set it to the resolution method to be safe and
// prevent dangling pointers.
if (method->IsMiranda() || !IsImageClass(declaring_class)) {
resolved_methods->SetElementPtrSize(i, resolution_method, target_ptr_size_);
} else {
// Check that the class is still in the classes table.
DCHECK(class_linker->ClassInClassTable(declaring_class)) << "Class "
<< PrettyClass(declaring_class) << " not in class linker table";
}
}
}
for (size_t i = 0; i < dex_cache->NumResolvedFields(); i++) {
ArtField* field = dex_cache->GetResolvedField(i, target_ptr_size_);
if (field != nullptr && !IsImageClass(field->GetDeclaringClass())) {
dex_cache->SetResolvedField(i, nullptr, target_ptr_size_);
}
}
// Clean the dex field. It might have been populated during the initialization phase, but
// contains data only valid during a real run.
dex_cache->SetFieldObject<false>(mirror::DexCache::DexOffset(), nullptr);
}
// Drop the array class cache in the ClassLinker, as these are roots holding those classes live.
class_linker->DropFindArrayClassCache();
}
bool ImageWriter::NonImageClassesVisitor(Class* klass, void* arg) {
NonImageClasses* context = reinterpret_cast<NonImageClasses*>(arg);
if (!context->image_writer->IsImageClass(klass)) {
std::string temp;
context->non_image_classes->insert(klass->GetDescriptor(&temp));
}
return true;
}
void ImageWriter::CheckNonImageClassesRemoved() {
if (compiler_driver_.GetImageClasses() != nullptr) {
gc::Heap* heap = Runtime::Current()->GetHeap();
heap->VisitObjects(CheckNonImageClassesRemovedCallback, this);
}
}
void ImageWriter::CheckNonImageClassesRemovedCallback(Object* obj, void* arg) {
ImageWriter* image_writer = reinterpret_cast<ImageWriter*>(arg);
if (obj->IsClass()) {
Class* klass = obj->AsClass();
if (!image_writer->IsImageClass(klass)) {
image_writer->DumpImageClasses();
std::string temp;
CHECK(image_writer->IsImageClass(klass)) << klass->GetDescriptor(&temp)
<< " " << PrettyDescriptor(klass);
}
}
}
void ImageWriter::DumpImageClasses() {
auto image_classes = compiler_driver_.GetImageClasses();
CHECK(image_classes != nullptr);
for (const std::string& image_class : *image_classes) {
LOG(INFO) << " " << image_class;
}
}
void ImageWriter::CalculateObjectBinSlots(Object* obj) {
DCHECK(obj != nullptr);
// if it is a string, we want to intern it if its not interned.
if (obj->GetClass()->IsStringClass()) {
// we must be an interned string that was forward referenced and already assigned
if (IsImageBinSlotAssigned(obj)) {
DCHECK_EQ(obj, obj->AsString()->Intern());
return;
}
mirror::String* const interned = Runtime::Current()->GetInternTable()->InternStrong(
obj->AsString()->Intern());
if (obj != interned) {
if (!IsImageBinSlotAssigned(interned)) {
// interned obj is after us, allocate its location early
AssignImageBinSlot(interned);
}
// point those looking for this object to the interned version.
SetImageBinSlot(obj, GetImageBinSlot(interned));
return;
}
// else (obj == interned), nothing to do but fall through to the normal case
}
AssignImageBinSlot(obj);
}
ObjectArray<Object>* ImageWriter::CreateImageRoots() const {
Runtime* runtime = Runtime::Current();
ClassLinker* class_linker = runtime->GetClassLinker();
Thread* self = Thread::Current();
StackHandleScope<3> hs(self);
Handle<Class> object_array_class(hs.NewHandle(
class_linker->FindSystemClass(self, "[Ljava/lang/Object;")));
// build an Object[] of all the DexCaches used in the source_space_.
// Since we can't hold the dex lock when allocating the dex_caches
// ObjectArray, we lock the dex lock twice, first to get the number
// of dex caches first and then lock it again to copy the dex
// caches. We check that the number of dex caches does not change.
size_t dex_cache_count;
{
ReaderMutexLock mu(self, *class_linker->DexLock());
dex_cache_count = class_linker->GetDexCacheCount();
}
Handle<ObjectArray<Object>> dex_caches(
hs.NewHandle(ObjectArray<Object>::Alloc(self, object_array_class.Get(),
dex_cache_count)));
CHECK(dex_caches.Get() != nullptr) << "Failed to allocate a dex cache array.";
{
ReaderMutexLock mu(self, *class_linker->DexLock());
CHECK_EQ(dex_cache_count, class_linker->GetDexCacheCount())
<< "The number of dex caches changed.";
for (size_t i = 0; i < dex_cache_count; ++i) {
dex_caches->Set<false>(i, class_linker->GetDexCache(i));
}
}
// build an Object[] of the roots needed to restore the runtime
auto image_roots(hs.NewHandle(
ObjectArray<Object>::Alloc(self, object_array_class.Get(), ImageHeader::kImageRootsMax)));
image_roots->Set<false>(ImageHeader::kDexCaches, dex_caches.Get());
image_roots->Set<false>(ImageHeader::kClassRoots, class_linker->GetClassRoots());
for (int i = 0; i < ImageHeader::kImageRootsMax; i++) {
CHECK(image_roots->Get(i) != nullptr);
}
return image_roots.Get();
}
// Walk instance fields of the given Class. Separate function to allow recursion on the super
// class.
void ImageWriter::WalkInstanceFields(mirror::Object* obj, mirror::Class* klass) {
// Visit fields of parent classes first.
StackHandleScope<1> hs(Thread::Current());
Handle<mirror::Class> h_class(hs.NewHandle(klass));
mirror::Class* super = h_class->GetSuperClass();
if (super != nullptr) {
WalkInstanceFields(obj, super);
}
//
size_t num_reference_fields = h_class->NumReferenceInstanceFields();
MemberOffset field_offset = h_class->GetFirstReferenceInstanceFieldOffset();
for (size_t i = 0; i < num_reference_fields; ++i) {
mirror::Object* value = obj->GetFieldObject<mirror::Object>(field_offset);
if (value != nullptr) {
WalkFieldsInOrder(value);
}
field_offset = MemberOffset(field_offset.Uint32Value() +
sizeof(mirror::HeapReference<mirror::Object>));
}
}
// For an unvisited object, visit it then all its children found via fields.
void ImageWriter::WalkFieldsInOrder(mirror::Object* obj) {
// Use our own visitor routine (instead of GC visitor) to get better locality between
// an object and its fields
if (!IsImageBinSlotAssigned(obj)) {
// Walk instance fields of all objects
StackHandleScope<2> hs(Thread::Current());
Handle<mirror::Object> h_obj(hs.NewHandle(obj));
Handle<mirror::Class> klass(hs.NewHandle(obj->GetClass()));
// visit the object itself.
CalculateObjectBinSlots(h_obj.Get());
WalkInstanceFields(h_obj.Get(), klass.Get());
// Walk static fields of a Class.
if (h_obj->IsClass()) {
size_t num_reference_static_fields = klass->NumReferenceStaticFields();
MemberOffset field_offset = klass->GetFirstReferenceStaticFieldOffset(target_ptr_size_);
for (size_t i = 0; i < num_reference_static_fields; ++i) {
mirror::Object* value = h_obj->GetFieldObject<mirror::Object>(field_offset);
if (value != nullptr) {
WalkFieldsInOrder(value);
}
field_offset = MemberOffset(field_offset.Uint32Value() +
sizeof(mirror::HeapReference<mirror::Object>));
}
// Visit and assign offsets for fields.
auto* as_klass = h_obj->AsClass();
ArtField* fields[] = { as_klass->GetSFields(), as_klass->GetIFields() };
size_t num_fields[] = { as_klass->NumStaticFields(), as_klass->NumInstanceFields() };
for (size_t i = 0; i < 2; ++i) {
for (size_t j = 0; j < num_fields[i]; ++j) {
auto* field = fields[i] + j;
auto it = native_object_reloc_.find(field);
CHECK(it == native_object_reloc_.end()) << "Field at index " << i << ":" << j
<< " already assigned " << PrettyField(field);
native_object_reloc_.emplace(
field, NativeObjectReloc { bin_slot_sizes_[kBinArtField], kBinArtField });
bin_slot_sizes_[kBinArtField] += sizeof(ArtField);
}
}
// Visit and assign offsets for methods.
IterationRange<StrideIterator<ArtMethod>> method_arrays[] = {
as_klass->GetDirectMethods(target_ptr_size_),
as_klass->GetVirtualMethods(target_ptr_size_)
};
for (auto& array : method_arrays) {
bool any_dirty = false;
size_t count = 0;
for (auto& m : array) {
any_dirty = any_dirty || WillMethodBeDirty(&m);
++count;
}
for (auto& m : array) {
AssignMethodOffset(&m, any_dirty ? kBinArtMethodDirty : kBinArtMethodClean);
}
(any_dirty ? dirty_methods_ : clean_methods_) += count;
}
} else if (h_obj->IsObjectArray()) {
// Walk elements of an object array.
int32_t length = h_obj->AsObjectArray<mirror::Object>()->GetLength();
for (int32_t i = 0; i < length; i++) {
mirror::ObjectArray<mirror::Object>* obj_array = h_obj->AsObjectArray<mirror::Object>();
mirror::Object* value = obj_array->Get(i);
if (value != nullptr) {
WalkFieldsInOrder(value);
}
}
}
}
}
void ImageWriter::AssignMethodOffset(ArtMethod* method, Bin bin) {
auto it = native_object_reloc_.find(method);
CHECK(it == native_object_reloc_.end()) << "Method " << method << " already assigned "
<< PrettyMethod(method);
native_object_reloc_.emplace(method, NativeObjectReloc { bin_slot_sizes_[bin], bin });
bin_slot_sizes_[bin] += ArtMethod::ObjectSize(target_ptr_size_);
}
void ImageWriter::WalkFieldsCallback(mirror::Object* obj, void* arg) {
ImageWriter* writer = reinterpret_cast<ImageWriter*>(arg);
DCHECK(writer != nullptr);
writer->WalkFieldsInOrder(obj);
}
void ImageWriter::UnbinObjectsIntoOffsetCallback(mirror::Object* obj, void* arg) {
ImageWriter* writer = reinterpret_cast<ImageWriter*>(arg);
DCHECK(writer != nullptr);
writer->UnbinObjectsIntoOffset(obj);
}
void ImageWriter::UnbinObjectsIntoOffset(mirror::Object* obj) {
CHECK(obj != nullptr);
// We know the bin slot, and the total bin sizes for all objects by now,
// so calculate the object's final image offset.
DCHECK(IsImageBinSlotAssigned(obj));
BinSlot bin_slot = GetImageBinSlot(obj);
// Change the lockword from a bin slot into an offset
AssignImageOffset(obj, bin_slot);
}
void ImageWriter::CalculateNewObjectOffsets() {
Thread* const self = Thread::Current();
StackHandleScope<1> hs(self);
Handle<ObjectArray<Object>> image_roots(hs.NewHandle(CreateImageRoots()));
auto* runtime = Runtime::Current();
auto* heap = runtime->GetHeap();
DCHECK_EQ(0U, image_end_);
// Leave space for the header, but do not write it yet, we need to
// know where image_roots is going to end up
image_end_ += RoundUp(sizeof(ImageHeader), kObjectAlignment); // 64-bit-alignment
image_objects_offset_begin_ = image_end_;
// Prepare bin slots for dex cache arrays.
PrepareDexCacheArraySlots();
// Clear any pre-existing monitors which may have been in the monitor words, assign bin slots.
heap->VisitObjects(WalkFieldsCallback, this);
// Write the image runtime methods.
image_methods_[ImageHeader::kResolutionMethod] = runtime->GetResolutionMethod();
image_methods_[ImageHeader::kImtConflictMethod] = runtime->GetImtConflictMethod();
image_methods_[ImageHeader::kImtUnimplementedMethod] = runtime->GetImtUnimplementedMethod();
image_methods_[ImageHeader::kCalleeSaveMethod] = runtime->GetCalleeSaveMethod(Runtime::kSaveAll);
image_methods_[ImageHeader::kRefsOnlySaveMethod] =
runtime->GetCalleeSaveMethod(Runtime::kRefsOnly);
image_methods_[ImageHeader::kRefsAndArgsSaveMethod] =
runtime->GetCalleeSaveMethod(Runtime::kRefsAndArgs);
for (auto* m : image_methods_) {
CHECK(m != nullptr);
CHECK(m->IsRuntimeMethod());
AssignMethodOffset(m, kBinArtMethodDirty);
}
// Calculate cumulative bin slot sizes.
size_t previous_sizes = 0u;
for (size_t i = 0; i != kBinSize; ++i) {
bin_slot_previous_sizes_[i] = previous_sizes;
previous_sizes += bin_slot_sizes_[i];
}
DCHECK_EQ(previous_sizes, GetBinSizeSum());
DCHECK_EQ(image_end_, GetBinSizeSum(kBinMirrorCount) + image_objects_offset_begin_);
// Transform each object's bin slot into an offset which will be used to do the final copy.
heap->VisitObjects(UnbinObjectsIntoOffsetCallback, this);
DCHECK_EQ(image_end_, GetBinSizeSum(kBinMirrorCount) + image_objects_offset_begin_);
image_roots_address_ = PointerToLowMemUInt32(GetImageAddress(image_roots.Get()));
// Update the native relocations by adding their bin sums.
for (auto& pair : native_object_reloc_) {
auto& native_reloc = pair.second;
native_reloc.offset += image_objects_offset_begin_ +
bin_slot_previous_sizes_[native_reloc.bin_type];
}
// Calculate how big the intern table will be after being serialized.
auto* const intern_table = Runtime::Current()->GetInternTable();
CHECK_EQ(intern_table->WeakSize(), 0u) << " should have strong interned all the strings";
intern_table_bytes_ = intern_table->WriteToMemory(nullptr);
// Note that image_end_ is left at end of used mirror object section.
}
void ImageWriter::CreateHeader(size_t oat_loaded_size, size_t oat_data_offset) {
CHECK_NE(0U, oat_loaded_size);
const uint8_t* oat_file_begin = GetOatFileBegin();
const uint8_t* oat_file_end = oat_file_begin + oat_loaded_size;
oat_data_begin_ = oat_file_begin + oat_data_offset;
const uint8_t* oat_data_end = oat_data_begin_ + oat_file_->Size();
// Create the image sections.
ImageSection sections[ImageHeader::kSectionCount];
// Objects section
auto* objects_section = §ions[ImageHeader::kSectionObjects];
*objects_section = ImageSection(0u, image_end_);
size_t cur_pos = objects_section->End();
// Add field section.
auto* field_section = §ions[ImageHeader::kSectionArtFields];
*field_section = ImageSection(cur_pos, bin_slot_sizes_[kBinArtField]);
CHECK_EQ(image_objects_offset_begin_ + bin_slot_previous_sizes_[kBinArtField],
field_section->Offset());
cur_pos = field_section->End();
// Add method section.
auto* methods_section = §ions[ImageHeader::kSectionArtMethods];
*methods_section = ImageSection(cur_pos, bin_slot_sizes_[kBinArtMethodClean] +
bin_slot_sizes_[kBinArtMethodDirty]);
CHECK_EQ(image_objects_offset_begin_ + bin_slot_previous_sizes_[kBinArtMethodClean],
methods_section->Offset());
cur_pos = methods_section->End();
// Calculate the size of the interned strings.
auto* interned_strings_section = §ions[ImageHeader::kSectionInternedStrings];
*interned_strings_section = ImageSection(cur_pos, intern_table_bytes_);
cur_pos = interned_strings_section->End();
// Finally bitmap section.
const size_t bitmap_bytes = image_bitmap_->Size();
auto* bitmap_section = §ions[ImageHeader::kSectionImageBitmap];
*bitmap_section = ImageSection(RoundUp(cur_pos, kPageSize), RoundUp(bitmap_bytes, kPageSize));
cur_pos = bitmap_section->End();
if (kIsDebugBuild) {
size_t idx = 0;
for (const ImageSection& section : sections) {
LOG(INFO) << static_cast<ImageHeader::ImageSections>(idx) << " " << section;
++idx;
}
LOG(INFO) << "Methods: clean=" << clean_methods_ << " dirty=" << dirty_methods_;
}
const size_t image_end = static_cast<uint32_t>(interned_strings_section->End());
CHECK_EQ(AlignUp(image_begin_ + image_end, kPageSize), oat_file_begin) <<
"Oat file should be right after the image.";
// Create the header.
new (image_->Begin()) ImageHeader(
PointerToLowMemUInt32(image_begin_), image_end,
sections, image_roots_address_, oat_file_->GetOatHeader().GetChecksum(),
PointerToLowMemUInt32(oat_file_begin), PointerToLowMemUInt32(oat_data_begin_),
PointerToLowMemUInt32(oat_data_end), PointerToLowMemUInt32(oat_file_end), target_ptr_size_,
compile_pic_);
}
ArtMethod* ImageWriter::GetImageMethodAddress(ArtMethod* method) {
auto it = native_object_reloc_.find(method);
CHECK(it != native_object_reloc_.end()) << PrettyMethod(method) << " @ " << method;
CHECK_GE(it->second.offset, image_end_) << "ArtMethods should be after Objects";
return reinterpret_cast<ArtMethod*>(image_begin_ + it->second.offset);
}
class FixupRootVisitor : public RootVisitor {
public:
explicit FixupRootVisitor(ImageWriter* image_writer) : image_writer_(image_writer) {
}
void VisitRoots(mirror::Object*** roots, size_t count, const RootInfo& info ATTRIBUTE_UNUSED)
OVERRIDE SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
for (size_t i = 0; i < count; ++i) {
*roots[i] = ImageAddress(*roots[i]);
}
}
void VisitRoots(mirror::CompressedReference<mirror::Object>** roots, size_t count,
const RootInfo& info ATTRIBUTE_UNUSED)
OVERRIDE SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
for (size_t i = 0; i < count; ++i) {
roots[i]->Assign(ImageAddress(roots[i]->AsMirrorPtr()));
}
}
private:
ImageWriter* const image_writer_;
mirror::Object* ImageAddress(mirror::Object* obj) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
const size_t offset = image_writer_->GetImageOffset(obj);
auto* const dest = reinterpret_cast<Object*>(image_writer_->image_begin_ + offset);
VLOG(compiler) << "Update root from " << obj << " to " << dest;
return dest;
}
};
void ImageWriter::CopyAndFixupNativeData() {
// Copy ArtFields and methods to their locations and update the array for convenience.
for (auto& pair : native_object_reloc_) {
auto& native_reloc = pair.second;
if (native_reloc.bin_type == kBinArtField) {
auto* dest = image_->Begin() + native_reloc.offset;
DCHECK_GE(dest, image_->Begin() + image_end_);
memcpy(dest, pair.first, sizeof(ArtField));
reinterpret_cast<ArtField*>(dest)->SetDeclaringClass(
GetImageAddress(reinterpret_cast<ArtField*>(pair.first)->GetDeclaringClass()));
} else {
CHECK(IsArtMethodBin(native_reloc.bin_type)) << native_reloc.bin_type;
auto* dest = image_->Begin() + native_reloc.offset;
DCHECK_GE(dest, image_->Begin() + image_end_);
CopyAndFixupMethod(reinterpret_cast<ArtMethod*>(pair.first),
reinterpret_cast<ArtMethod*>(dest));
}
}
// Fixup the image method roots.
auto* image_header = reinterpret_cast<ImageHeader*>(image_->Begin());
const ImageSection& methods_section = image_header->GetMethodsSection();
for (size_t i = 0; i < ImageHeader::kImageMethodsCount; ++i) {
auto* m = image_methods_[i];
CHECK(m != nullptr);
auto it = native_object_reloc_.find(m);
CHECK(it != native_object_reloc_.end()) << "No fowarding for " << PrettyMethod(m);
auto& native_reloc = it->second;
CHECK(methods_section.Contains(native_reloc.offset)) << native_reloc.offset << " not in "
<< methods_section;
CHECK(IsArtMethodBin(native_reloc.bin_type)) << native_reloc.bin_type;
auto* dest = reinterpret_cast<ArtMethod*>(image_begin_ + it->second.offset);
image_header->SetImageMethod(static_cast<ImageHeader::ImageMethod>(i), dest);
}
// Write the intern table into the image.
const ImageSection& intern_table_section = image_header->GetImageSection(
ImageHeader::kSectionInternedStrings);
InternTable* const intern_table = Runtime::Current()->GetInternTable();
uint8_t* const memory_ptr = image_->Begin() + intern_table_section.Offset();
const size_t intern_table_bytes = intern_table->WriteToMemory(memory_ptr);
// Fixup the pointers in the newly written intern table to contain image addresses.
InternTable temp_table;
// Note that we require that ReadFromMemory does not make an internal copy of the elements so that
// the VisitRoots() will update the memory directly rather than the copies.
// This also relies on visit roots not doing any verification which could fail after we update
// the roots to be the image addresses.
temp_table.ReadFromMemory(memory_ptr);
CHECK_EQ(temp_table.Size(), intern_table->Size());
FixupRootVisitor visitor(this);
temp_table.VisitRoots(&visitor, kVisitRootFlagAllRoots);
CHECK_EQ(intern_table_bytes, intern_table_bytes_);
}
void ImageWriter::CopyAndFixupObjects() {
gc::Heap* heap = Runtime::Current()->GetHeap();
heap->VisitObjects(CopyAndFixupObjectsCallback, this);
// Fix up the object previously had hash codes.
for (const auto& hash_pair : saved_hashcode_map_) {
Object* const obj = hash_pair.first;
DCHECK_EQ(obj->GetLockWord(false).ReadBarrierState(), 0U);
obj->SetLockWord(LockWord::FromHashCode(hash_pair.second, 0U), false);
}
saved_hashcode_map_.clear();
}
void ImageWriter::CopyAndFixupObjectsCallback(Object* obj, void* arg) {
DCHECK(obj != nullptr);
DCHECK(arg != nullptr);
reinterpret_cast<ImageWriter*>(arg)->CopyAndFixupObject(obj);
}
void ImageWriter::FixupPointerArray(mirror::Object* dst, mirror::PointerArray* arr,
mirror::Class* klass, Bin array_type) {
CHECK(klass->IsArrayClass());
CHECK(arr->IsIntArray() || arr->IsLongArray()) << PrettyClass(klass) << " " << arr;
// Fixup int and long pointers for the ArtMethod or ArtField arrays.
const size_t num_elements = arr->GetLength();
dst->SetClass(GetImageAddress(arr->GetClass()));
auto* dest_array = down_cast<mirror::PointerArray*>(dst);
for (size_t i = 0, count = num_elements; i < count; ++i) {
auto* elem = arr->GetElementPtrSize<void*>(i, target_ptr_size_);
if (elem != nullptr) {
auto it = native_object_reloc_.find(elem);
if (it == native_object_reloc_.end()) {
if (IsArtMethodBin(array_type)) {
auto* method = reinterpret_cast<ArtMethod*>(elem);
LOG(FATAL) << "No relocation entry for ArtMethod " << PrettyMethod(method) << " @ "
<< method << " idx=" << i << "/" << num_elements << " with declaring class "
<< PrettyClass(method->GetDeclaringClass());
} else {
CHECK_EQ(array_type, kBinArtField);
auto* field = reinterpret_cast<ArtField*>(elem);
LOG(FATAL) << "No relocation entry for ArtField " << PrettyField(field) << " @ "
<< field << " idx=" << i << "/" << num_elements << " with declaring class "
<< PrettyClass(field->GetDeclaringClass());
}
} else {
elem = image_begin_ + it->second.offset;
}
}
dest_array->SetElementPtrSize<false, true>(i, elem, target_ptr_size_);
}
}
void ImageWriter::CopyAndFixupObject(Object* obj) {
size_t offset = GetImageOffset(obj);
auto* dst = reinterpret_cast<Object*>(image_->Begin() + offset);
DCHECK_LT(offset, image_end_);
const auto* src = reinterpret_cast<const uint8_t*>(obj);
image_bitmap_->Set(dst); // Mark the obj as live.
const size_t n = obj->SizeOf();
DCHECK_LE(offset + n, image_->Size());
memcpy(dst, src, n);
// Write in a hash code of objects which have inflated monitors or a hash code in their monitor
// word.
const auto it = saved_hashcode_map_.find(obj);
dst->SetLockWord(it != saved_hashcode_map_.end() ?
LockWord::FromHashCode(it->second, 0u) : LockWord::Default(), false);
FixupObject(obj, dst);
}
// Rewrite all the references in the copied object to point to their image address equivalent
class FixupVisitor {
public:
FixupVisitor(ImageWriter* image_writer, Object* copy) : image_writer_(image_writer), copy_(copy) {
}
void operator()(Object* obj, MemberOffset offset, bool is_static ATTRIBUTE_UNUSED) const
EXCLUSIVE_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) {
Object* ref = obj->GetFieldObject<Object, kVerifyNone>(offset);
// Use SetFieldObjectWithoutWriteBarrier to avoid card marking since we are writing to the
// image.
copy_->SetFieldObjectWithoutWriteBarrier<false, true, kVerifyNone>(
offset, image_writer_->GetImageAddress(ref));
}
// java.lang.ref.Reference visitor.
void operator()(mirror::Class* klass ATTRIBUTE_UNUSED, mirror::Reference* ref) const
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) {
copy_->SetFieldObjectWithoutWriteBarrier<false, true, kVerifyNone>(
mirror::Reference::ReferentOffset(), image_writer_->GetImageAddress(ref->GetReferent()));
}
protected:
ImageWriter* const image_writer_;
mirror::Object* const copy_;
};
class FixupClassVisitor FINAL : public FixupVisitor {
public:
FixupClassVisitor(ImageWriter* image_writer, Object* copy) : FixupVisitor(image_writer, copy) {
}
void operator()(Object* obj, MemberOffset offset, bool is_static ATTRIBUTE_UNUSED) const
EXCLUSIVE_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) {
DCHECK(obj->IsClass());
FixupVisitor::operator()(obj, offset, /*is_static*/false);
}
void operator()(mirror::Class* klass ATTRIBUTE_UNUSED,
mirror::Reference* ref ATTRIBUTE_UNUSED) const
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) {
LOG(FATAL) << "Reference not expected here.";
}
};
void ImageWriter::FixupClass(mirror::Class* orig, mirror::Class* copy) {
// Copy and fix up ArtFields in the class.
ArtField* fields[2] = { orig->GetSFields(), orig->GetIFields() };
size_t num_fields[2] = { orig->NumStaticFields(), orig->NumInstanceFields() };
// Update the field arrays.
for (size_t i = 0; i < 2; ++i) {
if (num_fields[i] == 0) {
CHECK(fields[i] == nullptr);
continue;
}
auto it = native_object_reloc_.find(fields[i]);
CHECK(it != native_object_reloc_.end()) << PrettyClass(orig) << " : " << PrettyField(fields[i]);
auto* image_fields = reinterpret_cast<ArtField*>(image_begin_ + it->second.offset);
if (i == 0) {
copy->SetSFieldsUnchecked(image_fields);
} else {
copy->SetIFieldsUnchecked(image_fields);
}
}
// Update direct / virtual method arrays.
auto* direct_methods = orig->GetDirectMethodsPtr();
if (direct_methods != nullptr) {
auto it = native_object_reloc_.find(direct_methods);
CHECK(it != native_object_reloc_.end()) << PrettyClass(orig);
copy->SetDirectMethodsPtrUnchecked(
reinterpret_cast<ArtMethod*>(image_begin_ + it->second.offset));
}
auto* virtual_methods = orig->GetVirtualMethodsPtr();
if (virtual_methods != nullptr) {
auto it = native_object_reloc_.find(virtual_methods);
CHECK(it != native_object_reloc_.end()) << PrettyClass(orig);
copy->SetVirtualMethodsPtr(
reinterpret_cast<ArtMethod*>(image_begin_ + it->second.offset));
}
// Fix up embedded tables.
if (orig->ShouldHaveEmbeddedImtAndVTable()) {
for (int32_t i = 0; i < orig->GetEmbeddedVTableLength(); ++i) {
auto it = native_object_reloc_.find(orig->GetEmbeddedVTableEntry(i, target_ptr_size_));
CHECK(it != native_object_reloc_.end()) << PrettyClass(orig);
copy->SetEmbeddedVTableEntryUnchecked(
i, reinterpret_cast<ArtMethod*>(image_begin_ + it->second.offset), target_ptr_size_);
}
for (size_t i = 0; i < mirror::Class::kImtSize; ++i) {
auto it = native_object_reloc_.find(orig->GetEmbeddedImTableEntry(i, target_ptr_size_));
CHECK(it != native_object_reloc_.end()) << PrettyClass(orig);
copy->SetEmbeddedImTableEntry(
i, reinterpret_cast<ArtMethod*>(image_begin_ + it->second.offset), target_ptr_size_);
}
}
FixupClassVisitor visitor(this, copy);
static_cast<mirror::Object*>(orig)->VisitReferences<true /*visit class*/>(visitor, visitor);
}
void ImageWriter::FixupObject(Object* orig, Object* copy) {
DCHECK(orig != nullptr);
DCHECK(copy != nullptr);
if (kUseBakerOrBrooksReadBarrier) {
orig->AssertReadBarrierPointer();
if (kUseBrooksReadBarrier) {
// Note the address 'copy' isn't the same as the image address of 'orig'.
copy->SetReadBarrierPointer(GetImageAddress(orig));
DCHECK_EQ(copy->GetReadBarrierPointer(), GetImageAddress(orig));
}
}
auto* klass = orig->GetClass();
if (klass->IsIntArrayClass() || klass->IsLongArrayClass()) {
// Is this a native dex cache array?
auto it = pointer_arrays_.find(down_cast<mirror::PointerArray*>(orig));
if (it != pointer_arrays_.end()) {
// Should only need to fixup every pointer array exactly once.
FixupPointerArray(copy, down_cast<mirror::PointerArray*>(orig), klass, it->second);
pointer_arrays_.erase(it);
return;
}
CHECK(dex_cache_array_indexes_.find(orig) == dex_cache_array_indexes_.end())
<< "Should have been pointer array.";
}
if (orig->IsClass()) {
FixupClass(orig->AsClass<kVerifyNone>(), down_cast<mirror::Class*>(copy));
} else {
if (klass == mirror::Method::StaticClass() || klass == mirror::Constructor::StaticClass()) {
// Need to go update the ArtMethod.
auto* dest = down_cast<mirror::AbstractMethod*>(copy);
auto* src = down_cast<mirror::AbstractMethod*>(orig);
ArtMethod* src_method = src->GetArtMethod();
auto it = native_object_reloc_.find(src_method);
CHECK(it != native_object_reloc_.end()) << "Missing relocation for AbstractMethod.artMethod "
<< PrettyMethod(src_method);
dest->SetArtMethod(
reinterpret_cast<ArtMethod*>(image_begin_ + it->second.offset));
}
FixupVisitor visitor(this, copy);
orig->VisitReferences<true /*visit class*/>(visitor, visitor);
}
}
const uint8_t* ImageWriter::GetQuickCode(ArtMethod* method, bool* quick_is_interpreted) {
DCHECK(!method->IsResolutionMethod() && !method->IsImtConflictMethod() &&
!method->IsImtUnimplementedMethod() && !method->IsAbstract()) << PrettyMethod(method);
// Use original code if it exists. Otherwise, set the code pointer to the resolution
// trampoline.
// Quick entrypoint:
uint32_t quick_oat_code_offset = PointerToLowMemUInt32(
method->GetEntryPointFromQuickCompiledCodePtrSize(target_ptr_size_));
const uint8_t* quick_code = GetOatAddress(quick_oat_code_offset);
*quick_is_interpreted = false;
if (quick_code != nullptr && (!method->IsStatic() || method->IsConstructor() ||
method->GetDeclaringClass()->IsInitialized())) {
// We have code for a non-static or initialized method, just use the code.
DCHECK_GE(quick_code, oat_data_begin_);
} else if (quick_code == nullptr && method->IsNative() &&
(!method->IsStatic() || method->GetDeclaringClass()->IsInitialized())) {
// Non-static or initialized native method missing compiled code, use generic JNI version.
quick_code = GetOatAddress(quick_generic_jni_trampoline_offset_);
DCHECK_GE(quick_code, oat_data_begin_);
} else if (quick_code == nullptr && !method->IsNative()) {
// We don't have code at all for a non-native method, use the interpreter.
quick_code = GetOatAddress(quick_to_interpreter_bridge_offset_);
*quick_is_interpreted = true;
DCHECK_GE(quick_code, oat_data_begin_);
} else {
CHECK(!method->GetDeclaringClass()->IsInitialized());
// We have code for a static method, but need to go through the resolution stub for class
// initialization.
quick_code = GetOatAddress(quick_resolution_trampoline_offset_);
DCHECK_GE(quick_code, oat_data_begin_);
}
return quick_code;
}
const uint8_t* ImageWriter::GetQuickEntryPoint(ArtMethod* method) {
// Calculate the quick entry point following the same logic as FixupMethod() below.
// The resolution method has a special trampoline to call.
Runtime* runtime = Runtime::Current();
if (UNLIKELY(method == runtime->GetResolutionMethod())) {
return GetOatAddress(quick_resolution_trampoline_offset_);
} else if (UNLIKELY(method == runtime->GetImtConflictMethod() ||
method == runtime->GetImtUnimplementedMethod())) {
return GetOatAddress(quick_imt_conflict_trampoline_offset_);
} else {
// We assume all methods have code. If they don't currently then we set them to the use the
// resolution trampoline. Abstract methods never have code and so we need to make sure their
// use results in an AbstractMethodError. We use the interpreter to achieve this.
if (UNLIKELY(method->IsAbstract())) {
return GetOatAddress(quick_to_interpreter_bridge_offset_);
} else {
bool quick_is_interpreted;
return GetQuickCode(method, &quick_is_interpreted);
}
}
}
void ImageWriter::CopyAndFixupMethod(ArtMethod* orig, ArtMethod* copy) {
memcpy(copy, orig, ArtMethod::ObjectSize(target_ptr_size_));
copy->SetDeclaringClass(GetImageAddress(orig->GetDeclaringClassUnchecked()));
copy->SetDexCacheResolvedMethods(GetImageAddress(orig->GetDexCacheResolvedMethods()));
copy->SetDexCacheResolvedTypes(GetImageAddress(orig->GetDexCacheResolvedTypes()));
// OatWriter replaces the code_ with an offset value. Here we re-adjust to a pointer relative to
// oat_begin_
// The resolution method has a special trampoline to call.
Runtime* runtime = Runtime::Current();
if (UNLIKELY(orig == runtime->GetResolutionMethod())) {
copy->SetEntryPointFromQuickCompiledCodePtrSize(
GetOatAddress(quick_resolution_trampoline_offset_), target_ptr_size_);
} else if (UNLIKELY(orig == runtime->GetImtConflictMethod() ||
orig == runtime->GetImtUnimplementedMethod())) {
copy->SetEntryPointFromQuickCompiledCodePtrSize(
GetOatAddress(quick_imt_conflict_trampoline_offset_), target_ptr_size_);
} else if (UNLIKELY(orig->IsRuntimeMethod())) {
bool found_one = false;
for (size_t i = 0; i < static_cast<size_t>(Runtime::kLastCalleeSaveType); ++i) {
auto idx = static_cast<Runtime::CalleeSaveType>(i);
if (runtime->HasCalleeSaveMethod(idx) && runtime->GetCalleeSaveMethod(idx) == orig) {
found_one = true;
break;
}
}
CHECK(found_one) << "Expected to find callee save method but got " << PrettyMethod(orig);
CHECK(copy->IsRuntimeMethod());
} else {
// We assume all methods have code. If they don't currently then we set them to the use the
// resolution trampoline. Abstract methods never have code and so we need to make sure their
// use results in an AbstractMethodError. We use the interpreter to achieve this.
if (UNLIKELY(orig->IsAbstract())) {
copy->SetEntryPointFromQuickCompiledCodePtrSize(
GetOatAddress(quick_to_interpreter_bridge_offset_), target_ptr_size_);
copy->SetEntryPointFromInterpreterPtrSize(
reinterpret_cast<EntryPointFromInterpreter*>(const_cast<uint8_t*>(
GetOatAddress(interpreter_to_interpreter_bridge_offset_))), target_ptr_size_);
} else {
bool quick_is_interpreted;
const uint8_t* quick_code = GetQuickCode(orig, &quick_is_interpreted);
copy->SetEntryPointFromQuickCompiledCodePtrSize(quick_code, target_ptr_size_);
// JNI entrypoint:
if (orig->IsNative()) {
// The native method's pointer is set to a stub to lookup via dlsym.
// Note this is not the code_ pointer, that is handled above.
copy->SetEntryPointFromJniPtrSize(
GetOatAddress(jni_dlsym_lookup_offset_), target_ptr_size_);
}
// Interpreter entrypoint:
// Set the interpreter entrypoint depending on whether there is compiled code or not.
uint32_t interpreter_code = (quick_is_interpreted)
? interpreter_to_interpreter_bridge_offset_
: interpreter_to_compiled_code_bridge_offset_;
EntryPointFromInterpreter* interpreter_entrypoint =
reinterpret_cast<EntryPointFromInterpreter*>(
const_cast<uint8_t*>(GetOatAddress(interpreter_code)));
copy->SetEntryPointFromInterpreterPtrSize(interpreter_entrypoint, target_ptr_size_);
}
}
}
static OatHeader* GetOatHeaderFromElf(ElfFile* elf) {
uint64_t data_sec_offset;
bool has_data_sec = elf->GetSectionOffsetAndSize(".rodata", &data_sec_offset, nullptr);
if (!has_data_sec) {
return nullptr;
}
return reinterpret_cast<OatHeader*>(elf->Begin() + data_sec_offset);
}
void ImageWriter::SetOatChecksumFromElfFile(File* elf_file) {
std::string error_msg;
std::unique_ptr<ElfFile> elf(ElfFile::Open(elf_file, PROT_READ|PROT_WRITE,
MAP_SHARED, &error_msg));
if (elf.get() == nullptr) {
LOG(FATAL) << "Unable open oat file: " << error_msg;
return;
}
OatHeader* oat_header = GetOatHeaderFromElf(elf.get());
CHECK(oat_header != nullptr);
CHECK(oat_header->IsValid());
ImageHeader* image_header = reinterpret_cast<ImageHeader*>(image_->Begin());
image_header->SetOatChecksum(oat_header->GetChecksum());
}
size_t ImageWriter::GetBinSizeSum(ImageWriter::Bin up_to) const {
DCHECK_LE(up_to, kBinSize);
return std::accumulate(&bin_slot_sizes_[0], &bin_slot_sizes_[up_to], /*init*/0);
}
ImageWriter::BinSlot::BinSlot(uint32_t lockword) : lockword_(lockword) {
// These values may need to get updated if more bins are added to the enum Bin
static_assert(kBinBits == 3, "wrong number of bin bits");
static_assert(kBinShift == 27, "wrong number of shift");
static_assert(sizeof(BinSlot) == sizeof(LockWord), "BinSlot/LockWord must have equal sizes");
DCHECK_LT(GetBin(), kBinSize);
DCHECK_ALIGNED(GetIndex(), kObjectAlignment);
}
ImageWriter::BinSlot::BinSlot(Bin bin, uint32_t index)
: BinSlot(index | (static_cast<uint32_t>(bin) << kBinShift)) {
DCHECK_EQ(index, GetIndex());
}
ImageWriter::Bin ImageWriter::BinSlot::GetBin() const {
return static_cast<Bin>((lockword_ & kBinMask) >> kBinShift);
}
uint32_t ImageWriter::BinSlot::GetIndex() const {
return lockword_ & ~kBinMask;
}
uint8_t* ImageWriter::GetOatFileBegin() const {
DCHECK_GT(intern_table_bytes_, 0u);
return image_begin_ + RoundUp(
image_end_ + bin_slot_sizes_[kBinArtField] + bin_slot_sizes_[kBinArtMethodDirty] +
bin_slot_sizes_[kBinArtMethodClean] + intern_table_bytes_, kPageSize);
}
} // namespace art