third_party/tcmalloc/chromium/src/heap-profile-table.cc

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This source file includes following definitions.
ByAllocatedSpace
address_map_
GetBucket
GetCallerStackTrace
RecordAlloc
RecordFree
FindAlloc
FindAllocDetails
FindInsideAlloc
MarkAsLive
MarkAsIgnored
IterateAllocationAddresses
MarkCurrentAllocations
MarkUnmarkedAllocations
UnparseBucket
MakeSortedBucketList
DumpMarkedObjects
DumpTypeStatistics
IterateOrderedAllocContexts
FillOrderedProfile
DumpBucketIterator
TallyTypesItererator
DumpTypesIterator
DumpNonLiveIterator
DumpMarkedIterator
AllocationAddressesIterator
MarkIterator
AddIfNonLive
WriteProfile
CleanupOldProfiles
TakeSnapshot
ReleaseSnapshot
AddToSnapshot
NonLiveSnapshot
ReportCallback
ReportLeaks
ReportObject
ReportIndividualObjects
// Copyright (c) 2006, Google Inc.
// All rights reserved.
// 
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
// 
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

// ---
// Author: Sanjay Ghemawat
//         Maxim Lifantsev (refactoring)
//

#include <config.h>

#ifdef HAVE_UNISTD_H
#include <unistd.h>   // for write()
#endif
#include <fcntl.h>    // for open()
#ifdef HAVE_GLOB_H
#include <glob.h>
#ifndef GLOB_NOMATCH  // true on some old cygwins
# define GLOB_NOMATCH 0
#endif
#endif
#ifdef HAVE_INTTYPES_H
#include <inttypes.h> // for PRIxPTR
#endif
#ifdef HAVE_POLL_H
#include <poll.h>
#endif
#include <errno.h>
#include <stdarg.h>
#include <string>
#include <map>
#include <algorithm>  // for sort(), equal(), and copy()

#include "heap-profile-table.h"

#include "base/logging.h"
#include "raw_printer.h"
#include "symbolize.h"
#include <gperftools/stacktrace.h>
#include <gperftools/malloc_hook.h>
#include "memory_region_map.h"
#include "base/commandlineflags.h"
#include "base/logging.h"    // for the RawFD I/O commands
#include "base/sysinfo.h"

using std::sort;
using std::equal;
using std::copy;
using std::string;
using std::map;

using tcmalloc::FillProcSelfMaps;   // from sysinfo.h
using tcmalloc::DumpProcSelfMaps;   // from sysinfo.h

//----------------------------------------------------------------------

DEFINE_bool(cleanup_old_heap_profiles,
            EnvToBool("HEAP_PROFILE_CLEANUP", true),
            "At initialization time, delete old heap profiles.");

DEFINE_int32(heap_check_max_leaks,
             EnvToInt("HEAP_CHECK_MAX_LEAKS", 20),
             "The maximum number of leak reports to print.");

//----------------------------------------------------------------------

// header of the dumped heap profile
static const char kProfileHeader[] = "heap profile: ";
static const char kProcSelfMapsHeader[] = "\nMAPPED_LIBRARIES:\n";
#if defined(TYPE_PROFILING)
static const char kTypeProfileStatsHeader[] = "type statistics:\n";
#endif  // defined(TYPE_PROFILING)

//----------------------------------------------------------------------

const char HeapProfileTable::kFileExt[] = ".heap";

//----------------------------------------------------------------------

static const int kHashTableSize = 179999;   // Size for bucket_table_.
// GCC requires this declaration, but MSVC does not allow it.
#if !defined(COMPILER_MSVC)
/*static*/ const int HeapProfileTable::kMaxStackDepth;
#endif

//----------------------------------------------------------------------

// We strip out different number of stack frames in debug mode
// because less inlining happens in that case
#ifdef NDEBUG
static const int kStripFrames = 2;
#else
static const int kStripFrames = 3;
#endif

// For sorting Stats or Buckets by in-use space
static bool ByAllocatedSpace(HeapProfileTable::Stats* a,
                             HeapProfileTable::Stats* b) {
  // Return true iff "a" has more allocated space than "b"
  return (a->alloc_size - a->free_size) > (b->alloc_size - b->free_size);
}

//----------------------------------------------------------------------

HeapProfileTable::HeapProfileTable(Allocator alloc,
                                   DeAllocator dealloc,
                                   bool profile_mmap)
    : alloc_(alloc),
      dealloc_(dealloc),
      bucket_table_(NULL),
      profile_mmap_(profile_mmap),
      num_buckets_(0),
      address_map_(NULL) {
  // Make a hash table for buckets.
  const int table_bytes = kHashTableSize * sizeof(*bucket_table_);
  bucket_table_ = static_cast<Bucket**>(alloc_(table_bytes));
  memset(bucket_table_, 0, table_bytes);

  // Make an allocation map.
  address_map_ =
      new(alloc_(sizeof(AllocationMap))) AllocationMap(alloc_, dealloc_);

  // Initialize.
  memset(&total_, 0, sizeof(total_));
  num_buckets_ = 0;
}

HeapProfileTable::~HeapProfileTable() {
  // Free the allocation map.
  address_map_->~AllocationMap();
  dealloc_(address_map_);
  address_map_ = NULL;

  // Free the hash table.
  for (int i = 0; i < kHashTableSize; i++) {
    for (Bucket* curr = bucket_table_[i]; curr != 0; /**/) {
      Bucket* bucket = curr;
      curr = curr->next;
      dealloc_(bucket->stack);
      dealloc_(bucket);
    }
  }
  dealloc_(bucket_table_);
  bucket_table_ = NULL;
}

HeapProfileTable::Bucket* HeapProfileTable::GetBucket(int depth,
                                                      const void* const key[]) {
  // Make hash-value
  uintptr_t h = 0;
  for (int i = 0; i < depth; i++) {
    h += reinterpret_cast<uintptr_t>(key[i]);
    h += h << 10;
    h ^= h >> 6;
  }
  h += h << 3;
  h ^= h >> 11;

  // Lookup stack trace in table
  unsigned int buck = ((unsigned int) h) % kHashTableSize;
  for (Bucket* b = bucket_table_[buck]; b != 0; b = b->next) {
    if ((b->hash == h) &&
        (b->depth == depth) &&
        equal(key, key + depth, b->stack)) {
      return b;
    }
  }

  // Create new bucket
  const size_t key_size = sizeof(key[0]) * depth;
  const void** kcopy = reinterpret_cast<const void**>(alloc_(key_size));
  copy(key, key + depth, kcopy);
  Bucket* b = reinterpret_cast<Bucket*>(alloc_(sizeof(Bucket)));
  memset(b, 0, sizeof(*b));
  b->hash  = h;
  b->depth = depth;
  b->stack = kcopy;
  b->next  = bucket_table_[buck];
  bucket_table_[buck] = b;
  num_buckets_++;
  return b;
}

int HeapProfileTable::GetCallerStackTrace(
    int skip_count, void* stack[kMaxStackDepth]) {
  return MallocHook::GetCallerStackTrace(
      stack, kMaxStackDepth, kStripFrames + skip_count + 1);
}

void HeapProfileTable::RecordAlloc(
    const void* ptr, size_t bytes, int stack_depth,
    const void* const call_stack[]) {
  Bucket* b = GetBucket(stack_depth, call_stack);
  b->allocs++;
  b->alloc_size += bytes;
  total_.allocs++;
  total_.alloc_size += bytes;

  AllocValue v;
  v.set_bucket(b);  // also did set_live(false); set_ignore(false)
  v.bytes = bytes;
  address_map_->Insert(ptr, v);
}

void HeapProfileTable::RecordFree(const void* ptr) {
  AllocValue v;
  if (address_map_->FindAndRemove(ptr, &v)) {
    Bucket* b = v.bucket();
    b->frees++;
    b->free_size += v.bytes;
    total_.frees++;
    total_.free_size += v.bytes;
  }
}

bool HeapProfileTable::FindAlloc(const void* ptr, size_t* object_size) const {
  const AllocValue* alloc_value = address_map_->Find(ptr);
  if (alloc_value != NULL) *object_size = alloc_value->bytes;
  return alloc_value != NULL;
}

bool HeapProfileTable::FindAllocDetails(const void* ptr,
                                        AllocInfo* info) const {
  const AllocValue* alloc_value = address_map_->Find(ptr);
  if (alloc_value != NULL) {
    info->object_size = alloc_value->bytes;
    info->call_stack = alloc_value->bucket()->stack;
    info->stack_depth = alloc_value->bucket()->depth;
  }
  return alloc_value != NULL;
}

bool HeapProfileTable::FindInsideAlloc(const void* ptr,
                                       size_t max_size,
                                       const void** object_ptr,
                                       size_t* object_size) const {
  const AllocValue* alloc_value =
    address_map_->FindInside(&AllocValueSize, max_size, ptr, object_ptr);
  if (alloc_value != NULL) *object_size = alloc_value->bytes;
  return alloc_value != NULL;
}

bool HeapProfileTable::MarkAsLive(const void* ptr) {
  AllocValue* alloc = address_map_->FindMutable(ptr);
  if (alloc && !alloc->live()) {
    alloc->set_live(true);
    return true;
  }
  return false;
}

void HeapProfileTable::MarkAsIgnored(const void* ptr) {
  AllocValue* alloc = address_map_->FindMutable(ptr);
  if (alloc) {
    alloc->set_ignore(true);
  }
}

void HeapProfileTable::IterateAllocationAddresses(AddressIterator f,
                                                  void* data) {
  const AllocationAddressIteratorArgs args(f, data);
  address_map_->Iterate<const AllocationAddressIteratorArgs&>(
      AllocationAddressesIterator, args);
}

void HeapProfileTable::MarkCurrentAllocations(AllocationMark mark) {
  const MarkArgs args(mark, true);
  address_map_->Iterate<const MarkArgs&>(MarkIterator, args);
}

void HeapProfileTable::MarkUnmarkedAllocations(AllocationMark mark) {
  const MarkArgs args(mark, false);
  address_map_->Iterate<const MarkArgs&>(MarkIterator, args);
}

// We'd be happier using snprintfer, but we don't to reduce dependencies.
int HeapProfileTable::UnparseBucket(const Bucket& b,
                                    char* buf, int buflen, int bufsize,
                                    const char* extra,
                                    Stats* profile_stats) {
  if (profile_stats != NULL) {
    profile_stats->allocs += b.allocs;
    profile_stats->alloc_size += b.alloc_size;
    profile_stats->frees += b.frees;
    profile_stats->free_size += b.free_size;
  }
  int printed =
    snprintf(buf + buflen, bufsize - buflen,
             "%6d: %8" PRId64 " [%6d: %8" PRId64 "] @%s",
             b.allocs - b.frees,
             b.alloc_size - b.free_size,
             b.allocs,
             b.alloc_size,
             extra);
  // If it looks like the snprintf failed, ignore the fact we printed anything
  if (printed < 0 || printed >= bufsize - buflen) return buflen;
  buflen += printed;
  for (int d = 0; d < b.depth; d++) {
    printed = snprintf(buf + buflen, bufsize - buflen, " 0x%08" PRIxPTR,
                       reinterpret_cast<uintptr_t>(b.stack[d]));
    if (printed < 0 || printed >= bufsize - buflen) return buflen;
    buflen += printed;
  }
  printed = snprintf(buf + buflen, bufsize - buflen, "\n");
  if (printed < 0 || printed >= bufsize - buflen) return buflen;
  buflen += printed;
  return buflen;
}

HeapProfileTable::Bucket**
HeapProfileTable::MakeSortedBucketList() const {
  Bucket** list = static_cast<Bucket**>(alloc_(sizeof(Bucket) * num_buckets_));

  int bucket_count = 0;
  for (int i = 0; i < kHashTableSize; i++) {
    for (Bucket* curr = bucket_table_[i]; curr != 0; curr = curr->next) {
      list[bucket_count++] = curr;
    }
  }
  RAW_DCHECK(bucket_count == num_buckets_, "");

  sort(list, list + num_buckets_, ByAllocatedSpace);

  return list;
}

void HeapProfileTable::DumpMarkedObjects(AllocationMark mark,
                                         const char* file_name) {
  RawFD fd = RawOpenForWriting(file_name);
  if (fd == kIllegalRawFD) {
    RAW_LOG(ERROR, "Failed dumping live objects to %s", file_name);
    return;
  }
  const DumpMarkedArgs args(fd, mark);
  address_map_->Iterate<const DumpMarkedArgs&>(DumpMarkedIterator, args);
  RawClose(fd);
}

#if defined(TYPE_PROFILING)
void HeapProfileTable::DumpTypeStatistics(const char* file_name) const {
  RawFD fd = RawOpenForWriting(file_name);
  if (fd == kIllegalRawFD) {
    RAW_LOG(ERROR, "Failed dumping type statistics to %s", file_name);
    return;
  }

  AddressMap<TypeCount>* type_size_map;
  type_size_map = new(alloc_(sizeof(AddressMap<TypeCount>)))
      AddressMap<TypeCount>(alloc_, dealloc_);
  address_map_->Iterate(TallyTypesItererator, type_size_map);

  RawWrite(fd, kTypeProfileStatsHeader, strlen(kTypeProfileStatsHeader));
  const DumpArgs args(fd, NULL);
  type_size_map->Iterate<const DumpArgs&>(DumpTypesIterator, args);
  RawClose(fd);

  type_size_map->~AddressMap<TypeCount>();
  dealloc_(type_size_map);
}
#endif  // defined(TYPE_PROFILING)

void HeapProfileTable::IterateOrderedAllocContexts(
    AllocContextIterator callback) const {
  Bucket** list = MakeSortedBucketList();
  AllocContextInfo info;
  for (int i = 0; i < num_buckets_; ++i) {
    *static_cast<Stats*>(&info) = *static_cast<Stats*>(list[i]);
    info.stack_depth = list[i]->depth;
    info.call_stack = list[i]->stack;
    callback(info);
  }
  dealloc_(list);
}

int HeapProfileTable::FillOrderedProfile(char buf[], int size) const {
  Bucket** list = MakeSortedBucketList();

  // Our file format is "bucket, bucket, ..., bucket, proc_self_maps_info".
  // In the cases buf is too small, we'd rather leave out the last
  // buckets than leave out the /proc/self/maps info.  To ensure that,
  // we actually print the /proc/self/maps info first, then move it to
  // the end of the buffer, then write the bucket info into whatever
  // is remaining, and then move the maps info one last time to close
  // any gaps.  Whew!
  int map_length = snprintf(buf, size, "%s", kProcSelfMapsHeader);
  if (map_length < 0 || map_length >= size) return 0;
  bool dummy;   // "wrote_all" -- did /proc/self/maps fit in its entirety?
  map_length += FillProcSelfMaps(buf + map_length, size - map_length, &dummy);
  RAW_DCHECK(map_length <= size, "");
  char* const map_start = buf + size - map_length;      // move to end
  memmove(map_start, buf, map_length);
  size -= map_length;

  Stats stats;
  memset(&stats, 0, sizeof(stats));
  int bucket_length = snprintf(buf, size, "%s", kProfileHeader);
  if (bucket_length < 0 || bucket_length >= size) return 0;
  bucket_length = UnparseBucket(total_, buf, bucket_length, size,
                                " heapprofile", &stats);

  // Dump the mmap list first.
  if (profile_mmap_) {
    BufferArgs buffer(buf, bucket_length, size);
    MemoryRegionMap::IterateBuckets<BufferArgs*>(DumpBucketIterator, &buffer);
    bucket_length = buffer.buflen;
  }

  for (int i = 0; i < num_buckets_; i++) {
    bucket_length = UnparseBucket(*list[i], buf, bucket_length, size, "",
                                  &stats);
  }
  RAW_DCHECK(bucket_length < size, "");

  dealloc_(list);

  RAW_DCHECK(buf + bucket_length <= map_start, "");
  memmove(buf + bucket_length, map_start, map_length);  // close the gap

  return bucket_length + map_length;
}

// static
void HeapProfileTable::DumpBucketIterator(const Bucket* bucket,
                                          BufferArgs* args) {
  args->buflen = UnparseBucket(*bucket, args->buf, args->buflen, args->bufsize,
                               "", NULL);
}

#if defined(TYPE_PROFILING)
// static
void HeapProfileTable::TallyTypesItererator(
    const void* ptr,
    AllocValue* value,
    AddressMap<TypeCount>* type_size_map) {
  const std::type_info* type = LookupType(ptr);

  const void* key = NULL;
  if (type)
    key = type->name();

  TypeCount* count = type_size_map->FindMutable(key);
  if (count) {
    count->bytes += value->bytes;
    ++count->objects;
  } else {
    type_size_map->Insert(key, TypeCount(value->bytes, 1));
  }
}

// static
void HeapProfileTable::DumpTypesIterator(const void* ptr,
                                         TypeCount* count,
                                         const DumpArgs& args) {
  char buf[1024];
  int len;
  const char* mangled_type_name = static_cast<const char*>(ptr);
  len = snprintf(buf, sizeof(buf), "%6d: %8" PRId64 " @ %s\n",
                 count->objects, count->bytes,
                 mangled_type_name ? mangled_type_name : "(no_typeinfo)");
  RawWrite(args.fd, buf, len);
}
#endif  // defined(TYPE_PROFILING)

inline
void HeapProfileTable::DumpNonLiveIterator(const void* ptr, AllocValue* v,
                                           const DumpArgs& args) {
  if (v->live()) {
    v->set_live(false);
    return;
  }
  if (v->ignore()) {
    return;
  }
  Bucket b;
  memset(&b, 0, sizeof(b));
  b.allocs = 1;
  b.alloc_size = v->bytes;
  b.depth = v->bucket()->depth;
  b.stack = v->bucket()->stack;
  char buf[1024];
  int len = UnparseBucket(b, buf, 0, sizeof(buf), "", args.profile_stats);
  RawWrite(args.fd, buf, len);
}

inline
void HeapProfileTable::DumpMarkedIterator(const void* ptr, AllocValue* v,
                                          const DumpMarkedArgs& args) {
  if (v->mark() != args.mark)
    return;
  Bucket b;
  memset(&b, 0, sizeof(b));
  b.allocs = 1;
  b.alloc_size = v->bytes;
  b.depth = v->bucket()->depth;
  b.stack = v->bucket()->stack;
  char addr[16];
  snprintf(addr, 16, "0x%08" PRIxPTR, ptr);
  char buf[1024];
  int len = UnparseBucket(b, buf, 0, sizeof(buf), addr, NULL);
  RawWrite(args.fd, buf, len);
}

inline
void HeapProfileTable::AllocationAddressesIterator(
    const void* ptr,
    AllocValue* v,
    const AllocationAddressIteratorArgs& args) {
  args.callback(args.data, ptr);
}

inline
void HeapProfileTable::MarkIterator(const void* ptr, AllocValue* v,
                                    const MarkArgs& args) {
  if (!args.mark_all && v->mark() != UNMARKED)
    return;
  v->set_mark(args.mark);
}

// Callback from NonLiveSnapshot; adds entry to arg->dest
// if not the entry is not live and is not present in arg->base.
void HeapProfileTable::AddIfNonLive(const void* ptr, AllocValue* v,
                                    AddNonLiveArgs* arg) {
  if (v->live()) {
    v->set_live(false);
  } else {
    if (arg->base != NULL && arg->base->map_.Find(ptr) != NULL) {
      // Present in arg->base, so do not save
    } else {
      arg->dest->Add(ptr, *v);
    }
  }
}

bool HeapProfileTable::WriteProfile(const char* file_name,
                                    const Bucket& total,
                                    AllocationMap* allocations) {
  RAW_VLOG(1, "Dumping non-live heap profile to %s", file_name);
  RawFD fd = RawOpenForWriting(file_name);
  if (fd == kIllegalRawFD) {
    RAW_LOG(ERROR, "Failed dumping filtered heap profile to %s", file_name);
    return false;
  }
  RawWrite(fd, kProfileHeader, strlen(kProfileHeader));
  char buf[512];
  int len = UnparseBucket(total, buf, 0, sizeof(buf), " heapprofile",
                          NULL);
  RawWrite(fd, buf, len);
  const DumpArgs args(fd, NULL);
  allocations->Iterate<const DumpArgs&>(DumpNonLiveIterator, args);
  RawWrite(fd, kProcSelfMapsHeader, strlen(kProcSelfMapsHeader));
  DumpProcSelfMaps(fd);
  RawClose(fd);
  return true;
}

void HeapProfileTable::CleanupOldProfiles(const char* prefix) {
  if (!FLAGS_cleanup_old_heap_profiles)
    return;
  char buf[1000];
  snprintf(buf, 1000,"%s.%05d.", prefix, getpid());
  string pattern = string(buf) + ".*" + kFileExt;

#if defined(HAVE_GLOB_H)
  glob_t g;
  const int r = glob(pattern.c_str(), GLOB_ERR, NULL, &g);
  if (r == 0 || r == GLOB_NOMATCH) {
    const int prefix_length = strlen(prefix);
    for (int i = 0; i < g.gl_pathc; i++) {
      const char* fname = g.gl_pathv[i];
      if ((strlen(fname) >= prefix_length) &&
          (memcmp(fname, prefix, prefix_length) == 0)) {
        RAW_VLOG(1, "Removing old heap profile %s", fname);
        unlink(fname);
      }
    }
  }
  globfree(&g);
#else   /* HAVE_GLOB_H */
  RAW_LOG(WARNING, "Unable to remove old heap profiles (can't run glob())");
#endif
}

HeapProfileTable::Snapshot* HeapProfileTable::TakeSnapshot() {
  Snapshot* s = new (alloc_(sizeof(Snapshot))) Snapshot(alloc_, dealloc_);
  address_map_->Iterate(AddToSnapshot, s);
  return s;
}

void HeapProfileTable::ReleaseSnapshot(Snapshot* s) {
  s->~Snapshot();
  dealloc_(s);
}

// Callback from TakeSnapshot; adds a single entry to snapshot
void HeapProfileTable::AddToSnapshot(const void* ptr, AllocValue* v,
                                     Snapshot* snapshot) {
  snapshot->Add(ptr, *v);
}

HeapProfileTable::Snapshot* HeapProfileTable::NonLiveSnapshot(
    Snapshot* base) {
  RAW_VLOG(2, "NonLiveSnapshot input: %d %d\n",
           int(total_.allocs - total_.frees),
           int(total_.alloc_size - total_.free_size));

  Snapshot* s = new (alloc_(sizeof(Snapshot))) Snapshot(alloc_, dealloc_);
  AddNonLiveArgs args;
  args.dest = s;
  args.base = base;
  address_map_->Iterate<AddNonLiveArgs*>(AddIfNonLive, &args);
  RAW_VLOG(2, "NonLiveSnapshot output: %d %d\n",
           int(s->total_.allocs - s->total_.frees),
           int(s->total_.alloc_size - s->total_.free_size));
  return s;
}

// Information kept per unique bucket seen
struct HeapProfileTable::Snapshot::Entry {
  int count;
  int bytes;
  Bucket* bucket;
  Entry() : count(0), bytes(0) { }

  // Order by decreasing bytes
  bool operator<(const Entry& x) const {
    return this->bytes > x.bytes;
  }
};

// State used to generate leak report.  We keep a mapping from Bucket pointer
// the collected stats for that bucket.
struct HeapProfileTable::Snapshot::ReportState {
  map<Bucket*, Entry> buckets_;
};

// Callback from ReportLeaks; updates ReportState.
void HeapProfileTable::Snapshot::ReportCallback(const void* ptr,
                                                AllocValue* v,
                                                ReportState* state) {
  Entry* e = &state->buckets_[v->bucket()]; // Creates empty Entry first time
  e->bucket = v->bucket();
  e->count++;
  e->bytes += v->bytes;
}

void HeapProfileTable::Snapshot::ReportLeaks(const char* checker_name,
                                             const char* filename,
                                             bool should_symbolize) {
  // This is only used by the heap leak checker, but is intimately
  // tied to the allocation map that belongs in this module and is
  // therefore placed here.
  RAW_LOG(ERROR, "Leak check %s detected leaks of %" PRIuS " bytes "
          "in %" PRIuS " objects",
          checker_name,
          size_t(total_.alloc_size),
          size_t(total_.allocs));

  // Group objects by Bucket
  ReportState state;
  map_.Iterate(&ReportCallback, &state);

  // Sort buckets by decreasing leaked size
  const int n = state.buckets_.size();
  Entry* entries = new Entry[n];
  int dst = 0;
  for (map<Bucket*,Entry>::const_iterator iter = state.buckets_.begin();
       iter != state.buckets_.end();
       ++iter) {
    entries[dst++] = iter->second;
  }
  sort(entries, entries + n);

  // Report a bounded number of leaks to keep the leak report from
  // growing too long.
  const int to_report =
      (FLAGS_heap_check_max_leaks > 0 &&
       n > FLAGS_heap_check_max_leaks) ? FLAGS_heap_check_max_leaks : n;
  RAW_LOG(ERROR, "The %d largest leaks:", to_report);

  // Print
  SymbolTable symbolization_table;
  for (int i = 0; i < to_report; i++) {
    const Entry& e = entries[i];
    for (int j = 0; j < e.bucket->depth; j++) {
      symbolization_table.Add(e.bucket->stack[j]);
    }
  }
  static const int kBufSize = 2<<10;
  char buffer[kBufSize];
  if (should_symbolize)
    symbolization_table.Symbolize();
  for (int i = 0; i < to_report; i++) {
    const Entry& e = entries[i];
    base::RawPrinter printer(buffer, kBufSize);
    printer.Printf("Leak of %d bytes in %d objects allocated from:\n",
                   e.bytes, e.count);
    for (int j = 0; j < e.bucket->depth; j++) {
      const void* pc = e.bucket->stack[j];
      printer.Printf("\t@ %" PRIxPTR " %s\n",
          reinterpret_cast<uintptr_t>(pc), symbolization_table.GetSymbol(pc));
    }
    RAW_LOG(ERROR, "%s", buffer);
  }

  if (to_report < n) {
    RAW_LOG(ERROR, "Skipping leaks numbered %d..%d",
            to_report, n-1);
  }
  delete[] entries;

  // TODO: Dump the sorted Entry list instead of dumping raw data?
  // (should be much shorter)
  if (!HeapProfileTable::WriteProfile(filename, total_, &map_)) {
    RAW_LOG(ERROR, "Could not write pprof profile to %s", filename);
  }
}

void HeapProfileTable::Snapshot::ReportObject(const void* ptr,
                                              AllocValue* v,
                                              char* unused) {
  // Perhaps also log the allocation stack trace (unsymbolized)
  // on this line in case somebody finds it useful.
  RAW_LOG(ERROR, "leaked %" PRIuS " byte object %p", v->bytes, ptr);
}

void HeapProfileTable::Snapshot::ReportIndividualObjects() {
  char unused;
  map_.Iterate(ReportObject, &unused);
}
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root/third_party/tcmalloc/chromium/src/heap-profile-table.cc

DEFINITIONS
