Revert of [profiler] Implement POC Sampling Heap Profiler

src/profiler/sampling-heap-profiler.cc

Index: src/profiler/sampling-heap-profiler.cc
diff --git a/src/profiler/sampling-heap-profiler.cc b/src/profiler/sampling-heap-profiler.cc
deleted file mode 100644
index c26b70357eeac06f8aa8066c9ca856ad71539229..0000000000000000000000000000000000000000
--- a/src/profiler/sampling-heap-profiler.cc
+++ /dev/null
@@ -1,250 +0,0 @@
-// Copyright 2015 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/sampling-heap-profiler.h"
-
-#include <stdint.h>
-#include <memory>
-#include "src/api.h"
-#include "src/base/utils/random-number-generator.h"
-#include "src/frames-inl.h"
-#include "src/heap/heap.h"
-#include "src/isolate.h"
-#include "src/profiler/strings-storage.h"
-
-namespace v8 {
-namespace internal {
-
-SamplingHeapProfiler::SamplingHeapProfiler(Heap* heap, StringsStorage* names,
-                                           uint64_t rate, int stack_depth)
-    : InlineAllocationObserver(GetNextSampleInterval(
-          heap->isolate()->random_number_generator(), rate)),
-      isolate_(heap->isolate()),
-      heap_(heap),
-      random_(isolate_->random_number_generator()),
-      names_(names),
-      samples_(),
-      rate_(rate),
-      stack_depth_(stack_depth) {
-  heap->new_space()->AddInlineAllocationObserver(this);
-}
-
-
-SamplingHeapProfiler::~SamplingHeapProfiler() {
-  heap_->new_space()->RemoveInlineAllocationObserver(this);
-
-  // Clear samples and drop all the weak references we are keeping.
-  std::set<SampledAllocation*>::iterator it;
-  for (it = samples_.begin(); it != samples_.end(); ++it) {
-    delete *it;
-  }
-  std::set<SampledAllocation*> empty;
-  samples_.swap(empty);
-}
-
-void SamplingHeapProfiler::Step(int bytes_allocated, Address soon_object,
-                                size_t size) {
-  DCHECK(heap_->gc_state() == Heap::NOT_IN_GC);
-  DCHECK(soon_object);
-  SampleObject(soon_object, size);
-}
-
-
-void SamplingHeapProfiler::SampleObject(Address soon_object, size_t size) {
-  DisallowHeapAllocation no_allocation;
-
-  HandleScope scope(isolate_);
-  HeapObject* heap_object = HeapObject::FromAddress(soon_object);
-  Handle<Object> obj(heap_object, isolate_);
-
-  // Mark the new block as FreeSpace to make sure the heap is iterable while we
-  // are taking the sample.
-  heap()->CreateFillerObjectAt(soon_object, static_cast<int>(size));
-
-  Local<v8::Value> loc = v8::Utils::ToLocal(obj);
-
-  SampledAllocation* sample =
-      new SampledAllocation(this, isolate_, loc, size, stack_depth_);
-  samples_.insert(sample);
-}
-
-
-// We sample with a Poisson process, with constant average sampling interval.
-// This follows the exponential probability distribution with parameter
-// λ = 1/rate where rate is the average number of bytes between samples.
-//
-// Let u be a uniformly distributed random number between 0 and 1, then
-// next_sample = (- ln u) / λ
-intptr_t SamplingHeapProfiler::GetNextSampleInterval(
-    base::RandomNumberGenerator* random, uint64_t rate) {
-  double u = random->NextDouble();
-  double next = (-std::log(u)) * rate;
-  return next < kPointerSize
-             ? kPointerSize
-             : (next > INT_MAX ? INT_MAX : static_cast<intptr_t>(next));
-}
-
-
-void SamplingHeapProfiler::SampledAllocation::OnWeakCallback(
-    const WeakCallbackInfo<SampledAllocation>& data) {
-  SampledAllocation* sample = data.GetParameter();
-  sample->sampling_heap_profiler_->samples_.erase(sample);
-  delete sample;
-}
-
-
-SamplingHeapProfiler::FunctionInfo::FunctionInfo(SharedFunctionInfo* shared,
-                                                 StringsStorage* names)
-    : name_(names->GetFunctionName(shared->DebugName())),
-      script_name_(""),
-      script_id_(v8::UnboundScript::kNoScriptId),
-      start_position_(shared->start_position()) {
-  if (shared->script()->IsScript()) {
-    Script* script = Script::cast(shared->script());
-    script_id_ = script->id();
-    if (script->name()->IsName()) {
-      Name* name = Name::cast(script->name());
-      script_name_ = names->GetName(name);
-    }
-  }
-}
-
-
-SamplingHeapProfiler::SampledAllocation::SampledAllocation(
-    SamplingHeapProfiler* sampling_heap_profiler, Isolate* isolate,
-    Local<Value> local, size_t size, int max_frames)
-    : sampling_heap_profiler_(sampling_heap_profiler),
-      global_(reinterpret_cast<v8::Isolate*>(isolate), local),
-      size_(size) {
-  global_.SetWeak(this, OnWeakCallback, WeakCallbackType::kParameter);
-
-  StackTraceFrameIterator it(isolate);
-  int frames_captured = 0;
-  while (!it.done() && frames_captured < max_frames) {
-    JavaScriptFrame* frame = it.frame();
-    SharedFunctionInfo* shared = frame->function()->shared();
-    stack_.push_back(new FunctionInfo(shared, sampling_heap_profiler->names()));
-
-    frames_captured++;
-    it.Advance();
-  }
-
-  if (frames_captured == 0) {
-    const char* name = nullptr;
-    switch (isolate->current_vm_state()) {
-      case GC:
-        name = "(GC)";
-        break;
-      case COMPILER:
-        name = "(COMPILER)";
-        break;
-      case OTHER:
-        name = "(V8 API)";
-        break;
-      case EXTERNAL:
-        name = "(EXTERNAL)";
-        break;
-      case IDLE:
-        name = "(IDLE)";
-        break;
-      case JS:
-        name = "(JS)";
-        break;
-    }
-    stack_.push_back(new FunctionInfo(name));
-  }
-}
-
-
-SamplingHeapProfiler::Node* SamplingHeapProfiler::AllocateNode(
-    AllocationProfile* profile, const std::map<int, Script*>& scripts,
-    FunctionInfo* function_info) {
-  DCHECK(function_info->get_name());
-  DCHECK(function_info->get_script_name());
-
-  int line = v8::AllocationProfile::kNoLineNumberInfo;
-  int column = v8::AllocationProfile::kNoColumnNumberInfo;
-
-  if (function_info->get_script_id() != v8::UnboundScript::kNoScriptId) {
-    // Cannot use std::map<T>::at because it is not available on android.
-    auto non_const_scripts = const_cast<std::map<int, Script*>&>(scripts);
-    Handle<Script> script(non_const_scripts[function_info->get_script_id()]);
-
-    line =
-        1 + Script::GetLineNumber(script, function_info->get_start_position());
-    column = 1 + Script::GetColumnNumber(script,
-                                         function_info->get_start_position());
-  }
-
-  profile->nodes().push_back(
-      Node({ToApiHandle<v8::String>(isolate_->factory()->InternalizeUtf8String(
-                function_info->get_name())),
-            ToApiHandle<v8::String>(isolate_->factory()->InternalizeUtf8String(
-                function_info->get_script_name())),
-            function_info->get_script_id(), function_info->get_start_position(),
-            line, column, std::vector<Node*>(),
-            std::vector<v8::AllocationProfile::Allocation>()}));
-
-  return &profile->nodes().back();
-}
-
-
-SamplingHeapProfiler::Node* SamplingHeapProfiler::FindOrAddChildNode(
-    AllocationProfile* profile, const std::map<int, Script*>& scripts,
-    Node* parent, FunctionInfo* function_info) {
-  for (Node* child : parent->children) {
-    if (child->script_id == function_info->get_script_id() &&
-        child->start_position == function_info->get_start_position())
-      return child;
-  }
-  Node* child = AllocateNode(profile, scripts, function_info);
-  parent->children.push_back(child);
-  return child;
-}
-
-
-SamplingHeapProfiler::Node* SamplingHeapProfiler::AddStack(
-    AllocationProfile* profile, const std::map<int, Script*>& scripts,
-    const std::vector<FunctionInfo*>& stack) {
-  Node* node = profile->GetRootNode();
-
-  // We need to process the stack in reverse order as the top of the stack is
-  // the first element in the list.
-  for (auto it = stack.rbegin(); it != stack.rend(); ++it) {
-    FunctionInfo* function_info = *it;
-    node = FindOrAddChildNode(profile, scripts, node, function_info);
-  }
-  return node;
-}
-
-
-v8::AllocationProfile* SamplingHeapProfiler::GetAllocationProfile() {
-  // To resolve positions to line/column numbers, we will need to look up
-  // scripts. Build a map to allow fast mapping from script id to script.
-  std::map<int, Script*> scripts;
-  {
-    Script::Iterator iterator(isolate_);
-    Script* script;
-    while ((script = iterator.Next())) {
-      scripts[script->id()] = script;
-    }
-  }
-
-  auto profile = new v8::internal::AllocationProfile();
-
-  // Create the root node.
-  FunctionInfo function_info("(root)");
-  AllocateNode(profile, scripts, &function_info);
-
-  for (SampledAllocation* allocation : samples_) {
-    Node* node = AddStack(profile, scripts, allocation->get_stack());
-    node->allocations.push_back({allocation->get_size(), 1});
-  }
-
-  return profile;
-}
-
-
-}  // namespace internal
-}  // namespace v8