base/trace_event/winheap_dump_provider_win.cc

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/trace_event/winheap_dump_provider_win.h"
   6
   7 #include <windows.h>
   8
   9 #include "base/debug/profiler.h"
  10 #include "base/strings/string_util.h"
  11 #include "base/trace_event/process_memory_dump.h"
  12 #include "base/win/windows_version.h"
  13
  14 namespace base {
  15 namespace trace_event {
  16
  17 #define DUMP_ROOT_NAME "winheap"
  18 // static
  19 const char WinHeapDumpProvider::kAllocatedObjects[] =
  20     DUMP_ROOT_NAME "/allocated_objects";
  21
  22 namespace {
  23
  24 // Report a heap dump to a process memory dump. The |heap_info| structure
  25 // contains the information about this heap, and |dump_absolute_name| will be
  26 // used to represent it in the report.
  27 void ReportHeapDump(ProcessMemoryDump* pmd, const WinHeapInfo& heap_info) {
  28   MemoryAllocatorDump* outer_dump = pmd->CreateAllocatorDump(DUMP_ROOT_NAME);
  29   outer_dump->AddScalar(MemoryAllocatorDump::kNameSize,
  30                         MemoryAllocatorDump::kUnitsBytes,
  31                         heap_info.committed_size);
  32
  33   MemoryAllocatorDump* inner_dump =
  34       pmd->CreateAllocatorDump(WinHeapDumpProvider::kAllocatedObjects);
  35   inner_dump->AddScalar(MemoryAllocatorDump::kNameSize,
  36                         MemoryAllocatorDump::kUnitsBytes,
  37                         heap_info.allocated_size);
  38   inner_dump->AddScalar(MemoryAllocatorDump::kNameObjectCount,
  39                         MemoryAllocatorDump::kUnitsObjects,
  40                         heap_info.block_count);
  41 }
  42
  43 }  // namespace
  44
  45 WinHeapDumpProvider* WinHeapDumpProvider::GetInstance() {
  46   return Singleton<WinHeapDumpProvider,
  47                    LeakySingletonTraits<WinHeapDumpProvider>>::get();
  48 }
  49
  50 bool WinHeapDumpProvider::OnMemoryDump(const MemoryDumpArgs& args,
  51                                        ProcessMemoryDump* pmd) {
  52   // This method might be flaky for 2 reasons:
  53   //   - GetProcessHeaps is racy by design. It returns a snapshot of the
  54   //     available heaps, but there's no guarantee that that snapshot remains
  55   //     valid. If a heap disappears between GetProcessHeaps() and HeapWalk()
  56   //     then chaos should be assumed. This flakyness is acceptable for tracing.
  57   //   - The MSDN page for HeapLock says: "If the HeapLock function is called on
  58   //     a heap created with the HEAP_NO_SERIALIZATION flag, the results are
  59   //     undefined.". This is a problem on Windows XP where some system DLLs are
  60   //     known for creating heaps with this particular flag. For this reason
  61   //     this function should be disabled on XP.
  62   //
  63   // See https://crbug.com/487291 for more details about this.
  64   if (base::win::GetVersion() < base::win::VERSION_VISTA)
  65     return false;
  66
  67   // Disable this dump provider for the SyzyASan instrumented build
  68   // because they don't support the heap walking functions yet.
  69 #if defined(SYZYASAN)
  70   if (base::debug::IsBinaryInstrumented())
  71     return false;
  72 #endif
  73
  74   // Retrieves the number of heaps in the current process.
  75   DWORD number_of_heaps = ::GetProcessHeaps(0, NULL);
  76   WinHeapInfo all_heap_info = {0};
  77
  78   // Try to retrieve a handle to all the heaps owned by this process. Returns
  79   // false if the number of heaps has changed.
  80   //
  81   // This is inherently racy as is, but it's not something that we observe a lot
  82   // in Chrome, the heaps tend to be created at startup only.
  83   scoped_ptr<HANDLE[]> all_heaps(new HANDLE[number_of_heaps]);
  84   if (::GetProcessHeaps(number_of_heaps, all_heaps.get()) != number_of_heaps)
  85     return false;
  86
  87   // Skip the pointer to the heap array to avoid accounting the memory used by
  88   // this dump provider.
  89   std::set<void*> block_to_skip;
  90   block_to_skip.insert(all_heaps.get());
  91
  92   // Retrieves some metrics about each heap.
  93   for (size_t i = 0; i < number_of_heaps; ++i) {
  94     WinHeapInfo heap_info = {0};
  95     heap_info.heap_id = all_heaps[i];
  96     GetHeapInformation(&heap_info, block_to_skip);
  97
  98     all_heap_info.allocated_size += heap_info.allocated_size;
  99     all_heap_info.committed_size += heap_info.committed_size;
 100     all_heap_info.block_count += heap_info.block_count;
 101   }
 102   // Report the heap dump.
 103   ReportHeapDump(pmd, all_heap_info);
 104   return true;
 105 }
 106
 107 bool WinHeapDumpProvider::GetHeapInformation(
 108     WinHeapInfo* heap_info,
 109     const std::set<void*>& block_to_skip) {
 110   CHECK(::HeapLock(heap_info->heap_id) == TRUE);
 111   PROCESS_HEAP_ENTRY heap_entry;
 112   heap_entry.lpData = nullptr;
 113   // Walk over all the entries in this heap.
 114   while (::HeapWalk(heap_info->heap_id, &heap_entry) != FALSE) {
 115     if (block_to_skip.count(heap_entry.lpData) == 1)
 116       continue;
 117     if ((heap_entry.wFlags & PROCESS_HEAP_ENTRY_BUSY) != 0) {
 118       heap_info->allocated_size += heap_entry.cbData;
 119       heap_info->block_count++;
 120     } else if ((heap_entry.wFlags & PROCESS_HEAP_REGION) != 0) {
 121       heap_info->committed_size += heap_entry.Region.dwCommittedSize;
 122     }
 123   }
 124   CHECK(::HeapUnlock(heap_info->heap_id) == TRUE);
 125   return true;
 126 }
 127
 128 }  // namespace trace_event
 129 }  // namespace base