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// Copyright 2009-2010 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/heap-profiler.h"
#include "src/api/api-inl.h"
#include "src/debug/debug.h"
#include "src/heap/combined-heap.h"
#include "src/heap/heap-inl.h"
#include "src/profiler/allocation-tracker.h"
#include "src/profiler/heap-snapshot-generator-inl.h"
#include "src/profiler/sampling-heap-profiler.h"
namespace v8 {
namespace internal {
HeapProfiler::HeapProfiler(Heap* heap)
: ids_(new HeapObjectsMap(heap)),
names_(new StringsStorage()),
is_tracking_object_moves_(false) {}
HeapProfiler::~HeapProfiler() = default;
void HeapProfiler::DeleteAllSnapshots() {
snapshots_.clear();
MaybeClearStringsStorage();
}
void HeapProfiler::MaybeClearStringsStorage() {
if (snapshots_.empty() && !sampling_heap_profiler_ && !allocation_tracker_) {
names_.reset(new StringsStorage());
}
}
void HeapProfiler::RemoveSnapshot(HeapSnapshot* snapshot) {
snapshots_.erase(
std::find_if(snapshots_.begin(), snapshots_.end(),
[&](const std::unique_ptr<HeapSnapshot>& entry) {
return entry.get() == snapshot;
}));
}
void HeapProfiler::AddBuildEmbedderGraphCallback(
v8::HeapProfiler::BuildEmbedderGraphCallback callback, void* data) {
build_embedder_graph_callbacks_.push_back({callback, data});
}
void HeapProfiler::RemoveBuildEmbedderGraphCallback(
v8::HeapProfiler::BuildEmbedderGraphCallback callback, void* data) {
auto it = std::find(build_embedder_graph_callbacks_.begin(),
build_embedder_graph_callbacks_.end(),
std::make_pair(callback, data));
if (it != build_embedder_graph_callbacks_.end())
build_embedder_graph_callbacks_.erase(it);
}
void HeapProfiler::BuildEmbedderGraph(Isolate* isolate,
v8::EmbedderGraph* graph) {
for (const auto& cb : build_embedder_graph_callbacks_) {
cb.first(reinterpret_cast<v8::Isolate*>(isolate), graph, cb.second);
}
}
HeapSnapshot* HeapProfiler::TakeSnapshot(
v8::ActivityControl* control,
v8::HeapProfiler::ObjectNameResolver* resolver,
bool treat_global_objects_as_roots) {
HeapSnapshot* result = new HeapSnapshot(this, treat_global_objects_as_roots);
{
HeapSnapshotGenerator generator(result, control, resolver, heap());
if (!generator.GenerateSnapshot()) {
delete result;
result = nullptr;
} else {
snapshots_.emplace_back(result);
}
}
ids_->RemoveDeadEntries();
is_tracking_object_moves_ = true;
heap()->isolate()->debug()->feature_tracker()->Track(
DebugFeatureTracker::kHeapSnapshot);
return result;
}
bool HeapProfiler::StartSamplingHeapProfiler(
uint64_t sample_interval, int stack_depth,
v8::HeapProfiler::SamplingFlags flags) {
if (sampling_heap_profiler_.get()) {
return false;
}
sampling_heap_profiler_.reset(new SamplingHeapProfiler(
heap(), names_.get(), sample_interval, stack_depth, flags));
return true;
}
void HeapProfiler::StopSamplingHeapProfiler() {
sampling_heap_profiler_.reset();
MaybeClearStringsStorage();
}
v8::AllocationProfile* HeapProfiler::GetAllocationProfile() {
if (sampling_heap_profiler_.get()) {
return sampling_heap_profiler_->GetAllocationProfile();
} else {
return nullptr;
}
}
void HeapProfiler::StartHeapObjectsTracking(bool track_allocations) {
ids_->UpdateHeapObjectsMap();
is_tracking_object_moves_ = true;
DCHECK(!allocation_tracker_);
if (track_allocations) {
allocation_tracker_.reset(new AllocationTracker(ids_.get(), names_.get()));
heap()->AddHeapObjectAllocationTracker(this);
heap()->isolate()->debug()->feature_tracker()->Track(
DebugFeatureTracker::kAllocationTracking);
}
}
SnapshotObjectId HeapProfiler::PushHeapObjectsStats(OutputStream* stream,
int64_t* timestamp_us) {
return ids_->PushHeapObjectsStats(stream, timestamp_us);
}
void HeapProfiler::StopHeapObjectsTracking() {
ids_->StopHeapObjectsTracking();
if (allocation_tracker_) {
allocation_tracker_.reset();
MaybeClearStringsStorage();
heap()->RemoveHeapObjectAllocationTracker(this);
}
}
int HeapProfiler::GetSnapshotsCount() {
return static_cast<int>(snapshots_.size());
}
HeapSnapshot* HeapProfiler::GetSnapshot(int index) {
return snapshots_.at(index).get();
}
SnapshotObjectId HeapProfiler::GetSnapshotObjectId(Handle<Object> obj) {
if (!obj->IsHeapObject())
return v8::HeapProfiler::kUnknownObjectId;
return ids_->FindEntry(HeapObject::cast(*obj).address());
}
SnapshotObjectId HeapProfiler::GetSnapshotObjectId(NativeObject obj) {
// Try to find id of regular native node first.
SnapshotObjectId id = ids_->FindEntry(reinterpret_cast<Address>(obj));
// In case no id has been found, check whether there exists an entry where the
// native objects has been merged into a V8 entry.
if (id == v8::HeapProfiler::kUnknownObjectId) {
id = ids_->FindMergedNativeEntry(obj);
}
return id;
}
void HeapProfiler::ObjectMoveEvent(Address from, Address to, int size) {
base::MutexGuard guard(&profiler_mutex_);
bool known_object = ids_->MoveObject(from, to, size);
if (!known_object && allocation_tracker_) {
allocation_tracker_->address_to_trace()->MoveObject(from, to, size);
}
}
void HeapProfiler::AllocationEvent(Address addr, int size) {
DisallowHeapAllocation no_allocation;
if (allocation_tracker_) {
allocation_tracker_->AllocationEvent(addr, size);
}
}
void HeapProfiler::UpdateObjectSizeEvent(Address addr, int size) {
ids_->UpdateObjectSize(addr, size);
}
Handle<HeapObject> HeapProfiler::FindHeapObjectById(SnapshotObjectId id) {
HeapObject object;
CombinedHeapObjectIterator iterator(heap(),
HeapObjectIterator::kFilterUnreachable);
// Make sure that object with the given id is still reachable.
for (HeapObject obj = iterator.Next(); !obj.is_null();
obj = iterator.Next()) {
if (ids_->FindEntry(obj.address()) == id) {
DCHECK(object.is_null());
object = obj;
// Can't break -- kFilterUnreachable requires full heap traversal.
}
}
return !object.is_null() ? Handle<HeapObject>(object, isolate())
: Handle<HeapObject>();
}
void HeapProfiler::ClearHeapObjectMap() {
ids_.reset(new HeapObjectsMap(heap()));
if (!allocation_tracker_) is_tracking_object_moves_ = false;
}
Heap* HeapProfiler::heap() const { return ids_->heap(); }
Isolate* HeapProfiler::isolate() const { return heap()->isolate(); }
void HeapProfiler::QueryObjects(Handle<Context> context,
debug::QueryObjectPredicate* predicate,
PersistentValueVector<v8::Object>* objects) {
{
HandleScope handle_scope(isolate());
std::vector<Handle<JSTypedArray>> on_heap_typed_arrays;
CombinedHeapObjectIterator heap_iterator(
heap(), HeapObjectIterator::kFilterUnreachable);
for (HeapObject heap_obj = heap_iterator.Next(); !heap_obj.is_null();
heap_obj = heap_iterator.Next()) {
if (heap_obj.IsFeedbackVector()) {
FeedbackVector::cast(heap_obj).ClearSlots(isolate());
} else if (heap_obj.IsJSTypedArray() &&
JSTypedArray::cast(heap_obj).is_on_heap()) {
// Cannot call typed_array->GetBuffer() here directly because it may
// trigger GC. Defer that call by collecting the object in a vector.
on_heap_typed_arrays.push_back(
handle(JSTypedArray::cast(heap_obj), isolate()));
}
}
for (auto& typed_array : on_heap_typed_arrays) {
// Convert the on-heap typed array into off-heap typed array, so that
// its ArrayBuffer becomes valid and can be returned in the result.
typed_array->GetBuffer();
}
}
// We should return accurate information about live objects, so we need to
// collect all garbage first.
heap()->CollectAllAvailableGarbage(GarbageCollectionReason::kHeapProfiler);
CombinedHeapObjectIterator heap_iterator(
heap(), HeapObjectIterator::kFilterUnreachable);
for (HeapObject heap_obj = heap_iterator.Next(); !heap_obj.is_null();
heap_obj = heap_iterator.Next()) {
if (!heap_obj.IsJSObject() || heap_obj.IsExternal(isolate())) continue;
v8::Local<v8::Object> v8_obj(
Utils::ToLocal(handle(JSObject::cast(heap_obj), isolate())));
if (!predicate->Filter(v8_obj)) continue;
objects->Append(v8_obj);
}
}
} // namespace internal
} // namespace v8
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