Adding v8_isolate_memory_dump_provider.

gin/v8_isolate_memory_dump_provider.cc

+// Copyright 2015 The Chromium 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 "gin/v8_isolate_memory_dump_provider.h"
+
+#include "base/strings/stringprintf.h"
+#include "base/thread_task_runner_handle.h"
+#include "base/trace_event/memory_dump_manager.h"
+#include "base/trace_event/process_memory_dump.h"
+#include "gin/public/isolate_holder.h"
+#include "v8/include/v8.h"
+
+namespace gin {
+
+namespace {
+const char kDumperFriendlyName[] = "V8IsolateHeap";
+const char kRootDumpName[] = "v8";
+const char kIsolateDumpName[] = "isolate_%p/%s";
+const char kAvailableSizeAttribute[] = "available_size_in_bytes";
+}  // namespace
+
+V8IsolateMemoryDumpProvider::V8IsolateMemoryDumpProvider(
+    IsolateHolder* isolate_holder)
+    : MemoryDumpProvider(base::ThreadTaskRunnerHandle::Get()),
+      isolate_holder_(isolate_holder) {
+  DeclareAllocatorAttribute(kRootDumpName, kAvailableSizeAttribute, "bytes");
+  base::trace_event::MemoryDumpManager::GetInstance()->RegisterDumpProvider(
+      this);
+}
+
+V8IsolateMemoryDumpProvider::~V8IsolateMemoryDumpProvider() {
+  base::trace_event::MemoryDumpManager::GetInstance()->UnregisterDumpProvider(
+      this);
+}
+
+// Called at trace dump point time. Creates a snapshot with the memory counters
+// for the current isolate.
+bool V8IsolateMemoryDumpProvider::DumpInto(
+    base::trace_event::ProcessMemoryDump* pmd) {
+  if (isolate_holder_->access_mode() == IsolateHolder::kUseLocker) {
+    v8::Locker locked(isolate_holder_->isolate());
+    DumpMemoryStatistics_(pmd);
+  } else {
+    DumpMemoryStatistics_(pmd);
+  }
+  return true;
+}
+
+const char* V8IsolateMemoryDumpProvider::GetFriendlyName() const {
+  return kDumperFriendlyName;
+}
+
+void V8IsolateMemoryDumpProvider::DumpMemoryStatistics_(
+    base::trace_event::ProcessMemoryDump* pmd) {
+  v8::HeapStatistics heap_statistics;
+  isolate_holder_->isolate()->GetHeapStatistics(&heap_statistics);
+
+  size_t known_spaces_used_size = 0;
+  size_t known_spaces_size = 0;
+  size_t number_of_spaces = isolate_holder_->isolate()->NumberOfHeapSpaces();
+  for (size_t space = 0; space < number_of_spaces; space++) {
+    v8::HeapSpaceStatistics space_statistics;
+    isolate_holder_->isolate()->GetHeapSpaceStatistics(&space_statistics,
+                                                       space);
+    size_t space_size = space_statistics.space_size();
+    size_t space_used_size = space_statistics.space_used_size();
+
+    known_spaces_size += space_size;
+    known_spaces_used_size += space_used_size;
+
+    std::string allocator_name =
+        base::StringPrintf(kIsolateDumpName, isolate_holder_->isolate(),
+                           space_statistics.space_name());
+    base::trace_event::MemoryAllocatorDump* space_dump =
+        pmd->CreateAllocatorDump(kRootDumpName, allocator_name.c_str());
+    space_dump->set_physical_size_in_bytes(static_cast<int>((space_size)));

[Primiano Tucci (use gerrit), 2015/04/27 08:41:03]

set_physical_size_in_bytes takes a uint64, this should be casted to uint64

[ssid, 2015/04/27 12:15:28]

Done.

+    // TODO(ssid): It is possible to get the objects count of live objects
+    // after the last GC.

[Primiano Tucci (use gerrit), 2015/04/27 08:41:03]

Hmm not really sure I understand what is the message inside the TODO.
Does it suggest that you will possibly add more extra attribute in future?
if so file a bug, link it to the existing one and add a reference to it here.

[ssid, 2015/04/27 12:15:28]

Done.

+    space_dump->set_allocated_objects_count(0);
+    space_dump->set_allocated_objects_size_in_bytes(
+        static_cast<int>(space_used_size));

[Primiano Tucci (use gerrit), 2015/04/27 08:41:03]

ditto here for int <> uint64

+    space_dump->SetAttribute(
+        kAvailableSizeAttribute,
+        static_cast<int>(space_statistics.space_available_size()));
+  }
+  // Compute the rest of the memory, not accounted by the spaces above.
+  std::string allocator_name = base::StringPrintf(
+      kIsolateDumpName, isolate_holder_->isolate(), "other_spaces");
+  base::trace_event::MemoryAllocatorDump* other_spaces_dump =
+      pmd->CreateAllocatorDump(kRootDumpName, allocator_name.c_str());
+  other_spaces_dump->set_physical_size_in_bytes(
+      static_cast<int>(heap_statistics.total_heap_size() - known_spaces_size));
+  other_spaces_dump->set_allocated_objects_count(0);
+  other_spaces_dump->set_allocated_objects_size_in_bytes(static_cast<int>(
+      heap_statistics.used_heap_size() - known_spaces_used_size));
+  // TODO(ssid): Extend GetHeapStatistics api to return available size.

[Primiano Tucci (use gerrit), 2015/04/27 08:41:03]

Add a blank line before the TODO

+  other_spaces_dump->SetAttribute(kAvailableSizeAttribute, 0);
+}
+
+}  // namespace gin