v8  5.5.372(node7.10.1)
V8 is Google's open source JavaScript engine
v8-profiler.h
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1 // Copyright 2010 the V8 project 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 #ifndef V8_V8_PROFILER_H_
6 #define V8_V8_PROFILER_H_
7 
8 #include <vector>
9 #include "v8.h" // NOLINT(build/include)
10 
11 /**
12  * Profiler support for the V8 JavaScript engine.
13  */
14 namespace v8 {
15 
16 class HeapGraphNode;
18 
19 typedef uint32_t SnapshotObjectId;
20 
21 
23  int script_id;
25 };
26 
27 } // namespace v8
28 
29 #ifdef V8_OS_WIN
30 template class V8_EXPORT std::vector<v8::CpuProfileDeoptFrame>;
31 #endif
32 
33 namespace v8 {
34 
36  /** A pointer to a static string owned by v8. */
37  const char* deopt_reason;
39 };
40 
41 } // namespace v8
42 
43 #ifdef V8_OS_WIN
44 template class V8_EXPORT std::vector<v8::CpuProfileDeoptInfo>;
45 #endif
46 
47 namespace v8 {
48 
49 /**
50  * TracingCpuProfiler monitors tracing being enabled/disabled
51  * and emits CpuProfile trace events once v8.cpu_profile2 tracing category
52  * is enabled. It has no overhead unless the category is enabled.
53  */
55  public:
57  virtual ~TracingCpuProfiler() = default;
58 
59  protected:
60  TracingCpuProfiler() = default;
61 };
62 
63 // TickSample captures the information collected for each sample.
64 struct TickSample {
65  // Internal profiling (with --prof + tools/$OS-tick-processor) wants to
66  // include the runtime function we're calling. Externally exposed tick
67  // samples don't care.
69 
71  : state(OTHER),
72  pc(nullptr),
74  frames_count(0),
75  has_external_callback(false),
76  update_stats(true) {}
77 
78  /**
79  * Initialize a tick sample from the isolate.
80  * \param isolate The isolate.
81  * \param state Execution state.
82  * \param record_c_entry_frame Include or skip the runtime function.
83  * \param update_stats Whether update the sample to the aggregated stats.
84  * \param use_simulator_reg_state When set to true and V8 is running under a
85  * simulator, the method will use the simulator
86  * register state rather than the one provided
87  * with |state| argument. Otherwise the method
88  * will use provided register |state| as is.
89  */
90  void Init(Isolate* isolate, const v8::RegisterState& state,
91  RecordCEntryFrame record_c_entry_frame, bool update_stats,
92  bool use_simulator_reg_state = true);
93  /**
94  * Get a call stack sample from the isolate.
95  * \param isolate The isolate.
96  * \param state Register state.
97  * \param record_c_entry_frame Include or skip the runtime function.
98  * \param frames Caller allocated buffer to store stack frames.
99  * \param frames_limit Maximum number of frames to capture. The buffer must
100  * be large enough to hold the number of frames.
101  * \param sample_info The sample info is filled up by the function
102  * provides number of actual captured stack frames and
103  * the current VM state.
104  * \param use_simulator_reg_state When set to true and V8 is running under a
105  * simulator, the method will use the simulator
106  * register state rather than the one provided
107  * with |state| argument. Otherwise the method
108  * will use provided register |state| as is.
109  * \note GetStackSample is thread and signal safe and should only be called
110  * when the JS thread is paused or interrupted.
111  * Otherwise the behavior is undefined.
112  */
113  static bool GetStackSample(Isolate* isolate, v8::RegisterState* state,
114  RecordCEntryFrame record_c_entry_frame,
115  void** frames, size_t frames_limit,
116  v8::SampleInfo* sample_info,
117  bool use_simulator_reg_state = true);
118  StateTag state; // The state of the VM.
119  void* pc; // Instruction pointer.
120  union {
121  void* tos; // Top stack value (*sp).
122  void* external_callback_entry;
123  };
124  static const unsigned kMaxFramesCountLog2 = 8;
125  static const unsigned kMaxFramesCount = (1 << kMaxFramesCountLog2) - 1;
126  void* stack[kMaxFramesCount]; // Call stack.
127  unsigned frames_count : kMaxFramesCountLog2; // Number of captured frames.
129  bool update_stats : 1; // Whether the sample should update aggregated stats.
130 };
131 
132 /**
133  * CpuProfileNode represents a node in a call graph.
134  */
136  public:
137  struct LineTick {
138  /** The 1-based number of the source line where the function originates. */
139  int line;
140 
141  /** The count of samples associated with the source line. */
142  unsigned int hit_count;
143  };
144 
145  /** Returns function name (empty string for anonymous functions.) */
146  Local<String> GetFunctionName() const;
147 
148  /**
149  * Returns function name (empty string for anonymous functions.)
150  * The string ownership is *not* passed to the caller. It stays valid until
151  * profile is deleted. The function is thread safe.
152  */
153  const char* GetFunctionNameStr() const;
154 
155  /** Returns id of the script where function is located. */
156  int GetScriptId() const;
157 
158  /** Returns resource name for script from where the function originates. */
159  Local<String> GetScriptResourceName() const;
160 
161  /**
162  * Returns resource name for script from where the function originates.
163  * The string ownership is *not* passed to the caller. It stays valid until
164  * profile is deleted. The function is thread safe.
165  */
166  const char* GetScriptResourceNameStr() const;
167 
168  /**
169  * Returns the number, 1-based, of the line where the function originates.
170  * kNoLineNumberInfo if no line number information is available.
171  */
172  int GetLineNumber() const;
173 
174  /**
175  * Returns 1-based number of the column where the function originates.
176  * kNoColumnNumberInfo if no column number information is available.
177  */
178  int GetColumnNumber() const;
179 
180  /**
181  * Returns the number of the function's source lines that collect the samples.
182  */
183  unsigned int GetHitLineCount() const;
184 
185  /** Returns the set of source lines that collect the samples.
186  * The caller allocates buffer and responsible for releasing it.
187  * True if all available entries are copied, otherwise false.
188  * The function copies nothing if buffer is not large enough.
189  */
190  bool GetLineTicks(LineTick* entries, unsigned int length) const;
191 
192  /** Returns bailout reason for the function
193  * if the optimization was disabled for it.
194  */
195  const char* GetBailoutReason() const;
196 
197  /**
198  * Returns the count of samples where the function was currently executing.
199  */
200  unsigned GetHitCount() const;
201 
202  /** Returns function entry UID. */
204  "Use GetScriptId, GetLineNumber, and GetColumnNumber instead.",
205  unsigned GetCallUid() const);
206 
207  /** Returns id of the node. The id is unique within the tree */
208  unsigned GetNodeId() const;
209 
210  /** Returns child nodes count of the node. */
211  int GetChildrenCount() const;
212 
213  /** Retrieves a child node by index. */
214  const CpuProfileNode* GetChild(int index) const;
215 
216  /** Retrieves deopt infos for the node. */
217  const std::vector<CpuProfileDeoptInfo>& GetDeoptInfos() const;
218 
221 };
222 
223 
224 /**
225  * CpuProfile contains a CPU profile in a form of top-down call tree
226  * (from main() down to functions that do all the work).
227  */
229  public:
230  /** Returns CPU profile title. */
231  Local<String> GetTitle() const;
232 
233  /** Returns the root node of the top down call tree. */
234  const CpuProfileNode* GetTopDownRoot() const;
235 
236  /**
237  * Returns number of samples recorded. The samples are not recorded unless
238  * |record_samples| parameter of CpuProfiler::StartCpuProfiling is true.
239  */
240  int GetSamplesCount() const;
241 
242  /**
243  * Returns profile node corresponding to the top frame the sample at
244  * the given index.
245  */
246  const CpuProfileNode* GetSample(int index) const;
247 
248  /**
249  * Returns the timestamp of the sample. The timestamp is the number of
250  * microseconds since some unspecified starting point.
251  * The point is equal to the starting point used by GetStartTime.
252  */
253  int64_t GetSampleTimestamp(int index) const;
254 
255  /**
256  * Returns time when the profile recording was started (in microseconds)
257  * since some unspecified starting point.
258  */
259  int64_t GetStartTime() const;
260 
261  /**
262  * Returns time when the profile recording was stopped (in microseconds)
263  * since some unspecified starting point.
264  * The point is equal to the starting point used by GetStartTime.
265  */
266  int64_t GetEndTime() const;
267 
268  /**
269  * Deletes the profile and removes it from CpuProfiler's list.
270  * All pointers to nodes previously returned become invalid.
271  */
272  void Delete();
273 };
274 
275 /**
276  * Interface for controlling CPU profiling. Instance of the
277  * profiler can be created using v8::CpuProfiler::New method.
278  */
280  public:
281  /**
282  * Creates a new CPU profiler for the |isolate|. The isolate must be
283  * initialized. The profiler object must be disposed after use by calling
284  * |Dispose| method.
285  */
286  static CpuProfiler* New(Isolate* isolate);
287 
288  /**
289  * Disposes the CPU profiler object.
290  */
291  void Dispose();
292 
293  /**
294  * Changes default CPU profiler sampling interval to the specified number
295  * of microseconds. Default interval is 1000us. This method must be called
296  * when there are no profiles being recorded.
297  */
298  void SetSamplingInterval(int us);
299 
300  /**
301  * Starts collecting CPU profile. Title may be an empty string. It
302  * is allowed to have several profiles being collected at
303  * once. Attempts to start collecting several profiles with the same
304  * title are silently ignored. While collecting a profile, functions
305  * from all security contexts are included in it. The token-based
306  * filtering is only performed when querying for a profile.
307  *
308  * |record_samples| parameter controls whether individual samples should
309  * be recorded in addition to the aggregated tree.
310  */
311  void StartProfiling(Local<String> title, bool record_samples = false);
312 
313  /**
314  * Stops collecting CPU profile with a given title and returns it.
315  * If the title given is empty, finishes the last profile started.
316  */
317  CpuProfile* StopProfiling(Local<String> title);
318 
319  /**
320  * Force collection of a sample. Must be called on the VM thread.
321  * Recording the forced sample does not contribute to the aggregated
322  * profile statistics.
323  */
324  void CollectSample();
325 
326  /**
327  * Tells the profiler whether the embedder is idle.
328  */
329  void SetIdle(bool is_idle);
330 
331  private:
332  CpuProfiler();
333  ~CpuProfiler();
334  CpuProfiler(const CpuProfiler&);
335  CpuProfiler& operator=(const CpuProfiler&);
336 };
337 
338 
339 /**
340  * HeapSnapshotEdge represents a directed connection between heap
341  * graph nodes: from retainers to retained nodes.
342  */
344  public:
345  enum Type {
346  kContextVariable = 0, // A variable from a function context.
347  kElement = 1, // An element of an array.
348  kProperty = 2, // A named object property.
349  kInternal = 3, // A link that can't be accessed from JS,
350  // thus, its name isn't a real property name
351  // (e.g. parts of a ConsString).
352  kHidden = 4, // A link that is needed for proper sizes
353  // calculation, but may be hidden from user.
354  kShortcut = 5, // A link that must not be followed during
355  // sizes calculation.
356  kWeak = 6 // A weak reference (ignored by the GC).
357  };
358 
359  /** Returns edge type (see HeapGraphEdge::Type). */
360  Type GetType() const;
361 
362  /**
363  * Returns edge name. This can be a variable name, an element index, or
364  * a property name.
365  */
366  Local<Value> GetName() const;
367 
368  /** Returns origin node. */
369  const HeapGraphNode* GetFromNode() const;
370 
371  /** Returns destination node. */
372  const HeapGraphNode* GetToNode() const;
373 };
374 
375 
376 /**
377  * HeapGraphNode represents a node in a heap graph.
378  */
380  public:
381  enum Type {
382  kHidden = 0, // Hidden node, may be filtered when shown to user.
383  kArray = 1, // An array of elements.
384  kString = 2, // A string.
385  kObject = 3, // A JS object (except for arrays and strings).
386  kCode = 4, // Compiled code.
387  kClosure = 5, // Function closure.
388  kRegExp = 6, // RegExp.
389  kHeapNumber = 7, // Number stored in the heap.
390  kNative = 8, // Native object (not from V8 heap).
391  kSynthetic = 9, // Synthetic object, usualy used for grouping
392  // snapshot items together.
393  kConsString = 10, // Concatenated string. A pair of pointers to strings.
394  kSlicedString = 11, // Sliced string. A fragment of another string.
395  kSymbol = 12, // A Symbol (ES6).
396  kSimdValue = 13 // A SIMD value stored in the heap (Proposed ES7).
397  };
398 
399  /** Returns node type (see HeapGraphNode::Type). */
400  Type GetType() const;
401 
402  /**
403  * Returns node name. Depending on node's type this can be the name
404  * of the constructor (for objects), the name of the function (for
405  * closures), string value, or an empty string (for compiled code).
406  */
407  Local<String> GetName() const;
408 
409  /**
410  * Returns node id. For the same heap object, the id remains the same
411  * across all snapshots.
412  */
413  SnapshotObjectId GetId() const;
414 
415  /** Returns node's own size, in bytes. */
416  size_t GetShallowSize() const;
417 
418  /** Returns child nodes count of the node. */
419  int GetChildrenCount() const;
420 
421  /** Retrieves a child by index. */
422  const HeapGraphEdge* GetChild(int index) const;
423 };
424 
425 
426 /**
427  * An interface for exporting data from V8, using "push" model.
428  */
429 class V8_EXPORT OutputStream { // NOLINT
430  public:
431  enum WriteResult {
433  kAbort = 1
434  };
435  virtual ~OutputStream() {}
436  /** Notify about the end of stream. */
437  virtual void EndOfStream() = 0;
438  /** Get preferred output chunk size. Called only once. */
439  virtual int GetChunkSize() { return 1024; }
440  /**
441  * Writes the next chunk of snapshot data into the stream. Writing
442  * can be stopped by returning kAbort as function result. EndOfStream
443  * will not be called in case writing was aborted.
444  */
445  virtual WriteResult WriteAsciiChunk(char* data, int size) = 0;
446  /**
447  * Writes the next chunk of heap stats data into the stream. Writing
448  * can be stopped by returning kAbort as function result. EndOfStream
449  * will not be called in case writing was aborted.
450  */
451  virtual WriteResult WriteHeapStatsChunk(HeapStatsUpdate* data, int count) {
452  return kAbort;
453  }
454 };
455 
456 
457 /**
458  * HeapSnapshots record the state of the JS heap at some moment.
459  */
461  public:
463  kJSON = 0 // See format description near 'Serialize' method.
464  };
465 
466  /** Returns the root node of the heap graph. */
467  const HeapGraphNode* GetRoot() const;
468 
469  /** Returns a node by its id. */
470  const HeapGraphNode* GetNodeById(SnapshotObjectId id) const;
471 
472  /** Returns total nodes count in the snapshot. */
473  int GetNodesCount() const;
474 
475  /** Returns a node by index. */
476  const HeapGraphNode* GetNode(int index) const;
477 
478  /** Returns a max seen JS object Id. */
480 
481  /**
482  * Deletes the snapshot and removes it from HeapProfiler's list.
483  * All pointers to nodes, edges and paths previously returned become
484  * invalid.
485  */
486  void Delete();
487 
488  /**
489  * Prepare a serialized representation of the snapshot. The result
490  * is written into the stream provided in chunks of specified size.
491  * The total length of the serialized snapshot is unknown in
492  * advance, it can be roughly equal to JS heap size (that means,
493  * it can be really big - tens of megabytes).
494  *
495  * For the JSON format, heap contents are represented as an object
496  * with the following structure:
497  *
498  * {
499  * snapshot: {
500  * title: "...",
501  * uid: nnn,
502  * meta: { meta-info },
503  * node_count: nnn,
504  * edge_count: nnn
505  * },
506  * nodes: [nodes array],
507  * edges: [edges array],
508  * strings: [strings array]
509  * }
510  *
511  * Nodes reference strings, other nodes, and edges by their indexes
512  * in corresponding arrays.
513  */
514  void Serialize(OutputStream* stream,
515  SerializationFormat format = kJSON) const;
516 };
517 
518 
519 /**
520  * An interface for reporting progress and controlling long-running
521  * activities.
522  */
523 class V8_EXPORT ActivityControl { // NOLINT
524  public:
527  kAbort = 1
528  };
529  virtual ~ActivityControl() {}
530  /**
531  * Notify about current progress. The activity can be stopped by
532  * returning kAbort as the callback result.
533  */
534  virtual ControlOption ReportProgressValue(int done, int total) = 0;
535 };
536 
537 
538 /**
539  * AllocationProfile is a sampled profile of allocations done by the program.
540  * This is structured as a call-graph.
541  */
543  public:
544  struct Allocation {
545  /**
546  * Size of the sampled allocation object.
547  */
549 
550  /**
551  * The number of objects of such size that were sampled.
552  */
553  unsigned int count;
554  };
555 
556  /**
557  * Represents a node in the call-graph.
558  */
559  struct Node {
560  /**
561  * Name of the function. May be empty for anonymous functions or if the
562  * script corresponding to this function has been unloaded.
563  */
564  Local<String> name;
565 
566  /**
567  * Name of the script containing the function. May be empty if the script
568  * name is not available, or if the script has been unloaded.
569  */
571 
572  /**
573  * id of the script where the function is located. May be equal to
574  * v8::UnboundScript::kNoScriptId in cases where the script doesn't exist.
575  */
577 
578  /**
579  * Start position of the function in the script.
580  */
582 
583  /**
584  * 1-indexed line number where the function starts. May be
585  * kNoLineNumberInfo if no line number information is available.
586  */
588 
589  /**
590  * 1-indexed column number where the function starts. May be
591  * kNoColumnNumberInfo if no line number information is available.
592  */
594 
595  /**
596  * List of callees called from this node for which we have sampled
597  * allocations. The lifetime of the children is scoped to the containing
598  * AllocationProfile.
599  */
600  std::vector<Node*> children;
601 
602  /**
603  * List of self allocations done by this node in the call-graph.
604  */
605  std::vector<Allocation> allocations;
606  };
607 
608  /**
609  * Returns the root node of the call-graph. The root node corresponds to an
610  * empty JS call-stack. The lifetime of the returned Node* is scoped to the
611  * containing AllocationProfile.
612  */
613  virtual Node* GetRootNode() = 0;
614 
615  virtual ~AllocationProfile() {}
616 
619 };
620 
621 
622 /**
623  * Interface for controlling heap profiling. Instance of the
624  * profiler can be retrieved using v8::Isolate::GetHeapProfiler.
625  */
627  public:
631  };
632 
633  /**
634  * Callback function invoked for obtaining RetainedObjectInfo for
635  * the given JavaScript wrapper object. It is prohibited to enter V8
636  * while the callback is running: only getters on the handle and
637  * GetPointerFromInternalField on the objects are allowed.
638  */
639  typedef RetainedObjectInfo* (*WrapperInfoCallback)(uint16_t class_id,
640  Local<Value> wrapper);
641 
642  /** Returns the number of snapshots taken. */
643  int GetSnapshotCount();
644 
645  /** Returns a snapshot by index. */
646  const HeapSnapshot* GetHeapSnapshot(int index);
647 
648  /**
649  * Returns SnapshotObjectId for a heap object referenced by |value| if
650  * it has been seen by the heap profiler, kUnknownObjectId otherwise.
651  */
652  SnapshotObjectId GetObjectId(Local<Value> value);
653 
654  /**
655  * Returns heap object with given SnapshotObjectId if the object is alive,
656  * otherwise empty handle is returned.
657  */
659 
660  /**
661  * Clears internal map from SnapshotObjectId to heap object. The new objects
662  * will not be added into it unless a heap snapshot is taken or heap object
663  * tracking is kicked off.
664  */
665  void ClearObjectIds();
666 
667  /**
668  * A constant for invalid SnapshotObjectId. GetSnapshotObjectId will return
669  * it in case heap profiler cannot find id for the object passed as
670  * parameter. HeapSnapshot::GetNodeById will always return NULL for such id.
671  */
673 
674  /**
675  * Callback interface for retrieving user friendly names of global objects.
676  */
678  public:
679  /**
680  * Returns name to be used in the heap snapshot for given node. Returned
681  * string must stay alive until snapshot collection is completed.
682  */
683  virtual const char* GetName(Local<Object> object) = 0;
684 
685  protected:
686  virtual ~ObjectNameResolver() {}
687  };
688 
689  /**
690  * Takes a heap snapshot and returns it.
691  */
693  ActivityControl* control = NULL,
694  ObjectNameResolver* global_object_name_resolver = NULL);
695 
696  /**
697  * Starts tracking of heap objects population statistics. After calling
698  * this method, all heap objects relocations done by the garbage collector
699  * are being registered.
700  *
701  * |track_allocations| parameter controls whether stack trace of each
702  * allocation in the heap will be recorded and reported as part of
703  * HeapSnapshot.
704  */
705  void StartTrackingHeapObjects(bool track_allocations = false);
706 
707  /**
708  * Adds a new time interval entry to the aggregated statistics array. The
709  * time interval entry contains information on the current heap objects
710  * population size. The method also updates aggregated statistics and
711  * reports updates for all previous time intervals via the OutputStream
712  * object. Updates on each time interval are provided as a stream of the
713  * HeapStatsUpdate structure instances.
714  * If |timestamp_us| is supplied, timestamp of the new entry will be written
715  * into it. The return value of the function is the last seen heap object Id.
716  *
717  * StartTrackingHeapObjects must be called before the first call to this
718  * method.
719  */
721  int64_t* timestamp_us = NULL);
722 
723  /**
724  * Stops tracking of heap objects population statistics, cleans up all
725  * collected data. StartHeapObjectsTracking must be called again prior to
726  * calling GetHeapStats next time.
727  */
729 
730  /**
731  * Starts gathering a sampling heap profile. A sampling heap profile is
732  * similar to tcmalloc's heap profiler and Go's mprof. It samples object
733  * allocations and builds an online 'sampling' heap profile. At any point in
734  * time, this profile is expected to be a representative sample of objects
735  * currently live in the system. Each sampled allocation includes the stack
736  * trace at the time of allocation, which makes this really useful for memory
737  * leak detection.
738  *
739  * This mechanism is intended to be cheap enough that it can be used in
740  * production with minimal performance overhead.
741  *
742  * Allocations are sampled using a randomized Poisson process. On average, one
743  * allocation will be sampled every |sample_interval| bytes allocated. The
744  * |stack_depth| parameter controls the maximum number of stack frames to be
745  * captured on each allocation.
746  *
747  * NOTE: This is a proof-of-concept at this point. Right now we only sample
748  * newspace allocations. Support for paged space allocation (e.g. pre-tenured
749  * objects, large objects, code objects, etc.) and native allocations
750  * doesn't exist yet, but is anticipated in the future.
751  *
752  * Objects allocated before the sampling is started will not be included in
753  * the profile.
754  *
755  * Returns false if a sampling heap profiler is already running.
756  */
757  bool StartSamplingHeapProfiler(uint64_t sample_interval = 512 * 1024,
758  int stack_depth = 16,
760 
761  /**
762  * Stops the sampling heap profile and discards the current profile.
763  */
765 
766  /**
767  * Returns the sampled profile of allocations allocated (and still live) since
768  * StartSamplingHeapProfiler was called. The ownership of the pointer is
769  * transfered to the caller. Returns nullptr if sampling heap profiler is not
770  * active.
771  */
773 
774  /**
775  * Deletes all snapshots taken. All previously returned pointers to
776  * snapshots and their contents become invalid after this call.
777  */
778  void DeleteAllHeapSnapshots();
779 
780  /** Binds a callback to embedder's class ID. */
782  uint16_t class_id,
783  WrapperInfoCallback callback);
784 
785  /**
786  * Default value of persistent handle class ID. Must not be used to
787  * define a class. Can be used to reset a class of a persistent
788  * handle.
789  */
790  static const uint16_t kPersistentHandleNoClassId = 0;
791 
792  /** Returns memory used for profiler internal data and snapshots. */
794 
795  /**
796  * Sets a RetainedObjectInfo for an object group (see V8::SetObjectGroupId).
797  */
799 
800  private:
801  HeapProfiler();
802  ~HeapProfiler();
803  HeapProfiler(const HeapProfiler&);
804  HeapProfiler& operator=(const HeapProfiler&);
805 };
806 
807 /**
808  * Interface for providing information about embedder's objects
809  * held by global handles. This information is reported in two ways:
810  *
811  * 1. When calling AddObjectGroup, an embedder may pass
812  * RetainedObjectInfo instance describing the group. To collect
813  * this information while taking a heap snapshot, V8 calls GC
814  * prologue and epilogue callbacks.
815  *
816  * 2. When a heap snapshot is collected, V8 additionally
817  * requests RetainedObjectInfos for persistent handles that
818  * were not previously reported via AddObjectGroup.
819  *
820  * Thus, if an embedder wants to provide information about native
821  * objects for heap snapshots, it can do it in a GC prologue
822  * handler, and / or by assigning wrapper class ids in the following way:
823  *
824  * 1. Bind a callback to class id by calling SetWrapperClassInfoProvider.
825  * 2. Call SetWrapperClassId on certain persistent handles.
826  *
827  * V8 takes ownership of RetainedObjectInfo instances passed to it and
828  * keeps them alive only during snapshot collection. Afterwards, they
829  * are freed by calling the Dispose class function.
830  */
831 class V8_EXPORT RetainedObjectInfo { // NOLINT
832  public:
833  /** Called by V8 when it no longer needs an instance. */
834  virtual void Dispose() = 0;
835 
836  /** Returns whether two instances are equivalent. */
837  virtual bool IsEquivalent(RetainedObjectInfo* other) = 0;
838 
839  /**
840  * Returns hash value for the instance. Equivalent instances
841  * must have the same hash value.
842  */
843  virtual intptr_t GetHash() = 0;
844 
845  /**
846  * Returns human-readable label. It must be a null-terminated UTF-8
847  * encoded string. V8 copies its contents during a call to GetLabel.
848  */
849  virtual const char* GetLabel() = 0;
850 
851  /**
852  * Returns human-readable group label. It must be a null-terminated UTF-8
853  * encoded string. V8 copies its contents during a call to GetGroupLabel.
854  * Heap snapshot generator will collect all the group names, create
855  * top level entries with these names and attach the objects to the
856  * corresponding top level group objects. There is a default
857  * implementation which is required because embedders don't have their
858  * own implementation yet.
859  */
860  virtual const char* GetGroupLabel() { return GetLabel(); }
861 
862  /**
863  * Returns element count in case if a global handle retains
864  * a subgraph by holding one of its nodes.
865  */
866  virtual intptr_t GetElementCount() { return -1; }
867 
868  /** Returns embedder's object size in bytes. */
869  virtual intptr_t GetSizeInBytes() { return -1; }
870 
871  protected:
873  virtual ~RetainedObjectInfo() {}
874 
875  private:
876  RetainedObjectInfo(const RetainedObjectInfo&);
877  RetainedObjectInfo& operator=(const RetainedObjectInfo&);
878 };
879 
880 
881 /**
882  * A struct for exporting HeapStats data from V8, using "push" model.
883  * See HeapProfiler::GetHeapStats.
884  */
886  HeapStatsUpdate(uint32_t index, uint32_t count, uint32_t size)
887  : index(index), count(count), size(size) { }
888  uint32_t index; // Index of the time interval that was changed.
889  uint32_t count; // New value of count field for the interval with this index.
890  uint32_t size; // New value of size field for the interval with this index.
891 };
892 
893 
894 } // namespace v8
895 
896 
897 #endif // V8_V8_PROFILER_H_
void DeleteAllHeapSnapshots()
Local< Value > GetName() const
const char * GetFunctionNameStr() const
const HeapGraphNode * GetFromNode() const
static bool GetStackSample(Isolate *isolate, v8::RegisterState *state, RecordCEntryFrame record_c_entry_frame, void **frames, size_t frames_limit, v8::SampleInfo *sample_info, bool use_simulator_reg_state=true)
void StopTrackingHeapObjects()
Local< String > GetScriptResourceName() const
int64_t GetSampleTimestamp(int index) const
void SetWrapperClassInfoProvider(uint16_t class_id, WrapperInfoCallback callback)
virtual intptr_t GetHash()=0
const HeapGraphNode * GetToNode() const
Definition: v8.h:1911
Local< String > GetTitle() const
virtual ~OutputStream()
Definition: v8-profiler.h:435
StateTag
Definition: v8.h:1670
Definition: v8.h:1670
SnapshotObjectId GetId() const
int64_t GetStartTime() const
TracingCpuProfiler()=default
std::vector< Node * > children
Definition: v8-profiler.h:600
static const int kNoColumnInfo
Definition: v8.h:1547
static const int kNoColumnNumberInfo
Definition: v8-profiler.h:618
CpuProfile * StopProfiling(Local< String > title)
unsigned GetNodeId() const
static std::unique_ptr< TracingCpuProfiler > Create(Isolate *)
SnapshotObjectId GetObjectId(Local< Value > value)
const HeapSnapshot * TakeHeapSnapshot(ActivityControl *control=NULL, ObjectNameResolver *global_object_name_resolver=NULL)
size_t GetShallowSize() const
static const int kNoLineNumberInfo
Definition: v8.h:1546
void SetSamplingInterval(int us)
const HeapGraphEdge * GetChild(int index) const
virtual ControlOption ReportProgressValue(int done, int total)=0
SnapshotObjectId GetHeapStats(OutputStream *stream, int64_t *timestamp_us=NULL)
StateTag state
Definition: v8-profiler.h:118
void StartProfiling(Local< String > title, bool record_samples=false)
#define V8_DEPRECATE_SOON(message, declarator)
Definition: v8config.h:351
int GetChildrenCount() const
virtual bool IsEquivalent(RetainedObjectInfo *other)=0
const HeapGraphNode * GetRoot() const
void * stack[kMaxFramesCount]
Definition: v8-profiler.h:126
static const int kNoColumnNumberInfo
Definition: v8-profiler.h:220
SnapshotObjectId GetMaxSnapshotJSObjectId() const
Definition: libplatform.h:11
virtual int GetChunkSize()
Definition: v8-profiler.h:439
static const uint16_t kPersistentHandleNoClassId
Definition: v8-profiler.h:790
virtual const char * GetLabel()=0
int64_t GetEndTime() const
HeapStatsUpdate(uint32_t index, uint32_t count, uint32_t size)
Definition: v8-profiler.h:886
Type GetType() const
std::vector< CpuProfileDeoptFrame > stack
Definition: v8-profiler.h:38
virtual WriteResult WriteHeapStatsChunk(HeapStatsUpdate *data, int count)
Definition: v8-profiler.h:451
const CpuProfileNode * GetChild(int index) const
virtual ~RetainedObjectInfo()
Definition: v8-profiler.h:873
void StopSamplingHeapProfiler()
const std::vector< CpuProfileDeoptInfo > & GetDeoptInfos() const
size_t GetProfilerMemorySize()
void CollectSample()
virtual ~ActivityControl()
Definition: v8-profiler.h:529
const CpuProfileNode * GetTopDownRoot() const
bool GetLineTicks(LineTick *entries, unsigned int length) const
static const int kNoLineNumberInfo
Definition: v8-profiler.h:617
const char * GetScriptResourceNameStr() const
void SetRetainedObjectInfo(UniqueId id, RetainedObjectInfo *info)
int GetScriptId() const
std::vector< Allocation > allocations
Definition: v8-profiler.h:605
int GetSamplesCount() const
virtual ~AllocationProfile()
Definition: v8-profiler.h:615
Local< Value > FindObjectById(SnapshotObjectId id)
void Serialize(OutputStream *stream, SerializationFormat format=kJSON) const
virtual WriteResult WriteAsciiChunk(char *data, int size)=0
const HeapGraphNode * GetNode(int index) const
virtual void Dispose()=0
const char * deopt_reason
Definition: v8-profiler.h:37
unsigned int GetHitLineCount() const
bool has_external_callback
Definition: v8-profiler.h:128
uint32_t SnapshotObjectId
Definition: v8-profiler.h:17
int GetNodesCount() const
int GetChildrenCount() const
const CpuProfileNode * GetSample(int index) const
Local< String > GetName() const
AllocationProfile * GetAllocationProfile()
int GetColumnNumber() const
virtual Node * GetRootNode()=0
bool StartSamplingHeapProfiler(uint64_t sample_interval=512 *1024, int stack_depth=16, SamplingFlags flags=kSamplingNoFlags)
unsigned frames_count
Definition: v8-profiler.h:127
virtual intptr_t GetElementCount()
Definition: v8-profiler.h:866
unsigned GetHitCount() const
static const unsigned kMaxFramesCountLog2
Definition: v8-profiler.h:124
void StartTrackingHeapObjects(bool track_allocations=false)
Type GetType() const
void Init(Isolate *isolate, const v8::RegisterState &state, RecordCEntryFrame record_c_entry_frame, bool update_stats, bool use_simulator_reg_state=true)
void SetIdle(bool is_idle)
virtual ~TracingCpuProfiler()=default
virtual void EndOfStream()=0
static const unsigned kMaxFramesCount
Definition: v8-profiler.h:125
static const int kNoLineNumberInfo
Definition: v8-profiler.h:219
virtual intptr_t GetSizeInBytes()
Definition: v8-profiler.h:869
Local< String > script_name
Definition: v8-profiler.h:570
virtual const char * GetName(Local< Object > object)=0
const HeapGraphNode * GetNodeById(SnapshotObjectId id) const
const HeapSnapshot * GetHeapSnapshot(int index)
#define V8_EXPORT
Definition: v8.h:61
const char * GetBailoutReason() const
static CpuProfiler * New(Isolate *isolate)
virtual const char * GetGroupLabel()
Definition: v8-profiler.h:860
Local< String > GetFunctionName() const
int GetLineNumber() const
static const SnapshotObjectId kUnknownObjectId
Definition: v8-profiler.h:672