1 // Copyright 2011 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "src/v8.h"
6
7 #include "src/base/bits.h"
8 #include "src/base/platform/platform.h"
9 #include "src/full-codegen.h"
10 #include "src/heap/mark-compact.h"
11 #include "src/macro-assembler.h"
12 #include "src/msan.h"
13
14 namespace v8 {
15 namespace internal {
16
17
18 // ----------------------------------------------------------------------------
19 // HeapObjectIterator
20
HeapObjectIterator(PagedSpace * space)21 HeapObjectIterator::HeapObjectIterator(PagedSpace* space) {
22 // You can't actually iterate over the anchor page. It is not a real page,
23 // just an anchor for the double linked page list. Initialize as if we have
24 // reached the end of the anchor page, then the first iteration will move on
25 // to the first page.
26 Initialize(space, NULL, NULL, kAllPagesInSpace, NULL);
27 }
28
29
HeapObjectIterator(PagedSpace * space,HeapObjectCallback size_func)30 HeapObjectIterator::HeapObjectIterator(PagedSpace* space,
31 HeapObjectCallback size_func) {
32 // You can't actually iterate over the anchor page. It is not a real page,
33 // just an anchor for the double linked page list. Initialize the current
34 // address and end as NULL, then the first iteration will move on
35 // to the first page.
36 Initialize(space, NULL, NULL, kAllPagesInSpace, size_func);
37 }
38
39
HeapObjectIterator(Page * page,HeapObjectCallback size_func)40 HeapObjectIterator::HeapObjectIterator(Page* page,
41 HeapObjectCallback size_func) {
42 Space* owner = page->owner();
43 DCHECK(owner == page->heap()->old_pointer_space() ||
44 owner == page->heap()->old_data_space() ||
45 owner == page->heap()->map_space() ||
46 owner == page->heap()->cell_space() ||
47 owner == page->heap()->property_cell_space() ||
48 owner == page->heap()->code_space());
49 Initialize(reinterpret_cast<PagedSpace*>(owner), page->area_start(),
50 page->area_end(), kOnePageOnly, size_func);
51 DCHECK(page->WasSwept() || page->SweepingCompleted());
52 }
53
54
Initialize(PagedSpace * space,Address cur,Address end,HeapObjectIterator::PageMode mode,HeapObjectCallback size_f)55 void HeapObjectIterator::Initialize(PagedSpace* space, Address cur, Address end,
56 HeapObjectIterator::PageMode mode,
57 HeapObjectCallback size_f) {
58 space_ = space;
59 cur_addr_ = cur;
60 cur_end_ = end;
61 page_mode_ = mode;
62 size_func_ = size_f;
63 }
64
65
66 // We have hit the end of the page and should advance to the next block of
67 // objects. This happens at the end of the page.
AdvanceToNextPage()68 bool HeapObjectIterator::AdvanceToNextPage() {
69 DCHECK(cur_addr_ == cur_end_);
70 if (page_mode_ == kOnePageOnly) return false;
71 Page* cur_page;
72 if (cur_addr_ == NULL) {
73 cur_page = space_->anchor();
74 } else {
75 cur_page = Page::FromAddress(cur_addr_ - 1);
76 DCHECK(cur_addr_ == cur_page->area_end());
77 }
78 cur_page = cur_page->next_page();
79 if (cur_page == space_->anchor()) return false;
80 cur_addr_ = cur_page->area_start();
81 cur_end_ = cur_page->area_end();
82 DCHECK(cur_page->WasSwept() || cur_page->SweepingCompleted());
83 return true;
84 }
85
86
87 // -----------------------------------------------------------------------------
88 // CodeRange
89
90
CodeRange(Isolate * isolate)91 CodeRange::CodeRange(Isolate* isolate)
92 : isolate_(isolate),
93 code_range_(NULL),
94 free_list_(0),
95 allocation_list_(0),
96 current_allocation_block_index_(0) {}
97
98
SetUp(size_t requested)99 bool CodeRange::SetUp(size_t requested) {
100 DCHECK(code_range_ == NULL);
101
102 if (requested == 0) {
103 // When a target requires the code range feature, we put all code objects
104 // in a kMaximalCodeRangeSize range of virtual address space, so that
105 // they can call each other with near calls.
106 if (kRequiresCodeRange) {
107 requested = kMaximalCodeRangeSize;
108 } else {
109 return true;
110 }
111 }
112
113 DCHECK(!kRequiresCodeRange || requested <= kMaximalCodeRangeSize);
114 code_range_ = new base::VirtualMemory(requested);
115 CHECK(code_range_ != NULL);
116 if (!code_range_->IsReserved()) {
117 delete code_range_;
118 code_range_ = NULL;
119 return false;
120 }
121
122 // We are sure that we have mapped a block of requested addresses.
123 DCHECK(code_range_->size() == requested);
124 LOG(isolate_, NewEvent("CodeRange", code_range_->address(), requested));
125 Address base = reinterpret_cast<Address>(code_range_->address());
126 Address aligned_base =
127 RoundUp(reinterpret_cast<Address>(code_range_->address()),
128 MemoryChunk::kAlignment);
129 size_t size = code_range_->size() - (aligned_base - base);
130 allocation_list_.Add(FreeBlock(aligned_base, size));
131 current_allocation_block_index_ = 0;
132 return true;
133 }
134
135
CompareFreeBlockAddress(const FreeBlock * left,const FreeBlock * right)136 int CodeRange::CompareFreeBlockAddress(const FreeBlock* left,
137 const FreeBlock* right) {
138 // The entire point of CodeRange is that the difference between two
139 // addresses in the range can be represented as a signed 32-bit int,
140 // so the cast is semantically correct.
141 return static_cast<int>(left->start - right->start);
142 }
143
144
GetNextAllocationBlock(size_t requested)145 bool CodeRange::GetNextAllocationBlock(size_t requested) {
146 for (current_allocation_block_index_++;
147 current_allocation_block_index_ < allocation_list_.length();
148 current_allocation_block_index_++) {
149 if (requested <= allocation_list_[current_allocation_block_index_].size) {
150 return true; // Found a large enough allocation block.
151 }
152 }
153
154 // Sort and merge the free blocks on the free list and the allocation list.
155 free_list_.AddAll(allocation_list_);
156 allocation_list_.Clear();
157 free_list_.Sort(&CompareFreeBlockAddress);
158 for (int i = 0; i < free_list_.length();) {
159 FreeBlock merged = free_list_[i];
160 i++;
161 // Add adjacent free blocks to the current merged block.
162 while (i < free_list_.length() &&
163 free_list_[i].start == merged.start + merged.size) {
164 merged.size += free_list_[i].size;
165 i++;
166 }
167 if (merged.size > 0) {
168 allocation_list_.Add(merged);
169 }
170 }
171 free_list_.Clear();
172
173 for (current_allocation_block_index_ = 0;
174 current_allocation_block_index_ < allocation_list_.length();
175 current_allocation_block_index_++) {
176 if (requested <= allocation_list_[current_allocation_block_index_].size) {
177 return true; // Found a large enough allocation block.
178 }
179 }
180 current_allocation_block_index_ = 0;
181 // Code range is full or too fragmented.
182 return false;
183 }
184
185
AllocateRawMemory(const size_t requested_size,const size_t commit_size,size_t * allocated)186 Address CodeRange::AllocateRawMemory(const size_t requested_size,
187 const size_t commit_size,
188 size_t* allocated) {
189 DCHECK(commit_size <= requested_size);
190 DCHECK(allocation_list_.length() == 0 ||
191 current_allocation_block_index_ < allocation_list_.length());
192 if (allocation_list_.length() == 0 ||
193 requested_size > allocation_list_[current_allocation_block_index_].size) {
194 // Find an allocation block large enough.
195 if (!GetNextAllocationBlock(requested_size)) return NULL;
196 }
197 // Commit the requested memory at the start of the current allocation block.
198 size_t aligned_requested = RoundUp(requested_size, MemoryChunk::kAlignment);
199 FreeBlock current = allocation_list_[current_allocation_block_index_];
200 if (aligned_requested >= (current.size - Page::kPageSize)) {
201 // Don't leave a small free block, useless for a large object or chunk.
202 *allocated = current.size;
203 } else {
204 *allocated = aligned_requested;
205 }
206 DCHECK(*allocated <= current.size);
207 DCHECK(IsAddressAligned(current.start, MemoryChunk::kAlignment));
208 if (!isolate_->memory_allocator()->CommitExecutableMemory(
209 code_range_, current.start, commit_size, *allocated)) {
210 *allocated = 0;
211 return NULL;
212 }
213 allocation_list_[current_allocation_block_index_].start += *allocated;
214 allocation_list_[current_allocation_block_index_].size -= *allocated;
215 if (*allocated == current.size) {
216 // This block is used up, get the next one.
217 GetNextAllocationBlock(0);
218 }
219 return current.start;
220 }
221
222
CommitRawMemory(Address start,size_t length)223 bool CodeRange::CommitRawMemory(Address start, size_t length) {
224 return isolate_->memory_allocator()->CommitMemory(start, length, EXECUTABLE);
225 }
226
227
UncommitRawMemory(Address start,size_t length)228 bool CodeRange::UncommitRawMemory(Address start, size_t length) {
229 return code_range_->Uncommit(start, length);
230 }
231
232
FreeRawMemory(Address address,size_t length)233 void CodeRange::FreeRawMemory(Address address, size_t length) {
234 DCHECK(IsAddressAligned(address, MemoryChunk::kAlignment));
235 free_list_.Add(FreeBlock(address, length));
236 code_range_->Uncommit(address, length);
237 }
238
239
TearDown()240 void CodeRange::TearDown() {
241 delete code_range_; // Frees all memory in the virtual memory range.
242 code_range_ = NULL;
243 free_list_.Free();
244 allocation_list_.Free();
245 }
246
247
248 // -----------------------------------------------------------------------------
249 // MemoryAllocator
250 //
251
MemoryAllocator(Isolate * isolate)252 MemoryAllocator::MemoryAllocator(Isolate* isolate)
253 : isolate_(isolate),
254 capacity_(0),
255 capacity_executable_(0),
256 size_(0),
257 size_executable_(0),
258 lowest_ever_allocated_(reinterpret_cast<void*>(-1)),
259 highest_ever_allocated_(reinterpret_cast<void*>(0)) {}
260
261
SetUp(intptr_t capacity,intptr_t capacity_executable)262 bool MemoryAllocator::SetUp(intptr_t capacity, intptr_t capacity_executable) {
263 capacity_ = RoundUp(capacity, Page::kPageSize);
264 capacity_executable_ = RoundUp(capacity_executable, Page::kPageSize);
265 DCHECK_GE(capacity_, capacity_executable_);
266
267 size_ = 0;
268 size_executable_ = 0;
269
270 return true;
271 }
272
273
TearDown()274 void MemoryAllocator::TearDown() {
275 // Check that spaces were torn down before MemoryAllocator.
276 DCHECK(size_ == 0);
277 // TODO(gc) this will be true again when we fix FreeMemory.
278 // DCHECK(size_executable_ == 0);
279 capacity_ = 0;
280 capacity_executable_ = 0;
281 }
282
283
CommitMemory(Address base,size_t size,Executability executable)284 bool MemoryAllocator::CommitMemory(Address base, size_t size,
285 Executability executable) {
286 if (!base::VirtualMemory::CommitRegion(base, size,
287 executable == EXECUTABLE)) {
288 return false;
289 }
290 UpdateAllocatedSpaceLimits(base, base + size);
291 return true;
292 }
293
294
FreeMemory(base::VirtualMemory * reservation,Executability executable)295 void MemoryAllocator::FreeMemory(base::VirtualMemory* reservation,
296 Executability executable) {
297 // TODO(gc) make code_range part of memory allocator?
298 DCHECK(reservation->IsReserved());
299 size_t size = reservation->size();
300 DCHECK(size_ >= size);
301 size_ -= size;
302
303 isolate_->counters()->memory_allocated()->Decrement(static_cast<int>(size));
304
305 if (executable == EXECUTABLE) {
306 DCHECK(size_executable_ >= size);
307 size_executable_ -= size;
308 }
309 // Code which is part of the code-range does not have its own VirtualMemory.
310 DCHECK(isolate_->code_range() == NULL ||
311 !isolate_->code_range()->contains(
312 static_cast<Address>(reservation->address())));
313 DCHECK(executable == NOT_EXECUTABLE || isolate_->code_range() == NULL ||
314 !isolate_->code_range()->valid());
315 reservation->Release();
316 }
317
318
FreeMemory(Address base,size_t size,Executability executable)319 void MemoryAllocator::FreeMemory(Address base, size_t size,
320 Executability executable) {
321 // TODO(gc) make code_range part of memory allocator?
322 DCHECK(size_ >= size);
323 size_ -= size;
324
325 isolate_->counters()->memory_allocated()->Decrement(static_cast<int>(size));
326
327 if (executable == EXECUTABLE) {
328 DCHECK(size_executable_ >= size);
329 size_executable_ -= size;
330 }
331 if (isolate_->code_range() != NULL &&
332 isolate_->code_range()->contains(static_cast<Address>(base))) {
333 DCHECK(executable == EXECUTABLE);
334 isolate_->code_range()->FreeRawMemory(base, size);
335 } else {
336 DCHECK(executable == NOT_EXECUTABLE || isolate_->code_range() == NULL ||
337 !isolate_->code_range()->valid());
338 bool result = base::VirtualMemory::ReleaseRegion(base, size);
339 USE(result);
340 DCHECK(result);
341 }
342 }
343
344
ReserveAlignedMemory(size_t size,size_t alignment,base::VirtualMemory * controller)345 Address MemoryAllocator::ReserveAlignedMemory(size_t size, size_t alignment,
346 base::VirtualMemory* controller) {
347 base::VirtualMemory reservation(size, alignment);
348
349 if (!reservation.IsReserved()) return NULL;
350 size_ += reservation.size();
351 Address base =
352 RoundUp(static_cast<Address>(reservation.address()), alignment);
353 controller->TakeControl(&reservation);
354 return base;
355 }
356
357
AllocateAlignedMemory(size_t reserve_size,size_t commit_size,size_t alignment,Executability executable,base::VirtualMemory * controller)358 Address MemoryAllocator::AllocateAlignedMemory(
359 size_t reserve_size, size_t commit_size, size_t alignment,
360 Executability executable, base::VirtualMemory* controller) {
361 DCHECK(commit_size <= reserve_size);
362 base::VirtualMemory reservation;
363 Address base = ReserveAlignedMemory(reserve_size, alignment, &reservation);
364 if (base == NULL) return NULL;
365
366 if (executable == EXECUTABLE) {
367 if (!CommitExecutableMemory(&reservation, base, commit_size,
368 reserve_size)) {
369 base = NULL;
370 }
371 } else {
372 if (reservation.Commit(base, commit_size, false)) {
373 UpdateAllocatedSpaceLimits(base, base + commit_size);
374 } else {
375 base = NULL;
376 }
377 }
378
379 if (base == NULL) {
380 // Failed to commit the body. Release the mapping and any partially
381 // commited regions inside it.
382 reservation.Release();
383 return NULL;
384 }
385
386 controller->TakeControl(&reservation);
387 return base;
388 }
389
390
InitializeAsAnchor(PagedSpace * owner)391 void Page::InitializeAsAnchor(PagedSpace* owner) {
392 set_owner(owner);
393 set_prev_page(this);
394 set_next_page(this);
395 }
396
397
Initialize(Heap * heap,Address start,SemiSpace * semi_space)398 NewSpacePage* NewSpacePage::Initialize(Heap* heap, Address start,
399 SemiSpace* semi_space) {
400 Address area_start = start + NewSpacePage::kObjectStartOffset;
401 Address area_end = start + Page::kPageSize;
402
403 MemoryChunk* chunk =
404 MemoryChunk::Initialize(heap, start, Page::kPageSize, area_start,
405 area_end, NOT_EXECUTABLE, semi_space);
406 chunk->set_next_chunk(NULL);
407 chunk->set_prev_chunk(NULL);
408 chunk->initialize_scan_on_scavenge(true);
409 bool in_to_space = (semi_space->id() != kFromSpace);
410 chunk->SetFlag(in_to_space ? MemoryChunk::IN_TO_SPACE
411 : MemoryChunk::IN_FROM_SPACE);
412 DCHECK(!chunk->IsFlagSet(in_to_space ? MemoryChunk::IN_FROM_SPACE
413 : MemoryChunk::IN_TO_SPACE));
414 NewSpacePage* page = static_cast<NewSpacePage*>(chunk);
415 heap->incremental_marking()->SetNewSpacePageFlags(page);
416 return page;
417 }
418
419
InitializeAsAnchor(SemiSpace * semi_space)420 void NewSpacePage::InitializeAsAnchor(SemiSpace* semi_space) {
421 set_owner(semi_space);
422 set_next_chunk(this);
423 set_prev_chunk(this);
424 // Flags marks this invalid page as not being in new-space.
425 // All real new-space pages will be in new-space.
426 SetFlags(0, ~0);
427 }
428
429
Initialize(Heap * heap,Address base,size_t size,Address area_start,Address area_end,Executability executable,Space * owner)430 MemoryChunk* MemoryChunk::Initialize(Heap* heap, Address base, size_t size,
431 Address area_start, Address area_end,
432 Executability executable, Space* owner) {
433 MemoryChunk* chunk = FromAddress(base);
434
435 DCHECK(base == chunk->address());
436
437 chunk->heap_ = heap;
438 chunk->size_ = size;
439 chunk->area_start_ = area_start;
440 chunk->area_end_ = area_end;
441 chunk->flags_ = 0;
442 chunk->set_owner(owner);
443 chunk->InitializeReservedMemory();
444 chunk->slots_buffer_ = NULL;
445 chunk->skip_list_ = NULL;
446 chunk->write_barrier_counter_ = kWriteBarrierCounterGranularity;
447 chunk->progress_bar_ = 0;
448 chunk->high_water_mark_ = static_cast<int>(area_start - base);
449 chunk->set_parallel_sweeping(SWEEPING_DONE);
450 chunk->available_in_small_free_list_ = 0;
451 chunk->available_in_medium_free_list_ = 0;
452 chunk->available_in_large_free_list_ = 0;
453 chunk->available_in_huge_free_list_ = 0;
454 chunk->non_available_small_blocks_ = 0;
455 chunk->ResetLiveBytes();
456 Bitmap::Clear(chunk);
457 chunk->initialize_scan_on_scavenge(false);
458 chunk->SetFlag(WAS_SWEPT);
459
460 DCHECK(OFFSET_OF(MemoryChunk, flags_) == kFlagsOffset);
461 DCHECK(OFFSET_OF(MemoryChunk, live_byte_count_) == kLiveBytesOffset);
462
463 if (executable == EXECUTABLE) {
464 chunk->SetFlag(IS_EXECUTABLE);
465 }
466
467 if (owner == heap->old_data_space()) {
468 chunk->SetFlag(CONTAINS_ONLY_DATA);
469 }
470
471 return chunk;
472 }
473
474
475 // Commit MemoryChunk area to the requested size.
CommitArea(size_t requested)476 bool MemoryChunk::CommitArea(size_t requested) {
477 size_t guard_size =
478 IsFlagSet(IS_EXECUTABLE) ? MemoryAllocator::CodePageGuardSize() : 0;
479 size_t header_size = area_start() - address() - guard_size;
480 size_t commit_size =
481 RoundUp(header_size + requested, base::OS::CommitPageSize());
482 size_t committed_size = RoundUp(header_size + (area_end() - area_start()),
483 base::OS::CommitPageSize());
484
485 if (commit_size > committed_size) {
486 // Commit size should be less or equal than the reserved size.
487 DCHECK(commit_size <= size() - 2 * guard_size);
488 // Append the committed area.
489 Address start = address() + committed_size + guard_size;
490 size_t length = commit_size - committed_size;
491 if (reservation_.IsReserved()) {
492 Executability executable =
493 IsFlagSet(IS_EXECUTABLE) ? EXECUTABLE : NOT_EXECUTABLE;
494 if (!heap()->isolate()->memory_allocator()->CommitMemory(start, length,
495 executable)) {
496 return false;
497 }
498 } else {
499 CodeRange* code_range = heap_->isolate()->code_range();
500 DCHECK(code_range != NULL && code_range->valid() &&
501 IsFlagSet(IS_EXECUTABLE));
502 if (!code_range->CommitRawMemory(start, length)) return false;
503 }
504
505 if (Heap::ShouldZapGarbage()) {
506 heap_->isolate()->memory_allocator()->ZapBlock(start, length);
507 }
508 } else if (commit_size < committed_size) {
509 DCHECK(commit_size > 0);
510 // Shrink the committed area.
511 size_t length = committed_size - commit_size;
512 Address start = address() + committed_size + guard_size - length;
513 if (reservation_.IsReserved()) {
514 if (!reservation_.Uncommit(start, length)) return false;
515 } else {
516 CodeRange* code_range = heap_->isolate()->code_range();
517 DCHECK(code_range != NULL && code_range->valid() &&
518 IsFlagSet(IS_EXECUTABLE));
519 if (!code_range->UncommitRawMemory(start, length)) return false;
520 }
521 }
522
523 area_end_ = area_start_ + requested;
524 return true;
525 }
526
527
InsertAfter(MemoryChunk * other)528 void MemoryChunk::InsertAfter(MemoryChunk* other) {
529 MemoryChunk* other_next = other->next_chunk();
530
531 set_next_chunk(other_next);
532 set_prev_chunk(other);
533 other_next->set_prev_chunk(this);
534 other->set_next_chunk(this);
535 }
536
537
Unlink()538 void MemoryChunk::Unlink() {
539 MemoryChunk* next_element = next_chunk();
540 MemoryChunk* prev_element = prev_chunk();
541 next_element->set_prev_chunk(prev_element);
542 prev_element->set_next_chunk(next_element);
543 set_prev_chunk(NULL);
544 set_next_chunk(NULL);
545 }
546
547
AllocateChunk(intptr_t reserve_area_size,intptr_t commit_area_size,Executability executable,Space * owner)548 MemoryChunk* MemoryAllocator::AllocateChunk(intptr_t reserve_area_size,
549 intptr_t commit_area_size,
550 Executability executable,
551 Space* owner) {
552 DCHECK(commit_area_size <= reserve_area_size);
553
554 size_t chunk_size;
555 Heap* heap = isolate_->heap();
556 Address base = NULL;
557 base::VirtualMemory reservation;
558 Address area_start = NULL;
559 Address area_end = NULL;
560
561 //
562 // MemoryChunk layout:
563 //
564 // Executable
565 // +----------------------------+<- base aligned with MemoryChunk::kAlignment
566 // | Header |
567 // +----------------------------+<- base + CodePageGuardStartOffset
568 // | Guard |
569 // +----------------------------+<- area_start_
570 // | Area |
571 // +----------------------------+<- area_end_ (area_start + commit_area_size)
572 // | Committed but not used |
573 // +----------------------------+<- aligned at OS page boundary
574 // | Reserved but not committed |
575 // +----------------------------+<- aligned at OS page boundary
576 // | Guard |
577 // +----------------------------+<- base + chunk_size
578 //
579 // Non-executable
580 // +----------------------------+<- base aligned with MemoryChunk::kAlignment
581 // | Header |
582 // +----------------------------+<- area_start_ (base + kObjectStartOffset)
583 // | Area |
584 // +----------------------------+<- area_end_ (area_start + commit_area_size)
585 // | Committed but not used |
586 // +----------------------------+<- aligned at OS page boundary
587 // | Reserved but not committed |
588 // +----------------------------+<- base + chunk_size
589 //
590
591 if (executable == EXECUTABLE) {
592 chunk_size = RoundUp(CodePageAreaStartOffset() + reserve_area_size,
593 base::OS::CommitPageSize()) +
594 CodePageGuardSize();
595
596 // Check executable memory limit.
597 if (size_executable_ + chunk_size > capacity_executable_) {
598 LOG(isolate_, StringEvent("MemoryAllocator::AllocateRawMemory",
599 "V8 Executable Allocation capacity exceeded"));
600 return NULL;
601 }
602
603 // Size of header (not executable) plus area (executable).
604 size_t commit_size = RoundUp(CodePageGuardStartOffset() + commit_area_size,
605 base::OS::CommitPageSize());
606 // Allocate executable memory either from code range or from the
607 // OS.
608 if (isolate_->code_range() != NULL && isolate_->code_range()->valid()) {
609 base = isolate_->code_range()->AllocateRawMemory(chunk_size, commit_size,
610 &chunk_size);
611 DCHECK(
612 IsAligned(reinterpret_cast<intptr_t>(base), MemoryChunk::kAlignment));
613 if (base == NULL) return NULL;
614 size_ += chunk_size;
615 // Update executable memory size.
616 size_executable_ += chunk_size;
617 } else {
618 base = AllocateAlignedMemory(chunk_size, commit_size,
619 MemoryChunk::kAlignment, executable,
620 &reservation);
621 if (base == NULL) return NULL;
622 // Update executable memory size.
623 size_executable_ += reservation.size();
624 }
625
626 if (Heap::ShouldZapGarbage()) {
627 ZapBlock(base, CodePageGuardStartOffset());
628 ZapBlock(base + CodePageAreaStartOffset(), commit_area_size);
629 }
630
631 area_start = base + CodePageAreaStartOffset();
632 area_end = area_start + commit_area_size;
633 } else {
634 chunk_size = RoundUp(MemoryChunk::kObjectStartOffset + reserve_area_size,
635 base::OS::CommitPageSize());
636 size_t commit_size =
637 RoundUp(MemoryChunk::kObjectStartOffset + commit_area_size,
638 base::OS::CommitPageSize());
639 base =
640 AllocateAlignedMemory(chunk_size, commit_size, MemoryChunk::kAlignment,
641 executable, &reservation);
642
643 if (base == NULL) return NULL;
644
645 if (Heap::ShouldZapGarbage()) {
646 ZapBlock(base, Page::kObjectStartOffset + commit_area_size);
647 }
648
649 area_start = base + Page::kObjectStartOffset;
650 area_end = area_start + commit_area_size;
651 }
652
653 // Use chunk_size for statistics and callbacks because we assume that they
654 // treat reserved but not-yet committed memory regions of chunks as allocated.
655 isolate_->counters()->memory_allocated()->Increment(
656 static_cast<int>(chunk_size));
657
658 LOG(isolate_, NewEvent("MemoryChunk", base, chunk_size));
659 if (owner != NULL) {
660 ObjectSpace space = static_cast<ObjectSpace>(1 << owner->identity());
661 PerformAllocationCallback(space, kAllocationActionAllocate, chunk_size);
662 }
663
664 MemoryChunk* result = MemoryChunk::Initialize(
665 heap, base, chunk_size, area_start, area_end, executable, owner);
666 result->set_reserved_memory(&reservation);
667 return result;
668 }
669
670
ResetFreeListStatistics()671 void Page::ResetFreeListStatistics() {
672 non_available_small_blocks_ = 0;
673 available_in_small_free_list_ = 0;
674 available_in_medium_free_list_ = 0;
675 available_in_large_free_list_ = 0;
676 available_in_huge_free_list_ = 0;
677 }
678
679
AllocatePage(intptr_t size,PagedSpace * owner,Executability executable)680 Page* MemoryAllocator::AllocatePage(intptr_t size, PagedSpace* owner,
681 Executability executable) {
682 MemoryChunk* chunk = AllocateChunk(size, size, executable, owner);
683
684 if (chunk == NULL) return NULL;
685
686 return Page::Initialize(isolate_->heap(), chunk, executable, owner);
687 }
688
689
AllocateLargePage(intptr_t object_size,Space * owner,Executability executable)690 LargePage* MemoryAllocator::AllocateLargePage(intptr_t object_size,
691 Space* owner,
692 Executability executable) {
693 MemoryChunk* chunk =
694 AllocateChunk(object_size, object_size, executable, owner);
695 if (chunk == NULL) return NULL;
696 return LargePage::Initialize(isolate_->heap(), chunk);
697 }
698
699
Free(MemoryChunk * chunk)700 void MemoryAllocator::Free(MemoryChunk* chunk) {
701 LOG(isolate_, DeleteEvent("MemoryChunk", chunk));
702 if (chunk->owner() != NULL) {
703 ObjectSpace space =
704 static_cast<ObjectSpace>(1 << chunk->owner()->identity());
705 PerformAllocationCallback(space, kAllocationActionFree, chunk->size());
706 }
707
708 isolate_->heap()->RememberUnmappedPage(reinterpret_cast<Address>(chunk),
709 chunk->IsEvacuationCandidate());
710
711 delete chunk->slots_buffer();
712 delete chunk->skip_list();
713
714 base::VirtualMemory* reservation = chunk->reserved_memory();
715 if (reservation->IsReserved()) {
716 FreeMemory(reservation, chunk->executable());
717 } else {
718 FreeMemory(chunk->address(), chunk->size(), chunk->executable());
719 }
720 }
721
722
CommitBlock(Address start,size_t size,Executability executable)723 bool MemoryAllocator::CommitBlock(Address start, size_t size,
724 Executability executable) {
725 if (!CommitMemory(start, size, executable)) return false;
726
727 if (Heap::ShouldZapGarbage()) {
728 ZapBlock(start, size);
729 }
730
731 isolate_->counters()->memory_allocated()->Increment(static_cast<int>(size));
732 return true;
733 }
734
735
UncommitBlock(Address start,size_t size)736 bool MemoryAllocator::UncommitBlock(Address start, size_t size) {
737 if (!base::VirtualMemory::UncommitRegion(start, size)) return false;
738 isolate_->counters()->memory_allocated()->Decrement(static_cast<int>(size));
739 return true;
740 }
741
742
ZapBlock(Address start,size_t size)743 void MemoryAllocator::ZapBlock(Address start, size_t size) {
744 for (size_t s = 0; s + kPointerSize <= size; s += kPointerSize) {
745 Memory::Address_at(start + s) = kZapValue;
746 }
747 }
748
749
PerformAllocationCallback(ObjectSpace space,AllocationAction action,size_t size)750 void MemoryAllocator::PerformAllocationCallback(ObjectSpace space,
751 AllocationAction action,
752 size_t size) {
753 for (int i = 0; i < memory_allocation_callbacks_.length(); ++i) {
754 MemoryAllocationCallbackRegistration registration =
755 memory_allocation_callbacks_[i];
756 if ((registration.space & space) == space &&
757 (registration.action & action) == action)
758 registration.callback(space, action, static_cast<int>(size));
759 }
760 }
761
762
MemoryAllocationCallbackRegistered(MemoryAllocationCallback callback)763 bool MemoryAllocator::MemoryAllocationCallbackRegistered(
764 MemoryAllocationCallback callback) {
765 for (int i = 0; i < memory_allocation_callbacks_.length(); ++i) {
766 if (memory_allocation_callbacks_[i].callback == callback) return true;
767 }
768 return false;
769 }
770
771
AddMemoryAllocationCallback(MemoryAllocationCallback callback,ObjectSpace space,AllocationAction action)772 void MemoryAllocator::AddMemoryAllocationCallback(
773 MemoryAllocationCallback callback, ObjectSpace space,
774 AllocationAction action) {
775 DCHECK(callback != NULL);
776 MemoryAllocationCallbackRegistration registration(callback, space, action);
777 DCHECK(!MemoryAllocator::MemoryAllocationCallbackRegistered(callback));
778 return memory_allocation_callbacks_.Add(registration);
779 }
780
781
RemoveMemoryAllocationCallback(MemoryAllocationCallback callback)782 void MemoryAllocator::RemoveMemoryAllocationCallback(
783 MemoryAllocationCallback callback) {
784 DCHECK(callback != NULL);
785 for (int i = 0; i < memory_allocation_callbacks_.length(); ++i) {
786 if (memory_allocation_callbacks_[i].callback == callback) {
787 memory_allocation_callbacks_.Remove(i);
788 return;
789 }
790 }
791 UNREACHABLE();
792 }
793
794
795 #ifdef DEBUG
ReportStatistics()796 void MemoryAllocator::ReportStatistics() {
797 float pct = static_cast<float>(capacity_ - size_) / capacity_;
798 PrintF(" capacity: %" V8_PTR_PREFIX
799 "d"
800 ", used: %" V8_PTR_PREFIX
801 "d"
802 ", available: %%%d\n\n",
803 capacity_, size_, static_cast<int>(pct * 100));
804 }
805 #endif
806
807
CodePageGuardStartOffset()808 int MemoryAllocator::CodePageGuardStartOffset() {
809 // We are guarding code pages: the first OS page after the header
810 // will be protected as non-writable.
811 return RoundUp(Page::kObjectStartOffset, base::OS::CommitPageSize());
812 }
813
814
CodePageGuardSize()815 int MemoryAllocator::CodePageGuardSize() {
816 return static_cast<int>(base::OS::CommitPageSize());
817 }
818
819
CodePageAreaStartOffset()820 int MemoryAllocator::CodePageAreaStartOffset() {
821 // We are guarding code pages: the first OS page after the header
822 // will be protected as non-writable.
823 return CodePageGuardStartOffset() + CodePageGuardSize();
824 }
825
826
CodePageAreaEndOffset()827 int MemoryAllocator::CodePageAreaEndOffset() {
828 // We are guarding code pages: the last OS page will be protected as
829 // non-writable.
830 return Page::kPageSize - static_cast<int>(base::OS::CommitPageSize());
831 }
832
833
CommitExecutableMemory(base::VirtualMemory * vm,Address start,size_t commit_size,size_t reserved_size)834 bool MemoryAllocator::CommitExecutableMemory(base::VirtualMemory* vm,
835 Address start, size_t commit_size,
836 size_t reserved_size) {
837 // Commit page header (not executable).
838 if (!vm->Commit(start, CodePageGuardStartOffset(), false)) {
839 return false;
840 }
841
842 // Create guard page after the header.
843 if (!vm->Guard(start + CodePageGuardStartOffset())) {
844 return false;
845 }
846
847 // Commit page body (executable).
848 if (!vm->Commit(start + CodePageAreaStartOffset(),
849 commit_size - CodePageGuardStartOffset(), true)) {
850 return false;
851 }
852
853 // Create guard page before the end.
854 if (!vm->Guard(start + reserved_size - CodePageGuardSize())) {
855 return false;
856 }
857
858 UpdateAllocatedSpaceLimits(start, start + CodePageAreaStartOffset() +
859 commit_size -
860 CodePageGuardStartOffset());
861 return true;
862 }
863
864
865 // -----------------------------------------------------------------------------
866 // MemoryChunk implementation
867
IncrementLiveBytesFromMutator(Address address,int by)868 void MemoryChunk::IncrementLiveBytesFromMutator(Address address, int by) {
869 MemoryChunk* chunk = MemoryChunk::FromAddress(address);
870 if (!chunk->InNewSpace() && !static_cast<Page*>(chunk)->WasSwept()) {
871 static_cast<PagedSpace*>(chunk->owner())->IncrementUnsweptFreeBytes(-by);
872 }
873 chunk->IncrementLiveBytes(by);
874 }
875
876
877 // -----------------------------------------------------------------------------
878 // PagedSpace implementation
879
PagedSpace(Heap * heap,intptr_t max_capacity,AllocationSpace id,Executability executable)880 PagedSpace::PagedSpace(Heap* heap, intptr_t max_capacity, AllocationSpace id,
881 Executability executable)
882 : Space(heap, id, executable),
883 free_list_(this),
884 unswept_free_bytes_(0),
885 end_of_unswept_pages_(NULL),
886 emergency_memory_(NULL) {
887 if (id == CODE_SPACE) {
888 area_size_ = heap->isolate()->memory_allocator()->CodePageAreaSize();
889 } else {
890 area_size_ = Page::kPageSize - Page::kObjectStartOffset;
891 }
892 max_capacity_ =
893 (RoundDown(max_capacity, Page::kPageSize) / Page::kPageSize) * AreaSize();
894 accounting_stats_.Clear();
895
896 allocation_info_.set_top(NULL);
897 allocation_info_.set_limit(NULL);
898
899 anchor_.InitializeAsAnchor(this);
900 }
901
902
SetUp()903 bool PagedSpace::SetUp() { return true; }
904
905
HasBeenSetUp()906 bool PagedSpace::HasBeenSetUp() { return true; }
907
908
TearDown()909 void PagedSpace::TearDown() {
910 PageIterator iterator(this);
911 while (iterator.has_next()) {
912 heap()->isolate()->memory_allocator()->Free(iterator.next());
913 }
914 anchor_.set_next_page(&anchor_);
915 anchor_.set_prev_page(&anchor_);
916 accounting_stats_.Clear();
917 }
918
919
CommittedPhysicalMemory()920 size_t PagedSpace::CommittedPhysicalMemory() {
921 if (!base::VirtualMemory::HasLazyCommits()) return CommittedMemory();
922 MemoryChunk::UpdateHighWaterMark(allocation_info_.top());
923 size_t size = 0;
924 PageIterator it(this);
925 while (it.has_next()) {
926 size += it.next()->CommittedPhysicalMemory();
927 }
928 return size;
929 }
930
931
FindObject(Address addr)932 Object* PagedSpace::FindObject(Address addr) {
933 // Note: this function can only be called on iterable spaces.
934 DCHECK(!heap()->mark_compact_collector()->in_use());
935
936 if (!Contains(addr)) return Smi::FromInt(0); // Signaling not found.
937
938 Page* p = Page::FromAddress(addr);
939 HeapObjectIterator it(p, NULL);
940 for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next()) {
941 Address cur = obj->address();
942 Address next = cur + obj->Size();
943 if ((cur <= addr) && (addr < next)) return obj;
944 }
945
946 UNREACHABLE();
947 return Smi::FromInt(0);
948 }
949
950
CanExpand()951 bool PagedSpace::CanExpand() {
952 DCHECK(max_capacity_ % AreaSize() == 0);
953
954 if (Capacity() == max_capacity_) return false;
955
956 DCHECK(Capacity() < max_capacity_);
957
958 // Are we going to exceed capacity for this space?
959 if ((Capacity() + Page::kPageSize) > max_capacity_) return false;
960
961 return true;
962 }
963
964
Expand()965 bool PagedSpace::Expand() {
966 if (!CanExpand()) return false;
967
968 intptr_t size = AreaSize();
969
970 if (anchor_.next_page() == &anchor_) {
971 size = SizeOfFirstPage();
972 }
973
974 Page* p = heap()->isolate()->memory_allocator()->AllocatePage(size, this,
975 executable());
976 if (p == NULL) return false;
977
978 DCHECK(Capacity() <= max_capacity_);
979
980 p->InsertAfter(anchor_.prev_page());
981
982 return true;
983 }
984
985
SizeOfFirstPage()986 intptr_t PagedSpace::SizeOfFirstPage() {
987 // If using an ool constant pool then transfer the constant pool allowance
988 // from the code space to the old pointer space.
989 static const int constant_pool_delta = FLAG_enable_ool_constant_pool ? 48 : 0;
990 int size = 0;
991 switch (identity()) {
992 case OLD_POINTER_SPACE:
993 size = (112 + constant_pool_delta) * kPointerSize * KB;
994 break;
995 case OLD_DATA_SPACE:
996 size = 192 * KB;
997 break;
998 case MAP_SPACE:
999 size = 16 * kPointerSize * KB;
1000 break;
1001 case CELL_SPACE:
1002 size = 16 * kPointerSize * KB;
1003 break;
1004 case PROPERTY_CELL_SPACE:
1005 size = 8 * kPointerSize * KB;
1006 break;
1007 case CODE_SPACE: {
1008 CodeRange* code_range = heap()->isolate()->code_range();
1009 if (code_range != NULL && code_range->valid()) {
1010 // When code range exists, code pages are allocated in a special way
1011 // (from the reserved code range). That part of the code is not yet
1012 // upgraded to handle small pages.
1013 size = AreaSize();
1014 } else {
1015 size = RoundUp((480 - constant_pool_delta) * KB *
1016 FullCodeGenerator::kBootCodeSizeMultiplier / 100,
1017 kPointerSize);
1018 }
1019 break;
1020 }
1021 default:
1022 UNREACHABLE();
1023 }
1024 return Min(size, AreaSize());
1025 }
1026
1027
CountTotalPages()1028 int PagedSpace::CountTotalPages() {
1029 PageIterator it(this);
1030 int count = 0;
1031 while (it.has_next()) {
1032 it.next();
1033 count++;
1034 }
1035 return count;
1036 }
1037
1038
ObtainFreeListStatistics(Page * page,SizeStats * sizes)1039 void PagedSpace::ObtainFreeListStatistics(Page* page, SizeStats* sizes) {
1040 sizes->huge_size_ = page->available_in_huge_free_list();
1041 sizes->small_size_ = page->available_in_small_free_list();
1042 sizes->medium_size_ = page->available_in_medium_free_list();
1043 sizes->large_size_ = page->available_in_large_free_list();
1044 }
1045
1046
ResetFreeListStatistics()1047 void PagedSpace::ResetFreeListStatistics() {
1048 PageIterator page_iterator(this);
1049 while (page_iterator.has_next()) {
1050 Page* page = page_iterator.next();
1051 page->ResetFreeListStatistics();
1052 }
1053 }
1054
1055
IncreaseCapacity(int size)1056 void PagedSpace::IncreaseCapacity(int size) {
1057 accounting_stats_.ExpandSpace(size);
1058 }
1059
1060
ReleasePage(Page * page)1061 void PagedSpace::ReleasePage(Page* page) {
1062 DCHECK(page->LiveBytes() == 0);
1063 DCHECK(AreaSize() == page->area_size());
1064
1065 if (page->WasSwept()) {
1066 intptr_t size = free_list_.EvictFreeListItems(page);
1067 accounting_stats_.AllocateBytes(size);
1068 DCHECK_EQ(AreaSize(), static_cast<int>(size));
1069 } else {
1070 DecreaseUnsweptFreeBytes(page);
1071 }
1072
1073 if (page->IsFlagSet(MemoryChunk::SCAN_ON_SCAVENGE)) {
1074 heap()->decrement_scan_on_scavenge_pages();
1075 page->ClearFlag(MemoryChunk::SCAN_ON_SCAVENGE);
1076 }
1077
1078 DCHECK(!free_list_.ContainsPageFreeListItems(page));
1079
1080 if (Page::FromAllocationTop(allocation_info_.top()) == page) {
1081 allocation_info_.set_top(NULL);
1082 allocation_info_.set_limit(NULL);
1083 }
1084
1085 page->Unlink();
1086 if (page->IsFlagSet(MemoryChunk::CONTAINS_ONLY_DATA)) {
1087 heap()->isolate()->memory_allocator()->Free(page);
1088 } else {
1089 heap()->QueueMemoryChunkForFree(page);
1090 }
1091
1092 DCHECK(Capacity() > 0);
1093 accounting_stats_.ShrinkSpace(AreaSize());
1094 }
1095
1096
CreateEmergencyMemory()1097 void PagedSpace::CreateEmergencyMemory() {
1098 emergency_memory_ = heap()->isolate()->memory_allocator()->AllocateChunk(
1099 AreaSize(), AreaSize(), executable(), this);
1100 }
1101
1102
FreeEmergencyMemory()1103 void PagedSpace::FreeEmergencyMemory() {
1104 Page* page = static_cast<Page*>(emergency_memory_);
1105 DCHECK(page->LiveBytes() == 0);
1106 DCHECK(AreaSize() == page->area_size());
1107 DCHECK(!free_list_.ContainsPageFreeListItems(page));
1108 heap()->isolate()->memory_allocator()->Free(page);
1109 emergency_memory_ = NULL;
1110 }
1111
1112
UseEmergencyMemory()1113 void PagedSpace::UseEmergencyMemory() {
1114 Page* page = Page::Initialize(heap(), emergency_memory_, executable(), this);
1115 page->InsertAfter(anchor_.prev_page());
1116 emergency_memory_ = NULL;
1117 }
1118
1119
1120 #ifdef DEBUG
Print()1121 void PagedSpace::Print() {}
1122 #endif
1123
1124 #ifdef VERIFY_HEAP
Verify(ObjectVisitor * visitor)1125 void PagedSpace::Verify(ObjectVisitor* visitor) {
1126 bool allocation_pointer_found_in_space =
1127 (allocation_info_.top() == allocation_info_.limit());
1128 PageIterator page_iterator(this);
1129 while (page_iterator.has_next()) {
1130 Page* page = page_iterator.next();
1131 CHECK(page->owner() == this);
1132 if (page == Page::FromAllocationTop(allocation_info_.top())) {
1133 allocation_pointer_found_in_space = true;
1134 }
1135 CHECK(page->WasSwept());
1136 HeapObjectIterator it(page, NULL);
1137 Address end_of_previous_object = page->area_start();
1138 Address top = page->area_end();
1139 int black_size = 0;
1140 for (HeapObject* object = it.Next(); object != NULL; object = it.Next()) {
1141 CHECK(end_of_previous_object <= object->address());
1142
1143 // The first word should be a map, and we expect all map pointers to
1144 // be in map space.
1145 Map* map = object->map();
1146 CHECK(map->IsMap());
1147 CHECK(heap()->map_space()->Contains(map));
1148
1149 // Perform space-specific object verification.
1150 VerifyObject(object);
1151
1152 // The object itself should look OK.
1153 object->ObjectVerify();
1154
1155 // All the interior pointers should be contained in the heap.
1156 int size = object->Size();
1157 object->IterateBody(map->instance_type(), size, visitor);
1158 if (Marking::IsBlack(Marking::MarkBitFrom(object))) {
1159 black_size += size;
1160 }
1161
1162 CHECK(object->address() + size <= top);
1163 end_of_previous_object = object->address() + size;
1164 }
1165 CHECK_LE(black_size, page->LiveBytes());
1166 }
1167 CHECK(allocation_pointer_found_in_space);
1168 }
1169 #endif // VERIFY_HEAP
1170
1171 // -----------------------------------------------------------------------------
1172 // NewSpace implementation
1173
1174
SetUp(int reserved_semispace_capacity,int maximum_semispace_capacity)1175 bool NewSpace::SetUp(int reserved_semispace_capacity,
1176 int maximum_semispace_capacity) {
1177 // Set up new space based on the preallocated memory block defined by
1178 // start and size. The provided space is divided into two semi-spaces.
1179 // To support fast containment testing in the new space, the size of
1180 // this chunk must be a power of two and it must be aligned to its size.
1181 int initial_semispace_capacity = heap()->InitialSemiSpaceSize();
1182
1183 size_t size = 2 * reserved_semispace_capacity;
1184 Address base = heap()->isolate()->memory_allocator()->ReserveAlignedMemory(
1185 size, size, &reservation_);
1186 if (base == NULL) return false;
1187
1188 chunk_base_ = base;
1189 chunk_size_ = static_cast<uintptr_t>(size);
1190 LOG(heap()->isolate(), NewEvent("InitialChunk", chunk_base_, chunk_size_));
1191
1192 DCHECK(initial_semispace_capacity <= maximum_semispace_capacity);
1193 DCHECK(base::bits::IsPowerOfTwo32(maximum_semispace_capacity));
1194
1195 // Allocate and set up the histogram arrays if necessary.
1196 allocated_histogram_ = NewArray<HistogramInfo>(LAST_TYPE + 1);
1197 promoted_histogram_ = NewArray<HistogramInfo>(LAST_TYPE + 1);
1198
1199 #define SET_NAME(name) \
1200 allocated_histogram_[name].set_name(#name); \
1201 promoted_histogram_[name].set_name(#name);
1202 INSTANCE_TYPE_LIST(SET_NAME)
1203 #undef SET_NAME
1204
1205 DCHECK(reserved_semispace_capacity == heap()->ReservedSemiSpaceSize());
1206 DCHECK(static_cast<intptr_t>(chunk_size_) >=
1207 2 * heap()->ReservedSemiSpaceSize());
1208 DCHECK(IsAddressAligned(chunk_base_, 2 * reserved_semispace_capacity, 0));
1209
1210 to_space_.SetUp(chunk_base_, initial_semispace_capacity,
1211 maximum_semispace_capacity);
1212 from_space_.SetUp(chunk_base_ + reserved_semispace_capacity,
1213 initial_semispace_capacity, maximum_semispace_capacity);
1214 if (!to_space_.Commit()) {
1215 return false;
1216 }
1217 DCHECK(!from_space_.is_committed()); // No need to use memory yet.
1218
1219 start_ = chunk_base_;
1220 address_mask_ = ~(2 * reserved_semispace_capacity - 1);
1221 object_mask_ = address_mask_ | kHeapObjectTagMask;
1222 object_expected_ = reinterpret_cast<uintptr_t>(start_) | kHeapObjectTag;
1223
1224 ResetAllocationInfo();
1225
1226 return true;
1227 }
1228
1229
TearDown()1230 void NewSpace::TearDown() {
1231 if (allocated_histogram_) {
1232 DeleteArray(allocated_histogram_);
1233 allocated_histogram_ = NULL;
1234 }
1235 if (promoted_histogram_) {
1236 DeleteArray(promoted_histogram_);
1237 promoted_histogram_ = NULL;
1238 }
1239
1240 start_ = NULL;
1241 allocation_info_.set_top(NULL);
1242 allocation_info_.set_limit(NULL);
1243
1244 to_space_.TearDown();
1245 from_space_.TearDown();
1246
1247 LOG(heap()->isolate(), DeleteEvent("InitialChunk", chunk_base_));
1248
1249 DCHECK(reservation_.IsReserved());
1250 heap()->isolate()->memory_allocator()->FreeMemory(&reservation_,
1251 NOT_EXECUTABLE);
1252 chunk_base_ = NULL;
1253 chunk_size_ = 0;
1254 }
1255
1256
Flip()1257 void NewSpace::Flip() { SemiSpace::Swap(&from_space_, &to_space_); }
1258
1259
Grow()1260 void NewSpace::Grow() {
1261 // Double the semispace size but only up to maximum capacity.
1262 DCHECK(TotalCapacity() < MaximumCapacity());
1263 int new_capacity =
1264 Min(MaximumCapacity(), 2 * static_cast<int>(TotalCapacity()));
1265 if (to_space_.GrowTo(new_capacity)) {
1266 // Only grow from space if we managed to grow to-space.
1267 if (!from_space_.GrowTo(new_capacity)) {
1268 // If we managed to grow to-space but couldn't grow from-space,
1269 // attempt to shrink to-space.
1270 if (!to_space_.ShrinkTo(from_space_.TotalCapacity())) {
1271 // We are in an inconsistent state because we could not
1272 // commit/uncommit memory from new space.
1273 V8::FatalProcessOutOfMemory("Failed to grow new space.");
1274 }
1275 }
1276 }
1277 DCHECK_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_);
1278 }
1279
1280
Shrink()1281 void NewSpace::Shrink() {
1282 int new_capacity = Max(InitialTotalCapacity(), 2 * SizeAsInt());
1283 int rounded_new_capacity = RoundUp(new_capacity, Page::kPageSize);
1284 if (rounded_new_capacity < TotalCapacity() &&
1285 to_space_.ShrinkTo(rounded_new_capacity)) {
1286 // Only shrink from-space if we managed to shrink to-space.
1287 from_space_.Reset();
1288 if (!from_space_.ShrinkTo(rounded_new_capacity)) {
1289 // If we managed to shrink to-space but couldn't shrink from
1290 // space, attempt to grow to-space again.
1291 if (!to_space_.GrowTo(from_space_.TotalCapacity())) {
1292 // We are in an inconsistent state because we could not
1293 // commit/uncommit memory from new space.
1294 V8::FatalProcessOutOfMemory("Failed to shrink new space.");
1295 }
1296 }
1297 }
1298 DCHECK_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_);
1299 }
1300
1301
UpdateAllocationInfo()1302 void NewSpace::UpdateAllocationInfo() {
1303 MemoryChunk::UpdateHighWaterMark(allocation_info_.top());
1304 allocation_info_.set_top(to_space_.page_low());
1305 allocation_info_.set_limit(to_space_.page_high());
1306 UpdateInlineAllocationLimit(0);
1307 DCHECK_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_);
1308 }
1309
1310
ResetAllocationInfo()1311 void NewSpace::ResetAllocationInfo() {
1312 to_space_.Reset();
1313 UpdateAllocationInfo();
1314 pages_used_ = 0;
1315 // Clear all mark-bits in the to-space.
1316 NewSpacePageIterator it(&to_space_);
1317 while (it.has_next()) {
1318 Bitmap::Clear(it.next());
1319 }
1320 }
1321
1322
UpdateInlineAllocationLimit(int size_in_bytes)1323 void NewSpace::UpdateInlineAllocationLimit(int size_in_bytes) {
1324 if (heap()->inline_allocation_disabled()) {
1325 // Lowest limit when linear allocation was disabled.
1326 Address high = to_space_.page_high();
1327 Address new_top = allocation_info_.top() + size_in_bytes;
1328 allocation_info_.set_limit(Min(new_top, high));
1329 } else if (inline_allocation_limit_step() == 0) {
1330 // Normal limit is the end of the current page.
1331 allocation_info_.set_limit(to_space_.page_high());
1332 } else {
1333 // Lower limit during incremental marking.
1334 Address high = to_space_.page_high();
1335 Address new_top = allocation_info_.top() + size_in_bytes;
1336 Address new_limit = new_top + inline_allocation_limit_step_;
1337 allocation_info_.set_limit(Min(new_limit, high));
1338 }
1339 DCHECK_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_);
1340 }
1341
1342
AddFreshPage()1343 bool NewSpace::AddFreshPage() {
1344 Address top = allocation_info_.top();
1345 if (NewSpacePage::IsAtStart(top)) {
1346 // The current page is already empty. Don't try to make another.
1347
1348 // We should only get here if someone asks to allocate more
1349 // than what can be stored in a single page.
1350 // TODO(gc): Change the limit on new-space allocation to prevent this
1351 // from happening (all such allocations should go directly to LOSpace).
1352 return false;
1353 }
1354 if (!to_space_.AdvancePage()) {
1355 // Failed to get a new page in to-space.
1356 return false;
1357 }
1358
1359 // Clear remainder of current page.
1360 Address limit = NewSpacePage::FromLimit(top)->area_end();
1361 if (heap()->gc_state() == Heap::SCAVENGE) {
1362 heap()->promotion_queue()->SetNewLimit(limit);
1363 }
1364
1365 int remaining_in_page = static_cast<int>(limit - top);
1366 heap()->CreateFillerObjectAt(top, remaining_in_page);
1367 pages_used_++;
1368 UpdateAllocationInfo();
1369
1370 return true;
1371 }
1372
1373
SlowAllocateRaw(int size_in_bytes)1374 AllocationResult NewSpace::SlowAllocateRaw(int size_in_bytes) {
1375 Address old_top = allocation_info_.top();
1376 Address high = to_space_.page_high();
1377 if (allocation_info_.limit() < high) {
1378 // Either the limit has been lowered because linear allocation was disabled
1379 // or because incremental marking wants to get a chance to do a step. Set
1380 // the new limit accordingly.
1381 Address new_top = old_top + size_in_bytes;
1382 int bytes_allocated = static_cast<int>(new_top - top_on_previous_step_);
1383 heap()->incremental_marking()->Step(bytes_allocated,
1384 IncrementalMarking::GC_VIA_STACK_GUARD);
1385 UpdateInlineAllocationLimit(size_in_bytes);
1386 top_on_previous_step_ = new_top;
1387 return AllocateRaw(size_in_bytes);
1388 } else if (AddFreshPage()) {
1389 // Switched to new page. Try allocating again.
1390 int bytes_allocated = static_cast<int>(old_top - top_on_previous_step_);
1391 heap()->incremental_marking()->Step(bytes_allocated,
1392 IncrementalMarking::GC_VIA_STACK_GUARD);
1393 top_on_previous_step_ = to_space_.page_low();
1394 return AllocateRaw(size_in_bytes);
1395 } else {
1396 return AllocationResult::Retry();
1397 }
1398 }
1399
1400
1401 #ifdef VERIFY_HEAP
1402 // We do not use the SemiSpaceIterator because verification doesn't assume
1403 // that it works (it depends on the invariants we are checking).
Verify()1404 void NewSpace::Verify() {
1405 // The allocation pointer should be in the space or at the very end.
1406 DCHECK_SEMISPACE_ALLOCATION_INFO(allocation_info_, to_space_);
1407
1408 // There should be objects packed in from the low address up to the
1409 // allocation pointer.
1410 Address current = to_space_.first_page()->area_start();
1411 CHECK_EQ(current, to_space_.space_start());
1412
1413 while (current != top()) {
1414 if (!NewSpacePage::IsAtEnd(current)) {
1415 // The allocation pointer should not be in the middle of an object.
1416 CHECK(!NewSpacePage::FromLimit(current)->ContainsLimit(top()) ||
1417 current < top());
1418
1419 HeapObject* object = HeapObject::FromAddress(current);
1420
1421 // The first word should be a map, and we expect all map pointers to
1422 // be in map space.
1423 Map* map = object->map();
1424 CHECK(map->IsMap());
1425 CHECK(heap()->map_space()->Contains(map));
1426
1427 // The object should not be code or a map.
1428 CHECK(!object->IsMap());
1429 CHECK(!object->IsCode());
1430
1431 // The object itself should look OK.
1432 object->ObjectVerify();
1433
1434 // All the interior pointers should be contained in the heap.
1435 VerifyPointersVisitor visitor;
1436 int size = object->Size();
1437 object->IterateBody(map->instance_type(), size, &visitor);
1438
1439 current += size;
1440 } else {
1441 // At end of page, switch to next page.
1442 NewSpacePage* page = NewSpacePage::FromLimit(current)->next_page();
1443 // Next page should be valid.
1444 CHECK(!page->is_anchor());
1445 current = page->area_start();
1446 }
1447 }
1448
1449 // Check semi-spaces.
1450 CHECK_EQ(from_space_.id(), kFromSpace);
1451 CHECK_EQ(to_space_.id(), kToSpace);
1452 from_space_.Verify();
1453 to_space_.Verify();
1454 }
1455 #endif
1456
1457 // -----------------------------------------------------------------------------
1458 // SemiSpace implementation
1459
SetUp(Address start,int initial_capacity,int maximum_capacity)1460 void SemiSpace::SetUp(Address start, int initial_capacity,
1461 int maximum_capacity) {
1462 // Creates a space in the young generation. The constructor does not
1463 // allocate memory from the OS. A SemiSpace is given a contiguous chunk of
1464 // memory of size 'capacity' when set up, and does not grow or shrink
1465 // otherwise. In the mark-compact collector, the memory region of the from
1466 // space is used as the marking stack. It requires contiguous memory
1467 // addresses.
1468 DCHECK(maximum_capacity >= Page::kPageSize);
1469 initial_total_capacity_ = RoundDown(initial_capacity, Page::kPageSize);
1470 total_capacity_ = initial_capacity;
1471 maximum_total_capacity_ = RoundDown(maximum_capacity, Page::kPageSize);
1472 maximum_committed_ = 0;
1473 committed_ = false;
1474 start_ = start;
1475 address_mask_ = ~(maximum_capacity - 1);
1476 object_mask_ = address_mask_ | kHeapObjectTagMask;
1477 object_expected_ = reinterpret_cast<uintptr_t>(start) | kHeapObjectTag;
1478 age_mark_ = start_;
1479 }
1480
1481
TearDown()1482 void SemiSpace::TearDown() {
1483 start_ = NULL;
1484 total_capacity_ = 0;
1485 }
1486
1487
Commit()1488 bool SemiSpace::Commit() {
1489 DCHECK(!is_committed());
1490 int pages = total_capacity_ / Page::kPageSize;
1491 if (!heap()->isolate()->memory_allocator()->CommitBlock(
1492 start_, total_capacity_, executable())) {
1493 return false;
1494 }
1495
1496 NewSpacePage* current = anchor();
1497 for (int i = 0; i < pages; i++) {
1498 NewSpacePage* new_page =
1499 NewSpacePage::Initialize(heap(), start_ + i * Page::kPageSize, this);
1500 new_page->InsertAfter(current);
1501 current = new_page;
1502 }
1503
1504 SetCapacity(total_capacity_);
1505 committed_ = true;
1506 Reset();
1507 return true;
1508 }
1509
1510
Uncommit()1511 bool SemiSpace::Uncommit() {
1512 DCHECK(is_committed());
1513 Address start = start_ + maximum_total_capacity_ - total_capacity_;
1514 if (!heap()->isolate()->memory_allocator()->UncommitBlock(start,
1515 total_capacity_)) {
1516 return false;
1517 }
1518 anchor()->set_next_page(anchor());
1519 anchor()->set_prev_page(anchor());
1520
1521 committed_ = false;
1522 return true;
1523 }
1524
1525
CommittedPhysicalMemory()1526 size_t SemiSpace::CommittedPhysicalMemory() {
1527 if (!is_committed()) return 0;
1528 size_t size = 0;
1529 NewSpacePageIterator it(this);
1530 while (it.has_next()) {
1531 size += it.next()->CommittedPhysicalMemory();
1532 }
1533 return size;
1534 }
1535
1536
GrowTo(int new_capacity)1537 bool SemiSpace::GrowTo(int new_capacity) {
1538 if (!is_committed()) {
1539 if (!Commit()) return false;
1540 }
1541 DCHECK((new_capacity & Page::kPageAlignmentMask) == 0);
1542 DCHECK(new_capacity <= maximum_total_capacity_);
1543 DCHECK(new_capacity > total_capacity_);
1544 int pages_before = total_capacity_ / Page::kPageSize;
1545 int pages_after = new_capacity / Page::kPageSize;
1546
1547 size_t delta = new_capacity - total_capacity_;
1548
1549 DCHECK(IsAligned(delta, base::OS::AllocateAlignment()));
1550 if (!heap()->isolate()->memory_allocator()->CommitBlock(
1551 start_ + total_capacity_, delta, executable())) {
1552 return false;
1553 }
1554 SetCapacity(new_capacity);
1555 NewSpacePage* last_page = anchor()->prev_page();
1556 DCHECK(last_page != anchor());
1557 for (int i = pages_before; i < pages_after; i++) {
1558 Address page_address = start_ + i * Page::kPageSize;
1559 NewSpacePage* new_page =
1560 NewSpacePage::Initialize(heap(), page_address, this);
1561 new_page->InsertAfter(last_page);
1562 Bitmap::Clear(new_page);
1563 // Duplicate the flags that was set on the old page.
1564 new_page->SetFlags(last_page->GetFlags(),
1565 NewSpacePage::kCopyOnFlipFlagsMask);
1566 last_page = new_page;
1567 }
1568 return true;
1569 }
1570
1571
ShrinkTo(int new_capacity)1572 bool SemiSpace::ShrinkTo(int new_capacity) {
1573 DCHECK((new_capacity & Page::kPageAlignmentMask) == 0);
1574 DCHECK(new_capacity >= initial_total_capacity_);
1575 DCHECK(new_capacity < total_capacity_);
1576 if (is_committed()) {
1577 size_t delta = total_capacity_ - new_capacity;
1578 DCHECK(IsAligned(delta, base::OS::AllocateAlignment()));
1579
1580 MemoryAllocator* allocator = heap()->isolate()->memory_allocator();
1581 if (!allocator->UncommitBlock(start_ + new_capacity, delta)) {
1582 return false;
1583 }
1584
1585 int pages_after = new_capacity / Page::kPageSize;
1586 NewSpacePage* new_last_page =
1587 NewSpacePage::FromAddress(start_ + (pages_after - 1) * Page::kPageSize);
1588 new_last_page->set_next_page(anchor());
1589 anchor()->set_prev_page(new_last_page);
1590 DCHECK((current_page_ >= first_page()) && (current_page_ <= new_last_page));
1591 }
1592
1593 SetCapacity(new_capacity);
1594
1595 return true;
1596 }
1597
1598
FlipPages(intptr_t flags,intptr_t mask)1599 void SemiSpace::FlipPages(intptr_t flags, intptr_t mask) {
1600 anchor_.set_owner(this);
1601 // Fixup back-pointers to anchor. Address of anchor changes
1602 // when we swap.
1603 anchor_.prev_page()->set_next_page(&anchor_);
1604 anchor_.next_page()->set_prev_page(&anchor_);
1605
1606 bool becomes_to_space = (id_ == kFromSpace);
1607 id_ = becomes_to_space ? kToSpace : kFromSpace;
1608 NewSpacePage* page = anchor_.next_page();
1609 while (page != &anchor_) {
1610 page->set_owner(this);
1611 page->SetFlags(flags, mask);
1612 if (becomes_to_space) {
1613 page->ClearFlag(MemoryChunk::IN_FROM_SPACE);
1614 page->SetFlag(MemoryChunk::IN_TO_SPACE);
1615 page->ClearFlag(MemoryChunk::NEW_SPACE_BELOW_AGE_MARK);
1616 page->ResetLiveBytes();
1617 } else {
1618 page->SetFlag(MemoryChunk::IN_FROM_SPACE);
1619 page->ClearFlag(MemoryChunk::IN_TO_SPACE);
1620 }
1621 DCHECK(page->IsFlagSet(MemoryChunk::SCAN_ON_SCAVENGE));
1622 DCHECK(page->IsFlagSet(MemoryChunk::IN_TO_SPACE) ||
1623 page->IsFlagSet(MemoryChunk::IN_FROM_SPACE));
1624 page = page->next_page();
1625 }
1626 }
1627
1628
Reset()1629 void SemiSpace::Reset() {
1630 DCHECK(anchor_.next_page() != &anchor_);
1631 current_page_ = anchor_.next_page();
1632 }
1633
1634
Swap(SemiSpace * from,SemiSpace * to)1635 void SemiSpace::Swap(SemiSpace* from, SemiSpace* to) {
1636 // We won't be swapping semispaces without data in them.
1637 DCHECK(from->anchor_.next_page() != &from->anchor_);
1638 DCHECK(to->anchor_.next_page() != &to->anchor_);
1639
1640 // Swap bits.
1641 SemiSpace tmp = *from;
1642 *from = *to;
1643 *to = tmp;
1644
1645 // Fixup back-pointers to the page list anchor now that its address
1646 // has changed.
1647 // Swap to/from-space bits on pages.
1648 // Copy GC flags from old active space (from-space) to new (to-space).
1649 intptr_t flags = from->current_page()->GetFlags();
1650 to->FlipPages(flags, NewSpacePage::kCopyOnFlipFlagsMask);
1651
1652 from->FlipPages(0, 0);
1653 }
1654
1655
SetCapacity(int new_capacity)1656 void SemiSpace::SetCapacity(int new_capacity) {
1657 total_capacity_ = new_capacity;
1658 if (total_capacity_ > maximum_committed_) {
1659 maximum_committed_ = total_capacity_;
1660 }
1661 }
1662
1663
set_age_mark(Address mark)1664 void SemiSpace::set_age_mark(Address mark) {
1665 DCHECK(NewSpacePage::FromLimit(mark)->semi_space() == this);
1666 age_mark_ = mark;
1667 // Mark all pages up to the one containing mark.
1668 NewSpacePageIterator it(space_start(), mark);
1669 while (it.has_next()) {
1670 it.next()->SetFlag(MemoryChunk::NEW_SPACE_BELOW_AGE_MARK);
1671 }
1672 }
1673
1674
1675 #ifdef DEBUG
Print()1676 void SemiSpace::Print() {}
1677 #endif
1678
1679 #ifdef VERIFY_HEAP
Verify()1680 void SemiSpace::Verify() {
1681 bool is_from_space = (id_ == kFromSpace);
1682 NewSpacePage* page = anchor_.next_page();
1683 CHECK(anchor_.semi_space() == this);
1684 while (page != &anchor_) {
1685 CHECK(page->semi_space() == this);
1686 CHECK(page->InNewSpace());
1687 CHECK(page->IsFlagSet(is_from_space ? MemoryChunk::IN_FROM_SPACE
1688 : MemoryChunk::IN_TO_SPACE));
1689 CHECK(!page->IsFlagSet(is_from_space ? MemoryChunk::IN_TO_SPACE
1690 : MemoryChunk::IN_FROM_SPACE));
1691 CHECK(page->IsFlagSet(MemoryChunk::POINTERS_TO_HERE_ARE_INTERESTING));
1692 if (!is_from_space) {
1693 // The pointers-from-here-are-interesting flag isn't updated dynamically
1694 // on from-space pages, so it might be out of sync with the marking state.
1695 if (page->heap()->incremental_marking()->IsMarking()) {
1696 CHECK(page->IsFlagSet(MemoryChunk::POINTERS_FROM_HERE_ARE_INTERESTING));
1697 } else {
1698 CHECK(
1699 !page->IsFlagSet(MemoryChunk::POINTERS_FROM_HERE_ARE_INTERESTING));
1700 }
1701 // TODO(gc): Check that the live_bytes_count_ field matches the
1702 // black marking on the page (if we make it match in new-space).
1703 }
1704 CHECK(page->IsFlagSet(MemoryChunk::SCAN_ON_SCAVENGE));
1705 CHECK(page->prev_page()->next_page() == page);
1706 page = page->next_page();
1707 }
1708 }
1709 #endif
1710
1711 #ifdef DEBUG
AssertValidRange(Address start,Address end)1712 void SemiSpace::AssertValidRange(Address start, Address end) {
1713 // Addresses belong to same semi-space
1714 NewSpacePage* page = NewSpacePage::FromLimit(start);
1715 NewSpacePage* end_page = NewSpacePage::FromLimit(end);
1716 SemiSpace* space = page->semi_space();
1717 CHECK_EQ(space, end_page->semi_space());
1718 // Start address is before end address, either on same page,
1719 // or end address is on a later page in the linked list of
1720 // semi-space pages.
1721 if (page == end_page) {
1722 CHECK(start <= end);
1723 } else {
1724 while (page != end_page) {
1725 page = page->next_page();
1726 CHECK_NE(page, space->anchor());
1727 }
1728 }
1729 }
1730 #endif
1731
1732
1733 // -----------------------------------------------------------------------------
1734 // SemiSpaceIterator implementation.
SemiSpaceIterator(NewSpace * space)1735 SemiSpaceIterator::SemiSpaceIterator(NewSpace* space) {
1736 Initialize(space->bottom(), space->top(), NULL);
1737 }
1738
1739
SemiSpaceIterator(NewSpace * space,HeapObjectCallback size_func)1740 SemiSpaceIterator::SemiSpaceIterator(NewSpace* space,
1741 HeapObjectCallback size_func) {
1742 Initialize(space->bottom(), space->top(), size_func);
1743 }
1744
1745
SemiSpaceIterator(NewSpace * space,Address start)1746 SemiSpaceIterator::SemiSpaceIterator(NewSpace* space, Address start) {
1747 Initialize(start, space->top(), NULL);
1748 }
1749
1750
SemiSpaceIterator(Address from,Address to)1751 SemiSpaceIterator::SemiSpaceIterator(Address from, Address to) {
1752 Initialize(from, to, NULL);
1753 }
1754
1755
Initialize(Address start,Address end,HeapObjectCallback size_func)1756 void SemiSpaceIterator::Initialize(Address start, Address end,
1757 HeapObjectCallback size_func) {
1758 SemiSpace::AssertValidRange(start, end);
1759 current_ = start;
1760 limit_ = end;
1761 size_func_ = size_func;
1762 }
1763
1764
1765 #ifdef DEBUG
1766 // heap_histograms is shared, always clear it before using it.
ClearHistograms(Isolate * isolate)1767 static void ClearHistograms(Isolate* isolate) {
1768 // We reset the name each time, though it hasn't changed.
1769 #define DEF_TYPE_NAME(name) isolate->heap_histograms()[name].set_name(#name);
1770 INSTANCE_TYPE_LIST(DEF_TYPE_NAME)
1771 #undef DEF_TYPE_NAME
1772
1773 #define CLEAR_HISTOGRAM(name) isolate->heap_histograms()[name].clear();
1774 INSTANCE_TYPE_LIST(CLEAR_HISTOGRAM)
1775 #undef CLEAR_HISTOGRAM
1776
1777 isolate->js_spill_information()->Clear();
1778 }
1779
1780
ClearCodeKindStatistics(int * code_kind_statistics)1781 static void ClearCodeKindStatistics(int* code_kind_statistics) {
1782 for (int i = 0; i < Code::NUMBER_OF_KINDS; i++) {
1783 code_kind_statistics[i] = 0;
1784 }
1785 }
1786
1787
ReportCodeKindStatistics(int * code_kind_statistics)1788 static void ReportCodeKindStatistics(int* code_kind_statistics) {
1789 PrintF("\n Code kind histograms: \n");
1790 for (int i = 0; i < Code::NUMBER_OF_KINDS; i++) {
1791 if (code_kind_statistics[i] > 0) {
1792 PrintF(" %-20s: %10d bytes\n",
1793 Code::Kind2String(static_cast<Code::Kind>(i)),
1794 code_kind_statistics[i]);
1795 }
1796 }
1797 PrintF("\n");
1798 }
1799
1800
CollectHistogramInfo(HeapObject * obj)1801 static int CollectHistogramInfo(HeapObject* obj) {
1802 Isolate* isolate = obj->GetIsolate();
1803 InstanceType type = obj->map()->instance_type();
1804 DCHECK(0 <= type && type <= LAST_TYPE);
1805 DCHECK(isolate->heap_histograms()[type].name() != NULL);
1806 isolate->heap_histograms()[type].increment_number(1);
1807 isolate->heap_histograms()[type].increment_bytes(obj->Size());
1808
1809 if (FLAG_collect_heap_spill_statistics && obj->IsJSObject()) {
1810 JSObject::cast(obj)
1811 ->IncrementSpillStatistics(isolate->js_spill_information());
1812 }
1813
1814 return obj->Size();
1815 }
1816
1817
ReportHistogram(Isolate * isolate,bool print_spill)1818 static void ReportHistogram(Isolate* isolate, bool print_spill) {
1819 PrintF("\n Object Histogram:\n");
1820 for (int i = 0; i <= LAST_TYPE; i++) {
1821 if (isolate->heap_histograms()[i].number() > 0) {
1822 PrintF(" %-34s%10d (%10d bytes)\n",
1823 isolate->heap_histograms()[i].name(),
1824 isolate->heap_histograms()[i].number(),
1825 isolate->heap_histograms()[i].bytes());
1826 }
1827 }
1828 PrintF("\n");
1829
1830 // Summarize string types.
1831 int string_number = 0;
1832 int string_bytes = 0;
1833 #define INCREMENT(type, size, name, camel_name) \
1834 string_number += isolate->heap_histograms()[type].number(); \
1835 string_bytes += isolate->heap_histograms()[type].bytes();
1836 STRING_TYPE_LIST(INCREMENT)
1837 #undef INCREMENT
1838 if (string_number > 0) {
1839 PrintF(" %-34s%10d (%10d bytes)\n\n", "STRING_TYPE", string_number,
1840 string_bytes);
1841 }
1842
1843 if (FLAG_collect_heap_spill_statistics && print_spill) {
1844 isolate->js_spill_information()->Print();
1845 }
1846 }
1847 #endif // DEBUG
1848
1849
1850 // Support for statistics gathering for --heap-stats and --log-gc.
ClearHistograms()1851 void NewSpace::ClearHistograms() {
1852 for (int i = 0; i <= LAST_TYPE; i++) {
1853 allocated_histogram_[i].clear();
1854 promoted_histogram_[i].clear();
1855 }
1856 }
1857
1858
1859 // Because the copying collector does not touch garbage objects, we iterate
1860 // the new space before a collection to get a histogram of allocated objects.
1861 // This only happens when --log-gc flag is set.
CollectStatistics()1862 void NewSpace::CollectStatistics() {
1863 ClearHistograms();
1864 SemiSpaceIterator it(this);
1865 for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next())
1866 RecordAllocation(obj);
1867 }
1868
1869
DoReportStatistics(Isolate * isolate,HistogramInfo * info,const char * description)1870 static void DoReportStatistics(Isolate* isolate, HistogramInfo* info,
1871 const char* description) {
1872 LOG(isolate, HeapSampleBeginEvent("NewSpace", description));
1873 // Lump all the string types together.
1874 int string_number = 0;
1875 int string_bytes = 0;
1876 #define INCREMENT(type, size, name, camel_name) \
1877 string_number += info[type].number(); \
1878 string_bytes += info[type].bytes();
1879 STRING_TYPE_LIST(INCREMENT)
1880 #undef INCREMENT
1881 if (string_number > 0) {
1882 LOG(isolate,
1883 HeapSampleItemEvent("STRING_TYPE", string_number, string_bytes));
1884 }
1885
1886 // Then do the other types.
1887 for (int i = FIRST_NONSTRING_TYPE; i <= LAST_TYPE; ++i) {
1888 if (info[i].number() > 0) {
1889 LOG(isolate, HeapSampleItemEvent(info[i].name(), info[i].number(),
1890 info[i].bytes()));
1891 }
1892 }
1893 LOG(isolate, HeapSampleEndEvent("NewSpace", description));
1894 }
1895
1896
ReportStatistics()1897 void NewSpace::ReportStatistics() {
1898 #ifdef DEBUG
1899 if (FLAG_heap_stats) {
1900 float pct = static_cast<float>(Available()) / TotalCapacity();
1901 PrintF(" capacity: %" V8_PTR_PREFIX
1902 "d"
1903 ", available: %" V8_PTR_PREFIX "d, %%%d\n",
1904 TotalCapacity(), Available(), static_cast<int>(pct * 100));
1905 PrintF("\n Object Histogram:\n");
1906 for (int i = 0; i <= LAST_TYPE; i++) {
1907 if (allocated_histogram_[i].number() > 0) {
1908 PrintF(" %-34s%10d (%10d bytes)\n", allocated_histogram_[i].name(),
1909 allocated_histogram_[i].number(),
1910 allocated_histogram_[i].bytes());
1911 }
1912 }
1913 PrintF("\n");
1914 }
1915 #endif // DEBUG
1916
1917 if (FLAG_log_gc) {
1918 Isolate* isolate = heap()->isolate();
1919 DoReportStatistics(isolate, allocated_histogram_, "allocated");
1920 DoReportStatistics(isolate, promoted_histogram_, "promoted");
1921 }
1922 }
1923
1924
RecordAllocation(HeapObject * obj)1925 void NewSpace::RecordAllocation(HeapObject* obj) {
1926 InstanceType type = obj->map()->instance_type();
1927 DCHECK(0 <= type && type <= LAST_TYPE);
1928 allocated_histogram_[type].increment_number(1);
1929 allocated_histogram_[type].increment_bytes(obj->Size());
1930 }
1931
1932
RecordPromotion(HeapObject * obj)1933 void NewSpace::RecordPromotion(HeapObject* obj) {
1934 InstanceType type = obj->map()->instance_type();
1935 DCHECK(0 <= type && type <= LAST_TYPE);
1936 promoted_histogram_[type].increment_number(1);
1937 promoted_histogram_[type].increment_bytes(obj->Size());
1938 }
1939
1940
CommittedPhysicalMemory()1941 size_t NewSpace::CommittedPhysicalMemory() {
1942 if (!base::VirtualMemory::HasLazyCommits()) return CommittedMemory();
1943 MemoryChunk::UpdateHighWaterMark(allocation_info_.top());
1944 size_t size = to_space_.CommittedPhysicalMemory();
1945 if (from_space_.is_committed()) {
1946 size += from_space_.CommittedPhysicalMemory();
1947 }
1948 return size;
1949 }
1950
1951
1952 // -----------------------------------------------------------------------------
1953 // Free lists for old object spaces implementation
1954
set_size(Heap * heap,int size_in_bytes)1955 void FreeListNode::set_size(Heap* heap, int size_in_bytes) {
1956 DCHECK(size_in_bytes > 0);
1957 DCHECK(IsAligned(size_in_bytes, kPointerSize));
1958
1959 // We write a map and possibly size information to the block. If the block
1960 // is big enough to be a FreeSpace with at least one extra word (the next
1961 // pointer), we set its map to be the free space map and its size to an
1962 // appropriate array length for the desired size from HeapObject::Size().
1963 // If the block is too small (eg, one or two words), to hold both a size
1964 // field and a next pointer, we give it a filler map that gives it the
1965 // correct size.
1966 if (size_in_bytes > FreeSpace::kHeaderSize) {
1967 // Can't use FreeSpace::cast because it fails during deserialization.
1968 // We have to set the size first with a release store before we store
1969 // the map because a concurrent store buffer scan on scavenge must not
1970 // observe a map with an invalid size.
1971 FreeSpace* this_as_free_space = reinterpret_cast<FreeSpace*>(this);
1972 this_as_free_space->nobarrier_set_size(size_in_bytes);
1973 synchronized_set_map_no_write_barrier(heap->raw_unchecked_free_space_map());
1974 } else if (size_in_bytes == kPointerSize) {
1975 set_map_no_write_barrier(heap->raw_unchecked_one_pointer_filler_map());
1976 } else if (size_in_bytes == 2 * kPointerSize) {
1977 set_map_no_write_barrier(heap->raw_unchecked_two_pointer_filler_map());
1978 } else {
1979 UNREACHABLE();
1980 }
1981 // We would like to DCHECK(Size() == size_in_bytes) but this would fail during
1982 // deserialization because the free space map is not done yet.
1983 }
1984
1985
next()1986 FreeListNode* FreeListNode::next() {
1987 DCHECK(IsFreeListNode(this));
1988 if (map() == GetHeap()->raw_unchecked_free_space_map()) {
1989 DCHECK(map() == NULL || Size() >= kNextOffset + kPointerSize);
1990 return reinterpret_cast<FreeListNode*>(
1991 Memory::Address_at(address() + kNextOffset));
1992 } else {
1993 return reinterpret_cast<FreeListNode*>(
1994 Memory::Address_at(address() + kPointerSize));
1995 }
1996 }
1997
1998
next_address()1999 FreeListNode** FreeListNode::next_address() {
2000 DCHECK(IsFreeListNode(this));
2001 if (map() == GetHeap()->raw_unchecked_free_space_map()) {
2002 DCHECK(Size() >= kNextOffset + kPointerSize);
2003 return reinterpret_cast<FreeListNode**>(address() + kNextOffset);
2004 } else {
2005 return reinterpret_cast<FreeListNode**>(address() + kPointerSize);
2006 }
2007 }
2008
2009
set_next(FreeListNode * next)2010 void FreeListNode::set_next(FreeListNode* next) {
2011 DCHECK(IsFreeListNode(this));
2012 // While we are booting the VM the free space map will actually be null. So
2013 // we have to make sure that we don't try to use it for anything at that
2014 // stage.
2015 if (map() == GetHeap()->raw_unchecked_free_space_map()) {
2016 DCHECK(map() == NULL || Size() >= kNextOffset + kPointerSize);
2017 base::NoBarrier_Store(
2018 reinterpret_cast<base::AtomicWord*>(address() + kNextOffset),
2019 reinterpret_cast<base::AtomicWord>(next));
2020 } else {
2021 base::NoBarrier_Store(
2022 reinterpret_cast<base::AtomicWord*>(address() + kPointerSize),
2023 reinterpret_cast<base::AtomicWord>(next));
2024 }
2025 }
2026
2027
Concatenate(FreeListCategory * category)2028 intptr_t FreeListCategory::Concatenate(FreeListCategory* category) {
2029 intptr_t free_bytes = 0;
2030 if (category->top() != NULL) {
2031 // This is safe (not going to deadlock) since Concatenate operations
2032 // are never performed on the same free lists at the same time in
2033 // reverse order.
2034 base::LockGuard<base::Mutex> target_lock_guard(mutex());
2035 base::LockGuard<base::Mutex> source_lock_guard(category->mutex());
2036 DCHECK(category->end_ != NULL);
2037 free_bytes = category->available();
2038 if (end_ == NULL) {
2039 end_ = category->end();
2040 } else {
2041 category->end()->set_next(top());
2042 }
2043 set_top(category->top());
2044 base::NoBarrier_Store(&top_, category->top_);
2045 available_ += category->available();
2046 category->Reset();
2047 }
2048 return free_bytes;
2049 }
2050
2051
Reset()2052 void FreeListCategory::Reset() {
2053 set_top(NULL);
2054 set_end(NULL);
2055 set_available(0);
2056 }
2057
2058
EvictFreeListItemsInList(Page * p)2059 intptr_t FreeListCategory::EvictFreeListItemsInList(Page* p) {
2060 int sum = 0;
2061 FreeListNode* t = top();
2062 FreeListNode** n = &t;
2063 while (*n != NULL) {
2064 if (Page::FromAddress((*n)->address()) == p) {
2065 FreeSpace* free_space = reinterpret_cast<FreeSpace*>(*n);
2066 sum += free_space->Size();
2067 *n = (*n)->next();
2068 } else {
2069 n = (*n)->next_address();
2070 }
2071 }
2072 set_top(t);
2073 if (top() == NULL) {
2074 set_end(NULL);
2075 }
2076 available_ -= sum;
2077 return sum;
2078 }
2079
2080
ContainsPageFreeListItemsInList(Page * p)2081 bool FreeListCategory::ContainsPageFreeListItemsInList(Page* p) {
2082 FreeListNode* node = top();
2083 while (node != NULL) {
2084 if (Page::FromAddress(node->address()) == p) return true;
2085 node = node->next();
2086 }
2087 return false;
2088 }
2089
2090
PickNodeFromList(int * node_size)2091 FreeListNode* FreeListCategory::PickNodeFromList(int* node_size) {
2092 FreeListNode* node = top();
2093
2094 if (node == NULL) return NULL;
2095
2096 while (node != NULL &&
2097 Page::FromAddress(node->address())->IsEvacuationCandidate()) {
2098 available_ -= reinterpret_cast<FreeSpace*>(node)->Size();
2099 node = node->next();
2100 }
2101
2102 if (node != NULL) {
2103 set_top(node->next());
2104 *node_size = reinterpret_cast<FreeSpace*>(node)->Size();
2105 available_ -= *node_size;
2106 } else {
2107 set_top(NULL);
2108 }
2109
2110 if (top() == NULL) {
2111 set_end(NULL);
2112 }
2113
2114 return node;
2115 }
2116
2117
PickNodeFromList(int size_in_bytes,int * node_size)2118 FreeListNode* FreeListCategory::PickNodeFromList(int size_in_bytes,
2119 int* node_size) {
2120 FreeListNode* node = PickNodeFromList(node_size);
2121 if (node != NULL && *node_size < size_in_bytes) {
2122 Free(node, *node_size);
2123 *node_size = 0;
2124 return NULL;
2125 }
2126 return node;
2127 }
2128
2129
Free(FreeListNode * node,int size_in_bytes)2130 void FreeListCategory::Free(FreeListNode* node, int size_in_bytes) {
2131 node->set_next(top());
2132 set_top(node);
2133 if (end_ == NULL) {
2134 end_ = node;
2135 }
2136 available_ += size_in_bytes;
2137 }
2138
2139
RepairFreeList(Heap * heap)2140 void FreeListCategory::RepairFreeList(Heap* heap) {
2141 FreeListNode* n = top();
2142 while (n != NULL) {
2143 Map** map_location = reinterpret_cast<Map**>(n->address());
2144 if (*map_location == NULL) {
2145 *map_location = heap->free_space_map();
2146 } else {
2147 DCHECK(*map_location == heap->free_space_map());
2148 }
2149 n = n->next();
2150 }
2151 }
2152
2153
FreeList(PagedSpace * owner)2154 FreeList::FreeList(PagedSpace* owner) : owner_(owner), heap_(owner->heap()) {
2155 Reset();
2156 }
2157
2158
Concatenate(FreeList * free_list)2159 intptr_t FreeList::Concatenate(FreeList* free_list) {
2160 intptr_t free_bytes = 0;
2161 free_bytes += small_list_.Concatenate(free_list->small_list());
2162 free_bytes += medium_list_.Concatenate(free_list->medium_list());
2163 free_bytes += large_list_.Concatenate(free_list->large_list());
2164 free_bytes += huge_list_.Concatenate(free_list->huge_list());
2165 return free_bytes;
2166 }
2167
2168
Reset()2169 void FreeList::Reset() {
2170 small_list_.Reset();
2171 medium_list_.Reset();
2172 large_list_.Reset();
2173 huge_list_.Reset();
2174 }
2175
2176
Free(Address start,int size_in_bytes)2177 int FreeList::Free(Address start, int size_in_bytes) {
2178 if (size_in_bytes == 0) return 0;
2179
2180 FreeListNode* node = FreeListNode::FromAddress(start);
2181 node->set_size(heap_, size_in_bytes);
2182 Page* page = Page::FromAddress(start);
2183
2184 // Early return to drop too-small blocks on the floor.
2185 if (size_in_bytes < kSmallListMin) {
2186 page->add_non_available_small_blocks(size_in_bytes);
2187 return size_in_bytes;
2188 }
2189
2190 // Insert other blocks at the head of a free list of the appropriate
2191 // magnitude.
2192 if (size_in_bytes <= kSmallListMax) {
2193 small_list_.Free(node, size_in_bytes);
2194 page->add_available_in_small_free_list(size_in_bytes);
2195 } else if (size_in_bytes <= kMediumListMax) {
2196 medium_list_.Free(node, size_in_bytes);
2197 page->add_available_in_medium_free_list(size_in_bytes);
2198 } else if (size_in_bytes <= kLargeListMax) {
2199 large_list_.Free(node, size_in_bytes);
2200 page->add_available_in_large_free_list(size_in_bytes);
2201 } else {
2202 huge_list_.Free(node, size_in_bytes);
2203 page->add_available_in_huge_free_list(size_in_bytes);
2204 }
2205
2206 DCHECK(IsVeryLong() || available() == SumFreeLists());
2207 return 0;
2208 }
2209
2210
FindNodeFor(int size_in_bytes,int * node_size)2211 FreeListNode* FreeList::FindNodeFor(int size_in_bytes, int* node_size) {
2212 FreeListNode* node = NULL;
2213 Page* page = NULL;
2214
2215 if (size_in_bytes <= kSmallAllocationMax) {
2216 node = small_list_.PickNodeFromList(node_size);
2217 if (node != NULL) {
2218 DCHECK(size_in_bytes <= *node_size);
2219 page = Page::FromAddress(node->address());
2220 page->add_available_in_small_free_list(-(*node_size));
2221 DCHECK(IsVeryLong() || available() == SumFreeLists());
2222 return node;
2223 }
2224 }
2225
2226 if (size_in_bytes <= kMediumAllocationMax) {
2227 node = medium_list_.PickNodeFromList(node_size);
2228 if (node != NULL) {
2229 DCHECK(size_in_bytes <= *node_size);
2230 page = Page::FromAddress(node->address());
2231 page->add_available_in_medium_free_list(-(*node_size));
2232 DCHECK(IsVeryLong() || available() == SumFreeLists());
2233 return node;
2234 }
2235 }
2236
2237 if (size_in_bytes <= kLargeAllocationMax) {
2238 node = large_list_.PickNodeFromList(node_size);
2239 if (node != NULL) {
2240 DCHECK(size_in_bytes <= *node_size);
2241 page = Page::FromAddress(node->address());
2242 page->add_available_in_large_free_list(-(*node_size));
2243 DCHECK(IsVeryLong() || available() == SumFreeLists());
2244 return node;
2245 }
2246 }
2247
2248 int huge_list_available = huge_list_.available();
2249 FreeListNode* top_node = huge_list_.top();
2250 for (FreeListNode** cur = &top_node; *cur != NULL;
2251 cur = (*cur)->next_address()) {
2252 FreeListNode* cur_node = *cur;
2253 while (cur_node != NULL &&
2254 Page::FromAddress(cur_node->address())->IsEvacuationCandidate()) {
2255 int size = reinterpret_cast<FreeSpace*>(cur_node)->Size();
2256 huge_list_available -= size;
2257 page = Page::FromAddress(cur_node->address());
2258 page->add_available_in_huge_free_list(-size);
2259 cur_node = cur_node->next();
2260 }
2261
2262 *cur = cur_node;
2263 if (cur_node == NULL) {
2264 huge_list_.set_end(NULL);
2265 break;
2266 }
2267
2268 DCHECK((*cur)->map() == heap_->raw_unchecked_free_space_map());
2269 FreeSpace* cur_as_free_space = reinterpret_cast<FreeSpace*>(*cur);
2270 int size = cur_as_free_space->Size();
2271 if (size >= size_in_bytes) {
2272 // Large enough node found. Unlink it from the list.
2273 node = *cur;
2274 *cur = node->next();
2275 *node_size = size;
2276 huge_list_available -= size;
2277 page = Page::FromAddress(node->address());
2278 page->add_available_in_huge_free_list(-size);
2279 break;
2280 }
2281 }
2282
2283 huge_list_.set_top(top_node);
2284 if (huge_list_.top() == NULL) {
2285 huge_list_.set_end(NULL);
2286 }
2287 huge_list_.set_available(huge_list_available);
2288
2289 if (node != NULL) {
2290 DCHECK(IsVeryLong() || available() == SumFreeLists());
2291 return node;
2292 }
2293
2294 if (size_in_bytes <= kSmallListMax) {
2295 node = small_list_.PickNodeFromList(size_in_bytes, node_size);
2296 if (node != NULL) {
2297 DCHECK(size_in_bytes <= *node_size);
2298 page = Page::FromAddress(node->address());
2299 page->add_available_in_small_free_list(-(*node_size));
2300 }
2301 } else if (size_in_bytes <= kMediumListMax) {
2302 node = medium_list_.PickNodeFromList(size_in_bytes, node_size);
2303 if (node != NULL) {
2304 DCHECK(size_in_bytes <= *node_size);
2305 page = Page::FromAddress(node->address());
2306 page->add_available_in_medium_free_list(-(*node_size));
2307 }
2308 } else if (size_in_bytes <= kLargeListMax) {
2309 node = large_list_.PickNodeFromList(size_in_bytes, node_size);
2310 if (node != NULL) {
2311 DCHECK(size_in_bytes <= *node_size);
2312 page = Page::FromAddress(node->address());
2313 page->add_available_in_large_free_list(-(*node_size));
2314 }
2315 }
2316
2317 DCHECK(IsVeryLong() || available() == SumFreeLists());
2318 return node;
2319 }
2320
2321
2322 // Allocation on the old space free list. If it succeeds then a new linear
2323 // allocation space has been set up with the top and limit of the space. If
2324 // the allocation fails then NULL is returned, and the caller can perform a GC
2325 // or allocate a new page before retrying.
Allocate(int size_in_bytes)2326 HeapObject* FreeList::Allocate(int size_in_bytes) {
2327 DCHECK(0 < size_in_bytes);
2328 DCHECK(size_in_bytes <= kMaxBlockSize);
2329 DCHECK(IsAligned(size_in_bytes, kPointerSize));
2330 // Don't free list allocate if there is linear space available.
2331 DCHECK(owner_->limit() - owner_->top() < size_in_bytes);
2332
2333 int old_linear_size = static_cast<int>(owner_->limit() - owner_->top());
2334 // Mark the old linear allocation area with a free space map so it can be
2335 // skipped when scanning the heap. This also puts it back in the free list
2336 // if it is big enough.
2337 owner_->Free(owner_->top(), old_linear_size);
2338
2339 owner_->heap()->incremental_marking()->OldSpaceStep(size_in_bytes -
2340 old_linear_size);
2341
2342 int new_node_size = 0;
2343 FreeListNode* new_node = FindNodeFor(size_in_bytes, &new_node_size);
2344 if (new_node == NULL) {
2345 owner_->SetTopAndLimit(NULL, NULL);
2346 return NULL;
2347 }
2348
2349 int bytes_left = new_node_size - size_in_bytes;
2350 DCHECK(bytes_left >= 0);
2351
2352 #ifdef DEBUG
2353 for (int i = 0; i < size_in_bytes / kPointerSize; i++) {
2354 reinterpret_cast<Object**>(new_node->address())[i] =
2355 Smi::FromInt(kCodeZapValue);
2356 }
2357 #endif
2358
2359 // The old-space-step might have finished sweeping and restarted marking.
2360 // Verify that it did not turn the page of the new node into an evacuation
2361 // candidate.
2362 DCHECK(!MarkCompactCollector::IsOnEvacuationCandidate(new_node));
2363
2364 const int kThreshold = IncrementalMarking::kAllocatedThreshold;
2365
2366 // Memory in the linear allocation area is counted as allocated. We may free
2367 // a little of this again immediately - see below.
2368 owner_->Allocate(new_node_size);
2369
2370 if (owner_->heap()->inline_allocation_disabled()) {
2371 // Keep the linear allocation area empty if requested to do so, just
2372 // return area back to the free list instead.
2373 owner_->Free(new_node->address() + size_in_bytes, bytes_left);
2374 DCHECK(owner_->top() == NULL && owner_->limit() == NULL);
2375 } else if (bytes_left > kThreshold &&
2376 owner_->heap()->incremental_marking()->IsMarkingIncomplete() &&
2377 FLAG_incremental_marking_steps) {
2378 int linear_size = owner_->RoundSizeDownToObjectAlignment(kThreshold);
2379 // We don't want to give too large linear areas to the allocator while
2380 // incremental marking is going on, because we won't check again whether
2381 // we want to do another increment until the linear area is used up.
2382 owner_->Free(new_node->address() + size_in_bytes + linear_size,
2383 new_node_size - size_in_bytes - linear_size);
2384 owner_->SetTopAndLimit(new_node->address() + size_in_bytes,
2385 new_node->address() + size_in_bytes + linear_size);
2386 } else if (bytes_left > 0) {
2387 // Normally we give the rest of the node to the allocator as its new
2388 // linear allocation area.
2389 owner_->SetTopAndLimit(new_node->address() + size_in_bytes,
2390 new_node->address() + new_node_size);
2391 } else {
2392 // TODO(gc) Try not freeing linear allocation region when bytes_left
2393 // are zero.
2394 owner_->SetTopAndLimit(NULL, NULL);
2395 }
2396
2397 return new_node;
2398 }
2399
2400
EvictFreeListItems(Page * p)2401 intptr_t FreeList::EvictFreeListItems(Page* p) {
2402 intptr_t sum = huge_list_.EvictFreeListItemsInList(p);
2403 p->set_available_in_huge_free_list(0);
2404
2405 if (sum < p->area_size()) {
2406 sum += small_list_.EvictFreeListItemsInList(p) +
2407 medium_list_.EvictFreeListItemsInList(p) +
2408 large_list_.EvictFreeListItemsInList(p);
2409 p->set_available_in_small_free_list(0);
2410 p->set_available_in_medium_free_list(0);
2411 p->set_available_in_large_free_list(0);
2412 }
2413
2414 return sum;
2415 }
2416
2417
ContainsPageFreeListItems(Page * p)2418 bool FreeList::ContainsPageFreeListItems(Page* p) {
2419 return huge_list_.EvictFreeListItemsInList(p) ||
2420 small_list_.EvictFreeListItemsInList(p) ||
2421 medium_list_.EvictFreeListItemsInList(p) ||
2422 large_list_.EvictFreeListItemsInList(p);
2423 }
2424
2425
RepairLists(Heap * heap)2426 void FreeList::RepairLists(Heap* heap) {
2427 small_list_.RepairFreeList(heap);
2428 medium_list_.RepairFreeList(heap);
2429 large_list_.RepairFreeList(heap);
2430 huge_list_.RepairFreeList(heap);
2431 }
2432
2433
2434 #ifdef DEBUG
SumFreeList()2435 intptr_t FreeListCategory::SumFreeList() {
2436 intptr_t sum = 0;
2437 FreeListNode* cur = top();
2438 while (cur != NULL) {
2439 DCHECK(cur->map() == cur->GetHeap()->raw_unchecked_free_space_map());
2440 FreeSpace* cur_as_free_space = reinterpret_cast<FreeSpace*>(cur);
2441 sum += cur_as_free_space->nobarrier_size();
2442 cur = cur->next();
2443 }
2444 return sum;
2445 }
2446
2447
2448 static const int kVeryLongFreeList = 500;
2449
2450
FreeListLength()2451 int FreeListCategory::FreeListLength() {
2452 int length = 0;
2453 FreeListNode* cur = top();
2454 while (cur != NULL) {
2455 length++;
2456 cur = cur->next();
2457 if (length == kVeryLongFreeList) return length;
2458 }
2459 return length;
2460 }
2461
2462
IsVeryLong()2463 bool FreeList::IsVeryLong() {
2464 if (small_list_.FreeListLength() == kVeryLongFreeList) return true;
2465 if (medium_list_.FreeListLength() == kVeryLongFreeList) return true;
2466 if (large_list_.FreeListLength() == kVeryLongFreeList) return true;
2467 if (huge_list_.FreeListLength() == kVeryLongFreeList) return true;
2468 return false;
2469 }
2470
2471
2472 // This can take a very long time because it is linear in the number of entries
2473 // on the free list, so it should not be called if FreeListLength returns
2474 // kVeryLongFreeList.
SumFreeLists()2475 intptr_t FreeList::SumFreeLists() {
2476 intptr_t sum = small_list_.SumFreeList();
2477 sum += medium_list_.SumFreeList();
2478 sum += large_list_.SumFreeList();
2479 sum += huge_list_.SumFreeList();
2480 return sum;
2481 }
2482 #endif
2483
2484
2485 // -----------------------------------------------------------------------------
2486 // OldSpace implementation
2487
PrepareForMarkCompact()2488 void PagedSpace::PrepareForMarkCompact() {
2489 // We don't have a linear allocation area while sweeping. It will be restored
2490 // on the first allocation after the sweep.
2491 EmptyAllocationInfo();
2492
2493 // This counter will be increased for pages which will be swept by the
2494 // sweeper threads.
2495 unswept_free_bytes_ = 0;
2496
2497 // Clear the free list before a full GC---it will be rebuilt afterward.
2498 free_list_.Reset();
2499 }
2500
2501
SizeOfObjects()2502 intptr_t PagedSpace::SizeOfObjects() {
2503 DCHECK(heap()->mark_compact_collector()->sweeping_in_progress() ||
2504 (unswept_free_bytes_ == 0));
2505 return Size() - unswept_free_bytes_ - (limit() - top());
2506 }
2507
2508
2509 // After we have booted, we have created a map which represents free space
2510 // on the heap. If there was already a free list then the elements on it
2511 // were created with the wrong FreeSpaceMap (normally NULL), so we need to
2512 // fix them.
RepairFreeListsAfterBoot()2513 void PagedSpace::RepairFreeListsAfterBoot() { free_list_.RepairLists(heap()); }
2514
2515
EvictEvacuationCandidatesFromFreeLists()2516 void PagedSpace::EvictEvacuationCandidatesFromFreeLists() {
2517 if (allocation_info_.top() >= allocation_info_.limit()) return;
2518
2519 if (Page::FromAllocationTop(allocation_info_.top())
2520 ->IsEvacuationCandidate()) {
2521 // Create filler object to keep page iterable if it was iterable.
2522 int remaining =
2523 static_cast<int>(allocation_info_.limit() - allocation_info_.top());
2524 heap()->CreateFillerObjectAt(allocation_info_.top(), remaining);
2525
2526 allocation_info_.set_top(NULL);
2527 allocation_info_.set_limit(NULL);
2528 }
2529 }
2530
2531
WaitForSweeperThreadsAndRetryAllocation(int size_in_bytes)2532 HeapObject* PagedSpace::WaitForSweeperThreadsAndRetryAllocation(
2533 int size_in_bytes) {
2534 MarkCompactCollector* collector = heap()->mark_compact_collector();
2535 if (collector->sweeping_in_progress()) {
2536 // Wait for the sweeper threads here and complete the sweeping phase.
2537 collector->EnsureSweepingCompleted();
2538
2539 // After waiting for the sweeper threads, there may be new free-list
2540 // entries.
2541 return free_list_.Allocate(size_in_bytes);
2542 }
2543 return NULL;
2544 }
2545
2546
SlowAllocateRaw(int size_in_bytes)2547 HeapObject* PagedSpace::SlowAllocateRaw(int size_in_bytes) {
2548 // Allocation in this space has failed.
2549
2550 MarkCompactCollector* collector = heap()->mark_compact_collector();
2551 // Sweeping is still in progress.
2552 if (collector->sweeping_in_progress()) {
2553 // First try to refill the free-list, concurrent sweeper threads
2554 // may have freed some objects in the meantime.
2555 collector->RefillFreeList(this);
2556
2557 // Retry the free list allocation.
2558 HeapObject* object = free_list_.Allocate(size_in_bytes);
2559 if (object != NULL) return object;
2560
2561 // If sweeping is still in progress try to sweep pages on the main thread.
2562 int free_chunk = collector->SweepInParallel(this, size_in_bytes);
2563 collector->RefillFreeList(this);
2564 if (free_chunk >= size_in_bytes) {
2565 HeapObject* object = free_list_.Allocate(size_in_bytes);
2566 // We should be able to allocate an object here since we just freed that
2567 // much memory.
2568 DCHECK(object != NULL);
2569 if (object != NULL) return object;
2570 }
2571 }
2572
2573 // Free list allocation failed and there is no next page. Fail if we have
2574 // hit the old generation size limit that should cause a garbage
2575 // collection.
2576 if (!heap()->always_allocate() &&
2577 heap()->OldGenerationAllocationLimitReached()) {
2578 // If sweeper threads are active, wait for them at that point and steal
2579 // elements form their free-lists.
2580 HeapObject* object = WaitForSweeperThreadsAndRetryAllocation(size_in_bytes);
2581 if (object != NULL) return object;
2582 }
2583
2584 // Try to expand the space and allocate in the new next page.
2585 if (Expand()) {
2586 DCHECK(CountTotalPages() > 1 || size_in_bytes <= free_list_.available());
2587 return free_list_.Allocate(size_in_bytes);
2588 }
2589
2590 // If sweeper threads are active, wait for them at that point and steal
2591 // elements form their free-lists. Allocation may still fail their which
2592 // would indicate that there is not enough memory for the given allocation.
2593 return WaitForSweeperThreadsAndRetryAllocation(size_in_bytes);
2594 }
2595
2596
2597 #ifdef DEBUG
ReportCodeStatistics(Isolate * isolate)2598 void PagedSpace::ReportCodeStatistics(Isolate* isolate) {
2599 CommentStatistic* comments_statistics =
2600 isolate->paged_space_comments_statistics();
2601 ReportCodeKindStatistics(isolate->code_kind_statistics());
2602 PrintF(
2603 "Code comment statistics (\" [ comment-txt : size/ "
2604 "count (average)\"):\n");
2605 for (int i = 0; i <= CommentStatistic::kMaxComments; i++) {
2606 const CommentStatistic& cs = comments_statistics[i];
2607 if (cs.size > 0) {
2608 PrintF(" %-30s: %10d/%6d (%d)\n", cs.comment, cs.size, cs.count,
2609 cs.size / cs.count);
2610 }
2611 }
2612 PrintF("\n");
2613 }
2614
2615
ResetCodeStatistics(Isolate * isolate)2616 void PagedSpace::ResetCodeStatistics(Isolate* isolate) {
2617 CommentStatistic* comments_statistics =
2618 isolate->paged_space_comments_statistics();
2619 ClearCodeKindStatistics(isolate->code_kind_statistics());
2620 for (int i = 0; i < CommentStatistic::kMaxComments; i++) {
2621 comments_statistics[i].Clear();
2622 }
2623 comments_statistics[CommentStatistic::kMaxComments].comment = "Unknown";
2624 comments_statistics[CommentStatistic::kMaxComments].size = 0;
2625 comments_statistics[CommentStatistic::kMaxComments].count = 0;
2626 }
2627
2628
2629 // Adds comment to 'comment_statistics' table. Performance OK as long as
2630 // 'kMaxComments' is small
EnterComment(Isolate * isolate,const char * comment,int delta)2631 static void EnterComment(Isolate* isolate, const char* comment, int delta) {
2632 CommentStatistic* comments_statistics =
2633 isolate->paged_space_comments_statistics();
2634 // Do not count empty comments
2635 if (delta <= 0) return;
2636 CommentStatistic* cs = &comments_statistics[CommentStatistic::kMaxComments];
2637 // Search for a free or matching entry in 'comments_statistics': 'cs'
2638 // points to result.
2639 for (int i = 0; i < CommentStatistic::kMaxComments; i++) {
2640 if (comments_statistics[i].comment == NULL) {
2641 cs = &comments_statistics[i];
2642 cs->comment = comment;
2643 break;
2644 } else if (strcmp(comments_statistics[i].comment, comment) == 0) {
2645 cs = &comments_statistics[i];
2646 break;
2647 }
2648 }
2649 // Update entry for 'comment'
2650 cs->size += delta;
2651 cs->count += 1;
2652 }
2653
2654
2655 // Call for each nested comment start (start marked with '[ xxx', end marked
2656 // with ']'. RelocIterator 'it' must point to a comment reloc info.
CollectCommentStatistics(Isolate * isolate,RelocIterator * it)2657 static void CollectCommentStatistics(Isolate* isolate, RelocIterator* it) {
2658 DCHECK(!it->done());
2659 DCHECK(it->rinfo()->rmode() == RelocInfo::COMMENT);
2660 const char* tmp = reinterpret_cast<const char*>(it->rinfo()->data());
2661 if (tmp[0] != '[') {
2662 // Not a nested comment; skip
2663 return;
2664 }
2665
2666 // Search for end of nested comment or a new nested comment
2667 const char* const comment_txt =
2668 reinterpret_cast<const char*>(it->rinfo()->data());
2669 const byte* prev_pc = it->rinfo()->pc();
2670 int flat_delta = 0;
2671 it->next();
2672 while (true) {
2673 // All nested comments must be terminated properly, and therefore exit
2674 // from loop.
2675 DCHECK(!it->done());
2676 if (it->rinfo()->rmode() == RelocInfo::COMMENT) {
2677 const char* const txt =
2678 reinterpret_cast<const char*>(it->rinfo()->data());
2679 flat_delta += static_cast<int>(it->rinfo()->pc() - prev_pc);
2680 if (txt[0] == ']') break; // End of nested comment
2681 // A new comment
2682 CollectCommentStatistics(isolate, it);
2683 // Skip code that was covered with previous comment
2684 prev_pc = it->rinfo()->pc();
2685 }
2686 it->next();
2687 }
2688 EnterComment(isolate, comment_txt, flat_delta);
2689 }
2690
2691
2692 // Collects code size statistics:
2693 // - by code kind
2694 // - by code comment
CollectCodeStatistics()2695 void PagedSpace::CollectCodeStatistics() {
2696 Isolate* isolate = heap()->isolate();
2697 HeapObjectIterator obj_it(this);
2698 for (HeapObject* obj = obj_it.Next(); obj != NULL; obj = obj_it.Next()) {
2699 if (obj->IsCode()) {
2700 Code* code = Code::cast(obj);
2701 isolate->code_kind_statistics()[code->kind()] += code->Size();
2702 RelocIterator it(code);
2703 int delta = 0;
2704 const byte* prev_pc = code->instruction_start();
2705 while (!it.done()) {
2706 if (it.rinfo()->rmode() == RelocInfo::COMMENT) {
2707 delta += static_cast<int>(it.rinfo()->pc() - prev_pc);
2708 CollectCommentStatistics(isolate, &it);
2709 prev_pc = it.rinfo()->pc();
2710 }
2711 it.next();
2712 }
2713
2714 DCHECK(code->instruction_start() <= prev_pc &&
2715 prev_pc <= code->instruction_end());
2716 delta += static_cast<int>(code->instruction_end() - prev_pc);
2717 EnterComment(isolate, "NoComment", delta);
2718 }
2719 }
2720 }
2721
2722
ReportStatistics()2723 void PagedSpace::ReportStatistics() {
2724 int pct = static_cast<int>(Available() * 100 / Capacity());
2725 PrintF(" capacity: %" V8_PTR_PREFIX
2726 "d"
2727 ", waste: %" V8_PTR_PREFIX
2728 "d"
2729 ", available: %" V8_PTR_PREFIX "d, %%%d\n",
2730 Capacity(), Waste(), Available(), pct);
2731
2732 if (heap()->mark_compact_collector()->sweeping_in_progress()) {
2733 heap()->mark_compact_collector()->EnsureSweepingCompleted();
2734 }
2735 ClearHistograms(heap()->isolate());
2736 HeapObjectIterator obj_it(this);
2737 for (HeapObject* obj = obj_it.Next(); obj != NULL; obj = obj_it.Next())
2738 CollectHistogramInfo(obj);
2739 ReportHistogram(heap()->isolate(), true);
2740 }
2741 #endif
2742
2743
2744 // -----------------------------------------------------------------------------
2745 // MapSpace implementation
2746 // TODO(mvstanton): this is weird...the compiler can't make a vtable unless
2747 // there is at least one non-inlined virtual function. I would prefer to hide
2748 // the VerifyObject definition behind VERIFY_HEAP.
2749
VerifyObject(HeapObject * object)2750 void MapSpace::VerifyObject(HeapObject* object) { CHECK(object->IsMap()); }
2751
2752
2753 // -----------------------------------------------------------------------------
2754 // CellSpace and PropertyCellSpace implementation
2755 // TODO(mvstanton): this is weird...the compiler can't make a vtable unless
2756 // there is at least one non-inlined virtual function. I would prefer to hide
2757 // the VerifyObject definition behind VERIFY_HEAP.
2758
VerifyObject(HeapObject * object)2759 void CellSpace::VerifyObject(HeapObject* object) { CHECK(object->IsCell()); }
2760
2761
VerifyObject(HeapObject * object)2762 void PropertyCellSpace::VerifyObject(HeapObject* object) {
2763 CHECK(object->IsPropertyCell());
2764 }
2765
2766
2767 // -----------------------------------------------------------------------------
2768 // LargeObjectIterator
2769
LargeObjectIterator(LargeObjectSpace * space)2770 LargeObjectIterator::LargeObjectIterator(LargeObjectSpace* space) {
2771 current_ = space->first_page_;
2772 size_func_ = NULL;
2773 }
2774
2775
LargeObjectIterator(LargeObjectSpace * space,HeapObjectCallback size_func)2776 LargeObjectIterator::LargeObjectIterator(LargeObjectSpace* space,
2777 HeapObjectCallback size_func) {
2778 current_ = space->first_page_;
2779 size_func_ = size_func;
2780 }
2781
2782
Next()2783 HeapObject* LargeObjectIterator::Next() {
2784 if (current_ == NULL) return NULL;
2785
2786 HeapObject* object = current_->GetObject();
2787 current_ = current_->next_page();
2788 return object;
2789 }
2790
2791
2792 // -----------------------------------------------------------------------------
2793 // LargeObjectSpace
ComparePointers(void * key1,void * key2)2794 static bool ComparePointers(void* key1, void* key2) { return key1 == key2; }
2795
2796
LargeObjectSpace(Heap * heap,intptr_t max_capacity,AllocationSpace id)2797 LargeObjectSpace::LargeObjectSpace(Heap* heap, intptr_t max_capacity,
2798 AllocationSpace id)
2799 : Space(heap, id, NOT_EXECUTABLE), // Managed on a per-allocation basis
2800 max_capacity_(max_capacity),
2801 first_page_(NULL),
2802 size_(0),
2803 page_count_(0),
2804 objects_size_(0),
2805 chunk_map_(ComparePointers, 1024) {}
2806
2807
SetUp()2808 bool LargeObjectSpace::SetUp() {
2809 first_page_ = NULL;
2810 size_ = 0;
2811 maximum_committed_ = 0;
2812 page_count_ = 0;
2813 objects_size_ = 0;
2814 chunk_map_.Clear();
2815 return true;
2816 }
2817
2818
TearDown()2819 void LargeObjectSpace::TearDown() {
2820 while (first_page_ != NULL) {
2821 LargePage* page = first_page_;
2822 first_page_ = first_page_->next_page();
2823 LOG(heap()->isolate(), DeleteEvent("LargeObjectChunk", page->address()));
2824
2825 ObjectSpace space = static_cast<ObjectSpace>(1 << identity());
2826 heap()->isolate()->memory_allocator()->PerformAllocationCallback(
2827 space, kAllocationActionFree, page->size());
2828 heap()->isolate()->memory_allocator()->Free(page);
2829 }
2830 SetUp();
2831 }
2832
2833
AllocateRaw(int object_size,Executability executable)2834 AllocationResult LargeObjectSpace::AllocateRaw(int object_size,
2835 Executability executable) {
2836 // Check if we want to force a GC before growing the old space further.
2837 // If so, fail the allocation.
2838 if (!heap()->always_allocate() &&
2839 heap()->OldGenerationAllocationLimitReached()) {
2840 return AllocationResult::Retry(identity());
2841 }
2842
2843 if (Size() + object_size > max_capacity_) {
2844 return AllocationResult::Retry(identity());
2845 }
2846
2847 LargePage* page = heap()->isolate()->memory_allocator()->AllocateLargePage(
2848 object_size, this, executable);
2849 if (page == NULL) return AllocationResult::Retry(identity());
2850 DCHECK(page->area_size() >= object_size);
2851
2852 size_ += static_cast<int>(page->size());
2853 objects_size_ += object_size;
2854 page_count_++;
2855 page->set_next_page(first_page_);
2856 first_page_ = page;
2857
2858 if (size_ > maximum_committed_) {
2859 maximum_committed_ = size_;
2860 }
2861
2862 // Register all MemoryChunk::kAlignment-aligned chunks covered by
2863 // this large page in the chunk map.
2864 uintptr_t base = reinterpret_cast<uintptr_t>(page) / MemoryChunk::kAlignment;
2865 uintptr_t limit = base + (page->size() - 1) / MemoryChunk::kAlignment;
2866 for (uintptr_t key = base; key <= limit; key++) {
2867 HashMap::Entry* entry = chunk_map_.Lookup(reinterpret_cast<void*>(key),
2868 static_cast<uint32_t>(key), true);
2869 DCHECK(entry != NULL);
2870 entry->value = page;
2871 }
2872
2873 HeapObject* object = page->GetObject();
2874
2875 MSAN_ALLOCATED_UNINITIALIZED_MEMORY(object->address(), object_size);
2876
2877 if (Heap::ShouldZapGarbage()) {
2878 // Make the object consistent so the heap can be verified in OldSpaceStep.
2879 // We only need to do this in debug builds or if verify_heap is on.
2880 reinterpret_cast<Object**>(object->address())[0] =
2881 heap()->fixed_array_map();
2882 reinterpret_cast<Object**>(object->address())[1] = Smi::FromInt(0);
2883 }
2884
2885 heap()->incremental_marking()->OldSpaceStep(object_size);
2886 return object;
2887 }
2888
2889
CommittedPhysicalMemory()2890 size_t LargeObjectSpace::CommittedPhysicalMemory() {
2891 if (!base::VirtualMemory::HasLazyCommits()) return CommittedMemory();
2892 size_t size = 0;
2893 LargePage* current = first_page_;
2894 while (current != NULL) {
2895 size += current->CommittedPhysicalMemory();
2896 current = current->next_page();
2897 }
2898 return size;
2899 }
2900
2901
2902 // GC support
FindObject(Address a)2903 Object* LargeObjectSpace::FindObject(Address a) {
2904 LargePage* page = FindPage(a);
2905 if (page != NULL) {
2906 return page->GetObject();
2907 }
2908 return Smi::FromInt(0); // Signaling not found.
2909 }
2910
2911
FindPage(Address a)2912 LargePage* LargeObjectSpace::FindPage(Address a) {
2913 uintptr_t key = reinterpret_cast<uintptr_t>(a) / MemoryChunk::kAlignment;
2914 HashMap::Entry* e = chunk_map_.Lookup(reinterpret_cast<void*>(key),
2915 static_cast<uint32_t>(key), false);
2916 if (e != NULL) {
2917 DCHECK(e->value != NULL);
2918 LargePage* page = reinterpret_cast<LargePage*>(e->value);
2919 DCHECK(page->is_valid());
2920 if (page->Contains(a)) {
2921 return page;
2922 }
2923 }
2924 return NULL;
2925 }
2926
2927
FreeUnmarkedObjects()2928 void LargeObjectSpace::FreeUnmarkedObjects() {
2929 LargePage* previous = NULL;
2930 LargePage* current = first_page_;
2931 while (current != NULL) {
2932 HeapObject* object = current->GetObject();
2933 // Can this large page contain pointers to non-trivial objects. No other
2934 // pointer object is this big.
2935 bool is_pointer_object = object->IsFixedArray();
2936 MarkBit mark_bit = Marking::MarkBitFrom(object);
2937 if (mark_bit.Get()) {
2938 mark_bit.Clear();
2939 Page::FromAddress(object->address())->ResetProgressBar();
2940 Page::FromAddress(object->address())->ResetLiveBytes();
2941 previous = current;
2942 current = current->next_page();
2943 } else {
2944 LargePage* page = current;
2945 // Cut the chunk out from the chunk list.
2946 current = current->next_page();
2947 if (previous == NULL) {
2948 first_page_ = current;
2949 } else {
2950 previous->set_next_page(current);
2951 }
2952
2953 // Free the chunk.
2954 heap()->mark_compact_collector()->ReportDeleteIfNeeded(object,
2955 heap()->isolate());
2956 size_ -= static_cast<int>(page->size());
2957 objects_size_ -= object->Size();
2958 page_count_--;
2959
2960 // Remove entries belonging to this page.
2961 // Use variable alignment to help pass length check (<= 80 characters)
2962 // of single line in tools/presubmit.py.
2963 const intptr_t alignment = MemoryChunk::kAlignment;
2964 uintptr_t base = reinterpret_cast<uintptr_t>(page) / alignment;
2965 uintptr_t limit = base + (page->size() - 1) / alignment;
2966 for (uintptr_t key = base; key <= limit; key++) {
2967 chunk_map_.Remove(reinterpret_cast<void*>(key),
2968 static_cast<uint32_t>(key));
2969 }
2970
2971 if (is_pointer_object) {
2972 heap()->QueueMemoryChunkForFree(page);
2973 } else {
2974 heap()->isolate()->memory_allocator()->Free(page);
2975 }
2976 }
2977 }
2978 heap()->FreeQueuedChunks();
2979 }
2980
2981
Contains(HeapObject * object)2982 bool LargeObjectSpace::Contains(HeapObject* object) {
2983 Address address = object->address();
2984 MemoryChunk* chunk = MemoryChunk::FromAddress(address);
2985
2986 bool owned = (chunk->owner() == this);
2987
2988 SLOW_DCHECK(!owned || FindObject(address)->IsHeapObject());
2989
2990 return owned;
2991 }
2992
2993
2994 #ifdef VERIFY_HEAP
2995 // We do not assume that the large object iterator works, because it depends
2996 // on the invariants we are checking during verification.
Verify()2997 void LargeObjectSpace::Verify() {
2998 for (LargePage* chunk = first_page_; chunk != NULL;
2999 chunk = chunk->next_page()) {
3000 // Each chunk contains an object that starts at the large object page's
3001 // object area start.
3002 HeapObject* object = chunk->GetObject();
3003 Page* page = Page::FromAddress(object->address());
3004 CHECK(object->address() == page->area_start());
3005
3006 // The first word should be a map, and we expect all map pointers to be
3007 // in map space.
3008 Map* map = object->map();
3009 CHECK(map->IsMap());
3010 CHECK(heap()->map_space()->Contains(map));
3011
3012 // We have only code, sequential strings, external strings
3013 // (sequential strings that have been morphed into external
3014 // strings), fixed arrays, byte arrays, and constant pool arrays in the
3015 // large object space.
3016 CHECK(object->IsCode() || object->IsSeqString() ||
3017 object->IsExternalString() || object->IsFixedArray() ||
3018 object->IsFixedDoubleArray() || object->IsByteArray() ||
3019 object->IsConstantPoolArray());
3020
3021 // The object itself should look OK.
3022 object->ObjectVerify();
3023
3024 // Byte arrays and strings don't have interior pointers.
3025 if (object->IsCode()) {
3026 VerifyPointersVisitor code_visitor;
3027 object->IterateBody(map->instance_type(), object->Size(), &code_visitor);
3028 } else if (object->IsFixedArray()) {
3029 FixedArray* array = FixedArray::cast(object);
3030 for (int j = 0; j < array->length(); j++) {
3031 Object* element = array->get(j);
3032 if (element->IsHeapObject()) {
3033 HeapObject* element_object = HeapObject::cast(element);
3034 CHECK(heap()->Contains(element_object));
3035 CHECK(element_object->map()->IsMap());
3036 }
3037 }
3038 }
3039 }
3040 }
3041 #endif
3042
3043
3044 #ifdef DEBUG
Print()3045 void LargeObjectSpace::Print() {
3046 OFStream os(stdout);
3047 LargeObjectIterator it(this);
3048 for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next()) {
3049 obj->Print(os);
3050 }
3051 }
3052
3053
ReportStatistics()3054 void LargeObjectSpace::ReportStatistics() {
3055 PrintF(" size: %" V8_PTR_PREFIX "d\n", size_);
3056 int num_objects = 0;
3057 ClearHistograms(heap()->isolate());
3058 LargeObjectIterator it(this);
3059 for (HeapObject* obj = it.Next(); obj != NULL; obj = it.Next()) {
3060 num_objects++;
3061 CollectHistogramInfo(obj);
3062 }
3063
3064 PrintF(
3065 " number of objects %d, "
3066 "size of objects %" V8_PTR_PREFIX "d\n",
3067 num_objects, objects_size_);
3068 if (num_objects > 0) ReportHistogram(heap()->isolate(), false);
3069 }
3070
3071
CollectCodeStatistics()3072 void LargeObjectSpace::CollectCodeStatistics() {
3073 Isolate* isolate = heap()->isolate();
3074 LargeObjectIterator obj_it(this);
3075 for (HeapObject* obj = obj_it.Next(); obj != NULL; obj = obj_it.Next()) {
3076 if (obj->IsCode()) {
3077 Code* code = Code::cast(obj);
3078 isolate->code_kind_statistics()[code->kind()] += code->Size();
3079 }
3080 }
3081 }
3082
3083
Print()3084 void Page::Print() {
3085 // Make a best-effort to print the objects in the page.
3086 PrintF("Page@%p in %s\n", this->address(),
3087 AllocationSpaceName(this->owner()->identity()));
3088 printf(" --------------------------------------\n");
3089 HeapObjectIterator objects(this, heap()->GcSafeSizeOfOldObjectFunction());
3090 unsigned mark_size = 0;
3091 for (HeapObject* object = objects.Next(); object != NULL;
3092 object = objects.Next()) {
3093 bool is_marked = Marking::MarkBitFrom(object).Get();
3094 PrintF(" %c ", (is_marked ? '!' : ' ')); // Indent a little.
3095 if (is_marked) {
3096 mark_size += heap()->GcSafeSizeOfOldObjectFunction()(object);
3097 }
3098 object->ShortPrint();
3099 PrintF("\n");
3100 }
3101 printf(" --------------------------------------\n");
3102 printf(" Marked: %x, LiveCount: %x\n", mark_size, LiveBytes());
3103 }
3104
3105 #endif // DEBUG
3106 }
3107 } // namespace v8::internal
3108