blob: ba3f30ea9dbbb5bf9f6d7dad5c0b2bd236043f05 [file] [log] [blame]
// Copyright 2012 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/profiler/profile-generator.h"
#include <algorithm>
#include "src/objects/shared-function-info-inl.h"
#include "src/profiler/cpu-profiler.h"
#include "src/profiler/profile-generator-inl.h"
#include "src/tracing/trace-event.h"
#include "src/tracing/traced-value.h"
namespace v8 {
namespace internal {
void SourcePositionTable::SetPosition(int pc_offset, int line,
int inlining_id) {
DCHECK_GE(pc_offset, 0);
DCHECK_GT(line, 0); // The 1-based number of the source line.
// It's possible that we map multiple source positions to a pc_offset in
// optimized code. Usually these map to the same line, so there is no
// difference here as we only store line number and not line/col in the form
// of a script offset. Ignore any subsequent sets to the same offset.
if (!pc_offsets_to_lines_.empty() &&
pc_offsets_to_lines_.back().pc_offset == pc_offset) {
return;
}
// Check that we are inserting in ascending order, so that the vector remains
// sorted.
DCHECK(pc_offsets_to_lines_.empty() ||
pc_offsets_to_lines_.back().pc_offset < pc_offset);
if (pc_offsets_to_lines_.empty() ||
pc_offsets_to_lines_.back().line_number != line ||
pc_offsets_to_lines_.back().inlining_id != inlining_id) {
pc_offsets_to_lines_.push_back({pc_offset, line, inlining_id});
}
}
int SourcePositionTable::GetSourceLineNumber(int pc_offset) const {
if (pc_offsets_to_lines_.empty()) {
return v8::CpuProfileNode::kNoLineNumberInfo;
}
auto it = std::lower_bound(
pc_offsets_to_lines_.begin(), pc_offsets_to_lines_.end(),
SourcePositionTuple{pc_offset, 0, SourcePosition::kNotInlined});
if (it != pc_offsets_to_lines_.begin()) --it;
return it->line_number;
}
int SourcePositionTable::GetInliningId(int pc_offset) const {
if (pc_offsets_to_lines_.empty()) {
return SourcePosition::kNotInlined;
}
auto it = std::lower_bound(
pc_offsets_to_lines_.begin(), pc_offsets_to_lines_.end(),
SourcePositionTuple{pc_offset, 0, SourcePosition::kNotInlined});
if (it != pc_offsets_to_lines_.begin()) --it;
return it->inlining_id;
}
void SourcePositionTable::print() const {
base::OS::Print(" - source position table at %p\n", this);
for (const SourcePositionTuple& pos_info : pc_offsets_to_lines_) {
base::OS::Print(" %d --> line_number: %d inlining_id: %d\n",
pos_info.pc_offset, pos_info.line_number,
pos_info.inlining_id);
}
}
const char* const CodeEntry::kWasmResourceNamePrefix = "wasm ";
const char* const CodeEntry::kEmptyResourceName = "";
const char* const CodeEntry::kEmptyBailoutReason = "";
const char* const CodeEntry::kNoDeoptReason = "";
const char* const CodeEntry::kProgramEntryName = "(program)";
const char* const CodeEntry::kIdleEntryName = "(idle)";
const char* const CodeEntry::kGarbageCollectorEntryName = "(garbage collector)";
const char* const CodeEntry::kUnresolvedFunctionName = "(unresolved function)";
const char* const CodeEntry::kRootEntryName = "(root)";
base::LazyDynamicInstance<CodeEntry, CodeEntry::ProgramEntryCreateTrait>::type
CodeEntry::kProgramEntry = LAZY_DYNAMIC_INSTANCE_INITIALIZER;
base::LazyDynamicInstance<CodeEntry, CodeEntry::IdleEntryCreateTrait>::type
CodeEntry::kIdleEntry = LAZY_DYNAMIC_INSTANCE_INITIALIZER;
base::LazyDynamicInstance<CodeEntry, CodeEntry::GCEntryCreateTrait>::type
CodeEntry::kGCEntry = LAZY_DYNAMIC_INSTANCE_INITIALIZER;
base::LazyDynamicInstance<CodeEntry,
CodeEntry::UnresolvedEntryCreateTrait>::type
CodeEntry::kUnresolvedEntry = LAZY_DYNAMIC_INSTANCE_INITIALIZER;
base::LazyDynamicInstance<CodeEntry, CodeEntry::RootEntryCreateTrait>::type
CodeEntry::kRootEntry = LAZY_DYNAMIC_INSTANCE_INITIALIZER;
CodeEntry* CodeEntry::ProgramEntryCreateTrait::Create() {
return new CodeEntry(CodeEventListener::FUNCTION_TAG,
CodeEntry::kProgramEntryName);
}
CodeEntry* CodeEntry::IdleEntryCreateTrait::Create() {
return new CodeEntry(CodeEventListener::FUNCTION_TAG,
CodeEntry::kIdleEntryName);
}
CodeEntry* CodeEntry::GCEntryCreateTrait::Create() {
return new CodeEntry(CodeEventListener::BUILTIN_TAG,
CodeEntry::kGarbageCollectorEntryName);
}
CodeEntry* CodeEntry::UnresolvedEntryCreateTrait::Create() {
return new CodeEntry(CodeEventListener::FUNCTION_TAG,
CodeEntry::kUnresolvedFunctionName);
}
CodeEntry* CodeEntry::RootEntryCreateTrait::Create() {
return new CodeEntry(CodeEventListener::FUNCTION_TAG,
CodeEntry::kRootEntryName);
}
uint32_t CodeEntry::GetHash() const {
uint32_t hash = ComputeUnseededHash(tag());
if (script_id_ != v8::UnboundScript::kNoScriptId) {
hash ^= ComputeUnseededHash(static_cast<uint32_t>(script_id_));
hash ^= ComputeUnseededHash(static_cast<uint32_t>(position_));
} else {
hash ^= ComputeUnseededHash(
static_cast<uint32_t>(reinterpret_cast<uintptr_t>(name_)));
hash ^= ComputeUnseededHash(
static_cast<uint32_t>(reinterpret_cast<uintptr_t>(resource_name_)));
hash ^= ComputeUnseededHash(line_number_);
}
return hash;
}
bool CodeEntry::IsSameFunctionAs(const CodeEntry* entry) const {
if (this == entry) return true;
if (script_id_ != v8::UnboundScript::kNoScriptId) {
return script_id_ == entry->script_id_ && position_ == entry->position_;
}
return name_ == entry->name_ && resource_name_ == entry->resource_name_ &&
line_number_ == entry->line_number_;
}
void CodeEntry::SetBuiltinId(Builtins::Name id) {
bit_field_ = TagField::update(bit_field_, CodeEventListener::BUILTIN_TAG);
bit_field_ = BuiltinIdField::update(bit_field_, id);
}
int CodeEntry::GetSourceLine(int pc_offset) const {
if (line_info_) return line_info_->GetSourceLineNumber(pc_offset);
return v8::CpuProfileNode::kNoLineNumberInfo;
}
void CodeEntry::SetInlineStacks(
std::unordered_set<std::unique_ptr<CodeEntry>, Hasher, Equals>
inline_entries,
std::unordered_map<int, std::vector<CodeEntryAndLineNumber>>
inline_stacks) {
EnsureRareData()->inline_entries_ = std::move(inline_entries);
rare_data_->inline_stacks_ = std::move(inline_stacks);
}
const std::vector<CodeEntryAndLineNumber>* CodeEntry::GetInlineStack(
int pc_offset) const {
if (!line_info_) return nullptr;
int inlining_id = line_info_->GetInliningId(pc_offset);
if (inlining_id == SourcePosition::kNotInlined) return nullptr;
DCHECK(rare_data_);
auto it = rare_data_->inline_stacks_.find(inlining_id);
return it != rare_data_->inline_stacks_.end() ? &it->second : nullptr;
}
void CodeEntry::set_deopt_info(
const char* deopt_reason, int deopt_id,
std::vector<CpuProfileDeoptFrame> inlined_frames) {
DCHECK(!has_deopt_info());
RareData* rare_data = EnsureRareData();
rare_data->deopt_reason_ = deopt_reason;
rare_data->deopt_id_ = deopt_id;
rare_data->deopt_inlined_frames_ = std::move(inlined_frames);
}
void CodeEntry::FillFunctionInfo(SharedFunctionInfo shared) {
if (!shared.script().IsScript()) return;
Script script = Script::cast(shared.script());
set_script_id(script.id());
set_position(shared.StartPosition());
if (shared.optimization_disabled()) {
set_bailout_reason(GetBailoutReason(shared.disable_optimization_reason()));
}
}
CpuProfileDeoptInfo CodeEntry::GetDeoptInfo() {
DCHECK(has_deopt_info());
CpuProfileDeoptInfo info;
info.deopt_reason = rare_data_->deopt_reason_;
DCHECK_NE(kNoDeoptimizationId, rare_data_->deopt_id_);
if (rare_data_->deopt_inlined_frames_.empty()) {
info.stack.push_back(CpuProfileDeoptFrame(
{script_id_, static_cast<size_t>(std::max(0, position()))}));
} else {
info.stack = rare_data_->deopt_inlined_frames_;
}
return info;
}
CodeEntry::RareData* CodeEntry::EnsureRareData() {
if (!rare_data_) {
rare_data_.reset(new RareData());
}
return rare_data_.get();
}
void CodeEntry::print() const {
base::OS::Print("CodeEntry: at %p\n", this);
base::OS::Print(" - name: %s\n", name_);
base::OS::Print(" - resource_name: %s\n", resource_name_);
base::OS::Print(" - line_number: %d\n", line_number_);
base::OS::Print(" - column_number: %d\n", column_number_);
base::OS::Print(" - script_id: %d\n", script_id_);
base::OS::Print(" - position: %d\n", position_);
if (line_info_) {
line_info_->print();
}
if (rare_data_) {
base::OS::Print(" - deopt_reason: %s\n", rare_data_->deopt_reason_);
base::OS::Print(" - bailout_reason: %s\n", rare_data_->bailout_reason_);
base::OS::Print(" - deopt_id: %d\n", rare_data_->deopt_id_);
if (!rare_data_->inline_stacks_.empty()) {
base::OS::Print(" - inline stacks:\n");
for (auto it = rare_data_->inline_stacks_.begin();
it != rare_data_->inline_stacks_.end(); it++) {
base::OS::Print(" inlining_id: [%d]\n", it->first);
for (const auto& e : it->second) {
base::OS::Print(" %s --> %d\n", e.code_entry->name(),
e.line_number);
}
}
} else {
base::OS::Print(" - inline stacks: (empty)\n");
}
if (!rare_data_->deopt_inlined_frames_.empty()) {
base::OS::Print(" - deopt inlined frames:\n");
for (const CpuProfileDeoptFrame& frame :
rare_data_->deopt_inlined_frames_) {
base::OS::Print("script_id: %d position: %zu\n", frame.script_id,
frame.position);
}
} else {
base::OS::Print(" - deopt inlined frames: (empty)\n");
}
}
base::OS::Print("\n");
}
void ProfileNode::CollectDeoptInfo(CodeEntry* entry) {
deopt_infos_.push_back(entry->GetDeoptInfo());
entry->clear_deopt_info();
}
ProfileNode* ProfileNode::FindChild(CodeEntry* entry, int line_number) {
auto map_entry = children_.find({entry, line_number});
return map_entry != children_.end() ? map_entry->second : nullptr;
}
ProfileNode* ProfileNode::FindOrAddChild(CodeEntry* entry, int line_number) {
auto map_entry = children_.find({entry, line_number});
if (map_entry == children_.end()) {
ProfileNode* node = new ProfileNode(tree_, entry, this, line_number);
children_[{entry, line_number}] = node;
children_list_.push_back(node);
return node;
} else {
return map_entry->second;
}
}
void ProfileNode::IncrementLineTicks(int src_line) {
if (src_line == v8::CpuProfileNode::kNoLineNumberInfo) return;
// Increment a hit counter of a certain source line.
// Add a new source line if not found.
auto map_entry = line_ticks_.find(src_line);
if (map_entry == line_ticks_.end()) {
line_ticks_[src_line] = 1;
} else {
line_ticks_[src_line]++;
}
}
bool ProfileNode::GetLineTicks(v8::CpuProfileNode::LineTick* entries,
unsigned int length) const {
if (entries == nullptr || length == 0) return false;
unsigned line_count = static_cast<unsigned>(line_ticks_.size());
if (line_count == 0) return true;
if (length < line_count) return false;
v8::CpuProfileNode::LineTick* entry = entries;
for (auto p = line_ticks_.begin(); p != line_ticks_.end(); p++, entry++) {
entry->line = p->first;
entry->hit_count = p->second;
}
return true;
}
void ProfileNode::Print(int indent) const {
int line_number = line_number_ != 0 ? line_number_ : entry_->line_number();
base::OS::Print("%5u %*s %s:%d %d %d #%d", self_ticks_, indent, "",
entry_->name(), line_number, source_type(),
entry_->script_id(), id());
if (entry_->resource_name()[0] != '\0')
base::OS::Print(" %s:%d", entry_->resource_name(), entry_->line_number());
base::OS::Print("\n");
for (size_t i = 0; i < deopt_infos_.size(); ++i) {
const CpuProfileDeoptInfo& info = deopt_infos_[i];
base::OS::Print(
"%*s;;; deopted at script_id: %d position: %zu with reason '%s'.\n",
indent + 10, "", info.stack[0].script_id, info.stack[0].position,
info.deopt_reason);
for (size_t index = 1; index < info.stack.size(); ++index) {
base::OS::Print("%*s;;; Inline point: script_id %d position: %zu.\n",
indent + 10, "", info.stack[index].script_id,
info.stack[index].position);
}
}
const char* bailout_reason = entry_->bailout_reason();
if (bailout_reason != GetBailoutReason(BailoutReason::kNoReason) &&
bailout_reason != CodeEntry::kEmptyBailoutReason) {
base::OS::Print("%*s bailed out due to '%s'\n", indent + 10, "",
bailout_reason);
}
for (auto child : children_) {
child.second->Print(indent + 2);
}
}
class DeleteNodesCallback {
public:
void BeforeTraversingChild(ProfileNode*, ProfileNode*) { }
void AfterAllChildrenTraversed(ProfileNode* node) {
delete node;
}
void AfterChildTraversed(ProfileNode*, ProfileNode*) { }
};
ProfileTree::ProfileTree(Isolate* isolate)
: next_node_id_(1),
root_(new ProfileNode(this, CodeEntry::root_entry(), nullptr)),
isolate_(isolate) {}
ProfileTree::~ProfileTree() {
DeleteNodesCallback cb;
TraverseDepthFirst(&cb);
}
ProfileNode* ProfileTree::AddPathFromEnd(const std::vector<CodeEntry*>& path,
int src_line, bool update_stats) {
ProfileNode* node = root_;
CodeEntry* last_entry = nullptr;
for (auto it = path.rbegin(); it != path.rend(); ++it) {
if (*it == nullptr) continue;
last_entry = *it;
node = node->FindOrAddChild(*it, v8::CpuProfileNode::kNoLineNumberInfo);
}
if (last_entry && last_entry->has_deopt_info()) {
node->CollectDeoptInfo(last_entry);
}
if (update_stats) {
node->IncrementSelfTicks();
if (src_line != v8::CpuProfileNode::kNoLineNumberInfo) {
node->IncrementLineTicks(src_line);
}
}
return node;
}
ProfileNode* ProfileTree::AddPathFromEnd(const ProfileStackTrace& path,
int src_line, bool update_stats,
ProfilingMode mode,
ContextFilter* context_filter) {
ProfileNode* node = root_;
CodeEntry* last_entry = nullptr;
int parent_line_number = v8::CpuProfileNode::kNoLineNumberInfo;
for (auto it = path.rbegin(); it != path.rend(); ++it) {
if (it->entry.code_entry == nullptr) continue;
if (context_filter && !context_filter->Accept(*it)) continue;
last_entry = (*it).entry.code_entry;
node = node->FindOrAddChild((*it).entry.code_entry, parent_line_number);
parent_line_number = mode == ProfilingMode::kCallerLineNumbers
? (*it).entry.line_number
: v8::CpuProfileNode::kNoLineNumberInfo;
}
if (last_entry && last_entry->has_deopt_info()) {
node->CollectDeoptInfo(last_entry);
}
if (update_stats) {
node->IncrementSelfTicks();
if (src_line != v8::CpuProfileNode::kNoLineNumberInfo) {
node->IncrementLineTicks(src_line);
}
}
return node;
}
class Position {
public:
explicit Position(ProfileNode* node)
: node(node), child_idx_(0) { }
V8_INLINE ProfileNode* current_child() {
return node->children()->at(child_idx_);
}
V8_INLINE bool has_current_child() {
return child_idx_ < static_cast<int>(node->children()->size());
}
V8_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) {
std::vector<Position> stack;
stack.emplace_back(root_);
while (stack.size() > 0) {
Position& current = stack.back();
if (current.has_current_child()) {
callback->BeforeTraversingChild(current.node, current.current_child());
stack.emplace_back(current.current_child());
} else {
callback->AfterAllChildrenTraversed(current.node);
if (stack.size() > 1) {
Position& parent = stack[stack.size() - 2];
callback->AfterChildTraversed(parent.node, current.node);
parent.next_child();
}
// Remove child from the stack.
stack.pop_back();
}
}
}
bool ContextFilter::Accept(const ProfileStackFrame& frame) {
// If a frame should always be included in profiles (e.g. metadata frames),
// skip the context check.
if (!frame.filterable) return true;
// Strip heap object tag from frame.
return (frame.native_context & ~kHeapObjectTag) == native_context_address_;
}
void ContextFilter::OnMoveEvent(Address from_address, Address to_address) {
if (native_context_address() != from_address) return;
set_native_context_address(to_address);
}
using v8::tracing::TracedValue;
std::atomic<uint32_t> CpuProfile::last_id_;
CpuProfile::CpuProfile(CpuProfiler* profiler, const char* title,
CpuProfilingOptions options)
: title_(title),
options_(options),
start_time_(base::TimeTicks::HighResolutionNow()),
top_down_(profiler->isolate()),
profiler_(profiler),
streaming_next_sample_(0),
id_(++last_id_) {
auto value = TracedValue::Create();
value->SetDouble("startTime", start_time_.since_origin().InMicroseconds());
TRACE_EVENT_SAMPLE_WITH_ID1(TRACE_DISABLED_BY_DEFAULT("v8.cpu_profiler"),
"Profile", id_, "data", std::move(value));
if (options_.has_filter_context()) {
DisallowHeapAllocation no_gc;
i::Address raw_filter_context =
reinterpret_cast<i::Address>(options_.raw_filter_context());
context_filter_ = std::make_unique<ContextFilter>(raw_filter_context);
}
}
bool CpuProfile::CheckSubsample(base::TimeDelta source_sampling_interval) {
DCHECK_GE(source_sampling_interval, base::TimeDelta());
// If the sampling source's sampling interval is 0, record as many samples
// are possible irrespective of the profile's sampling interval. Manually
// taken samples (via CollectSample) fall into this case as well.
if (source_sampling_interval.IsZero()) return true;
next_sample_delta_ -= source_sampling_interval;
if (next_sample_delta_ <= base::TimeDelta()) {
next_sample_delta_ =
base::TimeDelta::FromMicroseconds(options_.sampling_interval_us());
return true;
}
return false;
}
void CpuProfile::AddPath(base::TimeTicks timestamp,
const ProfileStackTrace& path, int src_line,
bool update_stats, base::TimeDelta sampling_interval) {
if (!CheckSubsample(sampling_interval)) return;
ProfileNode* top_frame_node = top_down_.AddPathFromEnd(
path, src_line, update_stats, options_.mode(), context_filter_.get());
bool should_record_sample =
!timestamp.IsNull() && timestamp >= start_time_ &&
(options_.max_samples() == CpuProfilingOptions::kNoSampleLimit ||
samples_.size() < options_.max_samples());
if (should_record_sample)
samples_.push_back({top_frame_node, timestamp, src_line});
const int kSamplesFlushCount = 100;
const int kNodesFlushCount = 10;
if (samples_.size() - streaming_next_sample_ >= kSamplesFlushCount ||
top_down_.pending_nodes_count() >= kNodesFlushCount) {
StreamPendingTraceEvents();
}
}
namespace {
void BuildNodeValue(const ProfileNode* node, TracedValue* value) {
const CodeEntry* entry = node->entry();
value->BeginDictionary("callFrame");
value->SetString("functionName", entry->name());
if (*entry->resource_name()) {
value->SetString("url", entry->resource_name());
}
value->SetInteger("scriptId", entry->script_id());
if (entry->line_number()) {
value->SetInteger("lineNumber", entry->line_number() - 1);
}
if (entry->column_number()) {
value->SetInteger("columnNumber", entry->column_number() - 1);
}
value->EndDictionary();
value->SetInteger("id", node->id());
if (node->parent()) {
value->SetInteger("parent", node->parent()->id());
}
const char* deopt_reason = entry->bailout_reason();
if (deopt_reason && deopt_reason[0] && strcmp(deopt_reason, "no reason")) {
value->SetString("deoptReason", deopt_reason);
}
}
} // namespace
void CpuProfile::StreamPendingTraceEvents() {
std::vector<const ProfileNode*> pending_nodes = top_down_.TakePendingNodes();
if (pending_nodes.empty() && samples_.empty()) return;
auto value = TracedValue::Create();
if (!pending_nodes.empty() || streaming_next_sample_ != samples_.size()) {
value->BeginDictionary("cpuProfile");
if (!pending_nodes.empty()) {
value->BeginArray("nodes");
for (auto node : pending_nodes) {
value->BeginDictionary();
BuildNodeValue(node, value.get());
value->EndDictionary();
}
value->EndArray();
}
if (streaming_next_sample_ != samples_.size()) {
value->BeginArray("samples");
for (size_t i = streaming_next_sample_; i < samples_.size(); ++i) {
value->AppendInteger(samples_[i].node->id());
}
value->EndArray();
}
value->EndDictionary();
}
if (streaming_next_sample_ != samples_.size()) {
value->BeginArray("timeDeltas");
base::TimeTicks lastTimestamp =
streaming_next_sample_ ? samples_[streaming_next_sample_ - 1].timestamp
: start_time();
for (size_t i = streaming_next_sample_; i < samples_.size(); ++i) {
value->AppendInteger(static_cast<int>(
(samples_[i].timestamp - lastTimestamp).InMicroseconds()));
lastTimestamp = samples_[i].timestamp;
}
value->EndArray();
bool has_non_zero_lines =
std::any_of(samples_.begin() + streaming_next_sample_, samples_.end(),
[](const SampleInfo& sample) { return sample.line != 0; });
if (has_non_zero_lines) {
value->BeginArray("lines");
for (size_t i = streaming_next_sample_; i < samples_.size(); ++i) {
value->AppendInteger(samples_[i].line);
}
value->EndArray();
}
streaming_next_sample_ = samples_.size();
}
TRACE_EVENT_SAMPLE_WITH_ID1(TRACE_DISABLED_BY_DEFAULT("v8.cpu_profiler"),
"ProfileChunk", id_, "data", std::move(value));
}
void CpuProfile::FinishProfile() {
end_time_ = base::TimeTicks::HighResolutionNow();
// Stop tracking context movements after profiling stops.
context_filter_ = nullptr;
StreamPendingTraceEvents();
auto value = TracedValue::Create();
value->SetDouble("endTime", end_time_.since_origin().InMicroseconds());
TRACE_EVENT_SAMPLE_WITH_ID1(TRACE_DISABLED_BY_DEFAULT("v8.cpu_profiler"),
"ProfileChunk", id_, "data", std::move(value));
}
void CpuProfile::Print() {
base::OS::Print("[Top down]:\n");
top_down_.Print();
}
CodeMap::CodeMap() = default;
CodeMap::~CodeMap() {
// First clean the free list as it's otherwise impossible to tell
// the slot type.
unsigned free_slot = free_list_head_;
while (free_slot != kNoFreeSlot) {
unsigned next_slot = code_entries_[free_slot].next_free_slot;
code_entries_[free_slot].entry = nullptr;
free_slot = next_slot;
}
for (auto slot : code_entries_) delete slot.entry;
}
void CodeMap::AddCode(Address addr, CodeEntry* entry, unsigned size) {
ClearCodesInRange(addr, addr + size);
unsigned index = AddCodeEntry(addr, entry);
code_map_.emplace(addr, CodeEntryMapInfo{index, size});
}
void CodeMap::ClearCodesInRange(Address start, Address end) {
auto left = code_map_.upper_bound(start);
if (left != code_map_.begin()) {
--left;
if (left->first + left->second.size <= start) ++left;
}
auto right = left;
for (; right != code_map_.end() && right->first < end; ++right) {
if (!entry(right->second.index)->used()) {
DeleteCodeEntry(right->second.index);
}
}
code_map_.erase(left, right);
}
CodeEntry* CodeMap::FindEntry(Address addr, Address* out_instruction_start) {
auto it = code_map_.upper_bound(addr);
if (it == code_map_.begin()) return nullptr;
--it;
Address start_address = it->first;
Address end_address = start_address + it->second.size;
CodeEntry* ret = addr < end_address ? entry(it->second.index) : nullptr;
DCHECK(!ret || (addr >= start_address && addr < end_address));
if (ret && out_instruction_start) *out_instruction_start = start_address;
return ret;
}
void CodeMap::MoveCode(Address from, Address to) {
if (from == to) return;
auto it = code_map_.find(from);
if (it == code_map_.end()) return;
CodeEntryMapInfo info = it->second;
code_map_.erase(it);
DCHECK(from + info.size <= to || to + info.size <= from);
ClearCodesInRange(to, to + info.size);
code_map_.emplace(to, info);
}
unsigned CodeMap::AddCodeEntry(Address start, CodeEntry* entry) {
if (free_list_head_ == kNoFreeSlot) {
code_entries_.push_back(CodeEntrySlotInfo{entry});
return static_cast<unsigned>(code_entries_.size()) - 1;
}
unsigned index = free_list_head_;
free_list_head_ = code_entries_[index].next_free_slot;
code_entries_[index].entry = entry;
return index;
}
void CodeMap::DeleteCodeEntry(unsigned index) {
delete code_entries_[index].entry;
code_entries_[index].next_free_slot = free_list_head_;
free_list_head_ = index;
}
void CodeMap::Print() {
for (const auto& pair : code_map_) {
base::OS::Print("%p %5d %s\n", reinterpret_cast<void*>(pair.first),
pair.second.size, entry(pair.second.index)->name());
}
}
CpuProfilesCollection::CpuProfilesCollection(Isolate* isolate)
: profiler_(nullptr), current_profiles_semaphore_(1) {}
bool CpuProfilesCollection::StartProfiling(const char* title,
CpuProfilingOptions options) {
current_profiles_semaphore_.Wait();
if (static_cast<int>(current_profiles_.size()) >= kMaxSimultaneousProfiles) {
current_profiles_semaphore_.Signal();
return false;
}
for (const std::unique_ptr<CpuProfile>& profile : current_profiles_) {
if (strcmp(profile->title(), title) == 0) {
// Ignore attempts to start profile with the same title...
current_profiles_semaphore_.Signal();
// ... though return true to force it collect a sample.
return true;
}
}
current_profiles_.emplace_back(new CpuProfile(profiler_, title, options));
current_profiles_semaphore_.Signal();
return true;
}
CpuProfile* CpuProfilesCollection::StopProfiling(const char* title) {
const bool empty_title = (title[0] == '\0');
CpuProfile* profile = nullptr;
current_profiles_semaphore_.Wait();
auto it = std::find_if(current_profiles_.rbegin(), current_profiles_.rend(),
[&](const std::unique_ptr<CpuProfile>& p) {
return empty_title || strcmp(p->title(), title) == 0;
});
if (it != current_profiles_.rend()) {
(*it)->FinishProfile();
profile = it->get();
finished_profiles_.push_back(std::move(*it));
// Convert reverse iterator to matching forward iterator.
current_profiles_.erase(--(it.base()));
}
current_profiles_semaphore_.Signal();
return profile;
}
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_.size() != 1) return false;
return title[0] == '\0' || strcmp(current_profiles_[0]->title(), title) == 0;
}
void CpuProfilesCollection::RemoveProfile(CpuProfile* profile) {
// Called from VM thread for a completed profile.
auto pos =
std::find_if(finished_profiles_.begin(), finished_profiles_.end(),
[&](const std::unique_ptr<CpuProfile>& finished_profile) {
return finished_profile.get() == profile;
});
DCHECK(pos != finished_profiles_.end());
finished_profiles_.erase(pos);
}
namespace {
int64_t GreatestCommonDivisor(int64_t a, int64_t b) {
return b ? GreatestCommonDivisor(b, a % b) : a;
}
} // namespace
base::TimeDelta CpuProfilesCollection::GetCommonSamplingInterval() const {
DCHECK(profiler_);
int64_t base_sampling_interval_us =
profiler_->sampling_interval().InMicroseconds();
if (base_sampling_interval_us == 0) return base::TimeDelta();
int64_t interval_us = 0;
for (const auto& profile : current_profiles_) {
// Snap the profile's requested sampling interval to the next multiple of
// the base sampling interval.
int64_t profile_interval_us =
std::max<int64_t>(
(profile->sampling_interval_us() + base_sampling_interval_us - 1) /
base_sampling_interval_us,
1) *
base_sampling_interval_us;
interval_us = GreatestCommonDivisor(interval_us, profile_interval_us);
}
return base::TimeDelta::FromMicroseconds(interval_us);
}
void CpuProfilesCollection::AddPathToCurrentProfiles(
base::TimeTicks timestamp, const ProfileStackTrace& path, int src_line,
bool update_stats, base::TimeDelta sampling_interval) {
// 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 (const std::unique_ptr<CpuProfile>& profile : current_profiles_) {
profile->AddPath(timestamp, path, src_line, update_stats,
sampling_interval);
}
current_profiles_semaphore_.Signal();
}
void CpuProfilesCollection::UpdateNativeContextAddressForCurrentProfiles(
Address from, Address to) {
current_profiles_semaphore_.Wait();
for (const std::unique_ptr<CpuProfile>& profile : current_profiles_) {
if (auto* context_filter = profile->context_filter()) {
context_filter->OnMoveEvent(from, to);
}
}
current_profiles_semaphore_.Signal();
}
ProfileGenerator::ProfileGenerator(CpuProfilesCollection* profiles,
CodeMap* code_map)
: profiles_(profiles), code_map_(code_map) {}
void ProfileGenerator::RecordTickSample(const TickSample& sample) {
ProfileStackTrace stack_trace;
// Conservatively reserve space for stack frames + pc + function + vm-state.
// There could in fact be more of them because of inlined entries.
stack_trace.reserve(sample.frames_count + 3);
// The ProfileNode knows nothing about all versions of generated code for
// the same JS function. The line number information associated with
// the latest version of generated code is used to find a source line number
// for a JS function. Then, the detected source line is passed to
// ProfileNode to increase the tick count for this source line.
const int no_line_info = v8::CpuProfileNode::kNoLineNumberInfo;
int src_line = no_line_info;
bool src_line_not_found = true;
if (sample.pc != nullptr) {
if (sample.has_external_callback && sample.state == EXTERNAL) {
// Don't use PC when in external callback code, as it can point
// inside a callback's code, and we will erroneously report
// that a callback calls itself.
stack_trace.push_back({{FindEntry(reinterpret_cast<Address>(
sample.external_callback_entry)),
no_line_info},
reinterpret_cast<Address>(sample.top_context),
true});
} else {
Address attributed_pc = reinterpret_cast<Address>(sample.pc);
Address pc_entry_instruction_start = kNullAddress;
CodeEntry* pc_entry =
FindEntry(attributed_pc, &pc_entry_instruction_start);
// If there is no pc_entry, we're likely in native code. Find out if the
// top of the stack (the return address) was pointing inside a JS
// function, meaning that we have encountered a frameless invocation.
if (!pc_entry && !sample.has_external_callback) {
attributed_pc = reinterpret_cast<Address>(sample.tos);
pc_entry = FindEntry(attributed_pc, &pc_entry_instruction_start);
}
// If pc is in the function code before it set up stack frame or after the
// frame was destroyed, SafeStackFrameIterator incorrectly thinks that
// ebp contains the return address of the current function and skips the
// caller's frame. Check for this case and just skip such samples.
if (pc_entry) {
int pc_offset =
static_cast<int>(attributed_pc - pc_entry_instruction_start);
// TODO(petermarshall): pc_offset can still be negative in some cases.
src_line = pc_entry->GetSourceLine(pc_offset);
if (src_line == v8::CpuProfileNode::kNoLineNumberInfo) {
src_line = pc_entry->line_number();
}
src_line_not_found = false;
stack_trace.push_back({{pc_entry, src_line},
reinterpret_cast<Address>(sample.top_context),
true});
if (pc_entry->builtin_id() == Builtins::kFunctionPrototypeApply ||
pc_entry->builtin_id() == Builtins::kFunctionPrototypeCall) {
// When current function is either the Function.prototype.apply or the
// Function.prototype.call builtin the top frame is either frame of
// the calling JS function or internal frame.
// In the latter case we know the caller for sure but in the
// former case we don't so we simply replace the frame with
// 'unresolved' entry.
if (!sample.has_external_callback) {
stack_trace.push_back(
{{CodeEntry::unresolved_entry(), no_line_info},
kNullAddress,
true});
}
}
}
}
for (unsigned i = 0; i < sample.frames_count; ++i) {
Address stack_pos = reinterpret_cast<Address>(sample.stack[i]);
Address native_context = reinterpret_cast<Address>(sample.contexts[i]);
Address instruction_start = kNullAddress;
CodeEntry* entry = FindEntry(stack_pos, &instruction_start);
int line_number = no_line_info;
if (entry) {
// Find out if the entry has an inlining stack associated.
int pc_offset = static_cast<int>(stack_pos - instruction_start);
// TODO(petermarshall): pc_offset can still be negative in some cases.
const std::vector<CodeEntryAndLineNumber>* inline_stack =
entry->GetInlineStack(pc_offset);
if (inline_stack) {
int most_inlined_frame_line_number = entry->GetSourceLine(pc_offset);
for (auto entry : *inline_stack) {
// Set the native context of inlined frames to be equal to that of
// their parent. This is safe, as functions cannot inline themselves
// into a parent from another native context.
stack_trace.push_back({entry, native_context, true});
}
// This is a bit of a messy hack. The line number for the most-inlined
// frame (the function at the end of the chain of function calls) has
// the wrong line number in inline_stack. The actual line number in
// this function is stored in the SourcePositionTable in entry. We fix
// up the line number for the most-inlined frame here.
// TODO(petermarshall): Remove this and use a tree with a node per
// inlining_id.
DCHECK(!inline_stack->empty());
size_t index = stack_trace.size() - inline_stack->size();
stack_trace[index].entry.line_number = most_inlined_frame_line_number;
}
// Skip unresolved frames (e.g. internal frame) and get source line of
// the first JS caller.
if (src_line_not_found) {
src_line = entry->GetSourceLine(pc_offset);
if (src_line == v8::CpuProfileNode::kNoLineNumberInfo) {
src_line = entry->line_number();
}
src_line_not_found = false;
}
line_number = entry->GetSourceLine(pc_offset);
// The inline stack contains the top-level function i.e. the same
// function as entry. We don't want to add it twice. The one from the
// inline stack has the correct line number for this particular inlining
// so we use it instead of pushing entry to stack_trace.
if (inline_stack) continue;
}
stack_trace.push_back({{entry, line_number}, native_context, true});
}
}
if (FLAG_prof_browser_mode) {
bool no_symbolized_entries = true;
for (auto e : stack_trace) {
if (e.entry.code_entry != nullptr) {
no_symbolized_entries = false;
break;
}
}
// If no frames were symbolized, put the VM state entry in.
if (no_symbolized_entries) {
stack_trace.push_back(
{{EntryForVMState(sample.state), no_line_info}, kNullAddress, false});
}
}
profiles_->AddPathToCurrentProfiles(sample.timestamp, stack_trace, src_line,
sample.update_stats,
sample.sampling_interval);
}
void ProfileGenerator::UpdateNativeContextAddress(Address from, Address to) {
profiles_->UpdateNativeContextAddressForCurrentProfiles(from, to);
}
CodeEntry* ProfileGenerator::EntryForVMState(StateTag tag) {
switch (tag) {
case GC:
return CodeEntry::gc_entry();
case JS:
case PARSER:
case COMPILER:
case BYTECODE_COMPILER:
case ATOMICS_WAIT:
// DOM events handlers are reported as OTHER / EXTERNAL entries.
// To avoid confusing people, let's put all these entries into
// one bucket.
case OTHER:
case EXTERNAL:
return CodeEntry::program_entry();
case IDLE:
return CodeEntry::idle_entry();
}
UNREACHABLE();
}
} // namespace internal
} // namespace v8