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/*
* 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 <vector>
#include "base/logging.h"
#include "base/unix_file/fd_file.h"
#include "class_linker.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_patcher.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 "lock_word.h"
#include "mirror/art_field-inl.h"
#include "mirror/art_method-inl.h"
#include "mirror/array-inl.h"
#include "mirror/class-inl.h"
#include "mirror/class_loader.h"
#include "mirror/dex_cache-inl.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.h"
using ::art::mirror::ArtField;
using ::art::mirror::ArtMethod;
using ::art::mirror::Class;
using ::art::mirror::DexCache;
using ::art::mirror::EntryPointFromInterpreter;
using ::art::mirror::Object;
using ::art::mirror::ObjectArray;
using ::art::mirror::String;
namespace art {
bool ImageWriter::Write(const std::string& image_filename,
uintptr_t image_begin,
const std::string& oat_filename,
const std::string& oat_location,
bool compile_pic) {
CHECK(!image_filename.empty());
CHECK_NE(image_begin, 0U);
image_begin_ = reinterpret_cast<byte*>(image_begin);
compile_pic_ = compile_pic;
ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
std::unique_ptr<File> oat_file(OS::OpenFileReadWrite(oat_filename.c_str()));
if (oat_file.get() == NULL) {
LOG(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, &error_msg);
if (oat_file_ == nullptr) {
LOG(ERROR) << "Failed to open writable oat file " << oat_filename << " for " << oat_location
<< ": " << error_msg;
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();
portable_imt_conflict_trampoline_offset_ =
oat_file_->GetOatHeader().GetPortableImtConflictTrampolineOffset();
portable_resolution_trampoline_offset_ =
oat_file_->GetOatHeader().GetPortableResolutionTrampolineOffset();
portable_to_interpreter_bridge_offset_ =
oat_file_->GetOatHeader().GetPortableToInterpreterBridgeOffset();
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();
{
Thread::Current()->TransitionFromSuspendedToRunnable();
PruneNonImageClasses(); // Remove junk
ComputeLazyFieldsForImageClasses(); // Add useful information
ProcessStrings();
Thread::Current()->TransitionFromRunnableToSuspended(kNative);
}
gc::Heap* heap = Runtime::Current()->GetHeap();
heap->CollectGarbage(false); // Remove garbage.
if (!AllocMemory()) {
return false;
}
if (kIsDebugBuild) {
ScopedObjectAccess soa(Thread::Current());
CheckNonImageClassesRemoved();
}
Thread::Current()->TransitionFromSuspendedToRunnable();
size_t oat_loaded_size = 0;
size_t oat_data_offset = 0;
ElfWriter::GetOatElfInformation(oat_file.get(), oat_loaded_size, oat_data_offset);
CalculateNewObjectOffsets(oat_loaded_size, oat_data_offset);
CopyAndFixupObjects();
PatchOatCodeAndMethods(oat_file.get());
Thread::Current()->TransitionFromRunnableToSuspended(kNative);
std::unique_ptr<File> image_file(OS::CreateEmptyFile(image_filename.c_str()));
ImageHeader* image_header = reinterpret_cast<ImageHeader*>(image_->Begin());
if (image_file.get() == NULL) {
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;
return EXIT_FAILURE;
}
// Write out the image.
CHECK_EQ(image_end_, image_header->GetImageSize());
if (!image_file->WriteFully(image_->Begin(), image_end_)) {
PLOG(ERROR) << "Failed to write image file " << image_filename;
return false;
}
// Write out the image bitmap at the page aligned start of the image end.
CHECK_ALIGNED(image_header->GetImageBitmapOffset(), kPageSize);
if (!image_file->Write(reinterpret_cast<char*>(image_bitmap_->Begin()),
image_header->GetImageBitmapSize(),
image_header->GetImageBitmapOffset())) {
PLOG(ERROR) << "Failed to write image file " << image_filename;
return false;
}
return true;
}
void ImageWriter::SetImageOffset(mirror::Object* object, size_t offset) {
DCHECK(object != nullptr);
DCHECK_NE(offset, 0U);
DCHECK(!IsImageOffsetAssigned(object));
mirror::Object* obj = reinterpret_cast<mirror::Object*>(image_->Begin() + offset);
DCHECK_ALIGNED(obj, kObjectAlignment);
image_bitmap_->Set(obj);
// 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 " << obj << " found during object copy";
break;
}
case LockWord::kThinLocked: {
LOG(FATAL) << "Thin locked object " << obj << " found during object copy";
break;
}
case LockWord::kUnlocked:
// No hash, don't need to save it.
break;
case LockWord::kHashCode:
saved_hashes_.push_back(std::make_pair(obj, lw.GetHashCode()));
break;
default:
LOG(FATAL) << "Unreachable.";
break;
}
object->SetLockWord(LockWord::FromForwardingAddress(offset), false);
DCHECK(IsImageOffsetAssigned(object));
}
void ImageWriter::AssignImageOffset(mirror::Object* object) {
DCHECK(object != nullptr);
SetImageOffset(object, image_end_);
image_end_ += RoundUp(object->SizeOf(), 8); // 64-bit alignment
DCHECK_LT(image_end_, image_->Size());
}
bool ImageWriter::IsImageOffsetAssigned(mirror::Object* object) const {
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;
}
bool ImageWriter::AllocMemory() {
size_t length = RoundUp(Runtime::Current()->GetHeap()->GetTotalMemory(), kPageSize);
std::string error_msg;
image_.reset(MemMap::MapAnonymous("image writer image", NULL, length, PROT_READ | PROT_WRITE,
true, &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.
image_bitmap_.reset(gc::accounting::ContinuousSpaceBitmap::Create("image bitmap", image_->Begin(),
length));
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, NULL);
}
bool ImageWriter::ComputeLazyFieldsForClassesVisitor(Class* c, void* /*arg*/) {
Thread* self = Thread::Current();
StackHandleScope<1> hs(self);
mirror::Class::ComputeName(hs.NewHandle(c));
return true;
}
// Count the number of strings in the heap and put the result in arg as a size_t pointer.
static void CountStringsCallback(Object* obj, void* arg)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
if (obj->GetClass()->IsStringClass()) {
++*reinterpret_cast<size_t*>(arg);
}
}
// Collect all the java.lang.String in the heap and put them in the output strings_ array.
class StringCollector {
public:
StringCollector(Handle<mirror::ObjectArray<mirror::String>> strings, size_t index)
: strings_(strings), index_(index) {
}
static void Callback(Object* obj, void* arg) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
auto* collector = reinterpret_cast<StringCollector*>(arg);
if (obj->GetClass()->IsStringClass()) {
collector->strings_->SetWithoutChecks<false>(collector->index_++, obj->AsString());
}
}
size_t GetIndex() const {
return index_;
}
private:
Handle<mirror::ObjectArray<mirror::String>> strings_;
size_t index_;
};
// Compare strings based on length, used for sorting strings by length / reverse length.
class StringLengthComparator {
public:
explicit StringLengthComparator(Handle<mirror::ObjectArray<mirror::String>> strings)
: strings_(strings) {
}
bool operator()(size_t a, size_t b) const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
return strings_->GetWithoutChecks(a)->GetLength() < strings_->GetWithoutChecks(b)->GetLength();
}
private:
Handle<mirror::ObjectArray<mirror::String>> strings_;
};
// If string a is a prefix of b or b is a prefix of a then they are considered equal. This
// enables us to find prefixes instead of exact matches. Otherwise we do a normal string
// comparison. The strings compared of the form <position, length> inside of the chars_ array.
class SubstringComparator {
public:
explicit SubstringComparator(const std::vector<uint16_t>* const chars) : chars_(chars) {
}
bool operator()(const std::pair<size_t, size_t>& a, const std::pair<size_t, size_t>& b) {
size_t compare_length = std::min(a.second, b.second);
const uint16_t* ptr_a = &chars_->at(a.first);
const uint16_t* ptr_b = &chars_->at(b.first);
for (size_t i = 0; i < compare_length; ++i) {
if (ptr_a[i] != ptr_b[i]) {
return ptr_a[i] < ptr_b[i];
}
}
return false;
}
private:
const std::vector<uint16_t>* const chars_;
};
void ImageWriter::ProcessStrings() {
size_t total_strings = 0;
gc::Heap* heap = Runtime::Current()->GetHeap();
ClassLinker* cl = Runtime::Current()->GetClassLinker();
{
ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_);
heap->VisitObjects(CountStringsCallback, &total_strings); // Count the strings.
}
Thread* self = Thread::Current();
StackHandleScope<1> hs(self);
auto strings = hs.NewHandle(cl->AllocStringArray(self, total_strings));
StringCollector string_collector(strings, 0U);
{
ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_);
// Read strings into the array.
heap->VisitObjects(StringCollector::Callback, &string_collector);
}
// Some strings could have gotten freed if AllocStringArray caused a GC.
CHECK_LE(string_collector.GetIndex(), total_strings);
total_strings = string_collector.GetIndex();
size_t total_length = 0;
std::vector<size_t> reverse_sorted_strings;
for (size_t i = 0; i < total_strings; ++i) {
mirror::String* s = strings->GetWithoutChecks(i);
// Look up the string in the array.
total_length += s->GetLength();
reverse_sorted_strings.push_back(i);
}
// Sort by reverse length.
StringLengthComparator comparator(strings);
std::sort(reverse_sorted_strings.rbegin(), reverse_sorted_strings.rend(), comparator);
// Deduplicate prefixes and add strings to the char array.
std::vector<uint16_t> combined_chars(total_length, 0U);
size_t num_chars = 0;
// Characters of strings which are non equal prefix of another string (not the same string).
// We don't count the savings from equal strings since these would get interned later anyways.
size_t prefix_saved_chars = 0;
std::set<std::pair<size_t, size_t>, SubstringComparator> existing_strings((
SubstringComparator(&combined_chars)));
for (size_t i = 0; i < total_strings; ++i) {
mirror::String* s = strings->GetWithoutChecks(reverse_sorted_strings[i]);
// Add the string to the end of the char array.
size_t length = s->GetLength();
for (size_t j = 0; j < length; ++j) {
combined_chars[num_chars++] = s->CharAt(j);
}
// Try to see if the string exists as a prefix of an existing string.
size_t new_offset = 0;
std::pair<size_t, size_t> new_string(num_chars - length, length);
auto it = existing_strings.find(new_string);
if (it != existing_strings.end()) {
for (size_t j = 0; j < length; ++j) {
DCHECK_EQ(combined_chars[it->first + j], s->CharAt(j));
}
// Shares a prefix, set the offset to where the new offset will be.
new_offset = it->first;
// Remove the added chars.
num_chars -= length;
if (it->second != length) {
prefix_saved_chars += length;
}
} else {
new_offset = new_string.first;
existing_strings.insert(new_string);
}
s->SetOffset(new_offset);
}
// Allocate and update the char arrays.
auto* array = mirror::CharArray::Alloc(self, num_chars);
for (size_t i = 0; i < num_chars; ++i) {
array->SetWithoutChecks<false>(i, combined_chars[i]);
}
for (size_t i = 0; i < total_strings; ++i) {
strings->GetWithoutChecks(i)->SetArray(array);
}
VLOG(compiler) << "Total # image strings=" << total_strings << " combined length="
<< total_length << " prefix saved chars=" << prefix_saved_chars;
ComputeEagerResolvedStrings();
}
void ImageWriter::ComputeEagerResolvedStringsCallback(Object* obj, void* arg) {
if (!obj->GetClass()->IsStringClass()) {
return;
}
mirror::String* string = obj->AsString();
const uint16_t* utf16_string = string->GetCharArray()->GetData() + string->GetOffset();
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(string->GetLength() == 0)) {
string_id = dex_file.FindStringId("");
} else {
string_id = dex_file.FindStringId(utf16_string);
}
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) == NULL) {
dex_cache->SetResolvedString(string_idx, string);
}
}
}
}
void ImageWriter::ComputeEagerResolvedStrings() {
ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_);
Runtime::Current()->GetHeap()->VisitObjects(ComputeEagerResolvedStringsCallback, this);
}
bool ImageWriter::IsImageClass(Class* klass) {
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() == NULL) {
return;
}
Runtime* runtime = Runtime::Current();
ClassLinker* class_linker = runtime->GetClassLinker();
// 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(), NULL);
DCHECK(result);
}
// Clear references to removed classes from the DexCaches.
ArtMethod* resolution_method = runtime->GetResolutionMethod();
ReaderMutexLock mu(Thread::Current(), *class_linker->DexLock());
size_t dex_cache_count = class_linker->GetDexCacheCount();
for (size_t idx = 0; idx < dex_cache_count; ++idx) {
DexCache* dex_cache = class_linker->GetDexCache(idx);
for (size_t i = 0; i < dex_cache->NumResolvedTypes(); i++) {
Class* klass = dex_cache->GetResolvedType(i);
if (klass != NULL && !IsImageClass(klass)) {
dex_cache->SetResolvedType(i, NULL);
}
}
for (size_t i = 0; i < dex_cache->NumResolvedMethods(); i++) {
ArtMethod* method = dex_cache->GetResolvedMethod(i);
if (method != NULL && !IsImageClass(method->GetDeclaringClass())) {
dex_cache->SetResolvedMethod(i, resolution_method);
}
}
for (size_t i = 0; i < dex_cache->NumResolvedFields(); i++) {
ArtField* field = dex_cache->GetResolvedField(i);
if (field != NULL && !IsImageClass(field->GetDeclaringClass())) {
dex_cache->SetResolvedField(i, NULL);
}
}
}
}
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();
ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_);
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() {
const std::set<std::string>* image_classes = compiler_driver_.GetImageClasses();
CHECK(image_classes != NULL);
for (const std::string& image_class : *image_classes) {
LOG(INFO) << " " << image_class;
}
}
void ImageWriter::CalculateObjectOffsets(Object* obj) {
DCHECK(obj != NULL);
// 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 (IsImageOffsetAssigned(obj)) {
DCHECK_EQ(obj, obj->AsString()->Intern());
return;
}
mirror::String* const interned = obj->AsString()->Intern();
if (obj != interned) {
if (!IsImageOffsetAssigned(interned)) {
// interned obj is after us, allocate its location early
AssignImageOffset(interned);
}
// point those looking for this object to the interned version.
SetImageOffset(obj, GetImageOffset(interned));
return;
}
// else (obj == interned), nothing to do but fall through to the normal case
}
AssignImageOffset(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(Thread::Current(), *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(Thread::Current(), *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
Handle<ObjectArray<Object>> image_roots(hs.NewHandle(
ObjectArray<Object>::Alloc(self, object_array_class.Get(), ImageHeader::kImageRootsMax)));
image_roots->Set<false>(ImageHeader::kResolutionMethod, runtime->GetResolutionMethod());
image_roots->Set<false>(ImageHeader::kImtConflictMethod, runtime->GetImtConflictMethod());
image_roots->Set<false>(ImageHeader::kImtUnimplementedMethod,
runtime->GetImtUnimplementedMethod());
image_roots->Set<false>(ImageHeader::kDefaultImt, runtime->GetDefaultImt());
image_roots->Set<false>(ImageHeader::kCalleeSaveMethod,
runtime->GetCalleeSaveMethod(Runtime::kSaveAll));
image_roots->Set<false>(ImageHeader::kRefsOnlySaveMethod,
runtime->GetCalleeSaveMethod(Runtime::kRefsOnly));
image_roots->Set<false>(ImageHeader::kRefsAndArgsSaveMethod,
runtime->GetCalleeSaveMethod(Runtime::kRefsAndArgs));
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) != NULL);
}
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) {
if (!IsImageOffsetAssigned(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.
CalculateObjectOffsets(h_obj.Get());
WalkInstanceFields(h_obj.Get(), klass.Get());
// Walk static fields of a Class.
if (h_obj->IsClass()) {
size_t num_static_fields = klass->NumReferenceStaticFields();
MemberOffset field_offset = klass->GetFirstReferenceStaticFieldOffset();
for (size_t i = 0; i < num_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>));
}
} 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::WalkFieldsCallback(mirror::Object* obj, void* arg) {
ImageWriter* writer = reinterpret_cast<ImageWriter*>(arg);
DCHECK(writer != nullptr);
writer->WalkFieldsInOrder(obj);
}
void ImageWriter::CalculateNewObjectOffsets(size_t oat_loaded_size, size_t oat_data_offset) {
CHECK_NE(0U, oat_loaded_size);
Thread* self = Thread::Current();
StackHandleScope<1> hs(self);
Handle<ObjectArray<Object>> image_roots(hs.NewHandle(CreateImageRoots()));
gc::Heap* heap = Runtime::Current()->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), 8); // 64-bit-alignment
{
WriterMutexLock mu(self, *Locks::heap_bitmap_lock_);
// TODO: Image spaces only?
const char* old = self->StartAssertNoThreadSuspension("ImageWriter");
DCHECK_LT(image_end_, image_->Size());
// Clear any pre-existing monitors which may have been in the monitor words.
heap->VisitObjects(WalkFieldsCallback, this);
self->EndAssertNoThreadSuspension(old);
}
const byte* oat_file_begin = image_begin_ + RoundUp(image_end_, kPageSize);
const byte* oat_file_end = oat_file_begin + oat_loaded_size;
oat_data_begin_ = oat_file_begin + oat_data_offset;
const byte* oat_data_end = oat_data_begin_ + oat_file_->Size();
// Return to write header at start of image with future location of image_roots. At this point,
// image_end_ is the size of the image (excluding bitmaps).
const size_t heap_bytes_per_bitmap_byte = kBitsPerByte * kObjectAlignment;
const size_t bitmap_bytes = RoundUp(image_end_, heap_bytes_per_bitmap_byte) /
heap_bytes_per_bitmap_byte;
ImageHeader image_header(PointerToLowMemUInt32(image_begin_),
static_cast<uint32_t>(image_end_),
RoundUp(image_end_, kPageSize),
RoundUp(bitmap_bytes, kPageSize),
PointerToLowMemUInt32(GetImageAddress(image_roots.Get())),
oat_file_->GetOatHeader().GetChecksum(),
PointerToLowMemUInt32(oat_file_begin),
PointerToLowMemUInt32(oat_data_begin_),
PointerToLowMemUInt32(oat_data_end),
PointerToLowMemUInt32(oat_file_end),
compile_pic_);
memcpy(image_->Begin(), &image_header, sizeof(image_header));
// Note that image_end_ is left at end of used space
}
void ImageWriter::CopyAndFixupObjects() {
Thread* self = Thread::Current();
const char* old_cause = self->StartAssertNoThreadSuspension("ImageWriter");
gc::Heap* heap = Runtime::Current()->GetHeap();
// TODO: heap validation can't handle this fix up pass
heap->DisableObjectValidation();
// TODO: Image spaces only?
WriterMutexLock mu(self, *Locks::heap_bitmap_lock_);
heap->VisitObjects(CopyAndFixupObjectsCallback, this);
// Fix up the object previously had hash codes.
for (const std::pair<mirror::Object*, uint32_t>& hash_pair : saved_hashes_) {
hash_pair.first->SetLockWord(LockWord::FromHashCode(hash_pair.second), false);
}
saved_hashes_.clear();
self->EndAssertNoThreadSuspension(old_cause);
}
void ImageWriter::CopyAndFixupObjectsCallback(Object* obj, void* arg) {
DCHECK(obj != nullptr);
DCHECK(arg != nullptr);
ImageWriter* image_writer = reinterpret_cast<ImageWriter*>(arg);
// see GetLocalAddress for similar computation
size_t offset = image_writer->GetImageOffset(obj);
byte* dst = image_writer->image_->Begin() + offset;
const byte* src = reinterpret_cast<const byte*>(obj);
size_t n = obj->SizeOf();
DCHECK_LT(offset + n, image_writer->image_->Size());
memcpy(dst, src, n);
Object* copy = reinterpret_cast<Object*>(dst);
// Write in a hash code of objects which have inflated monitors or a hash code in their monitor
// word.
copy->SetLockWord(LockWord(), false);
image_writer->FixupObject(obj, copy);
}
class FixupVisitor {
public:
FixupVisitor(ImageWriter* image_writer, Object* copy) : image_writer_(image_writer), copy_(copy) {
}
void operator()(Object* obj, MemberOffset offset, bool /*is_static*/) 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*/, 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*/) const
EXCLUSIVE_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) {
DCHECK(obj->IsClass());
FixupVisitor::operator()(obj, offset, false);
if (offset.Uint32Value() < mirror::Class::EmbeddedVTableOffset().Uint32Value()) {
return;
}
}
void operator()(mirror::Class* /*klass*/, mirror::Reference* ref) const
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) {
LOG(FATAL) << "Reference not expected here.";
}
};
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));
}
}
if (orig->IsClass() && orig->AsClass()->ShouldHaveEmbeddedImtAndVTable()) {
FixupClassVisitor visitor(this, copy);
orig->VisitReferences<true /*visit class*/>(visitor, visitor);
} else {
FixupVisitor visitor(this, copy);
orig->VisitReferences<true /*visit class*/>(visitor, visitor);
}
if (orig->IsArtMethod<kVerifyNone>()) {
FixupMethod(orig->AsArtMethod<kVerifyNone>(), down_cast<ArtMethod*>(copy));
}
}
const byte* ImageWriter::GetQuickCode(mirror::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:
const byte* quick_code = GetOatAddress(method->GetQuickOatCodeOffset());
*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.
} 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_);
} 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;
} 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_);
}
return quick_code;
}
const byte* ImageWriter::GetQuickEntryPoint(mirror::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::FixupMethod(ArtMethod* orig, ArtMethod* copy) {
// 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())) {
#if defined(ART_USE_PORTABLE_COMPILER)
copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(GetOatAddress(portable_resolution_trampoline_offset_));
#endif
copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(GetOatAddress(quick_resolution_trampoline_offset_));
} else if (UNLIKELY(orig == runtime->GetImtConflictMethod() ||
orig == runtime->GetImtUnimplementedMethod())) {
#if defined(ART_USE_PORTABLE_COMPILER)
copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(GetOatAddress(portable_imt_conflict_trampoline_offset_));
#endif
copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(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(orig->IsAbstract())) {
#if defined(ART_USE_PORTABLE_COMPILER)
copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(GetOatAddress(portable_to_interpreter_bridge_offset_));
#endif
copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(GetOatAddress(quick_to_interpreter_bridge_offset_));
copy->SetEntryPointFromInterpreter<kVerifyNone>(reinterpret_cast<EntryPointFromInterpreter*>
(const_cast<byte*>(GetOatAddress(interpreter_to_interpreter_bridge_offset_))));
} else {
bool quick_is_interpreted;
const byte* quick_code = GetQuickCode(orig, &quick_is_interpreted);
copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(quick_code);
// Portable entrypoint:
bool portable_is_interpreted = false;
#if defined(ART_USE_PORTABLE_COMPILER)
const byte* portable_code = GetOatAddress(orig->GetPortableOatCodeOffset());
if (portable_code != nullptr &&
(!orig->IsStatic() || orig->IsConstructor() || orig->GetDeclaringClass()->IsInitialized())) {
// We have code for a non-static or initialized method, just use the code.
} else if (portable_code == nullptr && orig->IsNative() &&
(!orig->IsStatic() || orig->GetDeclaringClass()->IsInitialized())) {
// Non-static or initialized native method missing compiled code, use generic JNI version.
// TODO: generic JNI support for LLVM.
portable_code = GetOatAddress(portable_resolution_trampoline_offset_);
} else if (portable_code == nullptr && !orig->IsNative()) {
// We don't have code at all for a non-native method, use the interpreter.
portable_code = GetOatAddress(portable_to_interpreter_bridge_offset_);
portable_is_interpreted = true;
} else {
CHECK(!orig->GetDeclaringClass()->IsInitialized());
// We have code for a static method, but need to go through the resolution stub for class
// initialization.
portable_code = GetOatAddress(portable_resolution_trampoline_offset_);
}
copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(portable_code);
#endif
// 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->SetNativeMethod<kVerifyNone>(GetOatAddress(jni_dlsym_lookup_offset_));
} else {
// Normal (non-abstract non-native) methods have various tables to relocate.
uint32_t native_gc_map_offset = orig->GetOatNativeGcMapOffset();
const byte* native_gc_map = GetOatAddress(native_gc_map_offset);
copy->SetNativeGcMap<kVerifyNone>(reinterpret_cast<const uint8_t*>(native_gc_map));
}
// Interpreter entrypoint:
// Set the interpreter entrypoint depending on whether there is compiled code or not.
uint32_t interpreter_code = (quick_is_interpreted && portable_is_interpreted)
? interpreter_to_interpreter_bridge_offset_
: interpreter_to_compiled_code_bridge_offset_;
copy->SetEntryPointFromInterpreter<kVerifyNone>(
reinterpret_cast<EntryPointFromInterpreter*>(
const_cast<byte*>(GetOatAddress(interpreter_code))));
}
}
}
static OatHeader* GetOatHeaderFromElf(ElfFile* elf) {
Elf32_Shdr* data_sec = elf->FindSectionByName(".rodata");
if (data_sec == nullptr) {
return nullptr;
}
return reinterpret_cast<OatHeader*>(elf->Begin() + data_sec->sh_offset);
}
void ImageWriter::PatchOatCodeAndMethods(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 patch oat file: " << error_msg;
return;
}
if (!ElfPatcher::Patch(&compiler_driver_, elf.get(), oat_file_,
reinterpret_cast<uintptr_t>(oat_data_begin_),
GetImageAddressCallback, reinterpret_cast<void*>(this),
&error_msg)) {
LOG(FATAL) << "unable to patch 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());
}
} // namespace art