blob: 68522fccec653dc9c67fda812cfab11ec76b6d7c [file] [log] [blame]
// Copyright 2013 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/v8.h"
#include "src/heap-snapshot-generator-inl.h"
#include "src/allocation-tracker.h"
#include "src/code-stubs.h"
#include "src/conversions.h"
#include "src/debug.h"
#include "src/heap-profiler.h"
#include "src/types.h"
namespace v8 {
namespace internal {
HeapGraphEdge::HeapGraphEdge(Type type, const char* name, int from, int to)
: type_(type),
from_index_(from),
to_index_(to),
name_(name) {
DCHECK(type == kContextVariable
|| type == kProperty
|| type == kInternal
|| type == kShortcut
|| type == kWeak);
}
HeapGraphEdge::HeapGraphEdge(Type type, int index, int from, int to)
: type_(type),
from_index_(from),
to_index_(to),
index_(index) {
DCHECK(type == kElement || type == kHidden);
}
void HeapGraphEdge::ReplaceToIndexWithEntry(HeapSnapshot* snapshot) {
to_entry_ = &snapshot->entries()[to_index_];
}
const int HeapEntry::kNoEntry = -1;
HeapEntry::HeapEntry(HeapSnapshot* snapshot,
Type type,
const char* name,
SnapshotObjectId id,
size_t self_size,
unsigned trace_node_id)
: type_(type),
children_count_(0),
children_index_(-1),
self_size_(self_size),
snapshot_(snapshot),
name_(name),
id_(id),
trace_node_id_(trace_node_id) { }
void HeapEntry::SetNamedReference(HeapGraphEdge::Type type,
const char* name,
HeapEntry* entry) {
HeapGraphEdge edge(type, name, this->index(), entry->index());
snapshot_->edges().Add(edge);
++children_count_;
}
void HeapEntry::SetIndexedReference(HeapGraphEdge::Type type,
int index,
HeapEntry* entry) {
HeapGraphEdge edge(type, index, this->index(), entry->index());
snapshot_->edges().Add(edge);
++children_count_;
}
void HeapEntry::Print(
const char* prefix, const char* edge_name, int max_depth, int indent) {
STATIC_ASSERT(sizeof(unsigned) == sizeof(id()));
base::OS::Print("%6" V8PRIuPTR " @%6u %*c %s%s: ", self_size(), id(), indent,
' ', prefix, edge_name);
if (type() != kString) {
base::OS::Print("%s %.40s\n", TypeAsString(), name_);
} else {
base::OS::Print("\"");
const char* c = name_;
while (*c && (c - name_) <= 40) {
if (*c != '\n')
base::OS::Print("%c", *c);
else
base::OS::Print("\\n");
++c;
}
base::OS::Print("\"\n");
}
if (--max_depth == 0) return;
Vector<HeapGraphEdge*> ch = children();
for (int i = 0; i < ch.length(); ++i) {
HeapGraphEdge& edge = *ch[i];
const char* edge_prefix = "";
EmbeddedVector<char, 64> index;
const char* edge_name = index.start();
switch (edge.type()) {
case HeapGraphEdge::kContextVariable:
edge_prefix = "#";
edge_name = edge.name();
break;
case HeapGraphEdge::kElement:
SNPrintF(index, "%d", edge.index());
break;
case HeapGraphEdge::kInternal:
edge_prefix = "$";
edge_name = edge.name();
break;
case HeapGraphEdge::kProperty:
edge_name = edge.name();
break;
case HeapGraphEdge::kHidden:
edge_prefix = "$";
SNPrintF(index, "%d", edge.index());
break;
case HeapGraphEdge::kShortcut:
edge_prefix = "^";
edge_name = edge.name();
break;
case HeapGraphEdge::kWeak:
edge_prefix = "w";
edge_name = edge.name();
break;
default:
SNPrintF(index, "!!! unknown edge type: %d ", edge.type());
}
edge.to()->Print(edge_prefix, edge_name, max_depth, indent + 2);
}
}
const char* HeapEntry::TypeAsString() {
switch (type()) {
case kHidden: return "/hidden/";
case kObject: return "/object/";
case kClosure: return "/closure/";
case kString: return "/string/";
case kCode: return "/code/";
case kArray: return "/array/";
case kRegExp: return "/regexp/";
case kHeapNumber: return "/number/";
case kNative: return "/native/";
case kSynthetic: return "/synthetic/";
case kConsString: return "/concatenated string/";
case kSlicedString: return "/sliced string/";
case kSymbol: return "/symbol/";
default: return "???";
}
}
// It is very important to keep objects that form a heap snapshot
// as small as possible.
namespace { // Avoid littering the global namespace.
template <size_t ptr_size> struct SnapshotSizeConstants;
template <> struct SnapshotSizeConstants<4> {
static const int kExpectedHeapGraphEdgeSize = 12;
static const int kExpectedHeapEntrySize = 28;
};
template <> struct SnapshotSizeConstants<8> {
static const int kExpectedHeapGraphEdgeSize = 24;
static const int kExpectedHeapEntrySize = 40;
};
} // namespace
HeapSnapshot::HeapSnapshot(HeapProfiler* profiler,
const char* title,
unsigned uid)
: profiler_(profiler),
title_(title),
uid_(uid),
root_index_(HeapEntry::kNoEntry),
gc_roots_index_(HeapEntry::kNoEntry),
max_snapshot_js_object_id_(0) {
STATIC_ASSERT(
sizeof(HeapGraphEdge) ==
SnapshotSizeConstants<kPointerSize>::kExpectedHeapGraphEdgeSize);
STATIC_ASSERT(
sizeof(HeapEntry) ==
SnapshotSizeConstants<kPointerSize>::kExpectedHeapEntrySize);
USE(SnapshotSizeConstants<4>::kExpectedHeapGraphEdgeSize);
USE(SnapshotSizeConstants<4>::kExpectedHeapEntrySize);
USE(SnapshotSizeConstants<8>::kExpectedHeapGraphEdgeSize);
USE(SnapshotSizeConstants<8>::kExpectedHeapEntrySize);
for (int i = 0; i < VisitorSynchronization::kNumberOfSyncTags; ++i) {
gc_subroot_indexes_[i] = HeapEntry::kNoEntry;
}
}
void HeapSnapshot::Delete() {
profiler_->RemoveSnapshot(this);
delete this;
}
void HeapSnapshot::RememberLastJSObjectId() {
max_snapshot_js_object_id_ = profiler_->heap_object_map()->last_assigned_id();
}
void HeapSnapshot::AddSyntheticRootEntries() {
AddRootEntry();
AddGcRootsEntry();
SnapshotObjectId id = HeapObjectsMap::kGcRootsFirstSubrootId;
for (int tag = 0; tag < VisitorSynchronization::kNumberOfSyncTags; tag++) {
AddGcSubrootEntry(tag, id);
id += HeapObjectsMap::kObjectIdStep;
}
DCHECK(HeapObjectsMap::kFirstAvailableObjectId == id);
}
HeapEntry* HeapSnapshot::AddRootEntry() {
DCHECK(root_index_ == HeapEntry::kNoEntry);
DCHECK(entries_.is_empty()); // Root entry must be the first one.
HeapEntry* entry = AddEntry(HeapEntry::kSynthetic,
"",
HeapObjectsMap::kInternalRootObjectId,
0,
0);
root_index_ = entry->index();
DCHECK(root_index_ == 0);
return entry;
}
HeapEntry* HeapSnapshot::AddGcRootsEntry() {
DCHECK(gc_roots_index_ == HeapEntry::kNoEntry);
HeapEntry* entry = AddEntry(HeapEntry::kSynthetic,
"(GC roots)",
HeapObjectsMap::kGcRootsObjectId,
0,
0);
gc_roots_index_ = entry->index();
return entry;
}
HeapEntry* HeapSnapshot::AddGcSubrootEntry(int tag, SnapshotObjectId id) {
DCHECK(gc_subroot_indexes_[tag] == HeapEntry::kNoEntry);
DCHECK(0 <= tag && tag < VisitorSynchronization::kNumberOfSyncTags);
HeapEntry* entry = AddEntry(HeapEntry::kSynthetic,
VisitorSynchronization::kTagNames[tag], id, 0, 0);
gc_subroot_indexes_[tag] = entry->index();
return entry;
}
HeapEntry* HeapSnapshot::AddEntry(HeapEntry::Type type,
const char* name,
SnapshotObjectId id,
size_t size,
unsigned trace_node_id) {
HeapEntry entry(this, type, name, id, size, trace_node_id);
entries_.Add(entry);
return &entries_.last();
}
void HeapSnapshot::FillChildren() {
DCHECK(children().is_empty());
children().Allocate(edges().length());
int children_index = 0;
for (int i = 0; i < entries().length(); ++i) {
HeapEntry* entry = &entries()[i];
children_index = entry->set_children_index(children_index);
}
DCHECK(edges().length() == children_index);
for (int i = 0; i < edges().length(); ++i) {
HeapGraphEdge* edge = &edges()[i];
edge->ReplaceToIndexWithEntry(this);
edge->from()->add_child(edge);
}
}
class FindEntryById {
public:
explicit FindEntryById(SnapshotObjectId id) : id_(id) { }
int operator()(HeapEntry* const* entry) {
if ((*entry)->id() == id_) return 0;
return (*entry)->id() < id_ ? -1 : 1;
}
private:
SnapshotObjectId id_;
};
HeapEntry* HeapSnapshot::GetEntryById(SnapshotObjectId id) {
List<HeapEntry*>* entries_by_id = GetSortedEntriesList();
// Perform a binary search by id.
int index = SortedListBSearch(*entries_by_id, FindEntryById(id));
if (index == -1)
return NULL;
return entries_by_id->at(index);
}
template<class T>
static int SortByIds(const T* entry1_ptr,
const T* entry2_ptr) {
if ((*entry1_ptr)->id() == (*entry2_ptr)->id()) return 0;
return (*entry1_ptr)->id() < (*entry2_ptr)->id() ? -1 : 1;
}
List<HeapEntry*>* HeapSnapshot::GetSortedEntriesList() {
if (sorted_entries_.is_empty()) {
sorted_entries_.Allocate(entries_.length());
for (int i = 0; i < entries_.length(); ++i) {
sorted_entries_[i] = &entries_[i];
}
sorted_entries_.Sort(SortByIds);
}
return &sorted_entries_;
}
void HeapSnapshot::Print(int max_depth) {
root()->Print("", "", max_depth, 0);
}
size_t HeapSnapshot::RawSnapshotSize() const {
return
sizeof(*this) +
GetMemoryUsedByList(entries_) +
GetMemoryUsedByList(edges_) +
GetMemoryUsedByList(children_) +
GetMemoryUsedByList(sorted_entries_);
}
// We split IDs on evens for embedder objects (see
// HeapObjectsMap::GenerateId) and odds for native objects.
const SnapshotObjectId HeapObjectsMap::kInternalRootObjectId = 1;
const SnapshotObjectId HeapObjectsMap::kGcRootsObjectId =
HeapObjectsMap::kInternalRootObjectId + HeapObjectsMap::kObjectIdStep;
const SnapshotObjectId HeapObjectsMap::kGcRootsFirstSubrootId =
HeapObjectsMap::kGcRootsObjectId + HeapObjectsMap::kObjectIdStep;
const SnapshotObjectId HeapObjectsMap::kFirstAvailableObjectId =
HeapObjectsMap::kGcRootsFirstSubrootId +
VisitorSynchronization::kNumberOfSyncTags * HeapObjectsMap::kObjectIdStep;
static bool AddressesMatch(void* key1, void* key2) {
return key1 == key2;
}
HeapObjectsMap::HeapObjectsMap(Heap* heap)
: next_id_(kFirstAvailableObjectId),
entries_map_(AddressesMatch),
heap_(heap) {
// This dummy element solves a problem with entries_map_.
// When we do lookup in HashMap we see no difference between two cases:
// it has an entry with NULL as the value or it has created
// a new entry on the fly with NULL as the default value.
// With such dummy element we have a guaranty that all entries_map_ entries
// will have the value field grater than 0.
// This fact is using in MoveObject method.
entries_.Add(EntryInfo(0, NULL, 0));
}
bool HeapObjectsMap::MoveObject(Address from, Address to, int object_size) {
DCHECK(to != NULL);
DCHECK(from != NULL);
if (from == to) return false;
void* from_value = entries_map_.Remove(from, ComputePointerHash(from));
if (from_value == NULL) {
// It may occur that some untracked object moves to an address X and there
// is a tracked object at that address. In this case we should remove the
// entry as we know that the object has died.
void* to_value = entries_map_.Remove(to, ComputePointerHash(to));
if (to_value != NULL) {
int to_entry_info_index =
static_cast<int>(reinterpret_cast<intptr_t>(to_value));
entries_.at(to_entry_info_index).addr = NULL;
}
} else {
HashMap::Entry* to_entry = entries_map_.Lookup(to, ComputePointerHash(to),
true);
if (to_entry->value != NULL) {
// We found the existing entry with to address for an old object.
// Without this operation we will have two EntryInfo's with the same
// value in addr field. It is bad because later at RemoveDeadEntries
// one of this entry will be removed with the corresponding entries_map_
// entry.
int to_entry_info_index =
static_cast<int>(reinterpret_cast<intptr_t>(to_entry->value));
entries_.at(to_entry_info_index).addr = NULL;
}
int from_entry_info_index =
static_cast<int>(reinterpret_cast<intptr_t>(from_value));
entries_.at(from_entry_info_index).addr = to;
// Size of an object can change during its life, so to keep information
// about the object in entries_ consistent, we have to adjust size when the
// object is migrated.
if (FLAG_heap_profiler_trace_objects) {
PrintF("Move object from %p to %p old size %6d new size %6d\n",
from,
to,
entries_.at(from_entry_info_index).size,
object_size);
}
entries_.at(from_entry_info_index).size = object_size;
to_entry->value = from_value;
}
return from_value != NULL;
}
void HeapObjectsMap::UpdateObjectSize(Address addr, int size) {
FindOrAddEntry(addr, size, false);
}
SnapshotObjectId HeapObjectsMap::FindEntry(Address addr) {
HashMap::Entry* entry = entries_map_.Lookup(addr, ComputePointerHash(addr),
false);
if (entry == NULL) return 0;
int entry_index = static_cast<int>(reinterpret_cast<intptr_t>(entry->value));
EntryInfo& entry_info = entries_.at(entry_index);
DCHECK(static_cast<uint32_t>(entries_.length()) > entries_map_.occupancy());
return entry_info.id;
}
SnapshotObjectId HeapObjectsMap::FindOrAddEntry(Address addr,
unsigned int size,
bool accessed) {
DCHECK(static_cast<uint32_t>(entries_.length()) > entries_map_.occupancy());
HashMap::Entry* entry = entries_map_.Lookup(addr, ComputePointerHash(addr),
true);
if (entry->value != NULL) {
int entry_index =
static_cast<int>(reinterpret_cast<intptr_t>(entry->value));
EntryInfo& entry_info = entries_.at(entry_index);
entry_info.accessed = accessed;
if (FLAG_heap_profiler_trace_objects) {
PrintF("Update object size : %p with old size %d and new size %d\n",
addr,
entry_info.size,
size);
}
entry_info.size = size;
return entry_info.id;
}
entry->value = reinterpret_cast<void*>(entries_.length());
SnapshotObjectId id = next_id_;
next_id_ += kObjectIdStep;
entries_.Add(EntryInfo(id, addr, size, accessed));
DCHECK(static_cast<uint32_t>(entries_.length()) > entries_map_.occupancy());
return id;
}
void HeapObjectsMap::StopHeapObjectsTracking() {
time_intervals_.Clear();
}
void HeapObjectsMap::UpdateHeapObjectsMap() {
if (FLAG_heap_profiler_trace_objects) {
PrintF("Begin HeapObjectsMap::UpdateHeapObjectsMap. map has %d entries.\n",
entries_map_.occupancy());
}
heap_->CollectAllGarbage(Heap::kMakeHeapIterableMask,
"HeapObjectsMap::UpdateHeapObjectsMap");
HeapIterator iterator(heap_);
for (HeapObject* obj = iterator.next();
obj != NULL;
obj = iterator.next()) {
FindOrAddEntry(obj->address(), obj->Size());
if (FLAG_heap_profiler_trace_objects) {
PrintF("Update object : %p %6d. Next address is %p\n",
obj->address(),
obj->Size(),
obj->address() + obj->Size());
}
}
RemoveDeadEntries();
if (FLAG_heap_profiler_trace_objects) {
PrintF("End HeapObjectsMap::UpdateHeapObjectsMap. map has %d entries.\n",
entries_map_.occupancy());
}
}
namespace {
struct HeapObjectInfo {
HeapObjectInfo(HeapObject* obj, int expected_size)
: obj(obj),
expected_size(expected_size) {
}
HeapObject* obj;
int expected_size;
bool IsValid() const { return expected_size == obj->Size(); }
void Print() const {
if (expected_size == 0) {
PrintF("Untracked object : %p %6d. Next address is %p\n",
obj->address(),
obj->Size(),
obj->address() + obj->Size());
} else if (obj->Size() != expected_size) {
PrintF("Wrong size %6d: %p %6d. Next address is %p\n",
expected_size,
obj->address(),
obj->Size(),
obj->address() + obj->Size());
} else {
PrintF("Good object : %p %6d. Next address is %p\n",
obj->address(),
expected_size,
obj->address() + obj->Size());
}
}
};
static int comparator(const HeapObjectInfo* a, const HeapObjectInfo* b) {
if (a->obj < b->obj) return -1;
if (a->obj > b->obj) return 1;
return 0;
}
} // namespace
int HeapObjectsMap::FindUntrackedObjects() {
List<HeapObjectInfo> heap_objects(1000);
HeapIterator iterator(heap_);
int untracked = 0;
for (HeapObject* obj = iterator.next();
obj != NULL;
obj = iterator.next()) {
HashMap::Entry* entry = entries_map_.Lookup(
obj->address(), ComputePointerHash(obj->address()), false);
if (entry == NULL) {
++untracked;
if (FLAG_heap_profiler_trace_objects) {
heap_objects.Add(HeapObjectInfo(obj, 0));
}
} else {
int entry_index = static_cast<int>(
reinterpret_cast<intptr_t>(entry->value));
EntryInfo& entry_info = entries_.at(entry_index);
if (FLAG_heap_profiler_trace_objects) {
heap_objects.Add(HeapObjectInfo(obj,
static_cast<int>(entry_info.size)));
if (obj->Size() != static_cast<int>(entry_info.size))
++untracked;
} else {
CHECK_EQ(obj->Size(), static_cast<int>(entry_info.size));
}
}
}
if (FLAG_heap_profiler_trace_objects) {
PrintF("\nBegin HeapObjectsMap::FindUntrackedObjects. %d entries in map.\n",
entries_map_.occupancy());
heap_objects.Sort(comparator);
int last_printed_object = -1;
bool print_next_object = false;
for (int i = 0; i < heap_objects.length(); ++i) {
const HeapObjectInfo& object_info = heap_objects[i];
if (!object_info.IsValid()) {
++untracked;
if (last_printed_object != i - 1) {
if (i > 0) {
PrintF("%d objects were skipped\n", i - 1 - last_printed_object);
heap_objects[i - 1].Print();
}
}
object_info.Print();
last_printed_object = i;
print_next_object = true;
} else if (print_next_object) {
object_info.Print();
print_next_object = false;
last_printed_object = i;
}
}
if (last_printed_object < heap_objects.length() - 1) {
PrintF("Last %d objects were skipped\n",
heap_objects.length() - 1 - last_printed_object);
}
PrintF("End HeapObjectsMap::FindUntrackedObjects. %d entries in map.\n\n",
entries_map_.occupancy());
}
return untracked;
}
SnapshotObjectId HeapObjectsMap::PushHeapObjectsStats(OutputStream* stream) {
UpdateHeapObjectsMap();
time_intervals_.Add(TimeInterval(next_id_));
int prefered_chunk_size = stream->GetChunkSize();
List<v8::HeapStatsUpdate> stats_buffer;
DCHECK(!entries_.is_empty());
EntryInfo* entry_info = &entries_.first();
EntryInfo* end_entry_info = &entries_.last() + 1;
for (int time_interval_index = 0;
time_interval_index < time_intervals_.length();
++time_interval_index) {
TimeInterval& time_interval = time_intervals_[time_interval_index];
SnapshotObjectId time_interval_id = time_interval.id;
uint32_t entries_size = 0;
EntryInfo* start_entry_info = entry_info;
while (entry_info < end_entry_info && entry_info->id < time_interval_id) {
entries_size += entry_info->size;
++entry_info;
}
uint32_t entries_count =
static_cast<uint32_t>(entry_info - start_entry_info);
if (time_interval.count != entries_count ||
time_interval.size != entries_size) {
stats_buffer.Add(v8::HeapStatsUpdate(
time_interval_index,
time_interval.count = entries_count,
time_interval.size = entries_size));
if (stats_buffer.length() >= prefered_chunk_size) {
OutputStream::WriteResult result = stream->WriteHeapStatsChunk(
&stats_buffer.first(), stats_buffer.length());
if (result == OutputStream::kAbort) return last_assigned_id();
stats_buffer.Clear();
}
}
}
DCHECK(entry_info == end_entry_info);
if (!stats_buffer.is_empty()) {
OutputStream::WriteResult result = stream->WriteHeapStatsChunk(
&stats_buffer.first(), stats_buffer.length());
if (result == OutputStream::kAbort) return last_assigned_id();
}
stream->EndOfStream();
return last_assigned_id();
}
void HeapObjectsMap::RemoveDeadEntries() {
DCHECK(entries_.length() > 0 &&
entries_.at(0).id == 0 &&
entries_.at(0).addr == NULL);
int first_free_entry = 1;
for (int i = 1; i < entries_.length(); ++i) {
EntryInfo& entry_info = entries_.at(i);
if (entry_info.accessed) {
if (first_free_entry != i) {
entries_.at(first_free_entry) = entry_info;
}
entries_.at(first_free_entry).accessed = false;
HashMap::Entry* entry = entries_map_.Lookup(
entry_info.addr, ComputePointerHash(entry_info.addr), false);
DCHECK(entry);
entry->value = reinterpret_cast<void*>(first_free_entry);
++first_free_entry;
} else {
if (entry_info.addr) {
entries_map_.Remove(entry_info.addr,
ComputePointerHash(entry_info.addr));
}
}
}
entries_.Rewind(first_free_entry);
DCHECK(static_cast<uint32_t>(entries_.length()) - 1 ==
entries_map_.occupancy());
}
SnapshotObjectId HeapObjectsMap::GenerateId(v8::RetainedObjectInfo* info) {
SnapshotObjectId id = static_cast<SnapshotObjectId>(info->GetHash());
const char* label = info->GetLabel();
id ^= StringHasher::HashSequentialString(label,
static_cast<int>(strlen(label)),
heap_->HashSeed());
intptr_t element_count = info->GetElementCount();
if (element_count != -1)
id ^= ComputeIntegerHash(static_cast<uint32_t>(element_count),
v8::internal::kZeroHashSeed);
return id << 1;
}
size_t HeapObjectsMap::GetUsedMemorySize() const {
return
sizeof(*this) +
sizeof(HashMap::Entry) * entries_map_.capacity() +
GetMemoryUsedByList(entries_) +
GetMemoryUsedByList(time_intervals_);
}
HeapEntriesMap::HeapEntriesMap()
: entries_(HashMap::PointersMatch) {
}
int HeapEntriesMap::Map(HeapThing thing) {
HashMap::Entry* cache_entry = entries_.Lookup(thing, Hash(thing), false);
if (cache_entry == NULL) return HeapEntry::kNoEntry;
return static_cast<int>(reinterpret_cast<intptr_t>(cache_entry->value));
}
void HeapEntriesMap::Pair(HeapThing thing, int entry) {
HashMap::Entry* cache_entry = entries_.Lookup(thing, Hash(thing), true);
DCHECK(cache_entry->value == NULL);
cache_entry->value = reinterpret_cast<void*>(static_cast<intptr_t>(entry));
}
HeapObjectsSet::HeapObjectsSet()
: entries_(HashMap::PointersMatch) {
}
void HeapObjectsSet::Clear() {
entries_.Clear();
}
bool HeapObjectsSet::Contains(Object* obj) {
if (!obj->IsHeapObject()) return false;
HeapObject* object = HeapObject::cast(obj);
return entries_.Lookup(object, HeapEntriesMap::Hash(object), false) != NULL;
}
void HeapObjectsSet::Insert(Object* obj) {
if (!obj->IsHeapObject()) return;
HeapObject* object = HeapObject::cast(obj);
entries_.Lookup(object, HeapEntriesMap::Hash(object), true);
}
const char* HeapObjectsSet::GetTag(Object* obj) {
HeapObject* object = HeapObject::cast(obj);
HashMap::Entry* cache_entry =
entries_.Lookup(object, HeapEntriesMap::Hash(object), false);
return cache_entry != NULL
? reinterpret_cast<const char*>(cache_entry->value)
: NULL;
}
void HeapObjectsSet::SetTag(Object* obj, const char* tag) {
if (!obj->IsHeapObject()) return;
HeapObject* object = HeapObject::cast(obj);
HashMap::Entry* cache_entry =
entries_.Lookup(object, HeapEntriesMap::Hash(object), true);
cache_entry->value = const_cast<char*>(tag);
}
V8HeapExplorer::V8HeapExplorer(
HeapSnapshot* snapshot,
SnapshottingProgressReportingInterface* progress,
v8::HeapProfiler::ObjectNameResolver* resolver)
: heap_(snapshot->profiler()->heap_object_map()->heap()),
snapshot_(snapshot),
names_(snapshot_->profiler()->names()),
heap_object_map_(snapshot_->profiler()->heap_object_map()),
progress_(progress),
filler_(NULL),
global_object_name_resolver_(resolver) {
}
V8HeapExplorer::~V8HeapExplorer() {
}
HeapEntry* V8HeapExplorer::AllocateEntry(HeapThing ptr) {
return AddEntry(reinterpret_cast<HeapObject*>(ptr));
}
HeapEntry* V8HeapExplorer::AddEntry(HeapObject* object) {
if (object->IsJSFunction()) {
JSFunction* func = JSFunction::cast(object);
SharedFunctionInfo* shared = func->shared();
const char* name = shared->bound() ? "native_bind" :
names_->GetName(String::cast(shared->name()));
return AddEntry(object, HeapEntry::kClosure, name);
} else if (object->IsJSRegExp()) {
JSRegExp* re = JSRegExp::cast(object);
return AddEntry(object,
HeapEntry::kRegExp,
names_->GetName(re->Pattern()));
} else if (object->IsJSObject()) {
const char* name = names_->GetName(
GetConstructorName(JSObject::cast(object)));
if (object->IsJSGlobalObject()) {
const char* tag = objects_tags_.GetTag(object);
if (tag != NULL) {
name = names_->GetFormatted("%s / %s", name, tag);
}
}
return AddEntry(object, HeapEntry::kObject, name);
} else if (object->IsString()) {
String* string = String::cast(object);
if (string->IsConsString())
return AddEntry(object,
HeapEntry::kConsString,
"(concatenated string)");
if (string->IsSlicedString())
return AddEntry(object,
HeapEntry::kSlicedString,
"(sliced string)");
return AddEntry(object,
HeapEntry::kString,
names_->GetName(String::cast(object)));
} else if (object->IsSymbol()) {
return AddEntry(object, HeapEntry::kSymbol, "symbol");
} else if (object->IsCode()) {
return AddEntry(object, HeapEntry::kCode, "");
} else if (object->IsSharedFunctionInfo()) {
String* name = String::cast(SharedFunctionInfo::cast(object)->name());
return AddEntry(object,
HeapEntry::kCode,
names_->GetName(name));
} else if (object->IsScript()) {
Object* name = Script::cast(object)->name();
return AddEntry(object,
HeapEntry::kCode,
name->IsString()
? names_->GetName(String::cast(name))
: "");
} else if (object->IsNativeContext()) {
return AddEntry(object, HeapEntry::kHidden, "system / NativeContext");
} else if (object->IsContext()) {
return AddEntry(object, HeapEntry::kObject, "system / Context");
} else if (object->IsFixedArray() ||
object->IsFixedDoubleArray() ||
object->IsByteArray() ||
object->IsExternalArray()) {
return AddEntry(object, HeapEntry::kArray, "");
} else if (object->IsHeapNumber()) {
return AddEntry(object, HeapEntry::kHeapNumber, "number");
}
return AddEntry(object, HeapEntry::kHidden, GetSystemEntryName(object));
}
HeapEntry* V8HeapExplorer::AddEntry(HeapObject* object,
HeapEntry::Type type,
const char* name) {
return AddEntry(object->address(), type, name, object->Size());
}
HeapEntry* V8HeapExplorer::AddEntry(Address address,
HeapEntry::Type type,
const char* name,
size_t size) {
SnapshotObjectId object_id = heap_object_map_->FindOrAddEntry(
address, static_cast<unsigned int>(size));
unsigned trace_node_id = 0;
if (AllocationTracker* allocation_tracker =
snapshot_->profiler()->allocation_tracker()) {
trace_node_id =
allocation_tracker->address_to_trace()->GetTraceNodeId(address);
}
return snapshot_->AddEntry(type, name, object_id, size, trace_node_id);
}
class SnapshotFiller {
public:
explicit SnapshotFiller(HeapSnapshot* snapshot, HeapEntriesMap* entries)
: snapshot_(snapshot),
names_(snapshot->profiler()->names()),
entries_(entries) { }
HeapEntry* AddEntry(HeapThing ptr, HeapEntriesAllocator* allocator) {
HeapEntry* entry = allocator->AllocateEntry(ptr);
entries_->Pair(ptr, entry->index());
return entry;
}
HeapEntry* FindEntry(HeapThing ptr) {
int index = entries_->Map(ptr);
return index != HeapEntry::kNoEntry ? &snapshot_->entries()[index] : NULL;
}
HeapEntry* FindOrAddEntry(HeapThing ptr, HeapEntriesAllocator* allocator) {
HeapEntry* entry = FindEntry(ptr);
return entry != NULL ? entry : AddEntry(ptr, allocator);
}
void SetIndexedReference(HeapGraphEdge::Type type,
int parent,
int index,
HeapEntry* child_entry) {
HeapEntry* parent_entry = &snapshot_->entries()[parent];
parent_entry->SetIndexedReference(type, index, child_entry);
}
void SetIndexedAutoIndexReference(HeapGraphEdge::Type type,
int parent,
HeapEntry* child_entry) {
HeapEntry* parent_entry = &snapshot_->entries()[parent];
int index = parent_entry->children_count() + 1;
parent_entry->SetIndexedReference(type, index, child_entry);
}
void SetNamedReference(HeapGraphEdge::Type type,
int parent,
const char* reference_name,
HeapEntry* child_entry) {
HeapEntry* parent_entry = &snapshot_->entries()[parent];
parent_entry->SetNamedReference(type, reference_name, child_entry);
}
void SetNamedAutoIndexReference(HeapGraphEdge::Type type,
int parent,
HeapEntry* child_entry) {
HeapEntry* parent_entry = &snapshot_->entries()[parent];
int index = parent_entry->children_count() + 1;
parent_entry->SetNamedReference(
type,
names_->GetName(index),
child_entry);
}
private:
HeapSnapshot* snapshot_;
StringsStorage* names_;
HeapEntriesMap* entries_;
};
const char* V8HeapExplorer::GetSystemEntryName(HeapObject* object) {
switch (object->map()->instance_type()) {
case MAP_TYPE:
switch (Map::cast(object)->instance_type()) {
#define MAKE_STRING_MAP_CASE(instance_type, size, name, Name) \
case instance_type: return "system / Map (" #Name ")";
STRING_TYPE_LIST(MAKE_STRING_MAP_CASE)
#undef MAKE_STRING_MAP_CASE
default: return "system / Map";
}
case CELL_TYPE: return "system / Cell";
case PROPERTY_CELL_TYPE: return "system / PropertyCell";
case FOREIGN_TYPE: return "system / Foreign";
case ODDBALL_TYPE: return "system / Oddball";
#define MAKE_STRUCT_CASE(NAME, Name, name) \
case NAME##_TYPE: return "system / "#Name;
STRUCT_LIST(MAKE_STRUCT_CASE)
#undef MAKE_STRUCT_CASE
default: return "system";
}
}
int V8HeapExplorer::EstimateObjectsCount(HeapIterator* iterator) {
int objects_count = 0;
for (HeapObject* obj = iterator->next();
obj != NULL;
obj = iterator->next()) {
objects_count++;
}
return objects_count;
}
class IndexedReferencesExtractor : public ObjectVisitor {
public:
IndexedReferencesExtractor(V8HeapExplorer* generator,
HeapObject* parent_obj,
int parent)
: generator_(generator),
parent_obj_(parent_obj),
parent_(parent),
next_index_(0) {
}
void VisitCodeEntry(Address entry_address) {
Code* code = Code::cast(Code::GetObjectFromEntryAddress(entry_address));
generator_->SetInternalReference(parent_obj_, parent_, "code", code);
generator_->TagCodeObject(code);
}
void VisitPointers(Object** start, Object** end) {
for (Object** p = start; p < end; p++) {
++next_index_;
if (CheckVisitedAndUnmark(p)) continue;
generator_->SetHiddenReference(parent_obj_, parent_, next_index_, *p);
}
}
static void MarkVisitedField(HeapObject* obj, int offset) {
if (offset < 0) return;
Address field = obj->address() + offset;
DCHECK(Memory::Object_at(field)->IsHeapObject());
intptr_t p = reinterpret_cast<intptr_t>(Memory::Object_at(field));
DCHECK(!IsMarked(p));
intptr_t p_tagged = p | kTag;
Memory::Object_at(field) = reinterpret_cast<Object*>(p_tagged);
}
private:
bool CheckVisitedAndUnmark(Object** field) {
intptr_t p = reinterpret_cast<intptr_t>(*field);
if (IsMarked(p)) {
intptr_t p_untagged = (p & ~kTaggingMask) | kHeapObjectTag;
*field = reinterpret_cast<Object*>(p_untagged);
DCHECK((*field)->IsHeapObject());
return true;
}
return false;
}
static const intptr_t kTaggingMask = 3;
static const intptr_t kTag = 3;
static bool IsMarked(intptr_t p) { return (p & kTaggingMask) == kTag; }
V8HeapExplorer* generator_;
HeapObject* parent_obj_;
int parent_;
int next_index_;
};
bool V8HeapExplorer::ExtractReferencesPass1(int entry, HeapObject* obj) {
if (obj->IsFixedArray()) return false; // FixedArrays are processed on pass 2
if (obj->IsJSGlobalProxy()) {
ExtractJSGlobalProxyReferences(entry, JSGlobalProxy::cast(obj));
} else if (obj->IsJSArrayBuffer()) {
ExtractJSArrayBufferReferences(entry, JSArrayBuffer::cast(obj));
} else if (obj->IsJSObject()) {
if (obj->IsJSWeakSet()) {
ExtractJSWeakCollectionReferences(entry, JSWeakSet::cast(obj));
} else if (obj->IsJSWeakMap()) {
ExtractJSWeakCollectionReferences(entry, JSWeakMap::cast(obj));
} else if (obj->IsJSSet()) {
ExtractJSCollectionReferences(entry, JSSet::cast(obj));
} else if (obj->IsJSMap()) {
ExtractJSCollectionReferences(entry, JSMap::cast(obj));
}
ExtractJSObjectReferences(entry, JSObject::cast(obj));
} else if (obj->IsString()) {
ExtractStringReferences(entry, String::cast(obj));
} else if (obj->IsSymbol()) {
ExtractSymbolReferences(entry, Symbol::cast(obj));
} else if (obj->IsMap()) {
ExtractMapReferences(entry, Map::cast(obj));
} else if (obj->IsSharedFunctionInfo()) {
ExtractSharedFunctionInfoReferences(entry, SharedFunctionInfo::cast(obj));
} else if (obj->IsScript()) {
ExtractScriptReferences(entry, Script::cast(obj));
} else if (obj->IsAccessorInfo()) {
ExtractAccessorInfoReferences(entry, AccessorInfo::cast(obj));
} else if (obj->IsAccessorPair()) {
ExtractAccessorPairReferences(entry, AccessorPair::cast(obj));
} else if (obj->IsCodeCache()) {
ExtractCodeCacheReferences(entry, CodeCache::cast(obj));
} else if (obj->IsCode()) {
ExtractCodeReferences(entry, Code::cast(obj));
} else if (obj->IsBox()) {
ExtractBoxReferences(entry, Box::cast(obj));
} else if (obj->IsCell()) {
ExtractCellReferences(entry, Cell::cast(obj));
} else if (obj->IsPropertyCell()) {
ExtractPropertyCellReferences(entry, PropertyCell::cast(obj));
} else if (obj->IsAllocationSite()) {
ExtractAllocationSiteReferences(entry, AllocationSite::cast(obj));
}
return true;
}
bool V8HeapExplorer::ExtractReferencesPass2(int entry, HeapObject* obj) {
if (!obj->IsFixedArray()) return false;
if (obj->IsContext()) {
ExtractContextReferences(entry, Context::cast(obj));
} else {
ExtractFixedArrayReferences(entry, FixedArray::cast(obj));
}
return true;
}
void V8HeapExplorer::ExtractJSGlobalProxyReferences(
int entry, JSGlobalProxy* proxy) {
SetInternalReference(proxy, entry,
"native_context", proxy->native_context(),
JSGlobalProxy::kNativeContextOffset);
}
void V8HeapExplorer::ExtractJSObjectReferences(
int entry, JSObject* js_obj) {
HeapObject* obj = js_obj;
ExtractClosureReferences(js_obj, entry);
ExtractPropertyReferences(js_obj, entry);
ExtractElementReferences(js_obj, entry);
ExtractInternalReferences(js_obj, entry);
PrototypeIterator iter(heap_->isolate(), js_obj);
SetPropertyReference(obj, entry, heap_->proto_string(), iter.GetCurrent());
if (obj->IsJSFunction()) {
JSFunction* js_fun = JSFunction::cast(js_obj);
Object* proto_or_map = js_fun->prototype_or_initial_map();
if (!proto_or_map->IsTheHole()) {
if (!proto_or_map->IsMap()) {
SetPropertyReference(
obj, entry,
heap_->prototype_string(), proto_or_map,
NULL,
JSFunction::kPrototypeOrInitialMapOffset);
} else {
SetPropertyReference(
obj, entry,
heap_->prototype_string(), js_fun->prototype());
SetInternalReference(
obj, entry, "initial_map", proto_or_map,
JSFunction::kPrototypeOrInitialMapOffset);
}
}
SharedFunctionInfo* shared_info = js_fun->shared();
// JSFunction has either bindings or literals and never both.
bool bound = shared_info->bound();
TagObject(js_fun->literals_or_bindings(),
bound ? "(function bindings)" : "(function literals)");
SetInternalReference(js_fun, entry,
bound ? "bindings" : "literals",
js_fun->literals_or_bindings(),
JSFunction::kLiteralsOffset);
TagObject(shared_info, "(shared function info)");
SetInternalReference(js_fun, entry,
"shared", shared_info,
JSFunction::kSharedFunctionInfoOffset);
TagObject(js_fun->context(), "(context)");
SetInternalReference(js_fun, entry,
"context", js_fun->context(),
JSFunction::kContextOffset);
SetWeakReference(js_fun, entry,
"next_function_link", js_fun->next_function_link(),
JSFunction::kNextFunctionLinkOffset);
STATIC_ASSERT(JSFunction::kNextFunctionLinkOffset
== JSFunction::kNonWeakFieldsEndOffset);
STATIC_ASSERT(JSFunction::kNextFunctionLinkOffset + kPointerSize
== JSFunction::kSize);
} else if (obj->IsGlobalObject()) {
GlobalObject* global_obj = GlobalObject::cast(obj);
SetInternalReference(global_obj, entry,
"builtins", global_obj->builtins(),
GlobalObject::kBuiltinsOffset);
SetInternalReference(global_obj, entry,
"native_context", global_obj->native_context(),
GlobalObject::kNativeContextOffset);
SetInternalReference(global_obj, entry,
"global_context", global_obj->global_context(),
GlobalObject::kGlobalContextOffset);
SetInternalReference(global_obj, entry,
"global_proxy", global_obj->global_proxy(),
GlobalObject::kGlobalProxyOffset);
STATIC_ASSERT(GlobalObject::kHeaderSize - JSObject::kHeaderSize ==
4 * kPointerSize);
} else if (obj->IsJSArrayBufferView()) {
JSArrayBufferView* view = JSArrayBufferView::cast(obj);
SetInternalReference(view, entry, "buffer", view->buffer(),
JSArrayBufferView::kBufferOffset);
SetWeakReference(view, entry, "weak_next", view->weak_next(),
JSArrayBufferView::kWeakNextOffset);
}
TagObject(js_obj->properties(), "(object properties)");
SetInternalReference(obj, entry,
"properties", js_obj->properties(),
JSObject::kPropertiesOffset);
TagObject(js_obj->elements(), "(object elements)");
SetInternalReference(obj, entry,
"elements", js_obj->elements(),
JSObject::kElementsOffset);
}
void V8HeapExplorer::ExtractStringReferences(int entry, String* string) {
if (string->IsConsString()) {
ConsString* cs = ConsString::cast(string);
SetInternalReference(cs, entry, "first", cs->first(),
ConsString::kFirstOffset);
SetInternalReference(cs, entry, "second", cs->second(),
ConsString::kSecondOffset);
} else if (string->IsSlicedString()) {
SlicedString* ss = SlicedString::cast(string);
SetInternalReference(ss, entry, "parent", ss->parent(),
SlicedString::kParentOffset);
}
}
void V8HeapExplorer::ExtractSymbolReferences(int entry, Symbol* symbol) {
SetInternalReference(symbol, entry,
"name", symbol->name(),
Symbol::kNameOffset);
}
void V8HeapExplorer::ExtractJSCollectionReferences(int entry,
JSCollection* collection) {
SetInternalReference(collection, entry, "table", collection->table(),
JSCollection::kTableOffset);
}
void V8HeapExplorer::ExtractJSWeakCollectionReferences(
int entry, JSWeakCollection* collection) {
MarkAsWeakContainer(collection->table());
SetInternalReference(collection, entry,
"table", collection->table(),
JSWeakCollection::kTableOffset);
}
void V8HeapExplorer::ExtractContextReferences(int entry, Context* context) {
if (context == context->declaration_context()) {
ScopeInfo* scope_info = context->closure()->shared()->scope_info();
// Add context allocated locals.
int context_locals = scope_info->ContextLocalCount();
for (int i = 0; i < context_locals; ++i) {
String* local_name = scope_info->ContextLocalName(i);
int idx = Context::MIN_CONTEXT_SLOTS + i;
SetContextReference(context, entry, local_name, context->get(idx),
Context::OffsetOfElementAt(idx));
}
if (scope_info->HasFunctionName()) {
String* name = scope_info->FunctionName();
VariableMode mode;
int idx = scope_info->FunctionContextSlotIndex(name, &mode);
if (idx >= 0) {
SetContextReference(context, entry, name, context->get(idx),
Context::OffsetOfElementAt(idx));
}
}
}
#define EXTRACT_CONTEXT_FIELD(index, type, name) \
if (Context::index < Context::FIRST_WEAK_SLOT || \
Context::index == Context::MAP_CACHE_INDEX) { \
SetInternalReference(context, entry, #name, context->get(Context::index), \
FixedArray::OffsetOfElementAt(Context::index)); \
} else { \
SetWeakReference(context, entry, #name, context->get(Context::index), \
FixedArray::OffsetOfElementAt(Context::index)); \
}
EXTRACT_CONTEXT_FIELD(CLOSURE_INDEX, JSFunction, closure);
EXTRACT_CONTEXT_FIELD(PREVIOUS_INDEX, Context, previous);
EXTRACT_CONTEXT_FIELD(EXTENSION_INDEX, Object, extension);
EXTRACT_CONTEXT_FIELD(GLOBAL_OBJECT_INDEX, GlobalObject, global);
if (context->IsNativeContext()) {
TagObject(context->jsfunction_result_caches(),
"(context func. result caches)");
TagObject(context->normalized_map_cache(), "(context norm. map cache)");
TagObject(context->runtime_context(), "(runtime context)");
TagObject(context->embedder_data(), "(context data)");
NATIVE_CONTEXT_FIELDS(EXTRACT_CONTEXT_FIELD);
EXTRACT_CONTEXT_FIELD(OPTIMIZED_FUNCTIONS_LIST, unused,
optimized_functions_list);
EXTRACT_CONTEXT_FIELD(OPTIMIZED_CODE_LIST, unused, optimized_code_list);
EXTRACT_CONTEXT_FIELD(DEOPTIMIZED_CODE_LIST, unused, deoptimized_code_list);
EXTRACT_CONTEXT_FIELD(NEXT_CONTEXT_LINK, unused, next_context_link);
#undef EXTRACT_CONTEXT_FIELD
STATIC_ASSERT(Context::OPTIMIZED_FUNCTIONS_LIST ==
Context::FIRST_WEAK_SLOT);
STATIC_ASSERT(Context::NEXT_CONTEXT_LINK + 1 ==
Context::NATIVE_CONTEXT_SLOTS);
STATIC_ASSERT(Context::FIRST_WEAK_SLOT + 5 ==
Context::NATIVE_CONTEXT_SLOTS);
}
}
void V8HeapExplorer::ExtractMapReferences(int entry, Map* map) {
if (map->HasTransitionArray()) {
TransitionArray* transitions = map->transitions();
int transitions_entry = GetEntry(transitions)->index();
Object* back_pointer = transitions->back_pointer_storage();
TagObject(back_pointer, "(back pointer)");
SetInternalReference(transitions, transitions_entry,
"back_pointer", back_pointer);
if (FLAG_collect_maps && map->CanTransition()) {
if (!transitions->IsSimpleTransition()) {
if (transitions->HasPrototypeTransitions()) {
FixedArray* prototype_transitions =
transitions->GetPrototypeTransitions();
MarkAsWeakContainer(prototype_transitions);
TagObject(prototype_transitions, "(prototype transitions");
SetInternalReference(transitions, transitions_entry,
"prototype_transitions", prototype_transitions);
}
// TODO(alph): transitions keys are strong links.
MarkAsWeakContainer(transitions);
}
}
TagObject(transitions, "(transition array)");
SetInternalReference(map, entry,
"transitions", transitions,
Map::kTransitionsOrBackPointerOffset);
} else {
Object* back_pointer = map->GetBackPointer();
TagObject(back_pointer, "(back pointer)");
SetInternalReference(map, entry,
"back_pointer", back_pointer,
Map::kTransitionsOrBackPointerOffset);
}
DescriptorArray* descriptors = map->instance_descriptors();
TagObject(descriptors, "(map descriptors)");
SetInternalReference(map, entry,
"descriptors", descriptors,
Map::kDescriptorsOffset);
MarkAsWeakContainer(map->code_cache());
SetInternalReference(map, entry,
"code_cache", map->code_cache(),
Map::kCodeCacheOffset);
SetInternalReference(map, entry,
"prototype", map->prototype(), Map::kPrototypeOffset);
SetInternalReference(map, entry,
"constructor", map->constructor(),
Map::kConstructorOffset);
TagObject(map->dependent_code(), "(dependent code)");
MarkAsWeakContainer(map->dependent_code());
SetInternalReference(map, entry,
"dependent_code", map->dependent_code(),
Map::kDependentCodeOffset);
}
void V8HeapExplorer::ExtractSharedFunctionInfoReferences(
int entry, SharedFunctionInfo* shared) {
HeapObject* obj = shared;
String* shared_name = shared->DebugName();
const char* name = NULL;
if (shared_name != *heap_->isolate()->factory()->empty_string()) {
name = names_->GetName(shared_name);
TagObject(shared->code(), names_->GetFormatted("(code for %s)", name));
} else {
TagObject(shared->code(), names_->GetFormatted("(%s code)",
Code::Kind2String(shared->code()->kind())));
}
SetInternalReference(obj, entry,
"name", shared->name(),
SharedFunctionInfo::kNameOffset);
SetInternalReference(obj, entry,
"code", shared->code(),
SharedFunctionInfo::kCodeOffset);
TagObject(shared->scope_info(), "(function scope info)");
SetInternalReference(obj, entry,
"scope_info", shared->scope_info(),
SharedFunctionInfo::kScopeInfoOffset);
SetInternalReference(obj, entry,
"instance_class_name", shared->instance_class_name(),
SharedFunctionInfo::kInstanceClassNameOffset);
SetInternalReference(obj, entry,
"script", shared->script(),
SharedFunctionInfo::kScriptOffset);
const char* construct_stub_name = name ?
names_->GetFormatted("(construct stub code for %s)", name) :
"(construct stub code)";
TagObject(shared->construct_stub(), construct_stub_name);
SetInternalReference(obj, entry,
"construct_stub", shared->construct_stub(),
SharedFunctionInfo::kConstructStubOffset);
SetInternalReference(obj, entry,
"function_data", shared->function_data(),
SharedFunctionInfo::kFunctionDataOffset);
SetInternalReference(obj, entry,
"debug_info", shared->debug_info(),
SharedFunctionInfo::kDebugInfoOffset);
SetInternalReference(obj, entry,
"inferred_name", shared->inferred_name(),
SharedFunctionInfo::kInferredNameOffset);
SetInternalReference(obj, entry,
"optimized_code_map", shared->optimized_code_map(),
SharedFunctionInfo::kOptimizedCodeMapOffset);
SetInternalReference(obj, entry,
"feedback_vector", shared->feedback_vector(),
SharedFunctionInfo::kFeedbackVectorOffset);
}
void V8HeapExplorer::ExtractScriptReferences(int entry, Script* script) {
HeapObject* obj = script;
SetInternalReference(obj, entry,
"source", script->source(),
Script::kSourceOffset);
SetInternalReference(obj, entry,
"name", script->name(),
Script::kNameOffset);
SetInternalReference(obj, entry,
"context_data", script->context_data(),
Script::kContextOffset);
TagObject(script->line_ends(), "(script line ends)");
SetInternalReference(obj, entry,
"line_ends", script->line_ends(),
Script::kLineEndsOffset);
}
void V8HeapExplorer::ExtractAccessorInfoReferences(
int entry, AccessorInfo* accessor_info) {
SetInternalReference(accessor_info, entry, "name", accessor_info->name(),
AccessorInfo::kNameOffset);
SetInternalReference(accessor_info, entry, "expected_receiver_type",
accessor_info->expected_receiver_type(),
AccessorInfo::kExpectedReceiverTypeOffset);
if (accessor_info->IsDeclaredAccessorInfo()) {
DeclaredAccessorInfo* declared_accessor_info =
DeclaredAccessorInfo::cast(accessor_info);
SetInternalReference(declared_accessor_info, entry, "descriptor",
declared_accessor_info->descriptor(),
DeclaredAccessorInfo::kDescriptorOffset);
} else if (accessor_info->IsExecutableAccessorInfo()) {
ExecutableAccessorInfo* executable_accessor_info =
ExecutableAccessorInfo::cast(accessor_info);
SetInternalReference(executable_accessor_info, entry, "getter",
executable_accessor_info->getter(),
ExecutableAccessorInfo::kGetterOffset);
SetInternalReference(executable_accessor_info, entry, "setter",
executable_accessor_info->setter(),
ExecutableAccessorInfo::kSetterOffset);
SetInternalReference(executable_accessor_info, entry, "data",
executable_accessor_info->data(),
ExecutableAccessorInfo::kDataOffset);
}
}
void V8HeapExplorer::ExtractAccessorPairReferences(
int entry, AccessorPair* accessors) {
SetInternalReference(accessors, entry, "getter", accessors->getter(),
AccessorPair::kGetterOffset);
SetInternalReference(accessors, entry, "setter", accessors->setter(),
AccessorPair::kSetterOffset);
}
void V8HeapExplorer::ExtractCodeCacheReferences(
int entry, CodeCache* code_cache) {
TagObject(code_cache->default_cache(), "(default code cache)");
SetInternalReference(code_cache, entry,
"default_cache", code_cache->default_cache(),
CodeCache::kDefaultCacheOffset);
TagObject(code_cache->normal_type_cache(), "(code type cache)");
SetInternalReference(code_cache, entry,
"type_cache", code_cache->normal_type_cache(),
CodeCache::kNormalTypeCacheOffset);
}
void V8HeapExplorer::TagBuiltinCodeObject(Code* code, const char* name) {
TagObject(code, names_->GetFormatted("(%s builtin)", name));
}
void V8HeapExplorer::TagCodeObject(Code* code) {
if (code->kind() == Code::STUB) {
TagObject(code, names_->GetFormatted(
"(%s code)", CodeStub::MajorName(
CodeStub::GetMajorKey(code), true)));
}
}
void V8HeapExplorer::ExtractCodeReferences(int entry, Code* code) {
TagCodeObject(code);
TagObject(code->relocation_info(), "(code relocation info)");
SetInternalReference(code, entry,
"relocation_info", code->relocation_info(),
Code::kRelocationInfoOffset);
SetInternalReference(code, entry,
"handler_table", code->handler_table(),
Code::kHandlerTableOffset);
TagObject(code->deoptimization_data(), "(code deopt data)");
SetInternalReference(code, entry,
"deoptimization_data", code->deoptimization_data(),
Code::kDeoptimizationDataOffset);
if (code->kind() == Code::FUNCTION) {
SetInternalReference(code, entry,
"type_feedback_info", code->type_feedback_info(),
Code::kTypeFeedbackInfoOffset);
}
SetInternalReference(code, entry,
"gc_metadata", code->gc_metadata(),
Code::kGCMetadataOffset);
SetInternalReference(code, entry,
"constant_pool", code->constant_pool(),
Code::kConstantPoolOffset);
if (code->kind() == Code::OPTIMIZED_FUNCTION) {
SetWeakReference(code, entry,
"next_code_link", code->next_code_link(),
Code::kNextCodeLinkOffset);
}
}
void V8HeapExplorer::ExtractBoxReferences(int entry, Box* box) {
SetInternalReference(box, entry, "value", box->value(), Box::kValueOffset);
}
void V8HeapExplorer::ExtractCellReferences(int entry, Cell* cell) {
SetInternalReference(cell, entry, "value", cell->value(), Cell::kValueOffset);
}
void V8HeapExplorer::ExtractPropertyCellReferences(int entry,
PropertyCell* cell) {
ExtractCellReferences(entry, cell);
SetInternalReference(cell, entry, "type", cell->type(),
PropertyCell::kTypeOffset);
MarkAsWeakContainer(cell->dependent_code());
SetInternalReference(cell, entry, "dependent_code", cell->dependent_code(),
PropertyCell::kDependentCodeOffset);
}
void V8HeapExplorer::ExtractAllocationSiteReferences(int entry,
AllocationSite* site) {
SetInternalReference(site, entry, "transition_info", site->transition_info(),
AllocationSite::kTransitionInfoOffset);
SetInternalReference(site, entry, "nested_site", site->nested_site(),
AllocationSite::kNestedSiteOffset);
MarkAsWeakContainer(site->dependent_code());
SetInternalReference(site, entry, "dependent_code", site->dependent_code(),
AllocationSite::kDependentCodeOffset);
// Do not visit weak_next as it is not visited by the StaticVisitor,
// and we're not very interested in weak_next field here.
STATIC_ASSERT(AllocationSite::kWeakNextOffset >=
AllocationSite::BodyDescriptor::kEndOffset);
}
class JSArrayBufferDataEntryAllocator : public HeapEntriesAllocator {
public:
JSArrayBufferDataEntryAllocator(size_t size, V8HeapExplorer* explorer)
: size_(size)
, explorer_(explorer) {
}
virtual HeapEntry* AllocateEntry(HeapThing ptr) {
return explorer_->AddEntry(
static_cast<Address>(ptr),
HeapEntry::kNative, "system / JSArrayBufferData", size_);
}
private:
size_t size_;
V8HeapExplorer* explorer_;
};
void V8HeapExplorer::ExtractJSArrayBufferReferences(
int entry, JSArrayBuffer* buffer) {
SetWeakReference(buffer, entry, "weak_next", buffer->weak_next(),
JSArrayBuffer::kWeakNextOffset);
SetWeakReference(buffer, entry,
"weak_first_view", buffer->weak_first_view(),
JSArrayBuffer::kWeakFirstViewOffset);
// Setup a reference to a native memory backing_store object.
if (!buffer->backing_store())
return;
size_t data_size = NumberToSize(heap_->isolate(), buffer->byte_length());
JSArrayBufferDataEntryAllocator allocator(data_size, this);
HeapEntry* data_entry =
filler_->FindOrAddEntry(buffer->backing_store(), &allocator);
filler_->SetNamedReference(HeapGraphEdge::kInternal,
entry, "backing_store", data_entry);
}
void V8HeapExplorer::ExtractFixedArrayReferences(int entry, FixedArray* array) {
bool is_weak = weak_containers_.Contains(array);
for (int i = 0, l = array->length(); i < l; ++i) {
if (is_weak) {
SetWeakReference(array, entry,
i, array->get(i), array->OffsetOfElementAt(i));
} else {
SetInternalReference(array, entry,
i, array->get(i), array->OffsetOfElementAt(i));
}
}
}
void V8HeapExplorer::ExtractClosureReferences(JSObject* js_obj, int entry) {
if (!js_obj->IsJSFunction()) return;
JSFunction* func = JSFunction::cast(js_obj);
if (func->shared()->bound()) {
FixedArray* bindings = func->function_bindings();
SetNativeBindReference(js_obj, entry, "bound_this",
bindings->get(JSFunction::kBoundThisIndex));
SetNativeBindReference(js_obj, entry, "bound_function",
bindings->get(JSFunction::kBoundFunctionIndex));
for (int i = JSFunction::kBoundArgumentsStartIndex;
i < bindings->length(); i++) {
const char* reference_name = names_->GetFormatted(
"bound_argument_%d",
i - JSFunction::kBoundArgumentsStartIndex);
SetNativeBindReference(js_obj, entry, reference_name,
bindings->get(i));
}
}
}
void V8HeapExplorer::ExtractPropertyReferences(JSObject* js_obj, int entry) {
if (js_obj->HasFastProperties()) {
DescriptorArray* descs = js_obj->map()->instance_descriptors();
int real_size = js_obj->map()->NumberOfOwnDescriptors();
for (int i = 0; i < real_size; i++) {
switch (descs->GetType(i)) {
case FIELD: {
Representation r = descs->GetDetails(i).representation();
if (r.IsSmi() || r.IsDouble()) break;
int index = descs->GetFieldIndex(i);
Name* k = descs->GetKey(i);
if (index < js_obj->map()->inobject_properties()) {
Object* value = js_obj->InObjectPropertyAt(index);
if (k != heap_->hidden_string()) {
SetPropertyReference(
js_obj, entry,
k, value,
NULL,
js_obj->GetInObjectPropertyOffset(index));
} else {
TagObject(value, "(hidden properties)");
SetInternalReference(
js_obj, entry,
"hidden_properties", value,
js_obj->GetInObjectPropertyOffset(index));
}
} else {
FieldIndex field_index =
FieldIndex::ForDescriptor(js_obj->map(), i);
Object* value = js_obj->RawFastPropertyAt(field_index);
if (k != heap_->hidden_string()) {
SetPropertyReference(js_obj, entry, k, value);
} else {
TagObject(value, "(hidden properties)");
SetInternalReference(js_obj, entry, "hidden_properties", value);
}
}
break;
}
case CONSTANT:
SetPropertyReference(
js_obj, entry,
descs->GetKey(i), descs->GetConstant(i));
break;
case CALLBACKS:
ExtractAccessorPairProperty(
js_obj, entry,
descs->GetKey(i), descs->GetValue(i));
break;
case NORMAL: // only in slow mode
UNREACHABLE();
break;
}
}
} else {
NameDictionary* dictionary = js_obj->property_dictionary();
int length = dictionary->Capacity();
for (int i = 0; i < length; ++i) {
Object* k = dictionary->KeyAt(i);
if (dictionary->IsKey(k)) {
Object* target = dictionary->ValueAt(i);
// We assume that global objects can only have slow properties.
Object* value = target->IsPropertyCell()
? PropertyCell::cast(target)->value()
: target;
if (k == heap_->hidden_string()) {
TagObject(value, "(hidden properties)");
SetInternalReference(js_obj, entry, "hidden_properties", value);
continue;
}
if (ExtractAccessorPairProperty(js_obj, entry, k, value)) continue;
SetPropertyReference(js_obj, entry, Name::cast(k), value);
}
}
}
}
bool V8HeapExplorer::ExtractAccessorPairProperty(
JSObject* js_obj, int entry, Object* key, Object* callback_obj) {
if (!callback_obj->IsAccessorPair()) return false;
AccessorPair* accessors = AccessorPair::cast(callback_obj);
Object* getter = accessors->getter();
if (!getter->IsOddball()) {
SetPropertyReference(js_obj, entry, Name::cast(key), getter, "get %s");
}
Object* setter = accessors->setter();
if (!setter->IsOddball()) {
SetPropertyReference(js_obj, entry, Name::cast(key), setter, "set %s");
}
return true;
}
void V8HeapExplorer::ExtractElementReferences(JSObject* js_obj, int entry) {
if (js_obj->HasFastObjectElements()) {
FixedArray* elements = FixedArray::cast(js_obj->elements());
int length = js_obj->IsJSArray() ?
Smi::cast(JSArray::cast(js_obj)->length())->value() :
elements->length();
for (int i = 0; i < length; ++i) {
if (!elements->get(i)->IsTheHole()) {
SetElementReference(js_obj, entry, i, elements->get(i));
}
}
} else if (js_obj->HasDictionaryElements()) {
SeededNumberDictionary* dictionary = js_obj->element_dictionary();
int length = dictionary->Capacity();
for (int i = 0; i < length; ++i) {
Object* k = dictionary->KeyAt(i);
if (dictionary->IsKey(k)) {
DCHECK(k->IsNumber());
uint32_t index = static_cast<uint32_t>(k->Number());
SetElementReference(js_obj, entry, index, dictionary->ValueAt(i));
}
}
}
}
void V8HeapExplorer::ExtractInternalReferences(JSObject* js_obj, int entry) {
int length = js_obj->GetInternalFieldCount();
for (int i = 0; i < length; ++i) {
Object* o = js_obj->GetInternalField(i);
SetInternalReference(
js_obj, entry, i, o, js_obj->GetInternalFieldOffset(i));
}
}
String* V8HeapExplorer::GetConstructorName(JSObject* object) {
Heap* heap = object->GetHeap();
if (object->IsJSFunction()) return heap->closure_string();
String* constructor_name = object->constructor_name();
if (constructor_name == heap->Object_string()) {
// TODO(verwaest): Try to get object.constructor.name in this case.
// This requires handlification of the V8HeapExplorer.
}
return object->constructor_name();
}
HeapEntry* V8HeapExplorer::GetEntry(Object* obj) {
if (!obj->IsHeapObject()) return NULL;
return filler_->FindOrAddEntry(obj, this);
}
class RootsReferencesExtractor : public ObjectVisitor {
private:
struct IndexTag {
IndexTag(int index, VisitorSynchronization::SyncTag tag)
: index(index), tag(tag) { }
int index;
VisitorSynchronization::SyncTag tag;
};
public:
explicit RootsReferencesExtractor(Heap* heap)
: collecting_all_references_(false),
previous_reference_count_(0),
heap_(heap) {
}
void VisitPointers(Object** start, Object** end) {
if (collecting_all_references_) {
for (Object** p = start; p < end; p++) all_references_.Add(*p);
} else {
for (Object** p = start; p < end; p++) strong_references_.Add(*p);
}
}
void SetCollectingAllReferences() { collecting_all_references_ = true; }
void FillReferences(V8HeapExplorer* explorer) {
DCHECK(strong_references_.length() <= all_references_.length());
Builtins* builtins = heap_->isolate()->builtins();
int strong_index = 0, all_index = 0, tags_index = 0, builtin_index = 0;
while (all_index < all_references_.length()) {
bool is_strong = strong_index < strong_references_.length()
&& strong_references_[strong_index] == all_references_[all_index];
explorer->SetGcSubrootReference(reference_tags_[tags_index].tag,
!is_strong,
all_references_[all_index]);
if (reference_tags_[tags_index].tag ==
VisitorSynchronization::kBuiltins) {
DCHECK(all_references_[all_index]->IsCode());
explorer->TagBuiltinCodeObject(
Code::cast(all_references_[all_index]),
builtins->name(builtin_index++));
}
++all_index;
if (is_strong) ++strong_index;
if (reference_tags_[tags_index].index == all_index) ++tags_index;
}
}
void Synchronize(VisitorSynchronization::SyncTag tag) {
if (collecting_all_references_ &&
previous_reference_count_ != all_references_.length()) {
previous_reference_count_ = all_references_.length();
reference_tags_.Add(IndexTag(previous_reference_count_, tag));
}
}
private:
bool collecting_all_references_;
List<Object*> strong_references_;
List<Object*> all_references_;
int previous_reference_count_;
List<IndexTag> reference_tags_;
Heap* heap_;
};
bool V8HeapExplorer::IterateAndExtractReferences(
SnapshotFiller* filler) {
filler_ = filler;
// Create references to the synthetic roots.
SetRootGcRootsReference();
for (int tag = 0; tag < VisitorSynchronization::kNumberOfSyncTags; tag++) {
SetGcRootsReference(static_cast<VisitorSynchronization::SyncTag>(tag));
}
// Make sure builtin code objects get their builtin tags
// first. Otherwise a particular JSFunction object could set
// its custom name to a generic builtin.
RootsReferencesExtractor extractor(heap_);
heap_->IterateRoots(&extractor, VISIT_ONLY_STRONG);
extractor.SetCollectingAllReferences();
heap_->IterateRoots(&extractor, VISIT_ALL);
extractor.FillReferences(this);
// We have to do two passes as sometimes FixedArrays are used
// to weakly hold their items, and it's impossible to distinguish
// between these cases without processing the array owner first.
bool interrupted =
IterateAndExtractSinglePass<&V8HeapExplorer::ExtractReferencesPass1>() ||
IterateAndExtractSinglePass<&V8HeapExplorer::ExtractReferencesPass2>();
if (interrupted) {
filler_ = NULL;
return false;
}
filler_ = NULL;
return progress_->ProgressReport(true);
}
template<V8HeapExplorer::ExtractReferencesMethod extractor>
bool V8HeapExplorer::IterateAndExtractSinglePass() {
// Now iterate the whole heap.
bool interrupted = false;
HeapIterator iterator(heap_, HeapIterator::kFilterUnreachable);
// Heap iteration with filtering must be finished in any case.
for (HeapObject* obj = iterator.next();
obj != NULL;
obj = iterator.next(), progress_->ProgressStep()) {
if (interrupted) continue;
HeapEntry* heap_entry = GetEntry(obj);
int entry = heap_entry->index();
if ((this->*extractor)(entry, obj)) {
SetInternalReference(obj, entry,
"map", obj->map(), HeapObject::kMapOffset);
// Extract unvisited fields as hidden references and restore tags
// of visited fields.
IndexedReferencesExtractor refs_extractor(this, obj, entry);
obj->Iterate(&refs_extractor);
}
if (!progress_->ProgressReport(false)) interrupted = true;
}
return interrupted;
}
bool V8HeapExplorer::IsEssentialObject(Object* object) {
return object->IsHeapObject()
&& !object->IsOddball()
&& object != heap_->empty_byte_array()
&& object != heap_->empty_fixed_array()
&& object != heap_->empty_descriptor_array()
&& object != heap_->fixed_array_map()
&& object != heap_->cell_map()
&& object != heap_->global_property_cell_map()
&& object != heap_->shared_function_info_map()
&& object != heap_->free_space_map()
&& object != heap_->one_pointer_filler_map()
&& object != heap_->two_pointer_filler_map();
}
void V8HeapExplorer::SetContextReference(HeapObject* parent_obj,
int parent_entry,
String* reference_name,
Object* child_obj,
int field_offset) {
DCHECK(parent_entry == GetEntry(parent_obj)->index());
HeapEntry* child_entry = GetEntry(child_obj);
if (child_entry != NULL) {
filler_->SetNamedReference(HeapGraphEdge::kContextVariable,
parent_entry,
names_->GetName(reference_name),
child_entry);
IndexedReferencesExtractor::MarkVisitedField(parent_obj, field_offset);
}
}
void V8HeapExplorer::SetNativeBindReference(HeapObject* parent_obj,
int parent_entry,
const char* reference_name,
Object* child_obj) {
DCHECK(parent_entry == GetEntry(parent_obj)->index());
HeapEntry* child_entry = GetEntry(child_obj);
if (child_entry != NULL) {
filler_->SetNamedReference(HeapGraphEdge::kShortcut,
parent_entry,
reference_name,
child_entry);
}
}
void V8HeapExplorer::SetElementReference(HeapObject* parent_obj,
int parent_entry,
int index,
Object* child_obj) {
DCHECK(parent_entry == GetEntry(parent_obj)->index());
HeapEntry* child_entry = GetEntry(child_obj);
if (child_entry != NULL) {
filler_->SetIndexedReference(HeapGraphEdge::kElement,
parent_entry,
index,
child_entry);
}
}
void V8HeapExplorer::SetInternalReference(HeapObject* parent_obj,
int parent_entry,
const char* reference_name,
Object* child_obj,
int field_offset) {
DCHECK(parent_entry == GetEntry(parent_obj)->index());
HeapEntry* child_entry = GetEntry(child_obj);
if (child_entry == NULL) return;
if (IsEssentialObject(child_obj)) {
filler_->SetNamedReference(HeapGraphEdge::kInternal,
parent_entry,
reference_name,
child_entry);
}
IndexedReferencesExtractor::MarkVisitedField(parent_obj, field_offset);
}
void V8HeapExplorer::SetInternalReference(HeapObject* parent_obj,
int parent_entry,
int index,
Object* child_obj,
int field_offset) {
DCHECK(parent_entry == GetEntry(parent_obj)->index());
HeapEntry* child_entry = GetEntry(child_obj);
if (child_entry == NULL) return;
if (IsEssentialObject(child_obj)) {
filler_->SetNamedReference(HeapGraphEdge::kInternal,
parent_entry,
names_->GetName(index),
child_entry);
}
IndexedReferencesExtractor::MarkVisitedField(parent_obj, field_offset);
}
void V8HeapExplorer::SetHiddenReference(HeapObject* parent_obj,
int parent_entry,
int index,
Object* child_obj) {
DCHECK(parent_entry == GetEntry(parent_obj)->index());
HeapEntry* child_entry = GetEntry(child_obj);
if (child_entry != NULL && IsEssentialObject(child_obj)) {
filler_->SetIndexedReference(HeapGraphEdge::kHidden,
parent_entry,
index,
child_entry);
}
}
void V8HeapExplorer::SetWeakReference(HeapObject* parent_obj,
int parent_entry,
const char* reference_name,
Object* child_obj,
int field_offset) {
DCHECK(parent_entry == GetEntry(parent_obj)->index());
HeapEntry* child_entry = GetEntry(child_obj);
if (child_entry == NULL) return;
if (IsEssentialObject(child_obj)) {
filler_->SetNamedReference(HeapGraphEdge::kWeak,
parent_entry,
reference_name,
child_entry);
}
IndexedReferencesExtractor::MarkVisitedField(parent_obj, field_offset);
}
void V8HeapExplorer::SetWeakReference(HeapObject* parent_obj,
int parent_entry,
int index,
Object* child_obj,
int field_offset) {
DCHECK(parent_entry == GetEntry(parent_obj)->index());
HeapEntry* child_entry = GetEntry(child_obj);
if (child_entry == NULL) return;
if (IsEssentialObject(child_obj)) {
filler_->SetNamedReference(HeapGraphEdge::kWeak,
parent_entry,
names_->GetFormatted("%d", index),
child_entry);
}
IndexedReferencesExtractor::MarkVisitedField(parent_obj, field_offset);
}
void V8HeapExplorer::SetPropertyReference(HeapObject* parent_obj,
int parent_entry,
Name* reference_name,
Object* child_obj,
const char* name_format_string,
int field_offset) {
DCHECK(parent_entry == GetEntry(parent_obj)->index());
HeapEntry* child_entry = GetEntry(child_obj);
if (child_entry != NULL) {
HeapGraphEdge::Type type =
reference_name->IsSymbol() || String::cast(reference_name)->length() > 0
? HeapGraphEdge::kProperty : HeapGraphEdge::kInternal;
const char* name = name_format_string != NULL && reference_name->IsString()
? names_->GetFormatted(
name_format_string,
String::cast(reference_name)->ToCString(
DISALLOW_NULLS, ROBUST_STRING_TRAVERSAL).get()) :
names_->GetName(reference_name);
filler_->SetNamedReference(type,
parent_entry,
name,
child_entry);
IndexedReferencesExtractor::MarkVisitedField(parent_obj, field_offset);
}
}
void V8HeapExplorer::SetRootGcRootsReference() {
filler_->SetIndexedAutoIndexReference(
HeapGraphEdge::kElement,
snapshot_->root()->index(),
snapshot_->gc_roots());
}
void V8HeapExplorer::SetUserGlobalReference(Object* child_obj) {
HeapEntry* child_entry = GetEntry(child_obj);
DCHECK(child_entry != NULL);
filler_->SetNamedAutoIndexReference(
HeapGraphEdge::kShortcut,
snapshot_->root()->index(),
child_entry);
}
void V8HeapExplorer::SetGcRootsReference(VisitorSynchronization::SyncTag tag) {
filler_->SetIndexedAutoIndexReference(
HeapGraphEdge::kElement,
snapshot_->gc_roots()->index(),
snapshot_->gc_subroot(tag));
}
void V8HeapExplorer::SetGcSubrootReference(
VisitorSynchronization::SyncTag tag, bool is_weak, Object* child_obj) {
HeapEntry* child_entry = GetEntry(child_obj);
if (child_entry != NULL) {
const char* name = GetStrongGcSubrootName(child_obj);
if (name != NULL) {
filler_->SetNamedReference(
HeapGraphEdge::kInternal,
snapshot_->gc_subroot(tag)->index(),
name,
child_entry);
} else {
if (is_weak) {
filler_->SetNamedAutoIndexReference(
HeapGraphEdge::kWeak,
snapshot_->gc_subroot(tag)->index(),
child_entry);
} else {
filler_->SetIndexedAutoIndexReference(
HeapGraphEdge::kElement,
snapshot_->gc_subroot(tag)->index(),
child_entry);
}
}
// Add a shortcut to JS global object reference at snapshot root.
if (child_obj->IsNativeContext()) {
Context* context = Context::cast(child_obj);
GlobalObject* global = context->global_object();
if (global->IsJSGlobalObject()) {
bool is_debug_object = false;
is_debug_object = heap_->isolate()->debug()->IsDebugGlobal(global);
if (!is_debug_object && !user_roots_.Contains(global)) {
user_roots_.Insert(global);
SetUserGlobalReference(global);
}
}
}
}
}
const char* V8HeapExplorer::GetStrongGcSubrootName(Object* object) {
if (strong_gc_subroot_names_.is_empty()) {
#define NAME_ENTRY(name) strong_gc_subroot_names_.SetTag(heap_->name(), #name);
#define ROOT_NAME(type, name, camel_name) NAME_ENTRY(name)
STRONG_ROOT_LIST(ROOT_NAME)
#undef ROOT_NAME
#define STRUCT_MAP_NAME(NAME, Name, name) NAME_ENTRY(name##_map)
STRUCT_LIST(STRUCT_MAP_NAME)
#undef STRUCT_MAP_NAME
#define STRING_NAME(name, str) NAME_ENTRY(name)
INTERNALIZED_STRING_LIST(STRING_NAME)
#undef STRING_NAME
#define SYMBOL_NAME(name) NAME_ENTRY(name)
PRIVATE_SYMBOL_LIST(SYMBOL_NAME)
#undef SYMBOL_NAME
#undef NAME_ENTRY
CHECK(!strong_gc_subroot_names_.is_empty());
}
return strong_gc_subroot_names_.GetTag(object);
}
void V8HeapExplorer::TagObject(Object* obj, const char* tag) {
if (IsEssentialObject(obj)) {
HeapEntry* entry = GetEntry(obj);
if (entry->name()[0] == '\0') {
entry->set_name(tag);
}
}
}
void V8HeapExplorer::MarkAsWeakContainer(Object* object) {
if (IsEssentialObject(object) && object->IsFixedArray()) {
weak_containers_.Insert(object);
}
}
class GlobalObjectsEnumerator : public ObjectVisitor {
public:
virtual void VisitPointers(Object** start, Object** end) {
for (Object** p = start; p < end; p++) {
if ((*p)->IsNativeContext()) {
Context* context = Context::cast(*p);
JSObject* proxy = context->global_proxy();
if (proxy->IsJSGlobalProxy()) {
Object* global = proxy->map()->prototype();
if (global->IsJSGlobalObject()) {
objects_.Add(Handle<JSGlobalObject>(JSGlobalObject::cast(global)));
}
}
}
}
}
int count() { return objects_.length(); }
Handle<JSGlobalObject>& at(int i) { return objects_[i]; }
private:
List<Handle<JSGlobalObject> > objects_;
};
// Modifies heap. Must not be run during heap traversal.
void V8HeapExplorer::TagGlobalObjects() {
Isolate* isolate = heap_->isolate();
HandleScope scope(isolate);
GlobalObjectsEnumerator enumerator;
isolate->global_handles()->IterateAllRoots(&enumerator);
const char** urls = NewArray<const char*>(enumerator.count());
for (int i = 0, l = enumerator.count(); i < l; ++i) {
if (global_object_name_resolver_) {
HandleScope scope(isolate);
Handle<JSGlobalObject> global_obj = enumerator.at(i);
urls[i] = global_object_name_resolver_->GetName(
Utils::ToLocal(Handle<JSObject>::cast(global_obj)));
} else {
urls[i] = NULL;
}
}
DisallowHeapAllocation no_allocation;
for (int i = 0, l = enumerator.count(); i < l; ++i) {
objects_tags_.SetTag(*enumerator.at(i), urls[i]);
}
DeleteArray(urls);
}
class GlobalHandlesExtractor : public ObjectVisitor {
public:
explicit GlobalHandlesExtractor(NativeObjectsExplorer* explorer)
: explorer_(explorer) {}
virtual ~GlobalHandlesExtractor() {}
virtual void VisitPointers(Object** start, Object** end) {
UNREACHABLE();
}
virtual void VisitEmbedderReference(Object** p, uint16_t class_id) {
explorer_->VisitSubtreeWrapper(p, class_id);
}
private:
NativeObjectsExplorer* explorer_;
};
class BasicHeapEntriesAllocator : public HeapEntriesAllocator {
public:
BasicHeapEntriesAllocator(
HeapSnapshot* snapshot,
HeapEntry::Type entries_type)
: snapshot_(snapshot),
names_(snapshot_->profiler()->names()),
heap_object_map_(snapshot_->profiler()->heap_object_map()),
entries_type_(entries_type) {
}
virtual HeapEntry* AllocateEntry(HeapThing ptr);
private:
HeapSnapshot* snapshot_;
StringsStorage* names_;
HeapObjectsMap* heap_object_map_;
HeapEntry::Type entries_type_;
};
HeapEntry* BasicHeapEntriesAllocator::AllocateEntry(HeapThing ptr) {
v8::RetainedObjectInfo* info = reinterpret_cast<v8::RetainedObjectInfo*>(ptr);
intptr_t elements = info->GetElementCount();
intptr_t size = info->GetSizeInBytes();
const char* name = elements != -1
? names_->GetFormatted(
"%s / %" V8_PTR_PREFIX "d entries", info->GetLabel(), elements)
: names_->GetCopy(info->GetLabel());
return snapshot_->AddEntry(
entries_type_,
name,
heap_object_map_->GenerateId(info),
size != -1 ? static_cast<int>(size) : 0,
0);
}
NativeObjectsExplorer::NativeObjectsExplorer(
HeapSnapshot* snapshot,
SnapshottingProgressReportingInterface* progress)
: isolate_(snapshot->profiler()->heap_object_map()->heap()->isolate()),
snapshot_(snapshot),
names_(snapshot_->profiler()->names()),
embedder_queried_(false),
objects_by_info_(RetainedInfosMatch),
native_groups_(StringsMatch),
filler_(NULL) {
synthetic_entries_allocator_ =
new BasicHeapEntriesAllocator(snapshot, HeapEntry::kSynthetic);
native_entries_allocator_ =
new BasicHeapEntriesAllocator(snapshot, HeapEntry::kNative);
}
NativeObjectsExplorer::~NativeObjectsExplorer() {
for (HashMap::Entry* p = objects_by_info_.Start();
p != NULL;
p = objects_by_info_.Next(p)) {
v8::RetainedObjectInfo* info =
reinterpret_cast<v8::RetainedObjectInfo*>(p->key);
info->Dispose();
List<HeapObject*>* objects =
reinterpret_cast<List<HeapObject*>* >(p->value);
delete objects;
}
for (HashMap::Entry* p = native_groups_.Start();
p != NULL;
p = native_groups_.Next(p)) {
v8::RetainedObjectInfo* info =
reinterpret_cast<v8::RetainedObjectInfo*>(p->value);
info->Dispose();
}
delete synthetic_entries_allocator_;
delete native_entries_allocator_;
}
int NativeObjectsExplorer::EstimateObjectsCount() {
FillRetainedObjects();
return objects_by_info_.occupancy();
}
void NativeObjectsExplorer::FillRetainedObjects() {
if (embedder_queried_) return;
Isolate* isolate = isolate_;
const GCType major_gc_type = kGCTypeMarkSweepCompact;
// Record objects that are joined into ObjectGroups.
isolate->heap()->CallGCPrologueCallbacks(
major_gc_type, kGCCallbackFlagConstructRetainedObjectInfos);
List<ObjectGroup*>* groups = isolate->global_handles()->object_groups();
for (int i = 0; i < groups->length(); ++i) {
ObjectGroup* group = groups->at(i);
if (group->info == NULL) continue;
List<HeapObject*>* list = GetListMaybeDisposeInfo(group->info);
for (size_t j = 0; j < group->length; ++j) {
HeapObject* obj = HeapObject::cast(*group->objects[j]);
list->Add(obj);
in_groups_.Insert(obj);
}
group->info = NULL; // Acquire info object ownership.
}
isolate->global_handles()->RemoveObjectGroups();
isolate->heap()->CallGCEpilogueCallbacks(major_gc_type, kNoGCCallbackFlags);
// Record objects that are not in ObjectGroups, but have class ID.
GlobalHandlesExtractor extractor(this);
isolate->global_handles()->IterateAllRootsWithClassIds(&extractor);
embedder_queried_ = true;
}
void NativeObjectsExplorer::FillImplicitReferences() {
Isolate* isolate = isolate_;
List<ImplicitRefGroup*>* groups =
isolate->global_handles()->implicit_ref_groups();
for (int i = 0; i < groups->length(); ++i) {
ImplicitRefGroup* group = groups->at(i);
HeapObject* parent = *group->parent;
int parent_entry =
filler_->FindOrAddEntry(parent, native_entries_allocator_)->index();
DCHECK(parent_entry != HeapEntry::kNoEntry);
Object*** children = group->children;
for (size_t j = 0; j < group->length; ++j) {
Object* child = *children[j];
HeapEntry* child_entry =
filler_->FindOrAddEntry(child, native_entries_allocator_);
filler_->SetNamedReference(
HeapGraphEdge::kInternal,
parent_entry,
"native",
child_entry);
}
}
isolate->global_handles()->RemoveImplicitRefGroups();
}
List<HeapObject*>* NativeObjectsExplorer::GetListMaybeDisposeInfo(
v8::RetainedObjectInfo* info) {
HashMap::Entry* entry =
objects_by_info_.Lookup(info, InfoHash(info), true);
if (entry->value != NULL) {
info->Dispose();
} else {
entry->value = new List<HeapObject*>(4);
}
return reinterpret_cast<List<HeapObject*>* >(entry->value);
}
bool NativeObjectsExplorer::IterateAndExtractReferences(
SnapshotFiller* filler) {
filler_ = filler;
FillRetainedObjects();
FillImplicitReferences();
if (EstimateObjectsCount() > 0) {
for (HashMap::Entry* p = objects_by_info_.Start();
p != NULL;
p = objects_by_info_.Next(p)) {
v8::RetainedObjectInfo* info =
reinterpret_cast<v8::RetainedObjectInfo*>(p->key);
SetNativeRootReference(info);
List<HeapObject*>* objects =
reinterpret_cast<List<HeapObject*>* >(p->value);
for (int i = 0; i < objects->length(); ++i) {
SetWrapperNativeReferences(objects->at(i), info);
}
}
SetRootNativeRootsReference();
}
filler_ = NULL;
return true;
}
class NativeGroupRetainedObjectInfo : public v8::RetainedObjectInfo {
public:
explicit NativeGroupRetainedObjectInfo(const char* label)
: disposed_(false),
hash_(reinterpret_cast<intptr_t>(label)),
label_(label) {
}
virtual ~NativeGroupRetainedObjectInfo() {}
virtual void Dispose() {
CHECK(!disposed_);
disposed_ = true;
delete this;
}
virtual bool IsEquivalent(RetainedObjectInfo* other) {
return hash_ == other->GetHash() && !strcmp(label_, other->GetLabel());
}
virtual