Reland of https://codereview.chromium.org/1087133005/ (Add a WinHeap dump provider to the memory pr…

base/trace_event/winheap_dump_provider_win.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 "base/trace_event/winheap_dump_provider_win.h"
+
+#include <windows.h>
+
+#include "base/trace_event/process_memory_dump.h"
+
+namespace base {
+namespace trace_event {
+
+namespace {
+
+const char kDumperFriendlyName[] = "winheap";
+
+// Report a heap dump to a process memory dump. The |heap_info| structure
+// contains the information about this heap, and |heap_name| will be used to
+// represent it in the report.
+bool ReportHeapDump(ProcessMemoryDump* pmd,
+                    const WinHeapInfo& heap_info,
+                    const std::string& heap_name) {
+  MemoryAllocatorDump* dump =
+      pmd->CreateAllocatorDump(kDumperFriendlyName, heap_name);
+  if (!dump)
+    return false;
+  dump->set_physical_size_in_bytes(heap_info.committed_size);
+  dump->set_allocated_objects_count(heap_info.block_count);
+  dump->set_allocated_objects_size_in_bytes(heap_info.allocated_size);
+  return true;
+}
+
+}  // namespace
+
+WinHeapDumpProvider* WinHeapDumpProvider::GetInstance() {
+  return Singleton<WinHeapDumpProvider,
+                   LeakySingletonTraits<WinHeapDumpProvider>>::get();
+}
+
+bool WinHeapDumpProvider::DumpInto(ProcessMemoryDump* pmd) {
+  // Retrieves the number of heaps in the current process.
+  DWORD number_of_heaps = ::GetProcessHeaps(0, NULL);
+  WinHeapInfo all_heap_info = {0};
+
+  // Try to retrieve a handle to all the heaps owned by this process. Returns
+  // false if the number of heaps has changed.
+  //
+  // This is inherently racy as is, but it's not something that we observe a lot
+  // in Chrome, the heaps tend to be created at startup only.
+  scoped_ptr<HANDLE[]> all_heaps(new HANDLE[number_of_heaps]);
+  if (::GetProcessHeaps(number_of_heaps, all_heaps.get()) != number_of_heaps)
+    return false;
+
+  // Skip the pointer to the heap array to avoid accounting the memory used by
+  // this dump provider.
+  std::set<void*> block_to_skip;
+  block_to_skip.insert(all_heaps.get());
+
+  // Retrieves some metrics about each heap.
+  for (size_t i = 0; i < number_of_heaps; ++i) {
+    WinHeapInfo heap_info = {0};
+    heap_info.heap_id = all_heaps[i];
+    GetHeapInformation(&heap_info, block_to_skip);
+
+    all_heap_info.allocated_size += heap_info.allocated_size;
+    all_heap_info.committed_size += heap_info.committed_size;
+    all_heap_info.block_count += heap_info.block_count;
+  }
+  // Report the heap dump.
+  if (!ReportHeapDump(pmd, all_heap_info, MemoryAllocatorDump::kRootHeap))
+    return false;
+
+  return true;
+}
+
+const char* WinHeapDumpProvider::GetFriendlyName() const {
+  return kDumperFriendlyName;
+}
+
+bool WinHeapDumpProvider::GetHeapInformation(
+    WinHeapInfo* heap_info,
+    const std::set<void*>& block_to_skip) {
+  CHECK(::HeapLock(heap_info->heap_id) == TRUE);
+  PROCESS_HEAP_ENTRY heap_entry;
+  heap_entry.lpData = nullptr;
+  // Walk over all the entries in this heap.
+  while (::HeapWalk(heap_info->heap_id, &heap_entry) != FALSE) {
+    if (block_to_skip.count(heap_entry.lpData) == 1)
+      continue;
+    if ((heap_entry.wFlags & PROCESS_HEAP_ENTRY_BUSY) != 0) {
+      heap_info->allocated_size += heap_entry.cbData;
+      heap_info->block_count++;
+    } else if ((heap_entry.wFlags & PROCESS_HEAP_REGION) != 0) {
+      heap_info->committed_size += heap_entry.Region.dwCommittedSize;
+    }
+  }
+  CHECK(::HeapUnlock(heap_info->heap_id) == TRUE);
+  return true;
+}
+
+}  // namespace trace_event
+}  // namespace base