1 /*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "image_writer.h"
18
19 #include <sys/stat.h>
20
21 #include <memory>
22 #include <vector>
23
24 #include "base/logging.h"
25 #include "base/unix_file/fd_file.h"
26 #include "class_linker.h"
27 #include "compiled_method.h"
28 #include "dex_file-inl.h"
29 #include "driver/compiler_driver.h"
30 #include "elf_file.h"
31 #include "elf_utils.h"
32 #include "elf_patcher.h"
33 #include "elf_writer.h"
34 #include "gc/accounting/card_table-inl.h"
35 #include "gc/accounting/heap_bitmap.h"
36 #include "gc/accounting/space_bitmap-inl.h"
37 #include "gc/heap.h"
38 #include "gc/space/large_object_space.h"
39 #include "gc/space/space-inl.h"
40 #include "globals.h"
41 #include "image.h"
42 #include "intern_table.h"
43 #include "lock_word.h"
44 #include "mirror/art_field-inl.h"
45 #include "mirror/art_method-inl.h"
46 #include "mirror/array-inl.h"
47 #include "mirror/class-inl.h"
48 #include "mirror/class_loader.h"
49 #include "mirror/dex_cache-inl.h"
50 #include "mirror/object-inl.h"
51 #include "mirror/object_array-inl.h"
52 #include "mirror/string-inl.h"
53 #include "oat.h"
54 #include "oat_file.h"
55 #include "runtime.h"
56 #include "scoped_thread_state_change.h"
57 #include "handle_scope-inl.h"
58
59 #include <numeric>
60
61 using ::art::mirror::ArtField;
62 using ::art::mirror::ArtMethod;
63 using ::art::mirror::Class;
64 using ::art::mirror::DexCache;
65 using ::art::mirror::EntryPointFromInterpreter;
66 using ::art::mirror::Object;
67 using ::art::mirror::ObjectArray;
68 using ::art::mirror::String;
69
70 namespace art {
71
72 // Separate objects into multiple bins to optimize dirty memory use.
73 static constexpr bool kBinObjects = true;
74
Write(const std::string & image_filename,uintptr_t image_begin,const std::string & oat_filename,const std::string & oat_location,bool compile_pic)75 bool ImageWriter::Write(const std::string& image_filename,
76 uintptr_t image_begin,
77 const std::string& oat_filename,
78 const std::string& oat_location,
79 bool compile_pic) {
80 CHECK(!image_filename.empty());
81
82 CHECK_NE(image_begin, 0U);
83 image_begin_ = reinterpret_cast<byte*>(image_begin);
84 compile_pic_ = compile_pic;
85
86 ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
87
88 target_ptr_size_ = InstructionSetPointerSize(compiler_driver_.GetInstructionSet());
89 std::unique_ptr<File> oat_file(OS::OpenFileReadWrite(oat_filename.c_str()));
90 if (oat_file.get() == NULL) {
91 LOG(ERROR) << "Failed to open oat file " << oat_filename << " for " << oat_location;
92 return false;
93 }
94 std::string error_msg;
95 oat_file_ = OatFile::OpenReadable(oat_file.get(), oat_location, &error_msg);
96 if (oat_file_ == nullptr) {
97 LOG(ERROR) << "Failed to open writable oat file " << oat_filename << " for " << oat_location
98 << ": " << error_msg;
99 return false;
100 }
101 CHECK_EQ(class_linker->RegisterOatFile(oat_file_), oat_file_);
102
103 interpreter_to_interpreter_bridge_offset_ =
104 oat_file_->GetOatHeader().GetInterpreterToInterpreterBridgeOffset();
105 interpreter_to_compiled_code_bridge_offset_ =
106 oat_file_->GetOatHeader().GetInterpreterToCompiledCodeBridgeOffset();
107
108 jni_dlsym_lookup_offset_ = oat_file_->GetOatHeader().GetJniDlsymLookupOffset();
109
110 portable_imt_conflict_trampoline_offset_ =
111 oat_file_->GetOatHeader().GetPortableImtConflictTrampolineOffset();
112 portable_resolution_trampoline_offset_ =
113 oat_file_->GetOatHeader().GetPortableResolutionTrampolineOffset();
114 portable_to_interpreter_bridge_offset_ =
115 oat_file_->GetOatHeader().GetPortableToInterpreterBridgeOffset();
116
117 quick_generic_jni_trampoline_offset_ =
118 oat_file_->GetOatHeader().GetQuickGenericJniTrampolineOffset();
119 quick_imt_conflict_trampoline_offset_ =
120 oat_file_->GetOatHeader().GetQuickImtConflictTrampolineOffset();
121 quick_resolution_trampoline_offset_ =
122 oat_file_->GetOatHeader().GetQuickResolutionTrampolineOffset();
123 quick_to_interpreter_bridge_offset_ =
124 oat_file_->GetOatHeader().GetQuickToInterpreterBridgeOffset();
125 {
126 Thread::Current()->TransitionFromSuspendedToRunnable();
127 PruneNonImageClasses(); // Remove junk
128 ComputeLazyFieldsForImageClasses(); // Add useful information
129 ProcessStrings();
130 Thread::Current()->TransitionFromRunnableToSuspended(kNative);
131 }
132 gc::Heap* heap = Runtime::Current()->GetHeap();
133 heap->CollectGarbage(false); // Remove garbage.
134
135 if (!AllocMemory()) {
136 return false;
137 }
138
139 if (kIsDebugBuild) {
140 ScopedObjectAccess soa(Thread::Current());
141 CheckNonImageClassesRemoved();
142 }
143
144 Thread::Current()->TransitionFromSuspendedToRunnable();
145 size_t oat_loaded_size = 0;
146 size_t oat_data_offset = 0;
147 ElfWriter::GetOatElfInformation(oat_file.get(), oat_loaded_size, oat_data_offset);
148 CalculateNewObjectOffsets(oat_loaded_size, oat_data_offset);
149 CopyAndFixupObjects();
150
151 PatchOatCodeAndMethods(oat_file.get());
152
153 // Before flushing, which might fail, release the mutator lock.
154 Thread::Current()->TransitionFromRunnableToSuspended(kNative);
155
156 if (oat_file->FlushCloseOrErase() != 0) {
157 LOG(ERROR) << "Failed to flush and close oat file " << oat_filename << " for " << oat_location;
158 return false;
159 }
160
161 std::unique_ptr<File> image_file(OS::CreateEmptyFile(image_filename.c_str()));
162 ImageHeader* image_header = reinterpret_cast<ImageHeader*>(image_->Begin());
163 if (image_file.get() == NULL) {
164 LOG(ERROR) << "Failed to open image file " << image_filename;
165 return false;
166 }
167 if (fchmod(image_file->Fd(), 0644) != 0) {
168 PLOG(ERROR) << "Failed to make image file world readable: " << image_filename;
169 image_file->Erase();
170 return EXIT_FAILURE;
171 }
172
173 // Write out the image.
174 CHECK_EQ(image_end_, image_header->GetImageSize());
175 if (!image_file->WriteFully(image_->Begin(), image_end_)) {
176 PLOG(ERROR) << "Failed to write image file " << image_filename;
177 image_file->Erase();
178 return false;
179 }
180
181 // Write out the image bitmap at the page aligned start of the image end.
182 CHECK_ALIGNED(image_header->GetImageBitmapOffset(), kPageSize);
183 if (!image_file->Write(reinterpret_cast<char*>(image_bitmap_->Begin()),
184 image_header->GetImageBitmapSize(),
185 image_header->GetImageBitmapOffset())) {
186 PLOG(ERROR) << "Failed to write image file " << image_filename;
187 image_file->Erase();
188 return false;
189 }
190
191 if (image_file->FlushCloseOrErase() != 0) {
192 PLOG(ERROR) << "Failed to flush and close image file " << image_filename;
193 return false;
194 }
195 return true;
196 }
197
SetImageOffset(mirror::Object * object,ImageWriter::BinSlot bin_slot,size_t offset)198 void ImageWriter::SetImageOffset(mirror::Object* object,
199 ImageWriter::BinSlot bin_slot,
200 size_t offset) {
201 DCHECK(object != nullptr);
202 DCHECK_NE(offset, 0U);
203 mirror::Object* obj = reinterpret_cast<mirror::Object*>(image_->Begin() + offset);
204 DCHECK_ALIGNED(obj, kObjectAlignment);
205
206 image_bitmap_->Set(obj); // Mark the obj as mutated, since we will end up changing it.
207 {
208 // Remember the object-inside-of-the-image's hash code so we can restore it after the copy.
209 auto hash_it = saved_hashes_map_.find(bin_slot);
210 if (hash_it != saved_hashes_map_.end()) {
211 std::pair<BinSlot, uint32_t> slot_hash = *hash_it;
212 saved_hashes_.push_back(std::make_pair(obj, slot_hash.second));
213 saved_hashes_map_.erase(hash_it);
214 }
215 }
216 // The object is already deflated from when we set the bin slot. Just overwrite the lock word.
217 object->SetLockWord(LockWord::FromForwardingAddress(offset), false);
218 DCHECK(IsImageOffsetAssigned(object));
219 }
220
AssignImageOffset(mirror::Object * object,ImageWriter::BinSlot bin_slot)221 void ImageWriter::AssignImageOffset(mirror::Object* object, ImageWriter::BinSlot bin_slot) {
222 DCHECK(object != nullptr);
223 DCHECK_NE(image_objects_offset_begin_, 0u);
224
225 size_t previous_bin_sizes = GetBinSizeSum(bin_slot.GetBin()); // sum sizes in [0..bin#)
226 size_t new_offset = image_objects_offset_begin_ + previous_bin_sizes + bin_slot.GetIndex();
227 DCHECK_ALIGNED(new_offset, kObjectAlignment);
228
229 SetImageOffset(object, bin_slot, new_offset);
230 DCHECK_LT(new_offset, image_end_);
231 }
232
IsImageOffsetAssigned(mirror::Object * object) const233 bool ImageWriter::IsImageOffsetAssigned(mirror::Object* object) const {
234 // Will also return true if the bin slot was assigned since we are reusing the lock word.
235 DCHECK(object != nullptr);
236 return object->GetLockWord(false).GetState() == LockWord::kForwardingAddress;
237 }
238
GetImageOffset(mirror::Object * object) const239 size_t ImageWriter::GetImageOffset(mirror::Object* object) const {
240 DCHECK(object != nullptr);
241 DCHECK(IsImageOffsetAssigned(object));
242 LockWord lock_word = object->GetLockWord(false);
243 size_t offset = lock_word.ForwardingAddress();
244 DCHECK_LT(offset, image_end_);
245 return offset;
246 }
247
SetImageBinSlot(mirror::Object * object,BinSlot bin_slot)248 void ImageWriter::SetImageBinSlot(mirror::Object* object, BinSlot bin_slot) {
249 DCHECK(object != nullptr);
250 DCHECK(!IsImageOffsetAssigned(object));
251 DCHECK(!IsImageBinSlotAssigned(object));
252
253 // Before we stomp over the lock word, save the hash code for later.
254 Monitor::Deflate(Thread::Current(), object);;
255 LockWord lw(object->GetLockWord(false));
256 switch (lw.GetState()) {
257 case LockWord::kFatLocked: {
258 LOG(FATAL) << "Fat locked object " << object << " found during object copy";
259 break;
260 }
261 case LockWord::kThinLocked: {
262 LOG(FATAL) << "Thin locked object " << object << " found during object copy";
263 break;
264 }
265 case LockWord::kUnlocked:
266 // No hash, don't need to save it.
267 break;
268 case LockWord::kHashCode:
269 saved_hashes_map_[bin_slot] = lw.GetHashCode();
270 break;
271 default:
272 LOG(FATAL) << "Unreachable.";
273 break;
274 }
275 object->SetLockWord(LockWord::FromForwardingAddress(static_cast<uint32_t>(bin_slot)),
276 false);
277 DCHECK(IsImageBinSlotAssigned(object));
278 }
279
AssignImageBinSlot(mirror::Object * object)280 void ImageWriter::AssignImageBinSlot(mirror::Object* object) {
281 DCHECK(object != nullptr);
282 size_t object_size;
283 if (object->IsArtMethod()) {
284 // Methods are sized based on the target pointer size.
285 object_size = mirror::ArtMethod::InstanceSize(target_ptr_size_);
286 } else {
287 object_size = object->SizeOf();
288 }
289
290 // The magic happens here. We segregate objects into different bins based
291 // on how likely they are to get dirty at runtime.
292 //
293 // Likely-to-dirty objects get packed together into the same bin so that
294 // at runtime their page dirtiness ratio (how many dirty objects a page has) is
295 // maximized.
296 //
297 // This means more pages will stay either clean or shared dirty (with zygote) and
298 // the app will use less of its own (private) memory.
299 Bin bin = kBinRegular;
300
301 if (kBinObjects) {
302 //
303 // Changing the bin of an object is purely a memory-use tuning.
304 // It has no change on runtime correctness.
305 //
306 // Memory analysis has determined that the following types of objects get dirtied
307 // the most:
308 //
309 // * Class'es which are verified [their clinit runs only at runtime]
310 // - classes in general [because their static fields get overwritten]
311 // - initialized classes with all-final statics are unlikely to be ever dirty,
312 // so bin them separately
313 // * Art Methods that are:
314 // - native [their native entry point is not looked up until runtime]
315 // - have declaring classes that aren't initialized
316 // [their interpreter/quick entry points are trampolines until the class
317 // becomes initialized]
318 //
319 // We also assume the following objects get dirtied either never or extremely rarely:
320 // * Strings (they are immutable)
321 // * Art methods that aren't native and have initialized declared classes
322 //
323 // We assume that "regular" bin objects are highly unlikely to become dirtied,
324 // so packing them together will not result in a noticeably tighter dirty-to-clean ratio.
325 //
326 if (object->IsClass()) {
327 bin = kBinClassVerified;
328 mirror::Class* klass = object->AsClass();
329
330 if (klass->GetStatus() == Class::kStatusInitialized) {
331 bin = kBinClassInitialized;
332
333 // If the class's static fields are all final, put it into a separate bin
334 // since it's very likely it will stay clean.
335 uint32_t num_static_fields = klass->NumStaticFields();
336 if (num_static_fields == 0) {
337 bin = kBinClassInitializedFinalStatics;
338 } else {
339 // Maybe all the statics are final?
340 bool all_final = true;
341 for (uint32_t i = 0; i < num_static_fields; ++i) {
342 ArtField* field = klass->GetStaticField(i);
343 if (!field->IsFinal()) {
344 all_final = false;
345 break;
346 }
347 }
348
349 if (all_final) {
350 bin = kBinClassInitializedFinalStatics;
351 }
352 }
353 }
354 } else if (object->IsArtMethod<kVerifyNone>()) {
355 mirror::ArtMethod* art_method = down_cast<ArtMethod*>(object);
356 if (art_method->IsNative()) {
357 bin = kBinArtMethodNative;
358 } else {
359 mirror::Class* declaring_class = art_method->GetDeclaringClass();
360 if (declaring_class->GetStatus() != Class::kStatusInitialized) {
361 bin = kBinArtMethodNotInitialized;
362 } else {
363 // This is highly unlikely to dirty since there's no entry points to mutate.
364 bin = kBinArtMethodsManagedInitialized;
365 }
366 }
367 } else if (object->GetClass<kVerifyNone>()->IsStringClass()) {
368 bin = kBinString; // Strings are almost always immutable (except for object header).
369 } // else bin = kBinRegular
370 }
371
372 size_t current_offset = bin_slot_sizes_[bin]; // How many bytes the current bin is at (aligned).
373 // Move the current bin size up to accomodate the object we just assigned a bin slot.
374 size_t offset_delta = RoundUp(object_size, kObjectAlignment); // 64-bit alignment
375 bin_slot_sizes_[bin] += offset_delta;
376
377 BinSlot new_bin_slot(bin, current_offset);
378 SetImageBinSlot(object, new_bin_slot);
379
380 ++bin_slot_count_[bin];
381
382 DCHECK_LT(GetBinSizeSum(), image_->Size());
383
384 // Grow the image closer to the end by the object we just assigned.
385 image_end_ += offset_delta;
386 DCHECK_LT(image_end_, image_->Size());
387 }
388
IsImageBinSlotAssigned(mirror::Object * object) const389 bool ImageWriter::IsImageBinSlotAssigned(mirror::Object* object) const {
390 DCHECK(object != nullptr);
391
392 // We always stash the bin slot into a lockword, in the 'forwarding address' state.
393 // If it's in some other state, then we haven't yet assigned an image bin slot.
394 if (object->GetLockWord(false).GetState() != LockWord::kForwardingAddress) {
395 return false;
396 } else if (kIsDebugBuild) {
397 LockWord lock_word = object->GetLockWord(false);
398 size_t offset = lock_word.ForwardingAddress();
399 BinSlot bin_slot(offset);
400 DCHECK_LT(bin_slot.GetIndex(), bin_slot_sizes_[bin_slot.GetBin()])
401 << "bin slot offset should not exceed the size of that bin";
402 }
403 return true;
404 }
405
GetImageBinSlot(mirror::Object * object) const406 ImageWriter::BinSlot ImageWriter::GetImageBinSlot(mirror::Object* object) const {
407 DCHECK(object != nullptr);
408 DCHECK(IsImageBinSlotAssigned(object));
409
410 LockWord lock_word = object->GetLockWord(false);
411 size_t offset = lock_word.ForwardingAddress(); // TODO: ForwardingAddress should be uint32_t
412 DCHECK_LE(offset, std::numeric_limits<uint32_t>::max());
413
414 BinSlot bin_slot(static_cast<uint32_t>(offset));
415 DCHECK_LT(bin_slot.GetIndex(), bin_slot_sizes_[bin_slot.GetBin()]);
416
417 return bin_slot;
418 }
419
AllocMemory()420 bool ImageWriter::AllocMemory() {
421 size_t length = RoundUp(Runtime::Current()->GetHeap()->GetTotalMemory(), kPageSize);
422 std::string error_msg;
423 image_.reset(MemMap::MapAnonymous("image writer image", NULL, length, PROT_READ | PROT_WRITE,
424 true, &error_msg));
425 if (UNLIKELY(image_.get() == nullptr)) {
426 LOG(ERROR) << "Failed to allocate memory for image file generation: " << error_msg;
427 return false;
428 }
429
430 // Create the image bitmap.
431 image_bitmap_.reset(gc::accounting::ContinuousSpaceBitmap::Create("image bitmap", image_->Begin(),
432 length));
433 if (image_bitmap_.get() == nullptr) {
434 LOG(ERROR) << "Failed to allocate memory for image bitmap";
435 return false;
436 }
437 return true;
438 }
439
ComputeLazyFieldsForImageClasses()440 void ImageWriter::ComputeLazyFieldsForImageClasses() {
441 ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
442 class_linker->VisitClassesWithoutClassesLock(ComputeLazyFieldsForClassesVisitor, NULL);
443 }
444
ComputeLazyFieldsForClassesVisitor(Class * c,void *)445 bool ImageWriter::ComputeLazyFieldsForClassesVisitor(Class* c, void* /*arg*/) {
446 Thread* self = Thread::Current();
447 StackHandleScope<1> hs(self);
448 mirror::Class::ComputeName(hs.NewHandle(c));
449 return true;
450 }
451
452 // Count the number of strings in the heap and put the result in arg as a size_t pointer.
CountStringsCallback(Object * obj,void * arg)453 static void CountStringsCallback(Object* obj, void* arg)
454 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
455 if (obj->GetClass()->IsStringClass()) {
456 ++*reinterpret_cast<size_t*>(arg);
457 }
458 }
459
460 // Collect all the java.lang.String in the heap and put them in the output strings_ array.
461 class StringCollector {
462 public:
StringCollector(Handle<mirror::ObjectArray<mirror::String>> strings,size_t index)463 StringCollector(Handle<mirror::ObjectArray<mirror::String>> strings, size_t index)
464 : strings_(strings), index_(index) {
465 }
Callback(Object * obj,void * arg)466 static void Callback(Object* obj, void* arg) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
467 auto* collector = reinterpret_cast<StringCollector*>(arg);
468 if (obj->GetClass()->IsStringClass()) {
469 collector->strings_->SetWithoutChecks<false>(collector->index_++, obj->AsString());
470 }
471 }
GetIndex() const472 size_t GetIndex() const {
473 return index_;
474 }
475
476 private:
477 Handle<mirror::ObjectArray<mirror::String>> strings_;
478 size_t index_;
479 };
480
481 // Compare strings based on length, used for sorting strings by length / reverse length.
482 class StringLengthComparator {
483 public:
StringLengthComparator(Handle<mirror::ObjectArray<mirror::String>> strings)484 explicit StringLengthComparator(Handle<mirror::ObjectArray<mirror::String>> strings)
485 : strings_(strings) {
486 }
operator ()(size_t a,size_t b) const487 bool operator()(size_t a, size_t b) const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
488 return strings_->GetWithoutChecks(a)->GetLength() < strings_->GetWithoutChecks(b)->GetLength();
489 }
490
491 private:
492 Handle<mirror::ObjectArray<mirror::String>> strings_;
493 };
494
495 // Normal string < comparison through the chars_ array.
496 class SubstringComparator {
497 public:
SubstringComparator(const std::vector<uint16_t> * const chars)498 explicit SubstringComparator(const std::vector<uint16_t>* const chars) : chars_(chars) {
499 }
operator ()(const std::pair<size_t,size_t> & a,const std::pair<size_t,size_t> & b)500 bool operator()(const std::pair<size_t, size_t>& a, const std::pair<size_t, size_t>& b) {
501 return std::lexicographical_compare(chars_->begin() + a.first,
502 chars_->begin() + a.first + a.second,
503 chars_->begin() + b.first,
504 chars_->begin() + b.first + b.second);
505 }
506
507 private:
508 const std::vector<uint16_t>* const chars_;
509 };
510
ProcessStrings()511 void ImageWriter::ProcessStrings() {
512 size_t total_strings = 0;
513 gc::Heap* heap = Runtime::Current()->GetHeap();
514 ClassLinker* cl = Runtime::Current()->GetClassLinker();
515 {
516 ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_);
517 heap->VisitObjects(CountStringsCallback, &total_strings); // Count the strings.
518 }
519 Thread* self = Thread::Current();
520 StackHandleScope<1> hs(self);
521 auto strings = hs.NewHandle(cl->AllocStringArray(self, total_strings));
522 StringCollector string_collector(strings, 0U);
523 {
524 ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_);
525 // Read strings into the array.
526 heap->VisitObjects(StringCollector::Callback, &string_collector);
527 }
528 // Some strings could have gotten freed if AllocStringArray caused a GC.
529 CHECK_LE(string_collector.GetIndex(), total_strings);
530 total_strings = string_collector.GetIndex();
531 size_t total_length = 0;
532 std::vector<size_t> reverse_sorted_strings;
533 for (size_t i = 0; i < total_strings; ++i) {
534 mirror::String* s = strings->GetWithoutChecks(i);
535 // Look up the string in the array.
536 total_length += s->GetLength();
537 reverse_sorted_strings.push_back(i);
538 }
539 // Sort by reverse length.
540 StringLengthComparator comparator(strings);
541 std::sort(reverse_sorted_strings.rbegin(), reverse_sorted_strings.rend(), comparator);
542 // Deduplicate prefixes and add strings to the char array.
543 std::vector<uint16_t> combined_chars(total_length, 0U);
544 size_t num_chars = 0;
545 // Characters of strings which are non equal prefix of another string (not the same string).
546 // We don't count the savings from equal strings since these would get interned later anyways.
547 size_t prefix_saved_chars = 0;
548 std::set<std::pair<size_t, size_t>, SubstringComparator> existing_strings((
549 SubstringComparator(&combined_chars)));
550 for (size_t i = 0; i < total_strings; ++i) {
551 mirror::String* s = strings->GetWithoutChecks(reverse_sorted_strings[i]);
552 // Add the string to the end of the char array.
553 size_t length = s->GetLength();
554 for (size_t j = 0; j < length; ++j) {
555 combined_chars[num_chars++] = s->CharAt(j);
556 }
557 // Try to see if the string exists as a prefix of an existing string.
558 size_t new_offset = 0;
559 std::pair<size_t, size_t> new_string(num_chars - length, length);
560 auto it = existing_strings.lower_bound(new_string);
561 bool is_prefix = true;
562 if (it == existing_strings.end()) {
563 is_prefix = false;
564 } else {
565 CHECK_LE(length, it->second);
566 for (size_t j = 0; j < length; ++j) {
567 if (combined_chars[it->first + j] != s->CharAt(j)) {
568 is_prefix = false;
569 break;
570 }
571 }
572 }
573 if (is_prefix) {
574 // Shares a prefix, set the offset to where the new offset will be.
575 new_offset = it->first;
576 // Remove the added chars.
577 num_chars -= length;
578 if (it->second != length) {
579 prefix_saved_chars += length;
580 }
581 } else {
582 new_offset = new_string.first;
583 existing_strings.insert(new_string);
584 }
585 s->SetOffset(new_offset);
586 }
587 // Allocate and update the char arrays.
588 auto* array = mirror::CharArray::Alloc(self, num_chars);
589 for (size_t i = 0; i < num_chars; ++i) {
590 array->SetWithoutChecks<false>(i, combined_chars[i]);
591 }
592 for (size_t i = 0; i < total_strings; ++i) {
593 strings->GetWithoutChecks(i)->SetArray(array);
594 }
595 if (kIsDebugBuild || VLOG_IS_ON(compiler)) {
596 LOG(INFO) << "Total # image strings=" << total_strings << " combined length="
597 << total_length << " prefix saved chars=" << prefix_saved_chars;
598 }
599 ComputeEagerResolvedStrings();
600 }
601
ComputeEagerResolvedStringsCallback(Object * obj,void * arg)602 void ImageWriter::ComputeEagerResolvedStringsCallback(Object* obj, void* arg) {
603 if (!obj->GetClass()->IsStringClass()) {
604 return;
605 }
606 mirror::String* string = obj->AsString();
607 const uint16_t* utf16_string = string->GetCharArray()->GetData() + string->GetOffset();
608 ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
609 ReaderMutexLock mu(Thread::Current(), *class_linker->DexLock());
610 size_t dex_cache_count = class_linker->GetDexCacheCount();
611 for (size_t i = 0; i < dex_cache_count; ++i) {
612 DexCache* dex_cache = class_linker->GetDexCache(i);
613 const DexFile& dex_file = *dex_cache->GetDexFile();
614 const DexFile::StringId* string_id;
615 if (UNLIKELY(string->GetLength() == 0)) {
616 string_id = dex_file.FindStringId("");
617 } else {
618 string_id = dex_file.FindStringId(utf16_string);
619 }
620 if (string_id != nullptr) {
621 // This string occurs in this dex file, assign the dex cache entry.
622 uint32_t string_idx = dex_file.GetIndexForStringId(*string_id);
623 if (dex_cache->GetResolvedString(string_idx) == NULL) {
624 dex_cache->SetResolvedString(string_idx, string);
625 }
626 }
627 }
628 }
629
ComputeEagerResolvedStrings()630 void ImageWriter::ComputeEagerResolvedStrings() {
631 ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_);
632 Runtime::Current()->GetHeap()->VisitObjects(ComputeEagerResolvedStringsCallback, this);
633 }
634
IsImageClass(Class * klass)635 bool ImageWriter::IsImageClass(Class* klass) {
636 std::string temp;
637 return compiler_driver_.IsImageClass(klass->GetDescriptor(&temp));
638 }
639
640 struct NonImageClasses {
641 ImageWriter* image_writer;
642 std::set<std::string>* non_image_classes;
643 };
644
PruneNonImageClasses()645 void ImageWriter::PruneNonImageClasses() {
646 if (compiler_driver_.GetImageClasses() == NULL) {
647 return;
648 }
649 Runtime* runtime = Runtime::Current();
650 ClassLinker* class_linker = runtime->GetClassLinker();
651
652 // Make a list of classes we would like to prune.
653 std::set<std::string> non_image_classes;
654 NonImageClasses context;
655 context.image_writer = this;
656 context.non_image_classes = &non_image_classes;
657 class_linker->VisitClasses(NonImageClassesVisitor, &context);
658
659 // Remove the undesired classes from the class roots.
660 for (const std::string& it : non_image_classes) {
661 bool result = class_linker->RemoveClass(it.c_str(), NULL);
662 DCHECK(result);
663 }
664
665 // Clear references to removed classes from the DexCaches.
666 ArtMethod* resolution_method = runtime->GetResolutionMethod();
667 ReaderMutexLock mu(Thread::Current(), *class_linker->DexLock());
668 size_t dex_cache_count = class_linker->GetDexCacheCount();
669 for (size_t idx = 0; idx < dex_cache_count; ++idx) {
670 DexCache* dex_cache = class_linker->GetDexCache(idx);
671 for (size_t i = 0; i < dex_cache->NumResolvedTypes(); i++) {
672 Class* klass = dex_cache->GetResolvedType(i);
673 if (klass != NULL && !IsImageClass(klass)) {
674 dex_cache->SetResolvedType(i, NULL);
675 }
676 }
677 for (size_t i = 0; i < dex_cache->NumResolvedMethods(); i++) {
678 ArtMethod* method = dex_cache->GetResolvedMethod(i);
679 if (method != NULL && !IsImageClass(method->GetDeclaringClass())) {
680 dex_cache->SetResolvedMethod(i, resolution_method);
681 }
682 }
683 for (size_t i = 0; i < dex_cache->NumResolvedFields(); i++) {
684 ArtField* field = dex_cache->GetResolvedField(i);
685 if (field != NULL && !IsImageClass(field->GetDeclaringClass())) {
686 dex_cache->SetResolvedField(i, NULL);
687 }
688 }
689 }
690 }
691
NonImageClassesVisitor(Class * klass,void * arg)692 bool ImageWriter::NonImageClassesVisitor(Class* klass, void* arg) {
693 NonImageClasses* context = reinterpret_cast<NonImageClasses*>(arg);
694 if (!context->image_writer->IsImageClass(klass)) {
695 std::string temp;
696 context->non_image_classes->insert(klass->GetDescriptor(&temp));
697 }
698 return true;
699 }
700
CheckNonImageClassesRemoved()701 void ImageWriter::CheckNonImageClassesRemoved() {
702 if (compiler_driver_.GetImageClasses() != nullptr) {
703 gc::Heap* heap = Runtime::Current()->GetHeap();
704 ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_);
705 heap->VisitObjects(CheckNonImageClassesRemovedCallback, this);
706 }
707 }
708
CheckNonImageClassesRemovedCallback(Object * obj,void * arg)709 void ImageWriter::CheckNonImageClassesRemovedCallback(Object* obj, void* arg) {
710 ImageWriter* image_writer = reinterpret_cast<ImageWriter*>(arg);
711 if (obj->IsClass()) {
712 Class* klass = obj->AsClass();
713 if (!image_writer->IsImageClass(klass)) {
714 image_writer->DumpImageClasses();
715 std::string temp;
716 CHECK(image_writer->IsImageClass(klass)) << klass->GetDescriptor(&temp)
717 << " " << PrettyDescriptor(klass);
718 }
719 }
720 }
721
DumpImageClasses()722 void ImageWriter::DumpImageClasses() {
723 const std::set<std::string>* image_classes = compiler_driver_.GetImageClasses();
724 CHECK(image_classes != NULL);
725 for (const std::string& image_class : *image_classes) {
726 LOG(INFO) << " " << image_class;
727 }
728 }
729
CalculateObjectBinSlots(Object * obj)730 void ImageWriter::CalculateObjectBinSlots(Object* obj) {
731 DCHECK(obj != NULL);
732 // if it is a string, we want to intern it if its not interned.
733 if (obj->GetClass()->IsStringClass()) {
734 // we must be an interned string that was forward referenced and already assigned
735 if (IsImageBinSlotAssigned(obj)) {
736 DCHECK_EQ(obj, obj->AsString()->Intern());
737 return;
738 }
739 mirror::String* const interned = obj->AsString()->Intern();
740 if (obj != interned) {
741 if (!IsImageBinSlotAssigned(interned)) {
742 // interned obj is after us, allocate its location early
743 AssignImageBinSlot(interned);
744 }
745 // point those looking for this object to the interned version.
746 SetImageBinSlot(obj, GetImageBinSlot(interned));
747 return;
748 }
749 // else (obj == interned), nothing to do but fall through to the normal case
750 }
751
752 AssignImageBinSlot(obj);
753 }
754
CreateImageRoots() const755 ObjectArray<Object>* ImageWriter::CreateImageRoots() const {
756 Runtime* runtime = Runtime::Current();
757 ClassLinker* class_linker = runtime->GetClassLinker();
758 Thread* self = Thread::Current();
759 StackHandleScope<3> hs(self);
760 Handle<Class> object_array_class(hs.NewHandle(
761 class_linker->FindSystemClass(self, "[Ljava/lang/Object;")));
762
763 // build an Object[] of all the DexCaches used in the source_space_.
764 // Since we can't hold the dex lock when allocating the dex_caches
765 // ObjectArray, we lock the dex lock twice, first to get the number
766 // of dex caches first and then lock it again to copy the dex
767 // caches. We check that the number of dex caches does not change.
768 size_t dex_cache_count;
769 {
770 ReaderMutexLock mu(Thread::Current(), *class_linker->DexLock());
771 dex_cache_count = class_linker->GetDexCacheCount();
772 }
773 Handle<ObjectArray<Object>> dex_caches(
774 hs.NewHandle(ObjectArray<Object>::Alloc(self, object_array_class.Get(),
775 dex_cache_count)));
776 CHECK(dex_caches.Get() != nullptr) << "Failed to allocate a dex cache array.";
777 {
778 ReaderMutexLock mu(Thread::Current(), *class_linker->DexLock());
779 CHECK_EQ(dex_cache_count, class_linker->GetDexCacheCount())
780 << "The number of dex caches changed.";
781 for (size_t i = 0; i < dex_cache_count; ++i) {
782 dex_caches->Set<false>(i, class_linker->GetDexCache(i));
783 }
784 }
785
786 // build an Object[] of the roots needed to restore the runtime
787 Handle<ObjectArray<Object>> image_roots(hs.NewHandle(
788 ObjectArray<Object>::Alloc(self, object_array_class.Get(), ImageHeader::kImageRootsMax)));
789 image_roots->Set<false>(ImageHeader::kResolutionMethod, runtime->GetResolutionMethod());
790 image_roots->Set<false>(ImageHeader::kImtConflictMethod, runtime->GetImtConflictMethod());
791 image_roots->Set<false>(ImageHeader::kImtUnimplementedMethod,
792 runtime->GetImtUnimplementedMethod());
793 image_roots->Set<false>(ImageHeader::kDefaultImt, runtime->GetDefaultImt());
794 image_roots->Set<false>(ImageHeader::kCalleeSaveMethod,
795 runtime->GetCalleeSaveMethod(Runtime::kSaveAll));
796 image_roots->Set<false>(ImageHeader::kRefsOnlySaveMethod,
797 runtime->GetCalleeSaveMethod(Runtime::kRefsOnly));
798 image_roots->Set<false>(ImageHeader::kRefsAndArgsSaveMethod,
799 runtime->GetCalleeSaveMethod(Runtime::kRefsAndArgs));
800 image_roots->Set<false>(ImageHeader::kDexCaches, dex_caches.Get());
801 image_roots->Set<false>(ImageHeader::kClassRoots, class_linker->GetClassRoots());
802 for (int i = 0; i < ImageHeader::kImageRootsMax; i++) {
803 CHECK(image_roots->Get(i) != NULL);
804 }
805 return image_roots.Get();
806 }
807
808 // Walk instance fields of the given Class. Separate function to allow recursion on the super
809 // class.
WalkInstanceFields(mirror::Object * obj,mirror::Class * klass)810 void ImageWriter::WalkInstanceFields(mirror::Object* obj, mirror::Class* klass) {
811 // Visit fields of parent classes first.
812 StackHandleScope<1> hs(Thread::Current());
813 Handle<mirror::Class> h_class(hs.NewHandle(klass));
814 mirror::Class* super = h_class->GetSuperClass();
815 if (super != nullptr) {
816 WalkInstanceFields(obj, super);
817 }
818 //
819 size_t num_reference_fields = h_class->NumReferenceInstanceFields();
820 MemberOffset field_offset = h_class->GetFirstReferenceInstanceFieldOffset();
821 for (size_t i = 0; i < num_reference_fields; ++i) {
822 mirror::Object* value = obj->GetFieldObject<mirror::Object>(field_offset);
823 if (value != nullptr) {
824 WalkFieldsInOrder(value);
825 }
826 field_offset = MemberOffset(field_offset.Uint32Value() +
827 sizeof(mirror::HeapReference<mirror::Object>));
828 }
829 }
830
831 // For an unvisited object, visit it then all its children found via fields.
WalkFieldsInOrder(mirror::Object * obj)832 void ImageWriter::WalkFieldsInOrder(mirror::Object* obj) {
833 // Use our own visitor routine (instead of GC visitor) to get better locality between
834 // an object and its fields
835 if (!IsImageBinSlotAssigned(obj)) {
836 // Walk instance fields of all objects
837 StackHandleScope<2> hs(Thread::Current());
838 Handle<mirror::Object> h_obj(hs.NewHandle(obj));
839 Handle<mirror::Class> klass(hs.NewHandle(obj->GetClass()));
840 // visit the object itself.
841 CalculateObjectBinSlots(h_obj.Get());
842 WalkInstanceFields(h_obj.Get(), klass.Get());
843 // Walk static fields of a Class.
844 if (h_obj->IsClass()) {
845 size_t num_static_fields = klass->NumReferenceStaticFields();
846 MemberOffset field_offset = klass->GetFirstReferenceStaticFieldOffset();
847 for (size_t i = 0; i < num_static_fields; ++i) {
848 mirror::Object* value = h_obj->GetFieldObject<mirror::Object>(field_offset);
849 if (value != nullptr) {
850 WalkFieldsInOrder(value);
851 }
852 field_offset = MemberOffset(field_offset.Uint32Value() +
853 sizeof(mirror::HeapReference<mirror::Object>));
854 }
855 } else if (h_obj->IsObjectArray()) {
856 // Walk elements of an object array.
857 int32_t length = h_obj->AsObjectArray<mirror::Object>()->GetLength();
858 for (int32_t i = 0; i < length; i++) {
859 mirror::ObjectArray<mirror::Object>* obj_array = h_obj->AsObjectArray<mirror::Object>();
860 mirror::Object* value = obj_array->Get(i);
861 if (value != nullptr) {
862 WalkFieldsInOrder(value);
863 }
864 }
865 }
866 }
867 }
868
WalkFieldsCallback(mirror::Object * obj,void * arg)869 void ImageWriter::WalkFieldsCallback(mirror::Object* obj, void* arg) {
870 ImageWriter* writer = reinterpret_cast<ImageWriter*>(arg);
871 DCHECK(writer != nullptr);
872 writer->WalkFieldsInOrder(obj);
873 }
874
UnbinObjectsIntoOffsetCallback(mirror::Object * obj,void * arg)875 void ImageWriter::UnbinObjectsIntoOffsetCallback(mirror::Object* obj, void* arg) {
876 ImageWriter* writer = reinterpret_cast<ImageWriter*>(arg);
877 DCHECK(writer != nullptr);
878 writer->UnbinObjectsIntoOffset(obj);
879 }
880
UnbinObjectsIntoOffset(mirror::Object * obj)881 void ImageWriter::UnbinObjectsIntoOffset(mirror::Object* obj) {
882 CHECK(obj != nullptr);
883
884 // We know the bin slot, and the total bin sizes for all objects by now,
885 // so calculate the object's final image offset.
886
887 DCHECK(IsImageBinSlotAssigned(obj));
888 BinSlot bin_slot = GetImageBinSlot(obj);
889 // Change the lockword from a bin slot into an offset
890 AssignImageOffset(obj, bin_slot);
891 }
892
CalculateNewObjectOffsets(size_t oat_loaded_size,size_t oat_data_offset)893 void ImageWriter::CalculateNewObjectOffsets(size_t oat_loaded_size, size_t oat_data_offset) {
894 CHECK_NE(0U, oat_loaded_size);
895 Thread* self = Thread::Current();
896 StackHandleScope<1> hs(self);
897 Handle<ObjectArray<Object>> image_roots(hs.NewHandle(CreateImageRoots()));
898
899 gc::Heap* heap = Runtime::Current()->GetHeap();
900 DCHECK_EQ(0U, image_end_);
901
902 // Leave space for the header, but do not write it yet, we need to
903 // know where image_roots is going to end up
904 image_end_ += RoundUp(sizeof(ImageHeader), kObjectAlignment); // 64-bit-alignment
905
906 {
907 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_);
908 // TODO: Image spaces only?
909 const char* old = self->StartAssertNoThreadSuspension("ImageWriter");
910 DCHECK_LT(image_end_, image_->Size());
911 image_objects_offset_begin_ = image_end_;
912 // Clear any pre-existing monitors which may have been in the monitor words, assign bin slots.
913 heap->VisitObjects(WalkFieldsCallback, this);
914 // Transform each object's bin slot into an offset which will be used to do the final copy.
915 heap->VisitObjects(UnbinObjectsIntoOffsetCallback, this);
916 DCHECK(saved_hashes_map_.empty()); // All binslot hashes should've been put into vector by now.
917 self->EndAssertNoThreadSuspension(old);
918 }
919
920 DCHECK_GT(image_end_, GetBinSizeSum());
921
922 if (kIsDebugBuild) {
923 LOG(INFO) << "Bin summary (total size: " << GetBinSizeSum() << "): ";
924 for (size_t bin = 0; bin < kBinSize; ++bin) {
925 LOG(INFO) << " bin# " << bin << ", number objects: " << bin_slot_count_[bin] << ", "
926 << " total byte size: " << bin_slot_sizes_[bin];
927 }
928 }
929
930 const byte* oat_file_begin = image_begin_ + RoundUp(image_end_, kPageSize);
931 const byte* oat_file_end = oat_file_begin + oat_loaded_size;
932 oat_data_begin_ = oat_file_begin + oat_data_offset;
933 const byte* oat_data_end = oat_data_begin_ + oat_file_->Size();
934
935 // Return to write header at start of image with future location of image_roots. At this point,
936 // image_end_ is the size of the image (excluding bitmaps).
937 const size_t heap_bytes_per_bitmap_byte = kBitsPerByte * kObjectAlignment;
938 const size_t bitmap_bytes = RoundUp(image_end_, heap_bytes_per_bitmap_byte) /
939 heap_bytes_per_bitmap_byte;
940 ImageHeader image_header(PointerToLowMemUInt32(image_begin_),
941 static_cast<uint32_t>(image_end_),
942 RoundUp(image_end_, kPageSize),
943 RoundUp(bitmap_bytes, kPageSize),
944 PointerToLowMemUInt32(GetImageAddress(image_roots.Get())),
945 oat_file_->GetOatHeader().GetChecksum(),
946 PointerToLowMemUInt32(oat_file_begin),
947 PointerToLowMemUInt32(oat_data_begin_),
948 PointerToLowMemUInt32(oat_data_end),
949 PointerToLowMemUInt32(oat_file_end),
950 compile_pic_);
951 memcpy(image_->Begin(), &image_header, sizeof(image_header));
952
953 // Note that image_end_ is left at end of used space
954 }
955
CopyAndFixupObjects()956 void ImageWriter::CopyAndFixupObjects() {
957 Thread* self = Thread::Current();
958 const char* old_cause = self->StartAssertNoThreadSuspension("ImageWriter");
959 gc::Heap* heap = Runtime::Current()->GetHeap();
960 // TODO: heap validation can't handle this fix up pass
961 heap->DisableObjectValidation();
962 // TODO: Image spaces only?
963 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_);
964 heap->VisitObjects(CopyAndFixupObjectsCallback, this);
965 // Fix up the object previously had hash codes.
966 for (const std::pair<mirror::Object*, uint32_t>& hash_pair : saved_hashes_) {
967 hash_pair.first->SetLockWord(LockWord::FromHashCode(hash_pair.second), false);
968 }
969 saved_hashes_.clear();
970 self->EndAssertNoThreadSuspension(old_cause);
971 }
972
CopyAndFixupObjectsCallback(Object * obj,void * arg)973 void ImageWriter::CopyAndFixupObjectsCallback(Object* obj, void* arg) {
974 DCHECK(obj != nullptr);
975 DCHECK(arg != nullptr);
976 ImageWriter* image_writer = reinterpret_cast<ImageWriter*>(arg);
977 // see GetLocalAddress for similar computation
978 size_t offset = image_writer->GetImageOffset(obj);
979 byte* dst = image_writer->image_->Begin() + offset;
980 const byte* src = reinterpret_cast<const byte*>(obj);
981 size_t n;
982 if (obj->IsArtMethod()) {
983 // Size without pointer fields since we don't want to overrun the buffer if target art method
984 // is 32 bits but source is 64 bits.
985 n = mirror::ArtMethod::SizeWithoutPointerFields(sizeof(void*));
986 } else {
987 n = obj->SizeOf();
988 }
989 DCHECK_LT(offset + n, image_writer->image_->Size());
990 memcpy(dst, src, n);
991 Object* copy = reinterpret_cast<Object*>(dst);
992 // Write in a hash code of objects which have inflated monitors or a hash code in their monitor
993 // word.
994 copy->SetLockWord(LockWord(), false);
995 image_writer->FixupObject(obj, copy);
996 }
997
998 // Rewrite all the references in the copied object to point to their image address equivalent
999 class FixupVisitor {
1000 public:
FixupVisitor(ImageWriter * image_writer,Object * copy)1001 FixupVisitor(ImageWriter* image_writer, Object* copy) : image_writer_(image_writer), copy_(copy) {
1002 }
1003
operator ()(Object * obj,MemberOffset offset,bool) const1004 void operator()(Object* obj, MemberOffset offset, bool /*is_static*/) const
1005 EXCLUSIVE_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) {
1006 Object* ref = obj->GetFieldObject<Object, kVerifyNone>(offset);
1007 // Use SetFieldObjectWithoutWriteBarrier to avoid card marking since we are writing to the
1008 // image.
1009 copy_->SetFieldObjectWithoutWriteBarrier<false, true, kVerifyNone>(
1010 offset, image_writer_->GetImageAddress(ref));
1011 }
1012
1013 // java.lang.ref.Reference visitor.
operator ()(mirror::Class *,mirror::Reference * ref) const1014 void operator()(mirror::Class* /*klass*/, mirror::Reference* ref) const
1015 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
1016 EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) {
1017 copy_->SetFieldObjectWithoutWriteBarrier<false, true, kVerifyNone>(
1018 mirror::Reference::ReferentOffset(), image_writer_->GetImageAddress(ref->GetReferent()));
1019 }
1020
1021 protected:
1022 ImageWriter* const image_writer_;
1023 mirror::Object* const copy_;
1024 };
1025
1026 class FixupClassVisitor FINAL : public FixupVisitor {
1027 public:
FixupClassVisitor(ImageWriter * image_writer,Object * copy)1028 FixupClassVisitor(ImageWriter* image_writer, Object* copy) : FixupVisitor(image_writer, copy) {
1029 }
1030
operator ()(Object * obj,MemberOffset offset,bool) const1031 void operator()(Object* obj, MemberOffset offset, bool /*is_static*/) const
1032 EXCLUSIVE_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) {
1033 DCHECK(obj->IsClass());
1034 FixupVisitor::operator()(obj, offset, /*is_static*/false);
1035
1036 // TODO: Remove dead code
1037 if (offset.Uint32Value() < mirror::Class::EmbeddedVTableOffset().Uint32Value()) {
1038 return;
1039 }
1040 }
1041
operator ()(mirror::Class *,mirror::Reference * ref) const1042 void operator()(mirror::Class* /*klass*/, mirror::Reference* ref) const
1043 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
1044 EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) {
1045 LOG(FATAL) << "Reference not expected here.";
1046 }
1047 };
1048
FixupObject(Object * orig,Object * copy)1049 void ImageWriter::FixupObject(Object* orig, Object* copy) {
1050 DCHECK(orig != nullptr);
1051 DCHECK(copy != nullptr);
1052 if (kUseBakerOrBrooksReadBarrier) {
1053 orig->AssertReadBarrierPointer();
1054 if (kUseBrooksReadBarrier) {
1055 // Note the address 'copy' isn't the same as the image address of 'orig'.
1056 copy->SetReadBarrierPointer(GetImageAddress(orig));
1057 DCHECK_EQ(copy->GetReadBarrierPointer(), GetImageAddress(orig));
1058 }
1059 }
1060 if (orig->IsClass() && orig->AsClass()->ShouldHaveEmbeddedImtAndVTable()) {
1061 FixupClassVisitor visitor(this, copy);
1062 orig->VisitReferences<true /*visit class*/>(visitor, visitor);
1063 } else {
1064 FixupVisitor visitor(this, copy);
1065 orig->VisitReferences<true /*visit class*/>(visitor, visitor);
1066 }
1067 if (orig->IsArtMethod<kVerifyNone>()) {
1068 FixupMethod(orig->AsArtMethod<kVerifyNone>(), down_cast<ArtMethod*>(copy));
1069 } else if (orig->IsClass() && orig->AsClass()->IsArtMethodClass()) {
1070 // Set the right size for the target.
1071 size_t size = mirror::ArtMethod::InstanceSize(target_ptr_size_);
1072 down_cast<mirror::Class*>(copy)->SetObjectSizeWithoutChecks(size);
1073 }
1074 }
1075
GetQuickCode(mirror::ArtMethod * method,bool * quick_is_interpreted)1076 const byte* ImageWriter::GetQuickCode(mirror::ArtMethod* method, bool* quick_is_interpreted) {
1077 DCHECK(!method->IsResolutionMethod() && !method->IsImtConflictMethod() &&
1078 !method->IsImtUnimplementedMethod() && !method->IsAbstract()) << PrettyMethod(method);
1079
1080 // Use original code if it exists. Otherwise, set the code pointer to the resolution
1081 // trampoline.
1082
1083 // Quick entrypoint:
1084 const byte* quick_code = GetOatAddress(method->GetQuickOatCodeOffset());
1085 *quick_is_interpreted = false;
1086 if (quick_code != nullptr &&
1087 (!method->IsStatic() || method->IsConstructor() || method->GetDeclaringClass()->IsInitialized())) {
1088 // We have code for a non-static or initialized method, just use the code.
1089 } else if (quick_code == nullptr && method->IsNative() &&
1090 (!method->IsStatic() || method->GetDeclaringClass()->IsInitialized())) {
1091 // Non-static or initialized native method missing compiled code, use generic JNI version.
1092 quick_code = GetOatAddress(quick_generic_jni_trampoline_offset_);
1093 } else if (quick_code == nullptr && !method->IsNative()) {
1094 // We don't have code at all for a non-native method, use the interpreter.
1095 quick_code = GetOatAddress(quick_to_interpreter_bridge_offset_);
1096 *quick_is_interpreted = true;
1097 } else {
1098 CHECK(!method->GetDeclaringClass()->IsInitialized());
1099 // We have code for a static method, but need to go through the resolution stub for class
1100 // initialization.
1101 quick_code = GetOatAddress(quick_resolution_trampoline_offset_);
1102 }
1103 return quick_code;
1104 }
1105
GetQuickEntryPoint(mirror::ArtMethod * method)1106 const byte* ImageWriter::GetQuickEntryPoint(mirror::ArtMethod* method) {
1107 // Calculate the quick entry point following the same logic as FixupMethod() below.
1108 // The resolution method has a special trampoline to call.
1109 Runtime* runtime = Runtime::Current();
1110 if (UNLIKELY(method == runtime->GetResolutionMethod())) {
1111 return GetOatAddress(quick_resolution_trampoline_offset_);
1112 } else if (UNLIKELY(method == runtime->GetImtConflictMethod() ||
1113 method == runtime->GetImtUnimplementedMethod())) {
1114 return GetOatAddress(quick_imt_conflict_trampoline_offset_);
1115 } else {
1116 // We assume all methods have code. If they don't currently then we set them to the use the
1117 // resolution trampoline. Abstract methods never have code and so we need to make sure their
1118 // use results in an AbstractMethodError. We use the interpreter to achieve this.
1119 if (UNLIKELY(method->IsAbstract())) {
1120 return GetOatAddress(quick_to_interpreter_bridge_offset_);
1121 } else {
1122 bool quick_is_interpreted;
1123 return GetQuickCode(method, &quick_is_interpreted);
1124 }
1125 }
1126 }
1127
FixupMethod(ArtMethod * orig,ArtMethod * copy)1128 void ImageWriter::FixupMethod(ArtMethod* orig, ArtMethod* copy) {
1129 // OatWriter replaces the code_ with an offset value. Here we re-adjust to a pointer relative to
1130 // oat_begin_
1131 // For 64 bit targets we need to repack the current runtime pointer sized fields to the right
1132 // locations.
1133 // Copy all of the fields from the runtime methods to the target methods first since we did a
1134 // bytewise copy earlier.
1135 #if defined(ART_USE_PORTABLE_COMPILER)
1136 copy->SetEntryPointFromPortableCompiledCodePtrSize<kVerifyNone>(
1137 orig->GetEntryPointFromPortableCompiledCode(), target_ptr_size_);
1138 #endif
1139 copy->SetEntryPointFromInterpreterPtrSize<kVerifyNone>(orig->GetEntryPointFromInterpreter(),
1140 target_ptr_size_);
1141 copy->SetEntryPointFromJniPtrSize<kVerifyNone>(orig->GetEntryPointFromJni(), target_ptr_size_);
1142 copy->SetEntryPointFromQuickCompiledCodePtrSize<kVerifyNone>(
1143 orig->GetEntryPointFromQuickCompiledCode(), target_ptr_size_);
1144
1145 // The resolution method has a special trampoline to call.
1146 Runtime* runtime = Runtime::Current();
1147 if (UNLIKELY(orig == runtime->GetResolutionMethod())) {
1148 #if defined(ART_USE_PORTABLE_COMPILER)
1149 copy->SetEntryPointFromPortableCompiledCodePtrSize<kVerifyNone>(
1150 GetOatAddress(portable_resolution_trampoline_offset_), target_ptr_size_);
1151 #endif
1152 copy->SetEntryPointFromQuickCompiledCodePtrSize<kVerifyNone>(
1153 GetOatAddress(quick_resolution_trampoline_offset_), target_ptr_size_);
1154 } else if (UNLIKELY(orig == runtime->GetImtConflictMethod() ||
1155 orig == runtime->GetImtUnimplementedMethod())) {
1156 #if defined(ART_USE_PORTABLE_COMPILER)
1157 copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(
1158 GetOatAddress(portable_imt_conflict_trampoline_offset_), target_ptr_size_);
1159 #endif
1160 copy->SetEntryPointFromQuickCompiledCodePtrSize<kVerifyNone>(
1161 GetOatAddress(quick_imt_conflict_trampoline_offset_), target_ptr_size_);
1162 } else {
1163 // We assume all methods have code. If they don't currently then we set them to the use the
1164 // resolution trampoline. Abstract methods never have code and so we need to make sure their
1165 // use results in an AbstractMethodError. We use the interpreter to achieve this.
1166 if (UNLIKELY(orig->IsAbstract())) {
1167 #if defined(ART_USE_PORTABLE_COMPILER)
1168 copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(
1169 GetOatAddress(portable_to_interpreter_bridge_offset_), target_ptr_size_);
1170 #endif
1171 copy->SetEntryPointFromQuickCompiledCodePtrSize<kVerifyNone>(
1172 GetOatAddress(quick_to_interpreter_bridge_offset_), target_ptr_size_);
1173 copy->SetEntryPointFromInterpreterPtrSize<kVerifyNone>(
1174 reinterpret_cast<EntryPointFromInterpreter*>(const_cast<byte*>(
1175 GetOatAddress(interpreter_to_interpreter_bridge_offset_))), target_ptr_size_);
1176 } else {
1177 bool quick_is_interpreted;
1178 const byte* quick_code = GetQuickCode(orig, &quick_is_interpreted);
1179 copy->SetEntryPointFromQuickCompiledCodePtrSize<kVerifyNone>(quick_code, target_ptr_size_);
1180
1181 // Portable entrypoint:
1182 bool portable_is_interpreted = false;
1183 #if defined(ART_USE_PORTABLE_COMPILER)
1184 const byte* portable_code = GetOatAddress(orig->GetPortableOatCodeOffset());
1185 if (portable_code != nullptr && (!orig->IsStatic() || orig->IsConstructor() ||
1186 orig->GetDeclaringClass()->IsInitialized())) {
1187 // We have code for a non-static or initialized method, just use the code.
1188 } else if (portable_code == nullptr && orig->IsNative() &&
1189 (!orig->IsStatic() || orig->GetDeclaringClass()->IsInitialized())) {
1190 // Non-static or initialized native method missing compiled code, use generic JNI version.
1191 // TODO: generic JNI support for LLVM.
1192 portable_code = GetOatAddress(portable_resolution_trampoline_offset_);
1193 } else if (portable_code == nullptr && !orig->IsNative()) {
1194 // We don't have code at all for a non-native method, use the interpreter.
1195 portable_code = GetOatAddress(portable_to_interpreter_bridge_offset_);
1196 portable_is_interpreted = true;
1197 } else {
1198 CHECK(!orig->GetDeclaringClass()->IsInitialized());
1199 // We have code for a static method, but need to go through the resolution stub for class
1200 // initialization.
1201 portable_code = GetOatAddress(portable_resolution_trampoline_offset_);
1202 }
1203 copy->SetEntryPointFromPortableCompiledCodePtrSize<kVerifyNone>(
1204 portable_code, target_ptr_size_);
1205 #endif
1206 // JNI entrypoint:
1207 if (orig->IsNative()) {
1208 // The native method's pointer is set to a stub to lookup via dlsym.
1209 // Note this is not the code_ pointer, that is handled above.
1210 copy->SetEntryPointFromJniPtrSize<kVerifyNone>(GetOatAddress(jni_dlsym_lookup_offset_),
1211 target_ptr_size_);
1212 }
1213
1214 // Interpreter entrypoint:
1215 // Set the interpreter entrypoint depending on whether there is compiled code or not.
1216 uint32_t interpreter_code = (quick_is_interpreted && portable_is_interpreted)
1217 ? interpreter_to_interpreter_bridge_offset_
1218 : interpreter_to_compiled_code_bridge_offset_;
1219 EntryPointFromInterpreter* interpreter_entrypoint =
1220 reinterpret_cast<EntryPointFromInterpreter*>(
1221 const_cast<byte*>(GetOatAddress(interpreter_code)));
1222 copy->SetEntryPointFromInterpreterPtrSize<kVerifyNone>(
1223 interpreter_entrypoint, target_ptr_size_);
1224 }
1225 }
1226 }
1227
GetOatHeaderFromElf(ElfFile * elf)1228 static OatHeader* GetOatHeaderFromElf(ElfFile* elf) {
1229 Elf32_Shdr* data_sec = elf->FindSectionByName(".rodata");
1230 if (data_sec == nullptr) {
1231 return nullptr;
1232 }
1233 return reinterpret_cast<OatHeader*>(elf->Begin() + data_sec->sh_offset);
1234 }
1235
PatchOatCodeAndMethods(File * elf_file)1236 void ImageWriter::PatchOatCodeAndMethods(File* elf_file) {
1237 std::string error_msg;
1238 std::unique_ptr<ElfFile> elf(ElfFile::Open(elf_file, PROT_READ|PROT_WRITE,
1239 MAP_SHARED, &error_msg));
1240 if (elf.get() == nullptr) {
1241 LOG(FATAL) << "Unable patch oat file: " << error_msg;
1242 return;
1243 }
1244 if (!ElfPatcher::Patch(&compiler_driver_, elf.get(), oat_file_,
1245 reinterpret_cast<uintptr_t>(oat_data_begin_),
1246 GetImageAddressCallback, reinterpret_cast<void*>(this),
1247 &error_msg)) {
1248 LOG(FATAL) << "unable to patch oat file: " << error_msg;
1249 return;
1250 }
1251 OatHeader* oat_header = GetOatHeaderFromElf(elf.get());
1252 CHECK(oat_header != nullptr);
1253 CHECK(oat_header->IsValid());
1254
1255 ImageHeader* image_header = reinterpret_cast<ImageHeader*>(image_->Begin());
1256 image_header->SetOatChecksum(oat_header->GetChecksum());
1257 }
1258
GetBinSizeSum(ImageWriter::Bin up_to) const1259 size_t ImageWriter::GetBinSizeSum(ImageWriter::Bin up_to) const {
1260 DCHECK_LE(up_to, kBinSize);
1261 return std::accumulate(&bin_slot_sizes_[0], &bin_slot_sizes_[up_to], /*init*/0);
1262 }
1263
BinSlot(uint32_t lockword)1264 ImageWriter::BinSlot::BinSlot(uint32_t lockword) : lockword_(lockword) {
1265 // These values may need to get updated if more bins are added to the enum Bin
1266 static_assert(kBinBits == 3, "wrong number of bin bits");
1267 static_assert(kBinShift == 29, "wrong number of shift");
1268 static_assert(sizeof(BinSlot) == sizeof(LockWord), "BinSlot/LockWord must have equal sizes");
1269
1270 DCHECK_LT(GetBin(), kBinSize);
1271 DCHECK_ALIGNED(GetIndex(), kObjectAlignment);
1272 }
1273
BinSlot(Bin bin,uint32_t index)1274 ImageWriter::BinSlot::BinSlot(Bin bin, uint32_t index)
1275 : BinSlot(index | (static_cast<uint32_t>(bin) << kBinShift)) {
1276 DCHECK_EQ(index, GetIndex());
1277 }
1278
GetBin() const1279 ImageWriter::Bin ImageWriter::BinSlot::GetBin() const {
1280 return static_cast<Bin>((lockword_ & kBinMask) >> kBinShift);
1281 }
1282
GetIndex() const1283 uint32_t ImageWriter::BinSlot::GetIndex() const {
1284 return lockword_ & ~kBinMask;
1285 }
1286
1287 } // namespace art
1288