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 <sstream>
+
+#include "base/message_loop/message_loop.h"
+#include "base/threading/platform_thread.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";

[Primiano Tucci (use gerrit), 2015/04/21 16:43:42]

I think that you could have a string format here (see my suggesiton below),
e.g.:

kIsolateHeapSpaceFmt = "isolate_%d/%s"

[ssid, 2015/04/21 17:38:23]

Done.

+const char kAvailableSizeAttribute[] = "available_size_in_bytes";
+const char kPhysicalSizeAttribute[] = "physical_size_in_bytes";
+}  // namespace
+
+V8IsolateMemoryDumpProvider::V8IsolateMemoryDumpProvider(
+    IsolateHolder* isolate_holder)
+    : MemoryDumpProvider(base::MessageLoop::current()->task_runner()) {
+  DeclareAllocatorAttribute(kRootDumpName, kAvailableSizeAttribute, "bytes");
+  DeclareAllocatorAttribute(kRootDumpName, kPhysicalSizeAttribute, "bytes");
+  base::trace_event::MemoryDumpManager::GetInstance()->RegisterDumpProvider(
+      this);
+  isolate_holder_ = isolate_holder;
+}
+
+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) {
+  v8::HeapStatistics heap_statistics;
+  isolate_holder_->isolate()->GetHeapStatistics(&heap_statistics);
+
+  int thread_id = base::PlatformThread::CurrentId();
+  std::stringstream isolate_name;
+  // TODO(ssid): The thread_id is soon not going to be unique enough if we get
+  // more isolates per thread.
+  isolate_name << kIsolateDumpName << '_' << thread_id;

[Primiano Tucci (use gerrit), 2015/04/21 16:43:42]

You can simplify this by using StringPrintf (#include
"base/strings/stringprintf.h")

Do just this below:
std::string isolate_name = StringPrintf"isolate_%d/heap%d", thread_id,
space_name())

[ssid, 2015/04/21 17:38:23]

Done.

+
+  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::stringstream allocator_name;
+    allocator_name << isolate_name.str() << '/'
+                   << space_statistics.space_name();
+    base::trace_event::MemoryAllocatorDump* space_dump =
+        pmd->CreateAllocatorDump(kRootDumpName, allocator_name.str());
+    space_dump->set_physical_size_in_bytes(space_size);
+    space_dump->set_allocated_objects_count(0);
+    space_dump->set_allocated_objects_size_in_bytes(space_used_size);
+    space_dump->SetAttribute(kAvailableSizeAttribute,
+                             space_statistics.space_available_size());
+    // TODO(ssid): This should probably be the physical_size_in_bytes. Check
+    // with V8 owner.
+    space_dump->SetAttribute(kPhysicalSizeAttribute,
+                             space_statistics.physical_space_size());
+  }
+
+  std::stringstream allocator_name;
+  allocator_name << isolate_name.str() << '/' << "other_spaces";
+  // Compute the rest of the memory, not accounted by the spaces above.
+  base::trace_event::MemoryAllocatorDump* space_dump =

[Primiano Tucci (use gerrit), 2015/04/21 16:43:42]

s/space_dump/other_spaces_dump/

[ssid, 2015/04/21 17:38:22]

Note: other spaces are named as : new_space, old_space, etc ...

+      pmd->CreateAllocatorDump(kRootDumpName, allocator_name.str());
+  space_dump->set_physical_size_in_bytes(heap_statistics.total_heap_size() -
+                                         known_spaces_size);
+  space_dump->set_allocated_objects_count(0);
+  space_dump->set_allocated_objects_size_in_bytes(
+      heap_statistics.used_heap_size() - known_spaces_used_size);
+

[Primiano Tucci (use gerrit), 2015/04/21 16:43:42]

Can you please do the accounting of the two extra properties as well?

[ssid, 2015/04/21 17:38:23]

Cant be done for available memory because, there is no total available space
returned by getheapstatistics().

+  return true;
+}
+
+const char* V8IsolateMemoryDumpProvider::GetFriendlyName() const {
+  return kDumperFriendlyName;
+}
+
+}  // namespace gin