heap-profiler.h 12.4 KB
Newer Older
1
// Copyright 2009-2010 the V8 project authors. All rights reserved.
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
// 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.

#ifndef V8_HEAP_PROFILER_H_
#define V8_HEAP_PROFILER_H_

31
#include "zone-inl.h"
32

33 34 35 36 37
namespace v8 {
namespace internal {

#ifdef ENABLE_LOGGING_AND_PROFILING

38 39 40
class HeapSnapshot;
class HeapSnapshotsCollection;

41 42 43 44 45 46 47 48 49
#define HEAP_PROFILE(Call)                             \
  do {                                                 \
    if (v8::internal::HeapProfiler::is_profiling()) {  \
      v8::internal::HeapProfiler::Call;                \
    }                                                  \
  } while (false)
#else
#define HEAP_PROFILE(Call) ((void) 0)
#endif  // ENABLE_LOGGING_AND_PROFILING
50

51 52 53 54
// The HeapProfiler writes data to the log files, which can be postprocessed
// to generate .hp files for use by the GHC/Valgrind tool hp2ps.
class HeapProfiler {
 public:
55 56
  static void Setup();
  static void TearDown();
57 58

#ifdef ENABLE_LOGGING_AND_PROFILING
59 60 61 62 63 64
  static HeapSnapshot* TakeSnapshot(const char* name,
                                    int type,
                                    v8::ActivityControl* control);
  static HeapSnapshot* TakeSnapshot(String* name,
                                    int type,
                                    v8::ActivityControl* control);
65 66 67 68
  static int GetSnapshotsCount();
  static HeapSnapshot* GetSnapshot(int index);
  static HeapSnapshot* FindSnapshot(unsigned uid);

69 70 71 72 73 74
  static void ObjectMoveEvent(Address from, Address to);

  static INLINE(bool is_profiling()) {
    return singleton_ != NULL && singleton_->snapshots_->is_tracking_objects();
  }

75
  // Obsolete interface.
76 77 78 79
  // Write a single heap sample to the log file.
  static void WriteSample();

 private:
80 81
  HeapProfiler();
  ~HeapProfiler();
82 83 84 85 86 87
  HeapSnapshot* TakeSnapshotImpl(const char* name,
                                 int type,
                                 v8::ActivityControl* control);
  HeapSnapshot* TakeSnapshotImpl(String* name,
                                 int type,
                                 v8::ActivityControl* control);
88 89 90 91 92

  HeapSnapshotsCollection* snapshots_;
  unsigned next_snapshot_uid_;

  static HeapProfiler* singleton_;
93
#endif  // ENABLE_LOGGING_AND_PROFILING
94 95 96
};


97 98
#ifdef ENABLE_LOGGING_AND_PROFILING

99
// JSObjectsCluster describes a group of JS objects that are
100
// considered equivalent in terms of a particular profile.
101 102
class JSObjectsCluster BASE_EMBEDDED {
 public:
103
  // These special cases are used in retainer profile.
104 105
  enum SpecialCase {
    ROOTS = 1,
106
    GLOBAL_PROPERTY = 2,
107 108
    CODE = 3,
    SELF = 100  // This case is used in ClustersCoarser only.
109 110 111 112 113 114 115 116 117 118
  };

  JSObjectsCluster() : constructor_(NULL), instance_(NULL) {}
  explicit JSObjectsCluster(String* constructor)
      : constructor_(constructor), instance_(NULL) {}
  explicit JSObjectsCluster(SpecialCase special)
      : constructor_(FromSpecialCase(special)), instance_(NULL) {}
  JSObjectsCluster(String* constructor, Object* instance)
      : constructor_(constructor), instance_(instance) {}

119 120
  static int CompareConstructors(const JSObjectsCluster& a,
                                 const JSObjectsCluster& b) {
121 122 123 124 125 126 127 128 129 130 131
    // Strings are unique, so it is sufficient to compare their pointers.
    return a.constructor_ == b.constructor_ ? 0
        : (a.constructor_ < b.constructor_ ? -1 : 1);
  }
  static int Compare(const JSObjectsCluster& a, const JSObjectsCluster& b) {
    // Strings are unique, so it is sufficient to compare their pointers.
    const int cons_cmp = CompareConstructors(a, b);
    return cons_cmp == 0 ?
        (a.instance_ == b.instance_ ? 0 : (a.instance_ < b.instance_ ? -1 : 1))
        : cons_cmp;
  }
132 133 134
  static int Compare(const JSObjectsCluster* a, const JSObjectsCluster* b) {
    return Compare(*a, *b);
  }
135 136 137

  bool is_null() const { return constructor_ == NULL; }
  bool can_be_coarsed() const { return instance_ != NULL; }
138
  String* constructor() const { return constructor_; }
139
  Object* instance() const { return instance_; }
140

141
  const char* GetSpecialCaseName() const;
142 143 144 145 146 147 148 149 150 151 152
  void Print(StringStream* accumulator) const;
  // Allows null clusters to be printed.
  void DebugPrint(StringStream* accumulator) const;

 private:
  static String* FromSpecialCase(SpecialCase special) {
    // We use symbols that are illegal JS identifiers to identify special cases.
    // Their actual value is irrelevant for us.
    switch (special) {
      case ROOTS: return Heap::result_symbol();
      case GLOBAL_PROPERTY: return Heap::code_symbol();
153
      case CODE: return Heap::arguments_shadow_symbol();
154
      case SELF: return Heap::catch_var_symbol();
155 156 157 158 159 160 161 162 163 164 165
      default:
        UNREACHABLE();
        return NULL;
    }
  }

  String* constructor_;
  Object* instance_;
};


166 167 168 169 170 171 172 173 174
struct JSObjectsClusterTreeConfig {
  typedef JSObjectsCluster Key;
  typedef NumberAndSizeInfo Value;
  static const Key kNoKey;
  static const Value kNoValue;
  static int Compare(const Key& a, const Key& b) {
    return Key::Compare(a, b);
  }
};
175 176
typedef ZoneSplayTree<JSObjectsClusterTreeConfig> JSObjectsClusterTree;

177 178 179 180 181 182 183 184 185 186 187

// ConstructorHeapProfile is responsible for gathering and logging
// "constructor profile" of JS objects allocated on heap.
// It is run during garbage collection cycle, thus it doesn't need
// to use handles.
class ConstructorHeapProfile BASE_EMBEDDED {
 public:
  ConstructorHeapProfile();
  virtual ~ConstructorHeapProfile() {}
  void CollectStats(HeapObject* obj);
  void PrintStats();
188 189 190

  template<class Callback>
  void ForEach(Callback* callback) { js_objects_info_tree_.ForEach(callback); }
191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209
  // Used by ZoneSplayTree::ForEach. Made virtual to allow overriding in tests.
  virtual void Call(const JSObjectsCluster& cluster,
                    const NumberAndSizeInfo& number_and_size);

 private:
  ZoneScope zscope_;
  JSObjectsClusterTree js_objects_info_tree_;
};


// JSObjectsRetainerTree is used to represent retainer graphs using
// adjacency list form:
//
//   Cluster -> (Cluster -> NumberAndSizeInfo)
//
// Subordinate splay trees are stored by pointer. They are zone-allocated,
// so it isn't needed to manage their lifetime.
//
struct JSObjectsRetainerTreeConfig {
210 211 212 213 214 215 216 217
  typedef JSObjectsCluster Key;
  typedef JSObjectsClusterTree* Value;
  static const Key kNoKey;
  static const Value kNoValue;
  static int Compare(const Key& a, const Key& b) {
    return Key::Compare(a, b);
  }
};
218
typedef ZoneSplayTree<JSObjectsRetainerTreeConfig> JSObjectsRetainerTree;
219 220 221 222 223 224 225


class ClustersCoarser BASE_EMBEDDED {
 public:
  ClustersCoarser();

  // Processes a given retainer graph.
226
  void Process(JSObjectsRetainerTree* tree);
227 228 229 230 231 232 233 234

  // Returns an equivalent cluster (can be the cluster itself).
  // If the given cluster doesn't have an equivalent, returns null cluster.
  JSObjectsCluster GetCoarseEquivalent(const JSObjectsCluster& cluster);
  // Returns whether a cluster can be substitued with an equivalent and thus,
  // skipped in some cases.
  bool HasAnEquivalent(const JSObjectsCluster& cluster);

235
  // Used by JSObjectsRetainerTree::ForEach.
236
  void Call(const JSObjectsCluster& cluster, JSObjectsClusterTree* tree);
237 238
  void Call(const JSObjectsCluster& cluster,
            const NumberAndSizeInfo& number_and_size);
239 240 241 242 243 244 245 246 247

 private:
  // Stores a list of back references for a cluster.
  struct ClusterBackRefs {
    explicit ClusterBackRefs(const JSObjectsCluster& cluster_);
    ClusterBackRefs(const ClusterBackRefs& src);
    ClusterBackRefs& operator=(const ClusterBackRefs& src);

    static int Compare(const ClusterBackRefs& a, const ClusterBackRefs& b);
248 249
    void SortRefs() { refs.Sort(JSObjectsCluster::Compare); }
    static void SortRefsIterator(ClusterBackRefs* ref) { ref->SortRefs(); }
250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267

    JSObjectsCluster cluster;
    ZoneList<JSObjectsCluster> refs;
  };
  typedef ZoneList<ClusterBackRefs> SimilarityList;

  // A tree for storing a list of equivalents for a cluster.
  struct ClusterEqualityConfig {
    typedef JSObjectsCluster Key;
    typedef JSObjectsCluster Value;
    static const Key kNoKey;
    static const Value kNoValue;
    static int Compare(const Key& a, const Key& b) {
      return Key::Compare(a, b);
    }
  };
  typedef ZoneSplayTree<ClusterEqualityConfig> EqualityTree;

268 269
  static int ClusterBackRefsCmp(const ClusterBackRefs* a,
                                const ClusterBackRefs* b) {
270 271
    return ClusterBackRefs::Compare(*a, *b);
  }
272
  int DoProcess(JSObjectsRetainerTree* tree);
273 274
  int FillEqualityTree();

275 276
  static const int kInitialBackrefsListCapacity = 2;
  static const int kInitialSimilarityListCapacity = 2000;
277 278
  // Number of passes for finding equivalents. Limits the length of paths
  // that can be considered equivalent.
279
  static const int kMaxPassesCount = 10;
280 281

  ZoneScope zscope_;
282 283 284
  SimilarityList sim_list_;
  EqualityTree eq_tree_;
  ClusterBackRefs* current_pair_;
285
  JSObjectsRetainerTree* current_set_;
286
  const JSObjectsCluster* self_;
287 288 289 290 291 292 293
};


// RetainerHeapProfile is responsible for gathering and logging
// "retainer profile" of JS objects allocated on heap.
// It is run during garbage collection cycle, thus it doesn't need
// to use handles.
294 295
class RetainerTreeAggregator;

296 297 298 299 300
class RetainerHeapProfile BASE_EMBEDDED {
 public:
  class Printer {
   public:
    virtual ~Printer() {}
301 302
    virtual void PrintRetainers(const JSObjectsCluster& cluster,
                                const StringStream& retainers) = 0;
303 304 305
  };

  RetainerHeapProfile();
306 307 308 309 310 311
  ~RetainerHeapProfile();

  RetainerTreeAggregator* aggregator() { return aggregator_; }
  ClustersCoarser* coarser() { return &coarser_; }
  JSObjectsRetainerTree* retainers_tree() { return &retainers_tree_; }

312
  void CollectStats(HeapObject* obj);
313
  void CoarseAndAggregate();
314 315
  void PrintStats();
  void DebugPrintStats(Printer* printer);
316
  void StoreReference(const JSObjectsCluster& cluster, HeapObject* ref);
317 318 319

 private:
  ZoneScope zscope_;
320
  JSObjectsRetainerTree retainers_tree_;
321
  ClustersCoarser coarser_;
322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359
  RetainerTreeAggregator* aggregator_;
};


class AggregatedHeapSnapshot {
 public:
  AggregatedHeapSnapshot();
  ~AggregatedHeapSnapshot();

  HistogramInfo* info() { return info_; }
  ConstructorHeapProfile* js_cons_profile() { return &js_cons_profile_; }
  RetainerHeapProfile* js_retainer_profile() { return &js_retainer_profile_; }

 private:
  HistogramInfo* info_;
  ConstructorHeapProfile js_cons_profile_;
  RetainerHeapProfile js_retainer_profile_;
};


class HeapEntriesMap;
class HeapSnapshot;

class AggregatedHeapSnapshotGenerator {
 public:
  explicit AggregatedHeapSnapshotGenerator(AggregatedHeapSnapshot* snapshot);
  void GenerateSnapshot();
  void FillHeapSnapshot(HeapSnapshot* snapshot);

  static const int kAllStringsType = LAST_TYPE + 1;

 private:
  void CalculateStringsStats();
  void CollectStats(HeapObject* obj);
  template<class Iterator>
  void IterateRetainers(HeapEntriesMap* entries_map);

  AggregatedHeapSnapshot* agg_snapshot_;
360 361 362
};


363 364 365
class ProducerHeapProfile : public AllStatic {
 public:
  static void Setup();
366 367 368 369
  static void RecordJSObjectAllocation(Object* obj) {
    if (FLAG_log_producers) DoRecordJSObjectAllocation(obj);
  }

370
 private:
371
  static void DoRecordJSObjectAllocation(Object* obj);
372 373 374
  static bool can_log_;
};

375 376 377 378 379
#endif  // ENABLE_LOGGING_AND_PROFILING

} }  // namespace v8::internal

#endif  // V8_HEAP_PROFILER_H_