// Copyright 2012 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 "profile-generator-inl.h"
#include "global-handles.h"
#include "heap-profiler.h"
#include "scopeinfo.h"
#include "unicode.h"
#include "zone-inl.h"
namespace v8 {
namespace internal {
TokenEnumerator::TokenEnumerator()
: token_locations_(4),
token_removed_(4) {
}
TokenEnumerator::~TokenEnumerator() {
Isolate* isolate = Isolate::Current();
for (int i = 0; i < token_locations_.length(); ++i) {
if (!token_removed_[i]) {
isolate->global_handles()->ClearWeakness(token_locations_[i]);
isolate->global_handles()->Destroy(token_locations_[i]);
}
}
}
int TokenEnumerator::GetTokenId(Object* token) {
Isolate* isolate = Isolate::Current();
if (token == NULL) return TokenEnumerator::kNoSecurityToken;
for (int i = 0; i < token_locations_.length(); ++i) {
if (*token_locations_[i] == token && !token_removed_[i]) return i;
}
Handle<Object> handle = isolate->global_handles()->Create(token);
// handle.location() points to a memory cell holding a pointer
// to a token object in the V8's heap.
isolate->global_handles()->MakeWeak(handle.location(), this,
TokenRemovedCallback);
token_locations_.Add(handle.location());
token_removed_.Add(false);
return token_locations_.length() - 1;
}
void TokenEnumerator::TokenRemovedCallback(v8::Persistent<v8::Value> handle,
void* parameter) {
reinterpret_cast<TokenEnumerator*>(parameter)->TokenRemoved(
Utils::OpenHandle(*handle).location());
handle.Dispose();
}
void TokenEnumerator::TokenRemoved(Object** token_location) {
for (int i = 0; i < token_locations_.length(); ++i) {
if (token_locations_[i] == token_location && !token_removed_[i]) {
token_removed_[i] = true;
return;
}
}
}
StringsStorage::StringsStorage()
: names_(StringsMatch) {
}
StringsStorage::~StringsStorage() {
for (HashMap::Entry* p = names_.Start();
p != NULL;
p = names_.Next(p)) {
DeleteArray(reinterpret_cast<const char*>(p->value));
}
}
const char* StringsStorage::GetCopy(const char* src) {
int len = static_cast<int>(strlen(src));
Vector<char> dst = Vector<char>::New(len + 1);
OS::StrNCpy(dst, src, len);
dst[len] = '\0';
uint32_t hash =
HashSequentialString(dst.start(), len, HEAP->HashSeed());
return AddOrDisposeString(dst.start(), hash);
}
const char* StringsStorage::GetFormatted(const char* format, ...) {
va_list args;
va_start(args, format);
const char* result = GetVFormatted(format, args);
va_end(args);
return result;
}
const char* StringsStorage::AddOrDisposeString(char* str, uint32_t hash) {
HashMap::Entry* cache_entry = names_.Lookup(str, hash, true);
if (cache_entry->value == NULL) {
// New entry added.
cache_entry->value = str;
} else {
DeleteArray(str);
}
return reinterpret_cast<const char*>(cache_entry->value);
}
const char* StringsStorage::GetVFormatted(const char* format, va_list args) {
Vector<char> str = Vector<char>::New(1024);
int len = OS::VSNPrintF(str, format, args);
if (len == -1) {
DeleteArray(str.start());
return format;
}
uint32_t hash = HashSequentialString(
str.start(), len, HEAP->HashSeed());
return AddOrDisposeString(str.start(), hash);
}
const char* StringsStorage::GetName(String* name) {
if (name->IsString()) {
int length = Min(kMaxNameSize, name->length());
SmartArrayPointer<char> data =
name->ToCString(DISALLOW_NULLS, ROBUST_STRING_TRAVERSAL, 0, length);
uint32_t hash =
HashSequentialString(*data, length, name->GetHeap()->HashSeed());
return AddOrDisposeString(data.Detach(), hash);
}
return "";
}
const char* StringsStorage::GetName(int index) {
return GetFormatted("%d", index);
}
const char* const CodeEntry::kEmptyNamePrefix = "";
void CodeEntry::CopyData(const CodeEntry& source) {
tag_ = source.tag_;
name_prefix_ = source.name_prefix_;
name_ = source.name_;
resource_name_ = source.resource_name_;
line_number_ = source.line_number_;
}
uint32_t CodeEntry::GetCallUid() const {
uint32_t hash = ComputeIntegerHash(tag_, v8::internal::kZeroHashSeed);
if (shared_id_ != 0) {
hash ^= ComputeIntegerHash(static_cast<uint32_t>(shared_id_),
v8::internal::kZeroHashSeed);
} else {
hash ^= ComputeIntegerHash(
static_cast<uint32_t>(reinterpret_cast<uintptr_t>(name_prefix_)),
v8::internal::kZeroHashSeed);
hash ^= ComputeIntegerHash(
static_cast<uint32_t>(reinterpret_cast<uintptr_t>(name_)),
v8::internal::kZeroHashSeed);
hash ^= ComputeIntegerHash(
static_cast<uint32_t>(reinterpret_cast<uintptr_t>(resource_name_)),
v8::internal::kZeroHashSeed);
hash ^= ComputeIntegerHash(line_number_, v8::internal::kZeroHashSeed);
}
return hash;
}
bool CodeEntry::IsSameAs(CodeEntry* entry) const {
return this == entry
|| (tag_ == entry->tag_
&& shared_id_ == entry->shared_id_
&& (shared_id_ != 0
|| (name_prefix_ == entry->name_prefix_
&& name_ == entry->name_
&& resource_name_ == entry->resource_name_
&& line_number_ == entry->line_number_)));
}
ProfileNode* ProfileNode::FindChild(CodeEntry* entry) {
HashMap::Entry* map_entry =
children_.Lookup(entry, CodeEntryHash(entry), false);
return map_entry != NULL ?
reinterpret_cast<ProfileNode*>(map_entry->value) : NULL;
}
ProfileNode* ProfileNode::FindOrAddChild(CodeEntry* entry) {
HashMap::Entry* map_entry =
children_.Lookup(entry, CodeEntryHash(entry), true);
if (map_entry->value == NULL) {
// New node added.
ProfileNode* new_node = new ProfileNode(tree_, entry);
map_entry->value = new_node;
children_list_.Add(new_node);
}
return reinterpret_cast<ProfileNode*>(map_entry->value);
}
double ProfileNode::GetSelfMillis() const {
return tree_->TicksToMillis(self_ticks_);
}
double ProfileNode::GetTotalMillis() const {
return tree_->TicksToMillis(total_ticks_);
}
void ProfileNode::Print(int indent) {
OS::Print("%5u %5u %*c %s%s [%d]",
total_ticks_, self_ticks_,
indent, ' ',
entry_->name_prefix(),
entry_->name(),
entry_->security_token_id());
if (entry_->resource_name()[0] != '\0')
OS::Print(" %s:%d", entry_->resource_name(), entry_->line_number());
OS::Print("\n");
for (HashMap::Entry* p = children_.Start();
p != NULL;
p = children_.Next(p)) {
reinterpret_cast<ProfileNode*>(p->value)->Print(indent + 2);
}
}
class DeleteNodesCallback {
public:
void BeforeTraversingChild(ProfileNode*, ProfileNode*) { }
void AfterAllChildrenTraversed(ProfileNode* node) {
delete node;
}
void AfterChildTraversed(ProfileNode*, ProfileNode*) { }
};
ProfileTree::ProfileTree()
: root_entry_(Logger::FUNCTION_TAG,
"",
"(root)",
"",
0,
TokenEnumerator::kNoSecurityToken),
root_(new ProfileNode(this, &root_entry_)) {
}
ProfileTree::~ProfileTree() {
DeleteNodesCallback cb;
TraverseDepthFirst(&cb);
}
void ProfileTree::AddPathFromEnd(const Vector<CodeEntry*>& path) {
ProfileNode* node = root_;
for (CodeEntry** entry = path.start() + path.length() - 1;
entry != path.start() - 1;
--entry) {
if (*entry != NULL) {
node = node->FindOrAddChild(*entry);
}
}
node->IncrementSelfTicks();
}
void ProfileTree::AddPathFromStart(const Vector<CodeEntry*>& path) {
ProfileNode* node = root_;
for (CodeEntry** entry = path.start();
entry != path.start() + path.length();
++entry) {
if (*entry != NULL) {
node = node->FindOrAddChild(*entry);
}
}
node->IncrementSelfTicks();
}
struct NodesPair {
NodesPair(ProfileNode* src, ProfileNode* dst)
: src(src), dst(dst) { }
ProfileNode* src;
ProfileNode* dst;
};
class FilteredCloneCallback {
public:
FilteredCloneCallback(ProfileNode* dst_root, int security_token_id)
: stack_(10),
security_token_id_(security_token_id) {
stack_.Add(NodesPair(NULL, dst_root));
}
void BeforeTraversingChild(ProfileNode* parent, ProfileNode* child) {
if (IsTokenAcceptable(child->entry()->security_token_id(),
parent->entry()->security_token_id())) {
ProfileNode* clone = stack_.last().dst->FindOrAddChild(child->entry());
clone->IncreaseSelfTicks(child->self_ticks());
stack_.Add(NodesPair(child, clone));
} else {
// Attribute ticks to parent node.
stack_.last().dst->IncreaseSelfTicks(child->self_ticks());
}
}
void AfterAllChildrenTraversed(ProfileNode* parent) { }
void AfterChildTraversed(ProfileNode*, ProfileNode* child) {
if (stack_.last().src == child) {
stack_.RemoveLast();
}
}
private:
bool IsTokenAcceptable(int token, int parent_token) {
if (token == TokenEnumerator::kNoSecurityToken
|| token == security_token_id_) return true;
if (token == TokenEnumerator::kInheritsSecurityToken) {
ASSERT(parent_token != TokenEnumerator::kInheritsSecurityToken);
return parent_token == TokenEnumerator::kNoSecurityToken
|| parent_token == security_token_id_;
}
return false;
}
List<NodesPair> stack_;
int security_token_id_;
};
void ProfileTree::FilteredClone(ProfileTree* src, int security_token_id) {
ms_to_ticks_scale_ = src->ms_to_ticks_scale_;
FilteredCloneCallback cb(root_, security_token_id);
src->TraverseDepthFirst(&cb);
CalculateTotalTicks();
}
void ProfileTree::SetTickRatePerMs(double ticks_per_ms) {
ms_to_ticks_scale_ = ticks_per_ms > 0 ? 1.0 / ticks_per_ms : 1.0;
}
class Position {
public:
explicit Position(ProfileNode* node)
: node(node), child_idx_(0) { }
INLINE(ProfileNode* current_child()) {
return node->children()->at(child_idx_);
}
INLINE(bool has_current_child()) {
return child_idx_ < node->children()->length();
}
INLINE(void next_child()) { ++child_idx_; }
ProfileNode* node;
private:
int child_idx_;
};
// Non-recursive implementation of a depth-first post-order tree traversal.
template <typename Callback>
void ProfileTree::TraverseDepthFirst(Callback* callback) {
List<Position> stack(10);
stack.Add(Position(root_));
while (stack.length() > 0) {
Position& current = stack.last();
if (current.has_current_child()) {
callback->BeforeTraversingChild(current.node, current.current_child());
stack.Add(Position(current.current_child()));
} else {
callback->AfterAllChildrenTraversed(current.node);
if (stack.length() > 1) {
Position& parent = stack[stack.length() - 2];
callback->AfterChildTraversed(parent.node, current.node);
parent.next_child();
}
// Remove child from the stack.
stack.RemoveLast();
}
}
}
class CalculateTotalTicksCallback {
public:
void BeforeTraversingChild(ProfileNode*, ProfileNode*) { }
void AfterAllChildrenTraversed(ProfileNode* node) {
node->IncreaseTotalTicks(node->self_ticks());
}
void AfterChildTraversed(ProfileNode* parent, ProfileNode* child) {
parent->IncreaseTotalTicks(child->total_ticks());
}
};
void ProfileTree::CalculateTotalTicks() {
CalculateTotalTicksCallback cb;
TraverseDepthFirst(&cb);
}
void ProfileTree::ShortPrint() {
OS::Print("root: %u %u %.2fms %.2fms\n",
root_->total_ticks(), root_->self_ticks(),
root_->GetTotalMillis(), root_->GetSelfMillis());
}
void CpuProfile::AddPath(const Vector<CodeEntry*>& path) {
top_down_.AddPathFromEnd(path);
bottom_up_.AddPathFromStart(path);
}
void CpuProfile::CalculateTotalTicks() {
top_down_.CalculateTotalTicks();
bottom_up_.CalculateTotalTicks();
}
void CpuProfile::SetActualSamplingRate(double actual_sampling_rate) {
top_down_.SetTickRatePerMs(actual_sampling_rate);
bottom_up_.SetTickRatePerMs(actual_sampling_rate);
}
CpuProfile* CpuProfile::FilteredClone(int security_token_id) {
ASSERT(security_token_id != TokenEnumerator::kNoSecurityToken);
CpuProfile* clone = new CpuProfile(title_, uid_);
clone->top_down_.FilteredClone(&top_down_, security_token_id);
clone->bottom_up_.FilteredClone(&bottom_up_, security_token_id);
return clone;
}
void CpuProfile::ShortPrint() {
OS::Print("top down ");
top_down_.ShortPrint();
OS::Print("bottom up ");
bottom_up_.ShortPrint();
}
void CpuProfile::Print() {
OS::Print("[Top down]:\n");
top_down_.Print();
OS::Print("[Bottom up]:\n");
bottom_up_.Print();
}
CodeEntry* const CodeMap::kSharedFunctionCodeEntry = NULL;
const CodeMap::CodeTreeConfig::Key CodeMap::CodeTreeConfig::kNoKey = NULL;
void CodeMap::AddCode(Address addr, CodeEntry* entry, unsigned size) {
DeleteAllCoveredCode(addr, addr + size);
CodeTree::Locator locator;
tree_.Insert(addr, &locator);
locator.set_value(CodeEntryInfo(entry, size));
}
void CodeMap::DeleteAllCoveredCode(Address start, Address end) {
List<Address> to_delete;
Address addr = end - 1;
while (addr >= start) {
CodeTree::Locator locator;
if (!tree_.FindGreatestLessThan(addr, &locator)) break;
Address start2 = locator.key(), end2 = start2 + locator.value().size;
if (start2 < end && start < end2) to_delete.Add(start2);
addr = start2 - 1;
}
for (int i = 0; i < to_delete.length(); ++i) tree_.Remove(to_delete[i]);
}
CodeEntry* CodeMap::FindEntry(Address addr) {
CodeTree::Locator locator;
if (tree_.FindGreatestLessThan(addr, &locator)) {
// locator.key() <= addr. Need to check that addr is within entry.
const CodeEntryInfo& entry = locator.value();
if (addr < (locator.key() + entry.size))
return entry.entry;
}
return NULL;
}
int CodeMap::GetSharedId(Address addr) {
CodeTree::Locator locator;
// For shared function entries, 'size' field is used to store their IDs.
if (tree_.Find(addr, &locator)) {
const CodeEntryInfo& entry = locator.value();
ASSERT(entry.entry == kSharedFunctionCodeEntry);
return entry.size;
} else {
tree_.Insert(addr, &locator);
int id = next_shared_id_++;
locator.set_value(CodeEntryInfo(kSharedFunctionCodeEntry, id));
return id;
}
}
void CodeMap::MoveCode(Address from, Address to) {
if (from == to) return;
CodeTree::Locator locator;
if (!tree_.Find(from, &locator)) return;
CodeEntryInfo entry = locator.value();
tree_.Remove(from);
AddCode(to, entry.entry, entry.size);
}
void CodeMap::CodeTreePrinter::Call(
const Address& key, const CodeMap::CodeEntryInfo& value) {
OS::Print("%p %5d %s\n", key, value.size, value.entry->name());
}
void CodeMap::Print() {
CodeTreePrinter printer;
tree_.ForEach(&printer);
}
CpuProfilesCollection::CpuProfilesCollection()
: profiles_uids_(UidsMatch),
current_profiles_semaphore_(OS::CreateSemaphore(1)) {
// Create list of unabridged profiles.
profiles_by_token_.Add(new List<CpuProfile*>());
}
static void DeleteCodeEntry(CodeEntry** entry_ptr) {
delete *entry_ptr;
}
static void DeleteCpuProfile(CpuProfile** profile_ptr) {
delete *profile_ptr;
}
static void DeleteProfilesList(List<CpuProfile*>** list_ptr) {
if (*list_ptr != NULL) {
(*list_ptr)->Iterate(DeleteCpuProfile);
delete *list_ptr;
}
}
CpuProfilesCollection::~CpuProfilesCollection() {
delete current_profiles_semaphore_;
current_profiles_.Iterate(DeleteCpuProfile);
detached_profiles_.Iterate(DeleteCpuProfile);
profiles_by_token_.Iterate(DeleteProfilesList);
code_entries_.Iterate(DeleteCodeEntry);
}
bool CpuProfilesCollection::StartProfiling(const char* title, unsigned uid) {
ASSERT(uid > 0);
current_profiles_semaphore_->Wait();
if (current_profiles_.length() >= kMaxSimultaneousProfiles) {
current_profiles_semaphore_->Signal();
return false;
}
for (int i = 0; i < current_profiles_.length(); ++i) {
if (strcmp(current_profiles_[i]->title(), title) == 0) {
// Ignore attempts to start profile with the same title.
current_profiles_semaphore_->Signal();
return false;
}
}
current_profiles_.Add(new CpuProfile(title, uid));
current_profiles_semaphore_->Signal();
return true;
}
bool CpuProfilesCollection::StartProfiling(String* title, unsigned uid) {
return StartProfiling(GetName(title), uid);
}
CpuProfile* CpuProfilesCollection::StopProfiling(int security_token_id,
const char* title,
double actual_sampling_rate) {
const int title_len = StrLength(title);
CpuProfile* profile = NULL;
current_profiles_semaphore_->Wait();
for (int i = current_profiles_.length() - 1; i >= 0; --i) {
if (title_len == 0 || strcmp(current_profiles_[i]->title(), title) == 0) {
profile = current_profiles_.Remove(i);
break;
}
}
current_profiles_semaphore_->Signal();
if (profile != NULL) {
profile->CalculateTotalTicks();
profile->SetActualSamplingRate(actual_sampling_rate);
List<CpuProfile*>* unabridged_list =
profiles_by_token_[TokenToIndex(TokenEnumerator::kNoSecurityToken)];
unabridged_list->Add(profile);
HashMap::Entry* entry =
profiles_uids_.Lookup(reinterpret_cast<void*>(profile->uid()),
static_cast<uint32_t>(profile->uid()),
true);
ASSERT(entry->value == NULL);
entry->value = reinterpret_cast<void*>(unabridged_list->length() - 1);
return GetProfile(security_token_id, profile->uid());
}
return NULL;
}
CpuProfile* CpuProfilesCollection::GetProfile(int security_token_id,
unsigned uid) {
int index = GetProfileIndex(uid);
if (index < 0) return NULL;
List<CpuProfile*>* unabridged_list =
profiles_by_token_[TokenToIndex(TokenEnumerator::kNoSecurityToken)];
if (security_token_id == TokenEnumerator::kNoSecurityToken) {
return unabridged_list->at(index);
}
List<CpuProfile*>* list = GetProfilesList(security_token_id);
if (list->at(index) == NULL) {
(*list)[index] =
unabridged_list->at(index)->FilteredClone(security_token_id);
}
return list->at(index);
}
int CpuProfilesCollection::GetProfileIndex(unsigned uid) {
HashMap::Entry* entry = profiles_uids_.Lookup(reinterpret_cast<void*>(uid),
static_cast<uint32_t>(uid),
false);
return entry != NULL ?
static_cast<int>(reinterpret_cast<intptr_t>(entry->value)) : -1;
}
bool CpuProfilesCollection::IsLastProfile(const char* title) {
// Called from VM thread, and only it can mutate the list,
// so no locking is needed here.
if (current_profiles_.length() != 1) return false;
return StrLength(title) == 0
|| strcmp(current_profiles_[0]->title(), title) == 0;
}
void CpuProfilesCollection::RemoveProfile(CpuProfile* profile) {
// Called from VM thread for a completed profile.
unsigned uid = profile->uid();
int index = GetProfileIndex(uid);
if (index < 0) {
detached_profiles_.RemoveElement(profile);
return;
}
profiles_uids_.Remove(reinterpret_cast<void*>(uid),
static_cast<uint32_t>(uid));
// Decrement all indexes above the deleted one.
for (HashMap::Entry* p = profiles_uids_.Start();
p != NULL;
p = profiles_uids_.Next(p)) {
intptr_t p_index = reinterpret_cast<intptr_t>(p->value);
if (p_index > index) {
p->value = reinterpret_cast<void*>(p_index - 1);
}
}
for (int i = 0; i < profiles_by_token_.length(); ++i) {
List<CpuProfile*>* list = profiles_by_token_[i];
if (list != NULL && index < list->length()) {
// Move all filtered clones into detached_profiles_,
// so we can know that they are still in use.
CpuProfile* cloned_profile = list->Remove(index);
if (cloned_profile != NULL && cloned_profile != profile) {
detached_profiles_.Add(cloned_profile);
}
}
}
}
int CpuProfilesCollection::TokenToIndex(int security_token_id) {
ASSERT(TokenEnumerator::kNoSecurityToken == -1);
return security_token_id + 1; // kNoSecurityToken -> 0, 0 -> 1, ...
}
List<CpuProfile*>* CpuProfilesCollection::GetProfilesList(
int security_token_id) {
const int index = TokenToIndex(security_token_id);
const int lists_to_add = index - profiles_by_token_.length() + 1;
if (lists_to_add > 0) profiles_by_token_.AddBlock(NULL, lists_to_add);
List<CpuProfile*>* unabridged_list =
profiles_by_token_[TokenToIndex(TokenEnumerator::kNoSecurityToken)];
const int current_count = unabridged_list->length();
if (profiles_by_token_[index] == NULL) {
profiles_by_token_[index] = new List<CpuProfile*>(current_count);
}
List<CpuProfile*>* list = profiles_by_token_[index];
const int profiles_to_add = current_count - list->length();
if (profiles_to_add > 0) list->AddBlock(NULL, profiles_to_add);
return list;
}
List<CpuProfile*>* CpuProfilesCollection::Profiles(int security_token_id) {
List<CpuProfile*>* unabridged_list =
profiles_by_token_[TokenToIndex(TokenEnumerator::kNoSecurityToken)];
if (security_token_id == TokenEnumerator::kNoSecurityToken) {
return unabridged_list;
}
List<CpuProfile*>* list = GetProfilesList(security_token_id);
const int current_count = unabridged_list->length();
for (int i = 0; i < current_count; ++i) {
if (list->at(i) == NULL) {
(*list)[i] = unabridged_list->at(i)->FilteredClone(security_token_id);
}
}
return list;
}
CodeEntry* CpuProfilesCollection::NewCodeEntry(Logger::LogEventsAndTags tag,
String* name,
String* resource_name,
int line_number) {
CodeEntry* entry = new CodeEntry(tag,
CodeEntry::kEmptyNamePrefix,
GetFunctionName(name),
GetName(resource_name),
line_number,
TokenEnumerator::kNoSecurityToken);
code_entries_.Add(entry);
return entry;
}
CodeEntry* CpuProfilesCollection::NewCodeEntry(Logger::LogEventsAndTags tag,
const char* name) {
CodeEntry* entry = new CodeEntry(tag,
CodeEntry::kEmptyNamePrefix,
GetFunctionName(name),
"",
v8::CpuProfileNode::kNoLineNumberInfo,
TokenEnumerator::kNoSecurityToken);
code_entries_.Add(entry);
return entry;
}
CodeEntry* CpuProfilesCollection::NewCodeEntry(Logger::LogEventsAndTags tag,
const char* name_prefix,
String* name) {
CodeEntry* entry = new CodeEntry(tag,
name_prefix,
GetName(name),
"",
v8::CpuProfileNode::kNoLineNumberInfo,
TokenEnumerator::kInheritsSecurityToken);
code_entries_.Add(entry);
return entry;
}
CodeEntry* CpuProfilesCollection::NewCodeEntry(Logger::LogEventsAndTags tag,
int args_count) {
CodeEntry* entry = new CodeEntry(tag,
"args_count: ",
GetName(args_count),
"",
v8::CpuProfileNode::kNoLineNumberInfo,
TokenEnumerator::kInheritsSecurityToken);
code_entries_.Add(entry);
return entry;
}
void CpuProfilesCollection::AddPathToCurrentProfiles(
const Vector<CodeEntry*>& path) {
// As starting / stopping profiles is rare relatively to this
// method, we don't bother minimizing the duration of lock holding,
// e.g. copying contents of the list to a local vector.
current_profiles_semaphore_->Wait();
for (int i = 0; i < current_profiles_.length(); ++i) {
current_profiles_[i]->AddPath(path);
}
current_profiles_semaphore_->Signal();
}
void SampleRateCalculator::Tick() {
if (--wall_time_query_countdown_ == 0)
UpdateMeasurements(OS::TimeCurrentMillis());
}
void SampleRateCalculator::UpdateMeasurements(double current_time) {
if (measurements_count_++ != 0) {
const double measured_ticks_per_ms =
(kWallTimeQueryIntervalMs * ticks_per_ms_) /
(current_time - last_wall_time_);
// Update the average value.
ticks_per_ms_ +=
(measured_ticks_per_ms - ticks_per_ms_) / measurements_count_;
// Update the externally accessible result.
result_ = static_cast<AtomicWord>(ticks_per_ms_ * kResultScale);
}
last_wall_time_ = current_time;
wall_time_query_countdown_ =
static_cast<unsigned>(kWallTimeQueryIntervalMs * ticks_per_ms_);
}
const char* const ProfileGenerator::kAnonymousFunctionName =
"(anonymous function)";
const char* const ProfileGenerator::kProgramEntryName =
"(program)";
const char* const ProfileGenerator::kGarbageCollectorEntryName =
"(garbage collector)";
ProfileGenerator::ProfileGenerator(CpuProfilesCollection* profiles)
: profiles_(profiles),
program_entry_(
profiles->NewCodeEntry(Logger::FUNCTION_TAG, kProgramEntryName)),
gc_entry_(
profiles->NewCodeEntry(Logger::BUILTIN_TAG,
kGarbageCollectorEntryName)) {
}
void ProfileGenerator::RecordTickSample(const TickSample& sample) {
// Allocate space for stack frames + pc + function + vm-state.
ScopedVector<CodeEntry*> entries(sample.frames_count + 3);
// As actual number of decoded code entries may vary, initialize
// entries vector with NULL values.
CodeEntry** entry = entries.start();
memset(entry, 0, entries.length() * sizeof(*entry));
if (sample.pc != NULL) {
*entry++ = code_map_.FindEntry(sample.pc);
if (sample.has_external_callback) {
// Don't use PC when in external callback code, as it can point
// inside callback's code, and we will erroneously report
// that a callback calls itself.
*(entries.start()) = NULL;
*entry++ = code_map_.FindEntry(sample.external_callback);
} else if (sample.tos != NULL) {
// Find out, if top of stack was pointing inside a JS function
// meaning that we have encountered a frameless invocation.
*entry = code_map_.FindEntry(sample.tos);
if (*entry != NULL && !(*entry)->is_js_function()) {
*entry = NULL;
}
entry++;
}
for (const Address* stack_pos = sample.stack,
*stack_end = stack_pos + sample.frames_count;
stack_pos != stack_end;
++stack_pos) {
*entry++ = code_map_.FindEntry(*stack_pos);
}
}
if (FLAG_prof_browser_mode) {
bool no_symbolized_entries = true;
for (CodeEntry** e = entries.start(); e != entry; ++e) {
if (*e != NULL) {
no_symbolized_entries = false;
break;
}
}
// If no frames were symbolized, put the VM state entry in.
if (no_symbolized_entries) {
*entry++ = EntryForVMState(sample.state);
}
}
profiles_->AddPathToCurrentProfiles(entries);
}
void HeapGraphEdge::Init(
int child_index, Type type, const char* name, HeapEntry* to) {
ASSERT(type == kContextVariable
|| type == kProperty
|| type == kInternal
|| type == kShortcut);
child_index_ = child_index;
type_ = type;
name_ = name;
to_ = to;
}
void HeapGraphEdge::Init(int child_index, Type type, int index, HeapEntry* to) {
ASSERT(type == kElement || type == kHidden || type == kWeak);
child_index_ = child_index;
type_ = type;
index_ = index;
to_ = to;
}
void HeapGraphEdge::Init(int child_index, int index, HeapEntry* to) {
Init(child_index, kElement, index, to);
}
HeapEntry* HeapGraphEdge::From() {
return reinterpret_cast<HeapEntry*>(this - child_index_) - 1;
}
void HeapEntry::Init(HeapSnapshot* snapshot,
Type type,
const char* name,
SnapshotObjectId id,
int self_size,
int children_count,
int retainers_count) {
snapshot_ = snapshot;
type_ = type;
painted_ = false;
name_ = name;
self_size_ = self_size;
retained_size_ = 0;
children_count_ = children_count;
retainers_count_ = retainers_count;
dominator_ = NULL;
id_ = id;
}
void HeapEntry::SetNamedReference(HeapGraphEdge::Type type,
int child_index,
const char* name,
HeapEntry* entry,
int retainer_index) {
children()[child_index].Init(child_index, type, name, entry);
entry->retainers()[retainer_index] = children_arr() + child_index;
}
void HeapEntry::SetIndexedReference(HeapGraphEdge::Type type,
int child_index,
int index,
HeapEntry* entry,
int retainer_index) {
children()[child_index].Init(child_index, type, index, entry);
entry->retainers()[retainer_index] = children_arr() + child_index;
}
void HeapEntry::SetUnidirElementReference(
int child_index, int index, HeapEntry* entry) {
children()[child_index].Init(child_index, index, entry);
}
Handle<HeapObject> HeapEntry::GetHeapObject() {
return snapshot_->collection()->FindHeapObjectById(id());
}
void HeapEntry::Print(
const char* prefix, const char* edge_name, int max_depth, int indent) {
OS::Print("%6d %7d @%6llu %*c %s%s: ",
self_size(), retained_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 "???";
}
}
size_t HeapEntry::EntriesSize(int entries_count,
int children_count,
int retainers_count) {
return sizeof(HeapEntry) * entries_count // NOLINT
+ sizeof(HeapGraphEdge) * children_count // NOLINT
+ sizeof(HeapGraphEdge*) * retainers_count; // NOLINT
}
// 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 = 32;
static const size_t kMaxSerializableSnapshotRawSize = 256 * MB;
};
template <> struct SnapshotSizeConstants<8> {
static const int kExpectedHeapGraphEdgeSize = 24;
static const int kExpectedHeapEntrySize = 48;
static const uint64_t kMaxSerializableSnapshotRawSize =
static_cast<uint64_t>(6000) * MB;
};
} // namespace
HeapSnapshot::HeapSnapshot(HeapSnapshotsCollection* collection,
HeapSnapshot::Type type,
const char* title,
unsigned uid)
: collection_(collection),
type_(type),
title_(title),
uid_(uid),
root_entry_(NULL),
gc_roots_entry_(NULL),
natives_root_entry_(NULL),
raw_entries_(NULL),
entries_sorted_(false) {
STATIC_CHECK(
sizeof(HeapGraphEdge) ==
SnapshotSizeConstants<kPointerSize>::kExpectedHeapGraphEdgeSize);
STATIC_CHECK(
sizeof(HeapEntry) ==
SnapshotSizeConstants<kPointerSize>::kExpectedHeapEntrySize);
for (int i = 0; i < VisitorSynchronization::kNumberOfSyncTags; ++i) {
gc_subroot_entries_[i] = NULL;
}
}
HeapSnapshot::~HeapSnapshot() {
DeleteArray(raw_entries_);
}
void HeapSnapshot::Delete() {
collection_->RemoveSnapshot(this);
delete this;
}
void HeapSnapshot::AllocateEntries(int entries_count,
int children_count,
int retainers_count) {
ASSERT(raw_entries_ == NULL);
raw_entries_size_ =
HeapEntry::EntriesSize(entries_count, children_count, retainers_count);
raw_entries_ = NewArray<char>(raw_entries_size_);
}
static void HeapEntryClearPaint(HeapEntry** entry_ptr) {
(*entry_ptr)->clear_paint();
}
void HeapSnapshot::ClearPaint() {
entries_.Iterate(HeapEntryClearPaint);
}
HeapEntry* HeapSnapshot::AddRootEntry(int children_count) {
ASSERT(root_entry_ == NULL);
return (root_entry_ = AddEntry(HeapEntry::kObject,
"",
HeapObjectsMap::kInternalRootObjectId,
0,
children_count,
0));
}
HeapEntry* HeapSnapshot::AddGcRootsEntry(int children_count,
int retainers_count) {
ASSERT(gc_roots_entry_ == NULL);
return (gc_roots_entry_ = AddEntry(HeapEntry::kObject,
"(GC roots)",
HeapObjectsMap::kGcRootsObjectId,
0,
children_count,
retainers_count));
}
HeapEntry* HeapSnapshot::AddGcSubrootEntry(int tag,
int children_count,
int retainers_count) {
ASSERT(gc_subroot_entries_[tag] == NULL);
ASSERT(0 <= tag && tag < VisitorSynchronization::kNumberOfSyncTags);
return (gc_subroot_entries_[tag] = AddEntry(
HeapEntry::kObject,
VisitorSynchronization::kTagNames[tag],
HeapObjectsMap::GetNthGcSubrootId(tag),
0,
children_count,
retainers_count));
}
HeapEntry* HeapSnapshot::AddEntry(HeapEntry::Type type,
const char* name,
SnapshotObjectId id,
int size,
int children_count,
int retainers_count) {
HeapEntry* entry = GetNextEntryToInit();
entry->Init(this, type, name, id, size, children_count, retainers_count);
return entry;
}
void HeapSnapshot::SetDominatorsToSelf() {
for (int i = 0; i < entries_.length(); ++i) {
HeapEntry* entry = entries_[i];
if (entry->dominator() == NULL) entry->set_dominator(entry);
}
}
HeapEntry* HeapSnapshot::GetNextEntryToInit() {
if (entries_.length() > 0) {
HeapEntry* last_entry = entries_.last();
entries_.Add(reinterpret_cast<HeapEntry*>(
reinterpret_cast<char*>(last_entry) + last_entry->EntrySize()));
} else {
entries_.Add(reinterpret_cast<HeapEntry*>(raw_entries_));
}
ASSERT(reinterpret_cast<char*>(entries_.last()) <
(raw_entries_ + raw_entries_size_));
return entries_.last();
}
HeapEntry* HeapSnapshot::GetEntryById(SnapshotObjectId id) {
List<HeapEntry*>* entries_by_id = GetSortedEntriesList();
// Perform a binary search by id.
int low = 0;
int high = entries_by_id->length() - 1;
while (low <= high) {
int mid =
(static_cast<unsigned int>(low) + static_cast<unsigned int>(high)) >> 1;
SnapshotObjectId mid_id = entries_by_id->at(mid)->id();
if (mid_id > id)
high = mid - 1;
else if (mid_id < id)
low = mid + 1;
else
return entries_by_id->at(mid);
}
return NULL;
}
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 (!entries_sorted_) {
entries_.Sort(SortByIds);
entries_sorted_ = true;
}
return &entries_;
}
void HeapSnapshot::Print(int max_depth) {
root()->Print("", "", max_depth, 0);
}
// 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()
: initial_fill_mode_(true),
next_id_(kFirstAvailableObjectId),
entries_map_(AddressesMatch),
entries_(new List<EntryInfo>()) { }
HeapObjectsMap::~HeapObjectsMap() {
delete entries_;
}
void HeapObjectsMap::SnapshotGenerationFinished() {
initial_fill_mode_ = false;
RemoveDeadEntries();
}
SnapshotObjectId HeapObjectsMap::FindObject(Address addr) {
if (!initial_fill_mode_) {
SnapshotObjectId existing = FindEntry(addr);
if (existing != 0) return existing;
}
SnapshotObjectId id = next_id_;
next_id_ += kObjectIdStep;
AddEntry(addr, id);
return id;
}
void HeapObjectsMap::MoveObject(Address from, Address to) {
if (from == to) return;
HashMap::Entry* entry = entries_map_.Lookup(from, AddressHash(from), false);
if (entry != NULL) {
void* value = entry->value;
entries_map_.Remove(from, AddressHash(from));
if (to != NULL) {
entry = entries_map_.Lookup(to, AddressHash(to), true);
// We can have an entry at the new location, it is OK, as GC can overwrite
// dead objects with alive objects being moved.
entry->value = value;
}
}
}
void HeapObjectsMap::AddEntry(Address addr, SnapshotObjectId id) {
HashMap::Entry* entry = entries_map_.Lookup(addr, AddressHash(addr), true);
ASSERT(entry->value == NULL);
entry->value = reinterpret_cast<void*>(entries_->length());
entries_->Add(EntryInfo(id));
}
SnapshotObjectId HeapObjectsMap::FindEntry(Address addr) {
HashMap::Entry* entry = entries_map_.Lookup(addr, AddressHash(addr), false);
if (entry != NULL) {
int entry_index =
static_cast<int>(reinterpret_cast<intptr_t>(entry->value));
EntryInfo& entry_info = entries_->at(entry_index);
entry_info.accessed = true;
return entry_info.id;
} else {
return 0;
}
}
void HeapObjectsMap::RemoveDeadEntries() {
List<EntryInfo>* new_entries = new List<EntryInfo>();
List<void*> dead_entries;
for (HashMap::Entry* entry = entries_map_.Start();
entry != NULL;
entry = entries_map_.Next(entry)) {
int entry_index =
static_cast<int>(reinterpret_cast<intptr_t>(entry->value));
EntryInfo& entry_info = entries_->at(entry_index);
if (entry_info.accessed) {
entry->value = reinterpret_cast<void*>(new_entries->length());
new_entries->Add(EntryInfo(entry_info.id, false));
} else {
dead_entries.Add(entry->key);
}
}
for (int i = 0; i < dead_entries.length(); ++i) {
void* raw_entry = dead_entries[i];
entries_map_.Remove(
raw_entry, AddressHash(reinterpret_cast<Address>(raw_entry)));
}
delete entries_;
entries_ = new_entries;
}
SnapshotObjectId HeapObjectsMap::GenerateId(v8::RetainedObjectInfo* info) {
SnapshotObjectId id = static_cast<SnapshotObjectId>(info->GetHash());
const char* label = info->GetLabel();
id ^= 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;
}
HeapSnapshotsCollection::HeapSnapshotsCollection()
: is_tracking_objects_(false),
snapshots_uids_(HeapSnapshotsMatch),
token_enumerator_(new TokenEnumerator()) {
}
static void DeleteHeapSnapshot(HeapSnapshot** snapshot_ptr) {
delete *snapshot_ptr;
}
HeapSnapshotsCollection::~HeapSnapshotsCollection() {
delete token_enumerator_;
snapshots_.Iterate(DeleteHeapSnapshot);
}
HeapSnapshot* HeapSnapshotsCollection::NewSnapshot(HeapSnapshot::Type type,
const char* name,
unsigned uid) {
is_tracking_objects_ = true; // Start watching for heap objects moves.
return new HeapSnapshot(this, type, 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");
AssertNoAllocation no_allocation;
HeapObject* object = NULL;
HeapIterator iterator(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_.FindObject(obj->address()) == id) {
ASSERT(object == NULL);
object = obj;
// Can't break -- kFilterUnreachable requires full heap traversal.
}
}
return object != NULL ? Handle<HeapObject>(object) : Handle<HeapObject>();
}
HeapEntry* const HeapEntriesMap::kHeapEntryPlaceholder =
reinterpret_cast<HeapEntry*>(1);
HeapEntriesMap::HeapEntriesMap()
: entries_(HeapThingsMatch),
entries_count_(0),
total_children_count_(0),
total_retainers_count_(0) {
}
HeapEntriesMap::~HeapEntriesMap() {
for (HashMap::Entry* p = entries_.Start(); p != NULL; p = entries_.Next(p)) {
delete reinterpret_cast<EntryInfo*>(p->value);
}
}
void HeapEntriesMap::AllocateEntries() {
for (HashMap::Entry* p = entries_.Start();
p != NULL;
p = entries_.Next(p)) {
EntryInfo* entry_info = reinterpret_cast<EntryInfo*>(p->value);
entry_info->entry = entry_info->allocator->AllocateEntry(
p->key,
entry_info->children_count,
entry_info->retainers_count);
ASSERT(entry_info->entry != NULL);
ASSERT(entry_info->entry != kHeapEntryPlaceholder);
entry_info->children_count = 0;
entry_info->retainers_count = 0;
}
}
HeapEntry* HeapEntriesMap::Map(HeapThing thing) {
HashMap::Entry* cache_entry = entries_.Lookup(thing, Hash(thing), false);
if (cache_entry != NULL) {
EntryInfo* entry_info = reinterpret_cast<EntryInfo*>(cache_entry->value);
return entry_info->entry;
} else {
return NULL;
}
}
void HeapEntriesMap::Pair(
HeapThing thing, HeapEntriesAllocator* allocator, HeapEntry* entry) {
HashMap::Entry* cache_entry = entries_.Lookup(thing, Hash(thing), true);
ASSERT(cache_entry->value == NULL);
cache_entry->value = new EntryInfo(entry, allocator);
++entries_count_;
}
void HeapEntriesMap::CountReference(HeapThing from, HeapThing to,
int* prev_children_count,
int* prev_retainers_count) {
HashMap::Entry* from_cache_entry = entries_.Lookup(from, Hash(from), false);
HashMap::Entry* to_cache_entry = entries_.Lookup(to, Hash(to), false);
ASSERT(from_cache_entry != NULL);
ASSERT(to_cache_entry != NULL);
EntryInfo* from_entry_info =
reinterpret_cast<EntryInfo*>(from_cache_entry->value);
EntryInfo* to_entry_info =
reinterpret_cast<EntryInfo*>(to_cache_entry->value);
if (prev_children_count)
*prev_children_count = from_entry_info->children_count;
if (prev_retainers_count)
*prev_retainers_count = to_entry_info->retainers_count;
++from_entry_info->children_count;
++to_entry_info->retainers_count;
++total_children_count_;
++total_retainers_count_;
}
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);
HashMap::Entry* cache_entry =
entries_.Lookup(object, HeapEntriesMap::Hash(object), false);
return cache_entry != NULL;
}
void HeapObjectsSet::Insert(Object* obj) {
if (!obj->IsHeapObject()) return;
HeapObject* object = HeapObject::cast(obj);
HashMap::Entry* cache_entry =
entries_.Lookup(object, HeapEntriesMap::Hash(object), true);
if (cache_entry->value == NULL) {
cache_entry->value = HeapEntriesMap::kHeapEntryPlaceholder;
}
}
const char* HeapObjectsSet::GetTag(Object* obj) {
HeapObject* object = HeapObject::cast(obj);
HashMap::Entry* cache_entry =
entries_.Lookup(object, HeapEntriesMap::Hash(object), false);
if (cache_entry != NULL
&& cache_entry->value != HeapEntriesMap::kHeapEntryPlaceholder) {
return reinterpret_cast<const char*>(cache_entry->value);
} else {
return 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)
: heap_(Isolate::Current()->heap()),
snapshot_(snapshot),
collection_(snapshot_->collection()),
progress_(progress),
filler_(NULL) {
}
V8HeapExplorer::~V8HeapExplorer() {
}
HeapEntry* V8HeapExplorer::AllocateEntry(
HeapThing ptr, int children_count, int retainers_count) {
return AddEntry(
reinterpret_cast<HeapObject*>(ptr), children_count, retainers_count);
}
HeapEntry* V8HeapExplorer::AddEntry(HeapObject* object,
int children_count,
int retainers_count) {
if (object == kInternalRootObject) {
ASSERT(retainers_count == 0);
return snapshot_->AddRootEntry(children_count);
} else if (object == kGcRootsObject) {
return snapshot_->AddGcRootsEntry(children_count, retainers_count);
} else if (object >= kFirstGcSubrootObject && object < kLastGcSubrootObject) {
return snapshot_->AddGcSubrootEntry(
GetGcSubrootOrder(object),
children_count,
retainers_count);
} 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,
children_count,
retainers_count);
} else if (object->IsJSRegExp()) {
JSRegExp* re = JSRegExp::cast(object);
return AddEntry(object,
HeapEntry::kRegExp,
collection_->names()->GetName(re->Pattern()),
children_count,
retainers_count);
} else if (object->IsJSObject()) {
return AddEntry(object,
HeapEntry::kObject,
"",
children_count,
retainers_count);
} else if (object->IsString()) {
return AddEntry(object,
HeapEntry::kString,
collection_->names()->GetName(String::cast(object)),
children_count,
retainers_count);
} else if (object->IsCode()) {
return AddEntry(object,
HeapEntry::kCode,
"",
children_count,
retainers_count);
} else if (object->IsSharedFunctionInfo()) {
SharedFunctionInfo* shared = SharedFunctionInfo::cast(object);
return AddEntry(object,
HeapEntry::kCode,
collection_->names()->GetName(String::cast(shared->name())),
children_count,
retainers_count);
} else if (object->IsScript()) {
Script* script = Script::cast(object);
return AddEntry(object,
HeapEntry::kCode,
script->name()->IsString() ?
collection_->names()->GetName(
String::cast(script->name()))
: "",
children_count,
retainers_count);
} else if (object->IsGlobalContext()) {
return AddEntry(object,
HeapEntry::kHidden,
"system / GlobalContext",
children_count,
retainers_count);
} else if (object->IsContext()) {
return AddEntry(object,
HeapEntry::kHidden,
"system / Context",
children_count,
retainers_count);
} else if (object->IsFixedArray() ||
object->IsFixedDoubleArray() ||
object->IsByteArray() ||
object->IsExternalArray()) {
const char* tag = objects_tags_.GetTag(object);
return AddEntry(object,
HeapEntry::kArray,
tag != NULL ? tag : "",
children_count,
retainers_count);
} else if (object->IsHeapNumber()) {
return AddEntry(object,
HeapEntry::kHeapNumber,
"number",
children_count,
retainers_count);
}
return AddEntry(object,
HeapEntry::kHidden,
GetSystemEntryName(object),
children_count,
retainers_count);
}
HeapEntry* V8HeapExplorer::AddEntry(HeapObject* object,
HeapEntry::Type type,
const char* name,
int children_count,
int retainers_count) {
return snapshot_->AddEntry(type,
name,
collection_->GetObjectId(object->address()),
object->Size(),
children_count,
retainers_count);
}
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: return "system / Map";
case JS_GLOBAL_PROPERTY_CELL_TYPE: return "system / JSGlobalPropertyCell";
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,
HeapEntry* parent_entry)
: generator_(generator),
parent_obj_(parent_obj),
parent_(parent_entry),
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_;
HeapEntry* parent_;
int next_index_;
};
void V8HeapExplorer::ExtractReferences(HeapObject* obj) {
HeapEntry* entry = GetEntry(obj);
if (entry == NULL) return; // No interest in this object.
bool extract_indexed_refs = true;
if (obj->IsJSGlobalProxy()) {
// We need to reference JS global objects from snapshot's root.
// We use JSGlobalProxy because this is what embedder (e.g. browser)
// uses for the global object.
JSGlobalProxy* proxy = JSGlobalProxy::cast(obj);
SetRootShortcutReference(proxy->map()->prototype());
} else if (obj->IsJSObject()) {
JSObject* js_obj = JSObject::cast(obj);
ExtractClosureReferences(js_obj, entry);
ExtractPropertyReferences(js_obj, entry);
ExtractElementReferences(js_obj, entry);
ExtractInternalReferences(js_obj, entry);
SetPropertyReference(
obj, entry, heap_->Proto_symbol(), 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_symbol(), proto_or_map,
NULL,
JSFunction::kPrototypeOrInitialMapOffset);
} else {
SetPropertyReference(
obj, entry,
heap_->prototype_symbol(), 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);
SetInternalReference(js_fun, entry,
"shared", shared_info,
JSFunction::kSharedFunctionInfoOffset);
TagObject(js_fun->unchecked_context(), "(context)");
SetInternalReference(js_fun, entry,
"context", js_fun->unchecked_context(),
JSFunction::kContextOffset);
for (int i = JSFunction::kNonWeakFieldsEndOffset;
i < JSFunction::kSize;
i += kPointerSize) {
SetWeakReference(js_fun, entry, i, *HeapObject::RawField(js_fun, i), i);
}
}
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);
} else if (obj->IsString()) {
if (obj->IsConsString()) {
ConsString* cs = ConsString::cast(obj);
SetInternalReference(obj, entry, 1, cs->first());
SetInternalReference(obj, entry, 2, cs->second());
}
if (obj->IsSlicedString()) {
SlicedString* ss = SlicedString::cast(obj);
SetInternalReference(obj, entry, "parent", ss->parent());
}
extract_indexed_refs = false;
} else if (obj->IsGlobalContext()) {
Context* context = Context::cast(obj);
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->data(), "(context data)");
for (int i = Context::FIRST_WEAK_SLOT;
i < Context::GLOBAL_CONTEXT_SLOTS;
++i) {
SetWeakReference(obj, entry,
i, context->get(i),
FixedArray::OffsetOfElementAt(i));
}
} else if (obj->IsMap()) {
Map* map = Map::cast(obj);
SetInternalReference(obj, entry,
"prototype", map->prototype(), Map::kPrototypeOffset);
SetInternalReference(obj, entry,
"constructor", map->constructor(),
Map::kConstructorOffset);
if (!map->instance_descriptors()->IsEmpty()) {
TagObject(map->instance_descriptors(), "(map descriptors)");
SetInternalReference(obj, entry,
"descriptors", map->instance_descriptors(),
Map::kInstanceDescriptorsOrBitField3Offset);
}
if (map->prototype_transitions() != heap_->empty_fixed_array()) {
TagObject(map->prototype_transitions(), "(prototype transitions)");
SetInternalReference(obj,
entry,
"prototype_transitions",
map->prototype_transitions(),
Map::kPrototypeTransitionsOffset);
}
SetInternalReference(obj, entry,
"code_cache", map->code_cache(),
Map::kCodeCacheOffset);
} else if (obj->IsSharedFunctionInfo()) {
SharedFunctionInfo* shared = SharedFunctionInfo::cast(obj);
SetInternalReference(obj, entry,
"name", shared->name(),
SharedFunctionInfo::kNameOffset);
SetInternalReference(obj, entry,
"code", shared->unchecked_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);
SetWeakReference(obj, entry,
1, shared->initial_map(),
SharedFunctionInfo::kInitialMapOffset);
} else if (obj->IsScript()) {
Script* script = Script::cast(obj);
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);
} else if (obj->IsCodeCache()) {
CodeCache* code_cache = CodeCache::cast(obj);
TagObject(code_cache->default_cache(), "(default code cache)");
SetInternalReference(obj, entry,
"default_cache", code_cache->default_cache(),
CodeCache::kDefaultCacheOffset);
TagObject(code_cache->normal_type_cache(), "(code type cache)");
SetInternalReference(obj, entry,
"type_cache", code_cache->normal_type_cache(),
CodeCache::kNormalTypeCacheOffset);
} else if (obj->IsCode()) {
Code* code = Code::cast(obj);
TagObject(code->unchecked_relocation_info(), "(code relocation info)");
TagObject(code->unchecked_deoptimization_data(), "(code deopt data)");
}
if (extract_indexed_refs) {
SetInternalReference(obj, entry, "map", obj->map(), HeapObject::kMapOffset);
IndexedReferencesExtractor refs_extractor(this, obj, entry);
obj->Iterate(&refs_extractor);
}
}
void V8HeapExplorer::ExtractClosureReferences(JSObject* js_obj,
HeapEntry* entry) {
if (!js_obj->IsJSFunction()) return;
JSFunction* func = JSFunction::cast(js_obj);
Context* context = func->context();
ScopeInfo* scope_info = context->closure()->shared()->scope_info();
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));
}
} else {
// 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;
SetClosureReference(js_obj, entry, local_name, context->get(idx));
}
// Add function variable.
if (scope_info->HasFunctionName()) {
String* name = scope_info->FunctionName();
int idx = Context::MIN_CONTEXT_SLOTS + context_locals;
#ifdef DEBUG
VariableMode mode;
ASSERT(idx == scope_info->FunctionContextSlotIndex(name, &mode));
#endif
SetClosureReference(js_obj, entry, name, context->get(idx));
}
}
}
void V8HeapExplorer::ExtractPropertyReferences(JSObject* js_obj,
HeapEntry* entry) {
if (js_obj->HasFastProperties()) {
DescriptorArray* descs = js_obj->map()->instance_descriptors();
for (int i = 0; i < descs->number_of_descriptors(); i++) {
switch (descs->GetType(i)) {
case FIELD: {
int index = descs->GetFieldIndex(i);
if (index < js_obj->map()->inobject_properties()) {
SetPropertyReference(
js_obj, entry,
descs->GetKey(i), js_obj->InObjectPropertyAt(index),
NULL,
js_obj->GetInObjectPropertyOffset(index));
} else {
SetPropertyReference(
js_obj, entry,
descs->GetKey(i), js_obj->FastPropertyAt(index));
}
break;
}
case CONSTANT_FUNCTION:
SetPropertyReference(
js_obj, entry,
descs->GetKey(i), descs->GetConstantFunction(i));
break;
case CALLBACKS: {
Object* callback_obj = descs->GetValue(i);
if (callback_obj->IsAccessorPair()) {
AccessorPair* accessors = AccessorPair::cast(callback_obj);
if (Object* getter = accessors->getter()) {
SetPropertyReference(js_obj, entry, descs->GetKey(i),
getter, "get-%s");
}
if (Object* setter = accessors->setter()) {
SetPropertyReference(js_obj, entry, descs->GetKey(i),
setter, "set-%s");
}
}
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
case MAP_TRANSITION: // we do not care about transitions here...
case ELEMENTS_TRANSITION:
case CONSTANT_TRANSITION:
case NULL_DESCRIPTOR: // ... and not about "holes"
break;
}
}
} else {
StringDictionary* 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);
SetPropertyReference(
js_obj, entry, String::cast(k), target);
// We assume that global objects can only have slow properties.
if (target->IsJSGlobalPropertyCell()) {
SetPropertyShortcutReference(js_obj,
entry,
String::cast(k),
JSGlobalPropertyCell::cast(
target)->value());
}
}
}
}
}
void V8HeapExplorer::ExtractElementReferences(JSObject* js_obj,
HeapEntry* entry) {
if (js_obj->HasFastElements()) {
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,
HeapEntry* 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_symbol();
String* constructor_name = object->constructor_name();
if (constructor_name == heap->Object_symbol()) {
// 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_symbol(), &result);
if (result.IsProperty()) {
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(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(false);
}
bool V8HeapExplorer::IterateAndSetObjectNames(SnapshotFillerInterface* filler) {
HeapIterator iterator(HeapIterator::kFilterUnreachable);
filler_ = filler;
for (HeapObject* obj = iterator.next(); obj != NULL; obj = iterator.next()) {
SetObjectName(obj);
}
return true;
}
void V8HeapExplorer::SetObjectName(HeapObject* object) {
if (!object->IsJSObject() || object->IsJSRegExp() || object->IsJSFunction()) {
return;
}
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);
}
}
GetEntry(object)->set_name(name);
}
void V8HeapExplorer::SetClosureReference(HeapObject* parent_obj,
HeapEntry* parent_entry,
String* reference_name,
Object* child_obj) {
HeapEntry* child_entry = GetEntry(child_obj);
if (child_entry != NULL) {
filler_->SetNamedReference(HeapGraphEdge::kContextVariable,
parent_obj,
parent_entry,
collection_->names()->GetName(reference_name),
child_obj,
child_entry);
}
}
void V8HeapExplorer::SetNativeBindReference(HeapObject* parent_obj,
HeapEntry* parent_entry,
const char* reference_name,
Object* child_obj) {
HeapEntry* child_entry = GetEntry(child_obj);
if (child_entry != NULL) {
filler_->SetNamedReference(HeapGraphEdge::kShortcut,
parent_obj,
parent_entry,
reference_name,
child_obj,
child_entry);
}
}
void V8HeapExplorer::SetElementReference(HeapObject* parent_obj,
HeapEntry* parent_entry,
int index,
Object* child_obj) {
HeapEntry* child_entry = GetEntry(child_obj);
if (child_entry != NULL) {
filler_->SetIndexedReference(HeapGraphEdge::kElement,
parent_obj,
parent_entry,
index,
child_obj,
child_entry);
}
}
void V8HeapExplorer::SetInternalReference(HeapObject* parent_obj,
HeapEntry* parent_entry,
const char* reference_name,
Object* child_obj,
int field_offset) {
HeapEntry* child_entry = GetEntry(child_obj);
if (child_entry != NULL) {
filler_->SetNamedReference(HeapGraphEdge::kInternal,
parent_obj,
parent_entry,
reference_name,
child_obj,
child_entry);
IndexedReferencesExtractor::MarkVisitedField(parent_obj, field_offset);
}
}
void V8HeapExplorer::SetInternalReference(HeapObject* parent_obj,
HeapEntry* parent_entry,
int index,
Object* child_obj,
int field_offset) {
HeapEntry* child_entry = GetEntry(child_obj);
if (child_entry != NULL) {
filler_->SetNamedReference(HeapGraphEdge::kInternal,
parent_obj,
parent_entry,
collection_->names()->GetName(index),
child_obj,
child_entry);
IndexedReferencesExtractor::MarkVisitedField(parent_obj, field_offset);
}
}
void V8HeapExplorer::SetHiddenReference(HeapObject* parent_obj,
HeapEntry* parent_entry,
int index,
Object* child_obj) {
HeapEntry* child_entry = GetEntry(child_obj);
if (child_entry != NULL) {
filler_->SetIndexedReference(HeapGraphEdge::kHidden,
parent_obj,
parent_entry,
index,
child_obj,
child_entry);
}
}
void V8HeapExplorer::SetWeakReference(HeapObject* parent_obj,
HeapEntry* 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_obj,
parent_entry,
index,
child_obj,
child_entry);
IndexedReferencesExtractor::MarkVisitedField(parent_obj, field_offset);
}
}
void V8HeapExplorer::SetPropertyReference(HeapObject* parent_obj,
HeapEntry* parent_entry,
String* 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->length() > 0 ?
HeapGraphEdge::kProperty : HeapGraphEdge::kInternal;
const char* name = name_format_string != NULL ?
collection_->names()->GetFormatted(
name_format_string,
*reference_name->ToCString(DISALLOW_NULLS,
ROBUST_STRING_TRAVERSAL)) :
collection_->names()->GetName(reference_name);
filler_->SetNamedReference(type,
parent_obj,
parent_entry,
name,
child_obj,
child_entry);
IndexedReferencesExtractor::MarkVisitedField(parent_obj, field_offset);
}
}
void V8HeapExplorer::SetPropertyShortcutReference(HeapObject* parent_obj,
HeapEntry* parent_entry,
String* reference_name,
Object* child_obj) {
HeapEntry* child_entry = GetEntry(child_obj);
if (child_entry != NULL) {
filler_->SetNamedReference(HeapGraphEdge::kShortcut,
parent_obj,
parent_entry,
collection_->names()->GetName(reference_name),
child_obj,
child_entry);
}
}
void V8HeapExplorer::SetRootGcRootsReference() {
filler_->SetIndexedAutoIndexReference(
HeapGraphEdge::kElement,
kInternalRootObject, snapshot_->root(),
kGcRootsObject, snapshot_->gc_roots());
}
void V8HeapExplorer::SetRootShortcutReference(Object* child_obj) {
HeapEntry* child_entry = GetEntry(child_obj);
ASSERT(child_entry != NULL);
filler_->SetNamedAutoIndexReference(
HeapGraphEdge::kShortcut,
kInternalRootObject, snapshot_->root(),
child_obj, child_entry);
}
void V8HeapExplorer::SetGcRootsReference(VisitorSynchronization::SyncTag tag) {
filler_->SetIndexedAutoIndexReference(
HeapGraphEdge::kElement,
kGcRootsObject, snapshot_->gc_roots(),
GetNthGcSubrootObject(tag), 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) {
filler_->SetIndexedAutoIndexReference(
is_weak ? HeapGraphEdge::kWeak : HeapGraphEdge::kElement,
GetNthGcSubrootObject(tag), snapshot_->gc_subroot(tag),
child_obj, child_entry);
}
}
void V8HeapExplorer::TagObject(Object* obj, const char* tag) {
if (obj->IsHeapObject() &&
!obj->IsOddball() &&
obj != heap_->raw_unchecked_empty_byte_array() &&
obj != heap_->raw_unchecked_empty_fixed_array() &&
obj != heap_->raw_unchecked_empty_descriptor_array()) {
objects_tags_.SetTag(obj, tag);
}
}
class GlobalObjectsEnumerator : public ObjectVisitor {
public:
virtual void VisitPointers(Object** start, Object** end) {
for (Object** p = start; p < end; p++) {
if ((*p)->IsGlobalContext()) {
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() {
HandleScope scope;
Isolate* isolate = Isolate::Current();
GlobalObjectsEnumerator enumerator;
isolate->global_handles()->IterateAllRoots(&enumerator);
Handle<String> document_string =
isolate->factory()->NewStringFromAscii(CStrVector("document"));
Handle<String> url_string =
isolate->factory()->NewStringFromAscii(CStrVector("URL"));
const char** urls = NewArray<const char*>(enumerator.count());
for (int i = 0, l = enumerator.count(); i < l; ++i) {
urls[i] = NULL;
HandleScope scope;
Handle<JSGlobalObject> global_obj = enumerator.at(i);
Object* obj_document;
if (global_obj->GetProperty(*document_string)->ToObject(&obj_document) &&
obj_document->IsJSObject()) {
JSObject* document = JSObject::cast(obj_document);
Object* obj_url;
if (document->GetProperty(*url_string)->ToObject(&obj_url) &&
obj_url->IsString()) {
urls[i] = collection_->names()->GetName(String::cast(obj_url));
}
}
}
AssertNoAllocation 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, int children_count, int retainers_count);
private:
HeapSnapshot* snapshot_;
HeapSnapshotsCollection* collection_;
HeapEntry::Type entries_type_;
};
HeapEntry* BasicHeapEntriesAllocator::AllocateEntry(
HeapThing ptr, int children_count, int retainers_count) {
v8::RetainedObjectInfo* info = reinterpret_cast<v8::RetainedObjectInfo*>(ptr);
intptr_t elements = info->GetElementCount();
intptr_t size = info->GetSizeInBytes();
return snapshot_->AddEntry(
entries_type_,
elements != -1 ?
collection_->names()->GetFormatted(
"%s / %" V8_PTR_PREFIX "d entries",
info->GetLabel(),
info->GetElementCount()) :
collection_->names()->GetCopy(info->GetLabel()),
HeapObjectsMap::GenerateId(info),
size != -1 ? static_cast<int>(size) : 0,
children_count,
retainers_count);
}
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();
// Record objects that are joined into ObjectGroups.
isolate->heap()->CallGlobalGCPrologueCallback();
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()->CallGlobalGCEpilogueCallback();
// 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_;
HeapEntry* parent_entry =
filler_->FindOrAddEntry(parent, native_entries_allocator_);
ASSERT(parent_entry != NULL);
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, parent_entry,
"native",
child, child_entry);
}
}
}
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 = 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_info, group_entry,
info, 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, wrapper_entry,
"native",
info, info_entry);
filler_->SetIndexedAutoIndexReference(HeapGraphEdge::kElement,
info, info_entry,
wrapper, 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,
V8HeapExplorer::kInternalRootObject, snapshot_->root(),
group_info, 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 SnapshotCounter : public SnapshotFillerInterface {
public:
explicit SnapshotCounter(HeapEntriesMap* entries) : entries_(entries) { }
HeapEntry* AddEntry(HeapThing ptr, HeapEntriesAllocator* allocator) {
entries_->Pair(ptr, allocator, HeapEntriesMap::kHeapEntryPlaceholder);
return HeapEntriesMap::kHeapEntryPlaceholder;
}
HeapEntry* FindEntry(HeapThing ptr) {
return entries_->Map(ptr);
}
HeapEntry* FindOrAddEntry(HeapThing ptr, HeapEntriesAllocator* allocator) {
HeapEntry* entry = FindEntry(ptr);
return entry != NULL ? entry : AddEntry(ptr, allocator);
}
void SetIndexedReference(HeapGraphEdge::Type,
HeapThing parent_ptr,
HeapEntry*,
int,
HeapThing child_ptr,
HeapEntry*) {
entries_->CountReference(parent_ptr, child_ptr);
}
void SetIndexedAutoIndexReference(HeapGraphEdge::Type,
HeapThing parent_ptr,
HeapEntry*,
HeapThing child_ptr,
HeapEntry*) {
entries_->CountReference(parent_ptr, child_ptr);
}
void SetNamedReference(HeapGraphEdge::Type,
HeapThing parent_ptr,
HeapEntry*,
const char*,
HeapThing child_ptr,
HeapEntry*) {
entries_->CountReference(parent_ptr, child_ptr);
}
void SetNamedAutoIndexReference(HeapGraphEdge::Type,
HeapThing parent_ptr,
HeapEntry*,
HeapThing child_ptr,
HeapEntry*) {
entries_->CountReference(parent_ptr, child_ptr);
}
private:
HeapEntriesMap* entries_;
};
class SnapshotFiller : public SnapshotFillerInterface {
public:
explicit SnapshotFiller(HeapSnapshot* snapshot, HeapEntriesMap* entries)
: snapshot_(snapshot),
collection_(snapshot->collection()),
entries_(entries) { }
HeapEntry* AddEntry(HeapThing ptr, HeapEntriesAllocator* allocator) {
UNREACHABLE();
return NULL;
}
HeapEntry* FindEntry(HeapThing ptr) {
return entries_->Map(ptr);
}
HeapEntry* FindOrAddEntry(HeapThing ptr, HeapEntriesAllocator* allocator) {
HeapEntry* entry = FindEntry(ptr);
return entry != NULL ? entry : AddEntry(ptr, allocator);
}
void SetIndexedReference(HeapGraphEdge::Type type,
HeapThing parent_ptr,
HeapEntry* parent_entry,
int index,
HeapThing child_ptr,
HeapEntry* child_entry) {
int child_index, retainer_index;
entries_->CountReference(
parent_ptr, child_ptr, &child_index, &retainer_index);
parent_entry->SetIndexedReference(
type, child_index, index, child_entry, retainer_index);
}
void SetIndexedAutoIndexReference(HeapGraphEdge::Type type,
HeapThing parent_ptr,
HeapEntry* parent_entry,
HeapThing child_ptr,
HeapEntry* child_entry) {
int child_index, retainer_index;
entries_->CountReference(
parent_ptr, child_ptr, &child_index, &retainer_index);
parent_entry->SetIndexedReference(
type, child_index, child_index + 1, child_entry, retainer_index);
}
void SetNamedReference(HeapGraphEdge::Type type,
HeapThing parent_ptr,
HeapEntry* parent_entry,
const char* reference_name,
HeapThing child_ptr,
HeapEntry* child_entry) {
int child_index, retainer_index;
entries_->CountReference(
parent_ptr, child_ptr, &child_index, &retainer_index);
parent_entry->SetNamedReference(
type, child_index, reference_name, child_entry, retainer_index);
}
void SetNamedAutoIndexReference(HeapGraphEdge::Type type,
HeapThing parent_ptr,
HeapEntry* parent_entry,
HeapThing child_ptr,
HeapEntry* child_entry) {
int child_index, retainer_index;
entries_->CountReference(
parent_ptr, child_ptr, &child_index, &retainer_index);
parent_entry->SetNamedReference(type,
child_index,
collection_->names()->GetName(child_index + 1),
child_entry,
retainer_index);
}
private:
HeapSnapshot* snapshot_;
HeapSnapshotsCollection* collection_;
HeapEntriesMap* entries_;
};
HeapSnapshotGenerator::HeapSnapshotGenerator(HeapSnapshot* snapshot,
v8::ActivityControl* control)
: snapshot_(snapshot),
control_(control),
v8_heap_explorer_(snapshot_, this),
dom_explorer_(snapshot_, this) {
}
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 DEBUG
Heap* debug_heap = Isolate::Current()->heap();
ASSERT(!debug_heap->old_data_space()->was_swept_conservatively());
ASSERT(!debug_heap->old_pointer_space()->was_swept_conservatively());
ASSERT(!debug_heap->code_space()->was_swept_conservatively());
ASSERT(!debug_heap->cell_space()->was_swept_conservatively());
ASSERT(!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.
AssertNoAllocation no_alloc;
#ifdef DEBUG
debug_heap->Verify();
#endif
SetProgressTotal(2); // 2 passes.
#ifdef DEBUG
debug_heap->Verify();
#endif
// Pass 1. Iterate heap contents to count entries and references.
if (!CountEntriesAndReferences()) return false;
#ifdef DEBUG
debug_heap->Verify();
#endif
// Allocate memory for entries and references.
snapshot_->AllocateEntries(entries_.entries_count(),
entries_.total_children_count(),
entries_.total_retainers_count());
// Allocate heap objects to entries hash map.
entries_.AllocateEntries();
// Pass 2. Fill references.
if (!FillReferences()) return false;
if (!SetEntriesDominators()) return false;
if (!CalculateRetainedSizes()) return false;
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(HeapIterator::kFilterUnreachable);
progress_total_ = (
v8_heap_explorer_.EstimateObjectsCount(&iterator) +
dom_explorer_.EstimateObjectsCount()) * iterations_count;
progress_counter_ = 0;
}
bool HeapSnapshotGenerator::CountEntriesAndReferences() {
SnapshotCounter counter(&entries_);
v8_heap_explorer_.AddRootEntries(&counter);
return v8_heap_explorer_.IterateAndExtractReferences(&counter)
&& dom_explorer_.IterateAndExtractReferences(&counter);
}
bool HeapSnapshotGenerator::FillReferences() {
SnapshotFiller filler(snapshot_, &entries_);
// IterateAndExtractReferences cannot set object names because
// it makes call to JSObject::LocalLookupRealNamedProperty which
// in turn may relocate objects in property maps thus changing the heap
// layout and affecting retainer counts. This is not acceptable because
// number of retainers must not change between count and fill passes.
// To avoid this there's a separate postpass that set object names.
return v8_heap_explorer_.IterateAndExtractReferences(&filler)
&& dom_explorer_.IterateAndExtractReferences(&filler)
&& v8_heap_explorer_.IterateAndSetObjectNames(&filler);
}
void HeapSnapshotGenerator::FillReversePostorderIndexes(
Vector<HeapEntry*>* entries) {
snapshot_->ClearPaint();
int current_entry = 0;
List<HeapEntry*> nodes_to_visit;
nodes_to_visit.Add(snapshot_->root());
snapshot_->root()->paint();
while (!nodes_to_visit.is_empty()) {
HeapEntry* entry = nodes_to_visit.last();
Vector<HeapGraphEdge> children = entry->children();
bool has_new_edges = false;
for (int i = 0; i < children.length(); ++i) {
if (children[i].type() == HeapGraphEdge::kShortcut) continue;
HeapEntry* child = children[i].to();
if (!child->painted()) {
nodes_to_visit.Add(child);
child->paint();
has_new_edges = true;
}
}
if (!has_new_edges) {
entry->set_ordered_index(current_entry);
(*entries)[current_entry++] = entry;
nodes_to_visit.RemoveLast();
}
}
ASSERT_EQ(current_entry, entries->length());
}
static int Intersect(int i1, int i2, const Vector<int>& dominators) {
int finger1 = i1, finger2 = i2;
while (finger1 != finger2) {
while (finger1 < finger2) finger1 = dominators[finger1];
while (finger2 < finger1) finger2 = dominators[finger2];
}
return finger1;
}
// The algorithm is based on the article:
// K. Cooper, T. Harvey and K. Kennedy "A Simple, Fast Dominance Algorithm"
// Softw. Pract. Exper. 4 (2001), pp. 1-10.
bool HeapSnapshotGenerator::BuildDominatorTree(
const Vector<HeapEntry*>& entries,
Vector<int>* dominators) {
if (entries.length() == 0) return true;
const int entries_length = entries.length(), root_index = entries_length - 1;
static const int kNoDominator = -1;
for (int i = 0; i < root_index; ++i) (*dominators)[i] = kNoDominator;
(*dominators)[root_index] = root_index;
// The affected array is used to mark entries which dominators
// have to be racalculated because of changes in their retainers.
ScopedVector<bool> affected(entries_length);
for (int i = 0; i < affected.length(); ++i) affected[i] = false;
// Mark the root direct children as affected.
Vector<HeapGraphEdge> children = entries[root_index]->children();
for (int i = 0; i < children.length(); ++i) {
affected[children[i].to()->ordered_index()] = true;
}
bool changed = true;
while (changed) {
changed = false;
if (!ProgressReport(true)) return false;
for (int i = root_index - 1; i >= 0; --i) {
if (!affected[i]) continue;
affected[i] = false;
// If dominator of the entry has already been set to root,
// then it can't propagate any further.
if ((*dominators)[i] == root_index) continue;
int new_idom_index = kNoDominator;
Vector<HeapGraphEdge*> rets = entries[i]->retainers();
for (int j = 0; j < rets.length(); ++j) {
if (rets[j]->type() == HeapGraphEdge::kShortcut) continue;
int ret_index = rets[j]->From()->ordered_index();
if (dominators->at(ret_index) != kNoDominator) {
new_idom_index = new_idom_index == kNoDominator
? ret_index
: Intersect(ret_index, new_idom_index, *dominators);
// If idom has already reached the root, it doesn't make sense
// to check other retainers.
if (new_idom_index == root_index) break;
}
}
if (new_idom_index != kNoDominator
&& dominators->at(i) != new_idom_index) {
(*dominators)[i] = new_idom_index;
changed = true;
Vector<HeapGraphEdge> children = entries[i]->children();
for (int j = 0; j < children.length(); ++j) {
affected[children[j].to()->ordered_index()] = true;
}
}
}
}
return true;
}
bool HeapSnapshotGenerator::SetEntriesDominators() {
// This array is used for maintaining reverse postorder of nodes.
ScopedVector<HeapEntry*> ordered_entries(snapshot_->entries()->length());
FillReversePostorderIndexes(&ordered_entries);
ScopedVector<int> dominators(ordered_entries.length());
if (!BuildDominatorTree(ordered_entries, &dominators)) return false;
for (int i = 0; i < ordered_entries.length(); ++i) {
ASSERT(dominators[i] >= 0);
ordered_entries[i]->set_dominator(ordered_entries[dominators[i]]);
}
return true;
}
bool HeapSnapshotGenerator::CalculateRetainedSizes() {
// As for the dominators tree we only know parent nodes, not
// children, to sum up total sizes we "bubble" node's self size
// adding it to all of its parents.
List<HeapEntry*>& entries = *snapshot_->entries();
for (int i = 0; i < entries.length(); ++i) {
HeapEntry* entry = entries[i];
entry->set_retained_size(entry->self_size());
}
for (int i = 0; i < entries.length(); ++i) {
HeapEntry* entry = entries[i];
int entry_size = entry->self_size();
for (HeapEntry* dominator = entry->dominator();
dominator != entry;
entry = dominator, dominator = entry->dominator()) {
dominator->add_retained_size(entry_size);
}
}
return true;
}
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);
memcpy(chunk_.start() + chunk_pos_, s, s_chunk_size);
s += s_chunk_size;
chunk_pos_ += s_chunk_size;
MaybeWriteChunk();
}
}
void AddNumber(int n) { AddNumberImpl<int>(n, "%d"); }
void AddNumber(unsigned n) { AddNumberImpl<unsigned>(n, "%u"); }
void AddNumber(uint64_t n) { AddNumberImpl<uint64_t>(n, "%llu"); }
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_;
};
void HeapSnapshotJSONSerializer::Serialize(v8::OutputStream* stream) {
ASSERT(writer_ == NULL);
writer_ = new OutputStreamWriter(stream);
HeapSnapshot* original_snapshot = NULL;
if (snapshot_->raw_entries_size() >=
SnapshotSizeConstants<kPointerSize>::kMaxSerializableSnapshotRawSize) {
// The snapshot is too big. Serialize a fake snapshot.
original_snapshot = snapshot_;
snapshot_ = CreateFakeSnapshot();
}
// Since nodes graph is cyclic, we need the first pass to enumerate
// them. Strings can be serialized in one pass.
EnumerateNodes();
SerializeImpl();
delete writer_;
writer_ = NULL;
if (original_snapshot != NULL) {
delete snapshot_;
snapshot_ = original_snapshot;
}
}
HeapSnapshot* HeapSnapshotJSONSerializer::CreateFakeSnapshot() {
HeapSnapshot* result = new HeapSnapshot(snapshot_->collection(),
HeapSnapshot::kFull,
snapshot_->title(),
snapshot_->uid());
result->AllocateEntries(2, 1, 0);
HeapEntry* root = result->AddRootEntry(1);
const char* text = snapshot_->collection()->names()->GetFormatted(
"The snapshot is too big. "
"Maximum snapshot size is %" V8_PTR_PREFIX "u MB. "
"Actual snapshot size is %" V8_PTR_PREFIX "u MB.",
SnapshotSizeConstants<kPointerSize>::kMaxSerializableSnapshotRawSize / MB,
(snapshot_->raw_entries_size() + MB - 1) / MB);
HeapEntry* message = result->AddEntry(
HeapEntry::kString, text, 0, 4, 0, 0);
root->SetUnidirElementReference(0, 1, message);
result->SetDominatorsToSelf();
return result;
}
void HeapSnapshotJSONSerializer::SerializeImpl() {
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("\"strings\":[");
SerializeStrings();
if (writer_->aborted()) return;
writer_->AddCharacter(']');
writer_->AddCharacter('}');
writer_->Finalize();
}
class HeapSnapshotJSONSerializerEnumerator {
public:
explicit HeapSnapshotJSONSerializerEnumerator(HeapSnapshotJSONSerializer* s)
: s_(s) {
}
void Apply(HeapEntry** entry) {
s_->GetNodeId(*entry);
}
private:
HeapSnapshotJSONSerializer* s_;
};
void HeapSnapshotJSONSerializer::EnumerateNodes() {
GetNodeId(snapshot_->root()); // Make sure root gets the first id.
HeapSnapshotJSONSerializerEnumerator iter(this);
snapshot_->IterateEntries(&iter);
}
int HeapSnapshotJSONSerializer::GetNodeId(HeapEntry* entry) {
HashMap::Entry* cache_entry = nodes_.Lookup(entry, ObjectHash(entry), true);
if (cache_entry->value == NULL) {
cache_entry->value = reinterpret_cast<void*>(next_node_id_++);
}
return static_cast<int>(reinterpret_cast<intptr_t>(cache_entry->value));
}
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));
}
void HeapSnapshotJSONSerializer::SerializeEdge(HeapGraphEdge* edge) {
// The buffer needs space for 3 ints, 3 commas and \0
static const int kBufferSize =
MaxDecimalDigitsIn<sizeof(int)>::kSigned * 3 + 3 + 1; // 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());
STATIC_CHECK(sizeof(int) == sizeof(edge->type())); // NOLINT
STATIC_CHECK(sizeof(int) == sizeof(edge_name_or_index)); // NOLINT
STATIC_CHECK(sizeof(int) == sizeof(GetNodeId(edge->to()))); // NOLINT
int result = OS::SNPrintF(buffer, ",%d,%d,%d",
edge->type(), edge_name_or_index, GetNodeId(edge->to()));
USE(result);
ASSERT(result != -1);
writer_->AddString(buffer.start());
}
void HeapSnapshotJSONSerializer::SerializeNode(HeapEntry* entry) {
// The buffer needs space for 6 ints, 1 uint32_t, 7 commas, \n and \0
static const int kBufferSize =
6 * MaxDecimalDigitsIn<sizeof(int)>::kSigned // NOLINT
+ MaxDecimalDigitsIn<sizeof(uint32_t)>::kUnsigned // NOLINT
+ 7 + 1 + 1;
EmbeddedVector<char, kBufferSize> buffer;
Vector<HeapGraphEdge> children = entry->children();
STATIC_CHECK(sizeof(int) == sizeof(entry->type())); // NOLINT
STATIC_CHECK(sizeof(int) == sizeof(GetStringId(entry->name()))); // NOLINT
STATIC_CHECK(sizeof(unsigned) == sizeof(entry->id())); // NOLINT
STATIC_CHECK(sizeof(int) == sizeof(entry->self_size())); // NOLINT
STATIC_CHECK(sizeof(int) == sizeof(entry->retained_size())); // NOLINT
STATIC_CHECK(sizeof(int) == sizeof(GetNodeId(entry->dominator()))); // NOLINT
STATIC_CHECK(sizeof(int) == sizeof(children.length())); // NOLINT
int result = OS::SNPrintF(buffer, "\n,%d,%d,%u,%d,%d,%d,%d",
entry->type(),
GetStringId(entry->name()),
entry->id(),
entry->self_size(),
entry->retained_size(),
GetNodeId(entry->dominator()),
children.length());
USE(result);
ASSERT(result != -1);
writer_->AddString(buffer.start());
for (int i = 0; i < children.length(); ++i) {
SerializeEdge(&children[i]);
if (writer_->aborted()) return;
}
}
void HeapSnapshotJSONSerializer::SerializeNodes() {
// The first (zero) item of nodes array is an 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("fields") ":" JSON_A(
JSON_S("type")
"," JSON_S("name")
"," JSON_S("id")
"," JSON_S("self_size")
"," JSON_S("retained_size")
"," JSON_S("dominator")
"," JSON_S("children_count")
"," JSON_S("children"))
"," JSON_S("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_O(
JSON_S("fields") ":" JSON_A(
JSON_S("type")
"," JSON_S("name_or_index")
"," JSON_S("to_node"))
"," JSON_S("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
const int node_fields_count = 7;
// type,name,id,self_size,retained_size,dominator,children_count.
const int edge_fields_count = 3; // type,name|index,to_node.
List<HashMap::Entry*> sorted_nodes;
SortHashMap(&nodes_, &sorted_nodes);
// Rewrite node ids, so they refer to actual array positions.
if (sorted_nodes.length() > 1) {
// Nodes start from array index 1.
int prev_value = 1;
sorted_nodes[0]->value = reinterpret_cast<void*>(prev_value);
for (int i = 1; i < sorted_nodes.length(); ++i) {
HeapEntry* prev_heap_entry =
reinterpret_cast<HeapEntry*>(sorted_nodes[i-1]->key);
prev_value += node_fields_count +
prev_heap_entry->children().length() * edge_fields_count;
sorted_nodes[i]->value = reinterpret_cast<void*>(prev_value);
}
}
for (int i = 0; i < sorted_nodes.length(); ++i) {
SerializeNode(reinterpret_cast<HeapEntry*>(sorted_nodes[i]->key));
if (writer_->aborted()) return;
}
}
void HeapSnapshotJSONSerializer::SerializeSnapshot() {
writer_->AddString("\"title\":\"");
writer_->AddString(snapshot_->title());
writer_->AddString("\"");
writer_->AddString(",\"uid\":");
writer_->AddNumber(snapshot_->uid());
}
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