v8/src/heap-snapshot-generator.cc

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// Copyright 2013 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include "v8.h"
#include "heap-snapshot-generator-inl.h"
#include "heap-profiler.h"
#include "debug.h"
#include "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) {
ASSERT(type == kContextVariable
|| type == kProperty
|| type == kInternal
|| type == kShortcut);
}
HeapGraphEdge::HeapGraphEdge(Type type, int index, int from, int to)
: type_(type),
from_index_(from),
to_index_(to),
index_(index) {
ASSERT(type == kElement || type == kHidden || type == kWeak);
}
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,
int self_size)
: type_(type),
children_count_(0),
children_index_(-1),
self_size_(self_size),
id_(id),
snapshot_(snapshot),
name_(name) { }
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_;
}
Handle<HeapObject> HeapEntry::GetHeapObject() {
return snapshot_->collection()->FindHeapObjectById(id());
}
void HeapEntry::Print(
const char* prefix, const char* edge_name, int max_depth, int indent) {
STATIC_CHECK(sizeof(unsigned) == sizeof(id()));
OS::Print("%6d @%6u %*c %s%s: ",
self_size(), id(), indent, ' ', prefix, edge_name);
if (type() != kString) {
OS::Print("%s %.40s\n", TypeAsString(), name_);
} else {
OS::Print("\"");
const char* c = name_;
while (*c && (c - name_) <= 40) {
if (*c != '\n')
OS::Print("%c", *c);
else
OS::Print("\\n");
++c;
}
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:
OS::SNPrintF(index, "%d", edge.index());
break;
case HeapGraphEdge::kInternal:
edge_prefix = "$";
edge_name = edge.name();
break;
case HeapGraphEdge::kProperty:
edge_name = edge.name();
break;
case HeapGraphEdge::kHidden:
edge_prefix = "$";
OS::SNPrintF(index, "%d", edge.index());
break;
case HeapGraphEdge::kShortcut:
edge_prefix = "^";
edge_name = edge.name();
break;
case HeapGraphEdge::kWeak:
edge_prefix = "w";
OS::SNPrintF(index, "%d", edge.index());
break;
default:
OS::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/";
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 = 24;
static const int kExpectedHeapSnapshotsCollectionSize = 100;
static const int kExpectedHeapSnapshotSize = 132;
};
template <> struct SnapshotSizeConstants<8> {
static const int kExpectedHeapGraphEdgeSize = 24;
static const int kExpectedHeapEntrySize = 32;
static const int kExpectedHeapSnapshotsCollectionSize = 152;
static const int kExpectedHeapSnapshotSize = 160;
};
} // namespace
HeapSnapshot::HeapSnapshot(HeapSnapshotsCollection* collection,
const char* title,
unsigned uid)
: collection_(collection),
title_(title),
uid_(uid),
root_index_(HeapEntry::kNoEntry),
gc_roots_index_(HeapEntry::kNoEntry),
natives_root_index_(HeapEntry::kNoEntry),
max_snapshot_js_object_id_(0) {
STATIC_CHECK(
sizeof(HeapGraphEdge) ==
SnapshotSizeConstants<kPointerSize>::kExpectedHeapGraphEdgeSize);
STATIC_CHECK(
sizeof(HeapEntry) ==
SnapshotSizeConstants<kPointerSize>::kExpectedHeapEntrySize);
for (int i = 0; i < VisitorSynchronization::kNumberOfSyncTags; ++i) {
gc_subroot_indexes_[i] = HeapEntry::kNoEntry;
}
}
void HeapSnapshot::Delete() {
collection_->RemoveSnapshot(this);
delete this;
}
void HeapSnapshot::RememberLastJSObjectId() {
max_snapshot_js_object_id_ = collection_->last_assigned_id();
}
HeapEntry* HeapSnapshot::AddRootEntry() {
ASSERT(root_index_ == HeapEntry::kNoEntry);
ASSERT(entries_.is_empty()); // Root entry must be the first one.
HeapEntry* entry = AddEntry(HeapEntry::kObject,
"",
HeapObjectsMap::kInternalRootObjectId,
0);
root_index_ = entry->index();
ASSERT(root_index_ == 0);
return entry;
}
HeapEntry* HeapSnapshot::AddGcRootsEntry() {
ASSERT(gc_roots_index_ == HeapEntry::kNoEntry);
HeapEntry* entry = AddEntry(HeapEntry::kObject,
"(GC roots)",
HeapObjectsMap::kGcRootsObjectId,
0);
gc_roots_index_ = entry->index();
return entry;
}
HeapEntry* HeapSnapshot::AddGcSubrootEntry(int tag) {
ASSERT(gc_subroot_indexes_[tag] == HeapEntry::kNoEntry);
ASSERT(0 <= tag && tag < VisitorSynchronization::kNumberOfSyncTags);
HeapEntry* entry = AddEntry(
HeapEntry::kObject,
VisitorSynchronization::kTagNames[tag],
HeapObjectsMap::GetNthGcSubrootId(tag),
0);
gc_subroot_indexes_[tag] = entry->index();
return entry;
}
HeapEntry* HeapSnapshot::AddEntry(HeapEntry::Type type,
const char* name,
SnapshotObjectId id,
int size) {
HeapEntry entry(this, type, name, id, size);
entries_.Add(entry);
return &entries_.last();
}
void HeapSnapshot::FillChildren() {
ASSERT(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);
}
ASSERT(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);
}
template<typename T, class P>
static size_t GetMemoryUsedByList(const List<T, P>& list) {
return list.length() * sizeof(T) + sizeof(list);
}
size_t HeapSnapshot::RawSnapshotSize() const {
STATIC_CHECK(SnapshotSizeConstants<kPointerSize>::kExpectedHeapSnapshotSize ==
sizeof(HeapSnapshot)); // NOLINT
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;
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));
}
void HeapObjectsMap::SnapshotGenerationFinished() {
RemoveDeadEntries();
}
void HeapObjectsMap::MoveObject(Address from, Address to) {
ASSERT(to != NULL);
ASSERT(from != NULL);
if (from == to) return;
void* from_value = entries_map_.Remove(from, AddressHash(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, AddressHash(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, AddressHash(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;
to_entry->value = from_value;
}
}
SnapshotObjectId HeapObjectsMap::FindEntry(Address addr) {
HashMap::Entry* entry = entries_map_.Lookup(addr, AddressHash(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);
ASSERT(static_cast<uint32_t>(entries_.length()) > entries_map_.occupancy());
return entry_info.id;
}
SnapshotObjectId HeapObjectsMap::FindOrAddEntry(Address addr,
unsigned int size) {
ASSERT(static_cast<uint32_t>(entries_.length()) > entries_map_.occupancy());
HashMap::Entry* entry = entries_map_.Lookup(addr, AddressHash(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 = true;
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));
ASSERT(static_cast<uint32_t>(entries_.length()) > entries_map_.occupancy());
return id;
}
void HeapObjectsMap::StopHeapObjectsTracking() {
time_intervals_.Clear();
}
void HeapObjectsMap::UpdateHeapObjectsMap() {
HEAP->CollectAllGarbage(Heap::kMakeHeapIterableMask,
"HeapSnapshotsCollection::UpdateHeapObjectsMap");
HeapIterator iterator(heap_);
for (HeapObject* obj = iterator.next();
obj != NULL;
obj = iterator.next()) {
FindOrAddEntry(obj->address(), obj->Size());
}
RemoveDeadEntries();
}
SnapshotObjectId HeapObjectsMap::PushHeapObjectsStats(OutputStream* stream) {
UpdateHeapObjectsMap();
time_intervals_.Add(TimeInterval(next_id_));
int prefered_chunk_size = stream->GetChunkSize();
List<v8::HeapStatsUpdate> stats_buffer;
ASSERT(!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();
}
}
}
ASSERT(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() {
ASSERT(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, AddressHash(entry_info.addr), false);
ASSERT(entry);
entry->value = reinterpret_cast<void*>(first_free_entry);
++first_free_entry;
} else {
if (entry_info.addr) {
entries_map_.Remove(entry_info.addr, AddressHash(entry_info.addr));
}
}
}
entries_.Rewind(first_free_entry);
ASSERT(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_);
}
HeapSnapshotsCollection::HeapSnapshotsCollection(Heap* heap)
: is_tracking_objects_(false),
snapshots_uids_(HeapSnapshotsMatch),
token_enumerator_(new TokenEnumerator()),
ids_(heap) {
}
static void DeleteHeapSnapshot(HeapSnapshot** snapshot_ptr) {
delete *snapshot_ptr;
}
HeapSnapshotsCollection::~HeapSnapshotsCollection() {
delete token_enumerator_;
snapshots_.Iterate(DeleteHeapSnapshot);
}
HeapSnapshot* HeapSnapshotsCollection::NewSnapshot(const char* name,
unsigned uid) {
is_tracking_objects_ = true; // Start watching for heap objects moves.
return new HeapSnapshot(this, name, uid);
}
void HeapSnapshotsCollection::SnapshotGenerationFinished(
HeapSnapshot* snapshot) {
ids_.SnapshotGenerationFinished();
if (snapshot != NULL) {
snapshots_.Add(snapshot);
HashMap::Entry* entry =
snapshots_uids_.Lookup(reinterpret_cast<void*>(snapshot->uid()),
static_cast<uint32_t>(snapshot->uid()),
true);
ASSERT(entry->value == NULL);
entry->value = snapshot;
}
}
HeapSnapshot* HeapSnapshotsCollection::GetSnapshot(unsigned uid) {
HashMap::Entry* entry = snapshots_uids_.Lookup(reinterpret_cast<void*>(uid),
static_cast<uint32_t>(uid),
false);
return entry != NULL ? reinterpret_cast<HeapSnapshot*>(entry->value) : NULL;
}
void HeapSnapshotsCollection::RemoveSnapshot(HeapSnapshot* snapshot) {
snapshots_.RemoveElement(snapshot);
unsigned uid = snapshot->uid();
snapshots_uids_.Remove(reinterpret_cast<void*>(uid),
static_cast<uint32_t>(uid));
}
Handle<HeapObject> HeapSnapshotsCollection::FindHeapObjectById(
SnapshotObjectId id) {
// First perform a full GC in order to avoid dead objects.
HEAP->CollectAllGarbage(Heap::kMakeHeapIterableMask,
"HeapSnapshotsCollection::FindHeapObjectById");
DisallowHeapAllocation no_allocation;
HeapObject* object = NULL;
HeapIterator iterator(heap(), HeapIterator::kFilterUnreachable);
// Make sure that object with the given id is still reachable.
for (HeapObject* obj = iterator.next();
obj != NULL;
obj = iterator.next()) {
if (ids_.FindEntry(obj->address()) == id) {
ASSERT(object == NULL);
object = obj;
// Can't break -- kFilterUnreachable requires full heap traversal.
}
}
return object != NULL ? Handle<HeapObject>(object) : Handle<HeapObject>();
}
size_t HeapSnapshotsCollection::GetUsedMemorySize() const {
STATIC_CHECK(SnapshotSizeConstants<kPointerSize>::
kExpectedHeapSnapshotsCollectionSize ==
sizeof(HeapSnapshotsCollection)); // NOLINT
size_t size = sizeof(*this);
size += names_.GetUsedMemorySize();
size += ids_.GetUsedMemorySize();
size += sizeof(HashMap::Entry) * snapshots_uids_.capacity();
size += GetMemoryUsedByList(snapshots_);
for (int i = 0; i < snapshots_.length(); ++i) {
size += snapshots_[i]->RawSnapshotSize();
}
return size;
}
HeapEntriesMap::HeapEntriesMap()
: entries_(HeapThingsMatch) {
}
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);
ASSERT(cache_entry->value == NULL);
cache_entry->value = reinterpret_cast<void*>(static_cast<intptr_t>(entry));
}
HeapObjectsSet::HeapObjectsSet()
: entries_(HeapEntriesMap::HeapThingsMatch) {
}
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);
}
HeapObject* const V8HeapExplorer::kInternalRootObject =
reinterpret_cast<HeapObject*>(
static_cast<intptr_t>(HeapObjectsMap::kInternalRootObjectId));
HeapObject* const V8HeapExplorer::kGcRootsObject =
reinterpret_cast<HeapObject*>(
static_cast<intptr_t>(HeapObjectsMap::kGcRootsObjectId));
HeapObject* const V8HeapExplorer::kFirstGcSubrootObject =
reinterpret_cast<HeapObject*>(
static_cast<intptr_t>(HeapObjectsMap::kGcRootsFirstSubrootId));
HeapObject* const V8HeapExplorer::kLastGcSubrootObject =
reinterpret_cast<HeapObject*>(
static_cast<intptr_t>(HeapObjectsMap::kFirstAvailableObjectId));
V8HeapExplorer::V8HeapExplorer(
HeapSnapshot* snapshot,
SnapshottingProgressReportingInterface* progress,
v8::HeapProfiler::ObjectNameResolver* resolver)
: heap_(Isolate::Current()->heap()),
snapshot_(snapshot),
collection_(snapshot_->collection()),
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 == kInternalRootObject) {
snapshot_->AddRootEntry();
return snapshot_->root();
} else if (object == kGcRootsObject) {
HeapEntry* entry = snapshot_->AddGcRootsEntry();
return entry;
} else if (object >= kFirstGcSubrootObject && object < kLastGcSubrootObject) {
HeapEntry* entry = snapshot_->AddGcSubrootEntry(GetGcSubrootOrder(object));
return entry;
} else if (object->IsJSFunction()) {
JSFunction* func = JSFunction::cast(object);
SharedFunctionInfo* shared = func->shared();
const char* name = shared->bound() ? "native_bind" :
collection_->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,
collection_->names()->GetName(re->Pattern()));
} else if (object->IsJSObject()) {
const char* name = collection_->names()->GetName(
GetConstructorName(JSObject::cast(object)));
if (object->IsJSGlobalObject()) {
const char* tag = objects_tags_.GetTag(object);
if (tag != NULL) {
name = collection_->names()->GetFormatted("%s / %s", name, tag);
}
}
return AddEntry(object, HeapEntry::kObject, name);
} else if (object->IsString()) {
return AddEntry(object,
HeapEntry::kString,
collection_->names()->GetName(String::cast(object)));
} 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,
collection_->names()->GetName(name));
} else if (object->IsScript()) {
Object* name = Script::cast(object)->name();
return AddEntry(object,
HeapEntry::kCode,
name->IsString()
? collection_->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) {
int object_size = object->Size();
SnapshotObjectId object_id =
collection_->GetObjectId(object->address(), object_size);
return snapshot_->AddEntry(type, name, object_id, object_size);
}
class GcSubrootsEnumerator : public ObjectVisitor {
public:
GcSubrootsEnumerator(
SnapshotFillerInterface* filler, V8HeapExplorer* explorer)
: filler_(filler),
explorer_(explorer),
previous_object_count_(0),
object_count_(0) {
}
void VisitPointers(Object** start, Object** end) {
object_count_ += end - start;
}
void Synchronize(VisitorSynchronization::SyncTag tag) {
// Skip empty subroots.
if (previous_object_count_ != object_count_) {
previous_object_count_ = object_count_;
filler_->AddEntry(V8HeapExplorer::GetNthGcSubrootObject(tag), explorer_);
}
}
private:
SnapshotFillerInterface* filler_;
V8HeapExplorer* explorer_;
intptr_t previous_object_count_;
intptr_t object_count_;
};
void V8HeapExplorer::AddRootEntries(SnapshotFillerInterface* filler) {
filler->AddEntry(kInternalRootObject, this);
filler->AddEntry(kGcRootsObject, this);
GcSubrootsEnumerator enumerator(filler, this);
heap_->IterateRoots(&enumerator, VISIT_ALL);
}
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_(1) {
}
void VisitPointers(Object** start, Object** end) {
for (Object** p = start; p < end; p++) {
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;
ASSERT(!Memory::Object_at(field)->IsFailure());
ASSERT(Memory::Object_at(field)->IsHeapObject());
*field |= kFailureTag;
}
private:
bool CheckVisitedAndUnmark(Object** field) {
if ((*field)->IsFailure()) {
intptr_t untagged = reinterpret_cast<intptr_t>(*field) & ~kFailureTagMask;
*field = reinterpret_cast<Object*>(untagged | kHeapObjectTag);
ASSERT((*field)->IsHeapObject());
return true;
}
return false;
}
V8HeapExplorer* generator_;
HeapObject* parent_obj_;
int parent_;
int next_index_;
};
void V8HeapExplorer::ExtractReferences(HeapObject* obj) {
HeapEntry* heap_entry = GetEntry(obj);
if (heap_entry == NULL) return; // No interest in this object.
int entry = heap_entry->index();
bool extract_indexed_refs = true;
if (obj->IsJSGlobalProxy()) {
ExtractJSGlobalProxyReferences(entry, JSGlobalProxy::cast(obj));
} else if (obj->IsJSObject()) {
ExtractJSObjectReferences(entry, JSObject::cast(obj));
} else if (obj->IsString()) {
ExtractStringReferences(entry, String::cast(obj));
} else if (obj->IsContext()) {
ExtractContextReferences(entry, Context::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->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->IsCell()) {
ExtractCellReferences(entry, Cell::cast(obj));
extract_indexed_refs = false;
} else if (obj->IsPropertyCell()) {
ExtractPropertyCellReferences(
entry, PropertyCell::cast(obj));
extract_indexed_refs = false;
}
if (extract_indexed_refs) {
SetInternalReference(obj, entry, "map", obj->map(), HeapObject::kMapOffset);
IndexedReferencesExtractor refs_extractor(this, obj, entry);
obj->Iterate(&refs_extractor);
}
}
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);
SetPropertyReference(
obj, entry, heap_->proto_string(), js_obj->GetPrototype());
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());
}
}
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);
for (int i = JSFunction::kNonWeakFieldsEndOffset;
i < JSFunction::kSize;
i += kPointerSize) {
SetWeakReference(js_fun, entry, i, *HeapObject::RawField(js_fun, i), i);
}
} 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_receiver", global_obj->global_receiver(),
GlobalObject::kGlobalReceiverOffset);
}
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::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) \
SetInternalReference(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);
#undef EXTRACT_CONTEXT_FIELD
for (int i = Context::FIRST_WEAK_SLOT;
i < Context::NATIVE_CONTEXT_SLOTS;
++i) {
SetWeakReference(context, entry, i, context->get(i),
FixedArray::OffsetOfElementAt(i));
}
}
}
void V8HeapExplorer::ExtractMapReferences(int entry, Map* map) {
SetInternalReference(map, entry,
"prototype", map->prototype(), Map::kPrototypeOffset);
SetInternalReference(map, entry,
"constructor", map->constructor(),
Map::kConstructorOffset);
if (map->HasTransitionArray()) {
TransitionArray* transitions = map->transitions();
Object* back_pointer = transitions->back_pointer_storage();
TagObject(transitions->back_pointer_storage(), "(back pointer)");
SetInternalReference(transitions, entry,
"backpointer", back_pointer,
TransitionArray::kBackPointerStorageOffset);
IndexedReferencesExtractor transitions_refs(this, transitions, entry);
transitions->Iterate(&transitions_refs);
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,
"backpointer", back_pointer,
Map::kTransitionsOrBackPointerOffset);
}
DescriptorArray* descriptors = map->instance_descriptors();
TagObject(descriptors, "(map descriptors)");
SetInternalReference(map, entry,
"descriptors", descriptors,
Map::kDescriptorsOffset);
SetInternalReference(map, entry,
"code_cache", map->code_cache(),
Map::kCodeCacheOffset);
}
void V8HeapExplorer::ExtractSharedFunctionInfoReferences(
int entry, SharedFunctionInfo* shared) {
HeapObject* obj = shared;
SetInternalReference(obj, entry,
"name", shared->name(),
SharedFunctionInfo::kNameOffset);
TagObject(shared->code(), "(code)");
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);
TagObject(shared->construct_stub(), "(code)");
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);
SetWeakReference(obj, entry,
1, shared->initial_map(),
SharedFunctionInfo::kInitialMapOffset);
}
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,
"data", script->data(),
Script::kDataOffset);
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::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::ExtractCodeReferences(int entry, Code* 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);
}
void V8HeapExplorer::ExtractCellReferences(int entry, Cell* cell) {
SetInternalReference(cell, entry, "value", cell->value());
}
void V8HeapExplorer::ExtractPropertyCellReferences(int entry,
PropertyCell* cell) {
SetInternalReference(cell, entry, "value", cell->value());
SetInternalReference(cell, entry, "type", cell->type());
}
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 = collection_->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: {
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 {
Object* value = js_obj->RawFastPropertyAt(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_FUNCTION:
SetPropertyReference(
js_obj, entry,
descs->GetKey(i), descs->GetConstantFunction(i));
break;
case CALLBACKS:
ExtractAccessorPairProperty(
js_obj, entry,
descs->GetKey(i), descs->GetValue(i));
break;
case NORMAL: // only in slow mode
case HANDLER: // only in lookup results, not in descriptors
case INTERCEPTOR: // only in lookup results, not in descriptors
break;
case TRANSITION:
case NONEXISTENT:
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, String::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, String::cast(key), getter, "get %s");
}
Object* setter = accessors->setter();
if (!setter->IsOddball()) {
SetPropertyReference(js_obj, entry, String::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)) {
ASSERT(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()) {
// Look up an immediate "constructor" property, if it is a function,
// return its name. This is for instances of binding objects, which
// have prototype constructor type "Object".
Object* constructor_prop = NULL;
LookupResult result(heap->isolate());
object->LocalLookupRealNamedProperty(heap->constructor_string(), &result);
if (!result.IsFound()) return object->constructor_name();
constructor_prop = result.GetLazyValue();
if (constructor_prop->IsJSFunction()) {
Object* maybe_name =
JSFunction::cast(constructor_prop)->shared()->name();
if (maybe_name->IsString()) {
String* name = String::cast(maybe_name);
if (name->length() > 0) return name;
}
}
}
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:
RootsReferencesExtractor()
: collecting_all_references_(false),
previous_reference_count_(0) {
}
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) {
ASSERT(strong_references_.length() <= all_references_.length());
for (int i = 0; i < reference_tags_.length(); ++i) {
explorer->SetGcRootsReference(reference_tags_[i].tag);
}
int strong_index = 0, all_index = 0, tags_index = 0;
while (all_index < all_references_.length()) {
if (strong_index < strong_references_.length() &&
strong_references_[strong_index] == all_references_[all_index]) {
explorer->SetGcSubrootReference(reference_tags_[tags_index].tag,
false,
all_references_[all_index++]);
++strong_index;
} else {
explorer->SetGcSubrootReference(reference_tags_[tags_index].tag,
true,
all_references_[all_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_;
};
bool V8HeapExplorer::IterateAndExtractReferences(
SnapshotFillerInterface* filler) {
HeapIterator iterator(heap_, HeapIterator::kFilterUnreachable);
filler_ = filler;
bool interrupted = false;
// Heap iteration with filtering must be finished in any case.
for (HeapObject* obj = iterator.next();
obj != NULL;
obj = iterator.next(), progress_->ProgressStep()) {
if (!interrupted) {
ExtractReferences(obj);
if (!progress_->ProgressReport(false)) interrupted = true;
}
}
if (interrupted) {
filler_ = NULL;
return false;
}
SetRootGcRootsReference();
RootsReferencesExtractor extractor;
heap_->IterateRoots(&extractor, VISIT_ONLY_STRONG);
extractor.SetCollectingAllReferences();
heap_->IterateRoots(&extractor, VISIT_ALL);
extractor.FillReferences(this);
filler_ = NULL;
return progress_->ProgressReport(true);
}
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) {
HeapEntry* child_entry = GetEntry(child_obj);
if (child_entry != NULL) {
filler_->SetNamedReference(HeapGraphEdge::kContextVariable,
parent_entry,
collection_->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) {
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) {
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) {
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) {
HeapEntry* child_entry = GetEntry(child_obj);
if (child_entry == NULL) return;
if (IsEssentialObject(child_obj)) {
filler_->SetNamedReference(HeapGraphEdge::kInternal,
parent_entry,
collection_->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) {
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,
int index,
Object* child_obj,
int field_offset) {
HeapEntry* child_entry = GetEntry(child_obj);
if (child_entry != NULL) {
filler_->SetIndexedReference(HeapGraphEdge::kWeak,
parent_entry,
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) {
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()
? collection_->names()->GetFormatted(
name_format_string,
*String::cast(reference_name)->ToCString(
DISALLOW_NULLS, ROBUST_STRING_TRAVERSAL)) :
collection_->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);
ASSERT(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 {
filler_->SetIndexedAutoIndexReference(
is_weak ? HeapGraphEdge::kWeak : 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;
#ifdef ENABLE_DEBUGGER_SUPPORT
is_debug_object = heap_->isolate()->debug()->IsDebugGlobal(global);
#endif
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
#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);
}
}
}
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 = Isolate::Current();
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),
collection_(snapshot_->collection()),
entries_type_(entries_type) {
}
virtual HeapEntry* AllocateEntry(HeapThing ptr);
private:
HeapSnapshot* snapshot_;
HeapSnapshotsCollection* collection_;
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
? collection_->names()->GetFormatted(
"%s / %" V8_PTR_PREFIX "d entries", info->GetLabel(), elements)
: collection_->names()->GetCopy(info->GetLabel());
return snapshot_->AddEntry(
entries_type_,
name,
HeapObjectsMap::GenerateId(info),
size != -1 ? static_cast<int>(size) : 0);
}
NativeObjectsExplorer::NativeObjectsExplorer(
HeapSnapshot* snapshot, SnapshottingProgressReportingInterface* progress)
: snapshot_(snapshot),
collection_(snapshot_->collection()),
progress_(progress),
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::Current();
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);
// 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::Current();
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();
ASSERT(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(
SnapshotFillerInterface* 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 intptr_t GetHash() { return hash_; }
virtual const char* GetLabel() { return label_; }
private:
bool disposed_;
intptr_t hash_;
const char* label_;
};
NativeGroupRetainedObjectInfo* NativeObjectsExplorer::FindOrAddGroupInfo(
const char* label) {
const char* label_copy = collection_->names()->GetCopy(label);
uint32_t hash = StringHasher::HashSequentialString(
label_copy,
static_cast<int>(strlen(label_copy)),
HEAP->HashSeed());
HashMap::Entry* entry = native_groups_.Lookup(const_cast<char*>(label_copy),
hash, true);
if (entry->value == NULL) {
entry->value = new NativeGroupRetainedObjectInfo(label);
}
return static_cast<NativeGroupRetainedObjectInfo*>(entry->value);
}
void NativeObjectsExplorer::SetNativeRootReference(
v8::RetainedObjectInfo* info) {
HeapEntry* child_entry =
filler_->FindOrAddEntry(info, native_entries_allocator_);
ASSERT(child_entry != NULL);
NativeGroupRetainedObjectInfo* group_info =
FindOrAddGroupInfo(info->GetGroupLabel());
HeapEntry* group_entry =
filler_->FindOrAddEntry(group_info, synthetic_entries_allocator_);
filler_->SetNamedAutoIndexReference(
HeapGraphEdge::kInternal,
group_entry->index(),
child_entry);
}
void NativeObjectsExplorer::SetWrapperNativeReferences(
HeapObject* wrapper, v8::RetainedObjectInfo* info) {
HeapEntry* wrapper_entry = filler_->FindEntry(wrapper);
ASSERT(wrapper_entry != NULL);
HeapEntry* info_entry =
filler_->FindOrAddEntry(info, native_entries_allocator_);
ASSERT(info_entry != NULL);
filler_->SetNamedReference(HeapGraphEdge::kInternal,
wrapper_entry->index(),
"native",
info_entry);
filler_->SetIndexedAutoIndexReference(HeapGraphEdge::kElement,
info_entry->index(),
wrapper_entry);
}
void NativeObjectsExplorer::SetRootNativeRootsReference() {
for (HashMap::Entry* entry = native_groups_.Start();
entry;
entry = native_groups_.Next(entry)) {
NativeGroupRetainedObjectInfo* group_info =
static_cast<NativeGroupRetainedObjectInfo*>(entry->value);
HeapEntry* group_entry =
filler_->FindOrAddEntry(group_info, native_entries_allocator_);
ASSERT(group_entry != NULL);
filler_->SetIndexedAutoIndexReference(
HeapGraphEdge::kElement,
snapshot_->root()->index(),
group_entry);
}
}
void NativeObjectsExplorer::VisitSubtreeWrapper(Object** p, uint16_t class_id) {
if (in_groups_.Contains(*p)) return;
Isolate* isolate = Isolate::Current();
v8::RetainedObjectInfo* info =
isolate->heap_profiler()->ExecuteWrapperClassCallback(class_id, p);
if (info == NULL) return;
GetListMaybeDisposeInfo(info)->Add(HeapObject::cast(*p));
}
class SnapshotFiller : public SnapshotFillerInterface {
public:
explicit SnapshotFiller(HeapSnapshot* snapshot, HeapEntriesMap* entries)
: snapshot_(snapshot),
collection_(snapshot->collection()),
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,
collection_->names()->GetName(index),
child_entry);
}
private:
HeapSnapshot* snapshot_;
HeapSnapshotsCollection* collection_;
HeapEntriesMap* entries_;
};
HeapSnapshotGenerator::HeapSnapshotGenerator(
HeapSnapshot* snapshot,
v8::ActivityControl* control,
v8::HeapProfiler::ObjectNameResolver* resolver,
Heap* heap)
: snapshot_(snapshot),
control_(control),
v8_heap_explorer_(snapshot_, this, resolver),
dom_explorer_(snapshot_, this),
heap_(heap) {
}
bool HeapSnapshotGenerator::GenerateSnapshot() {
v8_heap_explorer_.TagGlobalObjects();
// TODO(1562) Profiler assumes that any object that is in the heap after
// full GC is reachable from the root when computing dominators.
// This is not true for weakly reachable objects.
// As a temporary solution we call GC twice.
Isolate::Current()->heap()->CollectAllGarbage(
Heap::kMakeHeapIterableMask,
"HeapSnapshotGenerator::GenerateSnapshot");
Isolate::Current()->heap()->CollectAllGarbage(
Heap::kMakeHeapIterableMask,
"HeapSnapshotGenerator::GenerateSnapshot");
#ifdef VERIFY_HEAP
Heap* debug_heap = Isolate::Current()->heap();
CHECK(!debug_heap->old_data_space()->was_swept_conservatively());
CHECK(!debug_heap->old_pointer_space()->was_swept_conservatively());
CHECK(!debug_heap->code_space()->was_swept_conservatively());
CHECK(!debug_heap->cell_space()->was_swept_conservatively());
CHECK(!debug_heap->property_cell_space()->
was_swept_conservatively());
CHECK(!debug_heap->map_space()->was_swept_conservatively());
#endif
// The following code uses heap iterators, so we want the heap to be
// stable. It should follow TagGlobalObjects as that can allocate.
DisallowHeapAllocation no_alloc;
#ifdef VERIFY_HEAP
debug_heap->Verify();
#endif
SetProgressTotal(1); // 1 pass.
#ifdef VERIFY_HEAP
debug_heap->Verify();
#endif
if (!FillReferences()) return false;
snapshot_->FillChildren();
snapshot_->RememberLastJSObjectId();
progress_counter_ = progress_total_;
if (!ProgressReport(true)) return false;
return true;
}
void HeapSnapshotGenerator::ProgressStep() {
++progress_counter_;
}
bool HeapSnapshotGenerator::ProgressReport(bool force) {
const int kProgressReportGranularity = 10000;
if (control_ != NULL
&& (force || progress_counter_ % kProgressReportGranularity == 0)) {
return
control_->ReportProgressValue(progress_counter_, progress_total_) ==
v8::ActivityControl::kContinue;
}
return true;
}
void HeapSnapshotGenerator::SetProgressTotal(int iterations_count) {
if (control_ == NULL) return;
HeapIterator iterator(heap_, HeapIterator::kFilterUnreachable);
progress_total_ = iterations_count * (
v8_heap_explorer_.EstimateObjectsCount(&iterator) +
dom_explorer_.EstimateObjectsCount());
progress_counter_ = 0;
}
bool HeapSnapshotGenerator::FillReferences() {
SnapshotFiller filler(snapshot_, &entries_);
v8_heap_explorer_.AddRootEntries(&filler);
return v8_heap_explorer_.IterateAndExtractReferences(&filler)
&& dom_explorer_.IterateAndExtractReferences(&filler);
}
template<int bytes> struct MaxDecimalDigitsIn;
template<> struct MaxDecimalDigitsIn<4> {
static const int kSigned = 11;
static const int kUnsigned = 10;
};
template<> struct MaxDecimalDigitsIn<8> {
static const int kSigned = 20;
static const int kUnsigned = 20;
};
class OutputStreamWriter {
public:
explicit OutputStreamWriter(v8::OutputStream* stream)
: stream_(stream),
chunk_size_(stream->GetChunkSize()),
chunk_(chunk_size_),
chunk_pos_(0),
aborted_(false) {
ASSERT(chunk_size_ > 0);
}
bool aborted() { return aborted_; }
void AddCharacter(char c) {
ASSERT(c != '\0');
ASSERT(chunk_pos_ < chunk_size_);
chunk_[chunk_pos_++] = c;
MaybeWriteChunk();
}
void AddString(const char* s) {
AddSubstring(s, StrLength(s));
}
void AddSubstring(const char* s, int n) {
if (n <= 0) return;
ASSERT(static_cast<size_t>(n) <= strlen(s));
const char* s_end = s + n;
while (s < s_end) {
int s_chunk_size = Min(
chunk_size_ - chunk_pos_, static_cast<int>(s_end - s));
ASSERT(s_chunk_size > 0);
OS::MemCopy(chunk_.start() + chunk_pos_, s, s_chunk_size);
s += s_chunk_size;
chunk_pos_ += s_chunk_size;
MaybeWriteChunk();
}
}
void AddNumber(unsigned n) { AddNumberImpl<unsigned>(n, "%u"); }
void Finalize() {
if (aborted_) return;
ASSERT(chunk_pos_ < chunk_size_);
if (chunk_pos_ != 0) {
WriteChunk();
}
stream_->EndOfStream();
}
private:
template<typename T>
void AddNumberImpl(T n, const char* format) {
// Buffer for the longest value plus trailing \0
static const int kMaxNumberSize =
MaxDecimalDigitsIn<sizeof(T)>::kUnsigned + 1;
if (chunk_size_ - chunk_pos_ >= kMaxNumberSize) {
int result = OS::SNPrintF(
chunk_.SubVector(chunk_pos_, chunk_size_), format, n);
ASSERT(result != -1);
chunk_pos_ += result;
MaybeWriteChunk();
} else {
EmbeddedVector<char, kMaxNumberSize> buffer;
int result = OS::SNPrintF(buffer, format, n);
USE(result);
ASSERT(result != -1);
AddString(buffer.start());
}
}
void MaybeWriteChunk() {
ASSERT(chunk_pos_ <= chunk_size_);
if (chunk_pos_ == chunk_size_) {
WriteChunk();
}
}
void WriteChunk() {
if (aborted_) return;
if (stream_->WriteAsciiChunk(chunk_.start(), chunk_pos_) ==
v8::OutputStream::kAbort) aborted_ = true;
chunk_pos_ = 0;
}
v8::OutputStream* stream_;
int chunk_size_;
ScopedVector<char> chunk_;
int chunk_pos_;
bool aborted_;
};
// type, name|index, to_node.
const int HeapSnapshotJSONSerializer::kEdgeFieldsCount = 3;
// type, name, id, self_size, children_index.
const int HeapSnapshotJSONSerializer::kNodeFieldsCount = 5;
void HeapSnapshotJSONSerializer::Serialize(v8::OutputStream* stream) {
ASSERT(writer_ == NULL);
writer_ = new OutputStreamWriter(stream);
SerializeImpl();
delete writer_;
writer_ = NULL;
}
void HeapSnapshotJSONSerializer::SerializeImpl() {
ASSERT(0 == snapshot_->root()->index());
writer_->AddCharacter('{');
writer_->AddString("\"snapshot\":{");
SerializeSnapshot();
if (writer_->aborted()) return;
writer_->AddString("},\n");
writer_->AddString("\"nodes\":[");
SerializeNodes();
if (writer_->aborted()) return;
writer_->AddString("],\n");
writer_->AddString("\"edges\":[");
SerializeEdges();
if (writer_->aborted()) return;
writer_->AddString("],\n");
writer_->AddString("\"strings\":[");
SerializeStrings();
if (writer_->aborted()) return;
writer_->AddCharacter(']');
writer_->AddCharacter('}');
writer_->Finalize();
}
int HeapSnapshotJSONSerializer::GetStringId(const char* s) {
HashMap::Entry* cache_entry = strings_.Lookup(
const_cast<char*>(s), ObjectHash(s), true);
if (cache_entry->value == NULL) {
cache_entry->value = reinterpret_cast<void*>(next_string_id_++);
}
return static_cast<int>(reinterpret_cast<intptr_t>(cache_entry->value));
}
static int utoa(unsigned value, const Vector<char>& buffer, int buffer_pos) {
int number_of_digits = 0;
unsigned t = value;
do {
++number_of_digits;
} while (t /= 10);
buffer_pos += number_of_digits;
int result = buffer_pos;
do {
int last_digit = value % 10;
buffer[--buffer_pos] = '0' + last_digit;
value /= 10;
} while (value);
return result;
}
void HeapSnapshotJSONSerializer::SerializeEdge(HeapGraphEdge* edge,
bool first_edge) {
// The buffer needs space for 3 unsigned ints, 3 commas, \n and \0
static const int kBufferSize =
MaxDecimalDigitsIn<sizeof(unsigned)>::kUnsigned * 3 + 3 + 2; // NOLINT
EmbeddedVector<char, kBufferSize> buffer;
int edge_name_or_index = edge->type() == HeapGraphEdge::kElement
|| edge->type() == HeapGraphEdge::kHidden
|| edge->type() == HeapGraphEdge::kWeak
? edge->index() : GetStringId(edge->name());
int buffer_pos = 0;
if (!first_edge) {
buffer[buffer_pos++] = ',';
}
buffer_pos = utoa(edge->type(), buffer, buffer_pos);
buffer[buffer_pos++] = ',';
buffer_pos = utoa(edge_name_or_index, buffer, buffer_pos);
buffer[buffer_pos++] = ',';
buffer_pos = utoa(entry_index(edge->to()), buffer, buffer_pos);
buffer[buffer_pos++] = '\n';
buffer[buffer_pos++] = '\0';
writer_->AddString(buffer.start());
}
void HeapSnapshotJSONSerializer::SerializeEdges() {
List<HeapGraphEdge*>& edges = snapshot_->children();
for (int i = 0; i < edges.length(); ++i) {
ASSERT(i == 0 ||
edges[i - 1]->from()->index() <= edges[i]->from()->index());
SerializeEdge(edges[i], i == 0);
if (writer_->aborted()) return;
}
}
void HeapSnapshotJSONSerializer::SerializeNode(HeapEntry* entry) {
// The buffer needs space for 5 unsigned ints, 5 commas, \n and \0
static const int kBufferSize =
5 * MaxDecimalDigitsIn<sizeof(unsigned)>::kUnsigned // NOLINT
+ 5 + 1 + 1;
EmbeddedVector<char, kBufferSize> buffer;
int buffer_pos = 0;
if (entry_index(entry) != 0) {
buffer[buffer_pos++] = ',';
}
buffer_pos = utoa(entry->type(), buffer, buffer_pos);
buffer[buffer_pos++] = ',';
buffer_pos = utoa(GetStringId(entry->name()), buffer, buffer_pos);
buffer[buffer_pos++] = ',';
buffer_pos = utoa(entry->id(), buffer, buffer_pos);
buffer[buffer_pos++] = ',';
buffer_pos = utoa(entry->self_size(), buffer, buffer_pos);
buffer[buffer_pos++] = ',';
buffer_pos = utoa(entry->children_count(), buffer, buffer_pos);
buffer[buffer_pos++] = '\n';
buffer[buffer_pos++] = '\0';
writer_->AddString(buffer.start());
}
void HeapSnapshotJSONSerializer::SerializeNodes() {
List<HeapEntry>& entries = snapshot_->entries();
for (int i = 0; i < entries.length(); ++i) {
SerializeNode(&entries[i]);
if (writer_->aborted()) return;
}
}
void HeapSnapshotJSONSerializer::SerializeSnapshot() {
writer_->AddString("\"title\":\"");
writer_->AddString(snapshot_->title());
writer_->AddString("\"");
writer_->AddString(",\"uid\":");
writer_->AddNumber(snapshot_->uid());
writer_->AddString(",\"meta\":");
// The object describing node serialization layout.
// We use a set of macros to improve readability.
#define JSON_A(s) "[" s "]"
#define JSON_O(s) "{" s "}"
#define JSON_S(s) "\"" s "\""
writer_->AddString(JSON_O(
JSON_S("node_fields") ":" JSON_A(
JSON_S("type") ","
JSON_S("name") ","
JSON_S("id") ","
JSON_S("self_size") ","
JSON_S("edge_count")) ","
JSON_S("node_types") ":" JSON_A(
JSON_A(
JSON_S("hidden") ","
JSON_S("array") ","
JSON_S("string") ","
JSON_S("object") ","
JSON_S("code") ","
JSON_S("closure") ","
JSON_S("regexp") ","
JSON_S("number") ","
JSON_S("native") ","
JSON_S("synthetic")) ","
JSON_S("string") ","
JSON_S("number") ","
JSON_S("number") ","
JSON_S("number") ","
JSON_S("number") ","
JSON_S("number")) ","
JSON_S("edge_fields") ":" JSON_A(
JSON_S("type") ","
JSON_S("name_or_index") ","
JSON_S("to_node")) ","
JSON_S("edge_types") ":" JSON_A(
JSON_A(
JSON_S("context") ","
JSON_S("element") ","
JSON_S("property") ","
JSON_S("internal") ","
JSON_S("hidden") ","
JSON_S("shortcut") ","
JSON_S("weak")) ","
JSON_S("string_or_number") ","
JSON_S("node"))));
#undef JSON_S
#undef JSON_O
#undef JSON_A
writer_->AddString(",\"node_count\":");
writer_->AddNumber(snapshot_->entries().length());
writer_->AddString(",\"edge_count\":");
writer_->AddNumber(snapshot_->edges().length());
}
static void WriteUChar(OutputStreamWriter* w, unibrow::uchar u) {
static const char hex_chars[] = "0123456789ABCDEF";
w->AddString("\\u");
w->AddCharacter(hex_chars[(u >> 12) & 0xf]);
w->AddCharacter(hex_chars[(u >> 8) & 0xf]);
w->AddCharacter(hex_chars[(u >> 4) & 0xf]);
w->AddCharacter(hex_chars[u & 0xf]);
}
void HeapSnapshotJSONSerializer::SerializeString(const unsigned char* s) {
writer_->AddCharacter('\n');
writer_->AddCharacter('\"');
for ( ; *s != '\0'; ++s) {
switch (*s) {
case '\b':
writer_->AddString("\\b");
continue;
case '\f':
writer_->AddString("\\f");
continue;
case '\n':
writer_->AddString("\\n");
continue;
case '\r':
writer_->AddString("\\r");
continue;
case '\t':
writer_->AddString("\\t");
continue;
case '\"':
case '\\':
writer_->AddCharacter('\\');
writer_->AddCharacter(*s);
continue;
default:
if (*s > 31 && *s < 128) {
writer_->AddCharacter(*s);
} else if (*s <= 31) {
// Special character with no dedicated literal.
WriteUChar(writer_, *s);
} else {
// Convert UTF-8 into \u UTF-16 literal.
unsigned length = 1, cursor = 0;
for ( ; length <= 4 && *(s + length) != '\0'; ++length) { }
unibrow::uchar c = unibrow::Utf8::CalculateValue(s, length, &cursor);
if (c != unibrow::Utf8::kBadChar) {
WriteUChar(writer_, c);
ASSERT(cursor != 0);
s += cursor - 1;
} else {
writer_->AddCharacter('?');
}
}
}
}
writer_->AddCharacter('\"');
}
void HeapSnapshotJSONSerializer::SerializeStrings() {
List<HashMap::Entry*> sorted_strings;
SortHashMap(&strings_, &sorted_strings);
writer_->AddString("\"<dummy>\"");
for (int i = 0; i < sorted_strings.length(); ++i) {
writer_->AddCharacter(',');
SerializeString(
reinterpret_cast<const unsigned char*>(sorted_strings[i]->key));
if (writer_->aborted()) return;
}
}
template<typename T>
inline static int SortUsingEntryValue(const T* x, const T* y) {
uintptr_t x_uint = reinterpret_cast<uintptr_t>((*x)->value);
uintptr_t y_uint = reinterpret_cast<uintptr_t>((*y)->value);
if (x_uint > y_uint) {
return 1;
} else if (x_uint == y_uint) {
return 0;
} else {
return -1;
}
}
void HeapSnapshotJSONSerializer::SortHashMap(
HashMap* map, List<HashMap::Entry*>* sorted_entries) {
for (HashMap::Entry* p = map->Start(); p != NULL; p = map->Next(p))
sorted_entries->Add(p);
sorted_entries->Sort(SortUsingEntryValue);
}
} } // namespace v8::internal