v8-profiler.h

Go to the documentation of this file.

// Copyright 2010 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
 
#ifndef V8_V8_PROFILER_H_
#define V8_V8_PROFILER_H_
 
#include <unordered_set>
#include <vector>
#include "v8.h"  // NOLINT(build/include)
 
namespace v8 {
 
class HeapGraphNode;
struct HeapStatsUpdate;
 
typedef uint32_t SnapshotObjectId;
 
 
struct CpuProfileDeoptFrame {
  int script_id;
  size_t position;
};
 
}  // namespace v8
 
#ifdef V8_OS_WIN
template class V8_EXPORT std::vector<v8::CpuProfileDeoptFrame>;
#endif
 
namespace v8 {
 
struct V8_EXPORT CpuProfileDeoptInfo {
  const char* deopt_reason;
  std::vector<CpuProfileDeoptFrame> stack;
};
 
}  // namespace v8
 
#ifdef V8_OS_WIN
template class V8_EXPORT std::vector<v8::CpuProfileDeoptInfo>;
#endif
 
namespace v8 {
 
class V8_EXPORT TracingCpuProfiler {
 public:
  static std::unique_ptr<TracingCpuProfiler> Create(Isolate*);
  virtual ~TracingCpuProfiler() = default;
 
 protected:
  TracingCpuProfiler() = default;
};
 
// TickSample captures the information collected for each sample.
struct TickSample {
  // Internal profiling (with --prof + tools/$OS-tick-processor) wants to
  // include the runtime function we're calling. Externally exposed tick
  // samples don't care.
  enum RecordCEntryFrame { kIncludeCEntryFrame, kSkipCEntryFrame };
 
  TickSample()
      : state(OTHER),
        pc(nullptr),
        external_callback_entry(nullptr),
        frames_count(0),
        has_external_callback(false),
        update_stats(true) {}
 
  void Init(Isolate* isolate, const v8::RegisterState& state,
            RecordCEntryFrame record_c_entry_frame, bool update_stats,
            bool use_simulator_reg_state = true);
  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);
  StateTag state;  // The state of the VM.
  void* pc;        // Instruction pointer.
  union {
    void* tos;  // Top stack value (*sp).
    void* external_callback_entry;
  };
  static const unsigned kMaxFramesCountLog2 = 8;
  static const unsigned kMaxFramesCount = (1 << kMaxFramesCountLog2) - 1;
  void* stack[kMaxFramesCount];                 // Call stack.
  unsigned frames_count : kMaxFramesCountLog2;  // Number of captured frames.
  bool has_external_callback : 1;
  bool update_stats : 1;  // Whether the sample should update aggregated stats.
};
 
class V8_EXPORT CpuProfileNode {
 public:
  struct LineTick {
    int line;
 
    unsigned int hit_count;
  };
 
  Local<String> GetFunctionName() const;
 
  const char* GetFunctionNameStr() const;
 
  int GetScriptId() const;
 
  Local<String> GetScriptResourceName() const;
 
  const char* GetScriptResourceNameStr() const;
 
  int GetLineNumber() const;
 
  int GetColumnNumber() const;
 
  unsigned int GetHitLineCount() const;
 
  bool GetLineTicks(LineTick* entries, unsigned int length) const;
 
  const char* GetBailoutReason() const;
 
  unsigned GetHitCount() const;
 
  V8_DEPRECATE_SOON(
      "Use GetScriptId, GetLineNumber, and GetColumnNumber instead.",
      unsigned GetCallUid() const);
 
  unsigned GetNodeId() const;
 
  int GetChildrenCount() const;
 
  const CpuProfileNode* GetChild(int index) const;
 
  const std::vector<CpuProfileDeoptInfo>& GetDeoptInfos() const;
 
  static const int kNoLineNumberInfo = Message::kNoLineNumberInfo;
  static const int kNoColumnNumberInfo = Message::kNoColumnInfo;
};
 
 
class V8_EXPORT CpuProfile {
 public:
  Local<String> GetTitle() const;
 
  const CpuProfileNode* GetTopDownRoot() const;
 
  int GetSamplesCount() const;
 
  const CpuProfileNode* GetSample(int index) const;
 
  int64_t GetSampleTimestamp(int index) const;
 
  int64_t GetStartTime() const;
 
  int64_t GetEndTime() const;
 
  void Delete();
};
 
class V8_EXPORT CpuProfiler {
 public:
  static CpuProfiler* New(Isolate* isolate);
 
  void Dispose();
 
  void SetSamplingInterval(int us);
 
  void StartProfiling(Local<String> title, bool record_samples = false);
 
  CpuProfile* StopProfiling(Local<String> title);
 
  void CollectSample();
 
  void SetIdle(bool is_idle);
 
 private:
  CpuProfiler();
  ~CpuProfiler();
  CpuProfiler(const CpuProfiler&);
  CpuProfiler& operator=(const CpuProfiler&);
};
 
 
class V8_EXPORT HeapGraphEdge {
 public:
  enum Type {
    kContextVariable = 0,  // A variable from a function context.
    kElement = 1,          // An element of an array.
    kProperty = 2,         // A named object property.
    kInternal = 3,         // A link that can't be accessed from JS,
                           // thus, its name isn't a real property name
                           // (e.g. parts of a ConsString).
    kHidden = 4,           // A link that is needed for proper sizes
                           // calculation, but may be hidden from user.
    kShortcut = 5,         // A link that must not be followed during
                           // sizes calculation.
    kWeak = 6              // A weak reference (ignored by the GC).
  };
 
  Type GetType() const;
 
  Local<Value> GetName() const;
 
  const HeapGraphNode* GetFromNode() const;
 
  const HeapGraphNode* GetToNode() const;
};
 
 
class V8_EXPORT HeapGraphNode {
 public:
  enum Type {
    kHidden = 0,         // Hidden node, may be filtered when shown to user.
    kArray = 1,          // An array of elements.
    kString = 2,         // A string.
    kObject = 3,         // A JS object (except for arrays and strings).
    kCode = 4,           // Compiled code.
    kClosure = 5,        // Function closure.
    kRegExp = 6,         // RegExp.
    kHeapNumber = 7,     // Number stored in the heap.
    kNative = 8,         // Native object (not from V8 heap).
    kSynthetic = 9,      // Synthetic object, usually used for grouping
                         // snapshot items together.
    kConsString = 10,    // Concatenated string. A pair of pointers to strings.
    kSlicedString = 11,  // Sliced string. A fragment of another string.
    kSymbol = 12         // A Symbol (ES6).
  };
 
  Type GetType() const;
 
  Local<String> GetName() const;
 
  SnapshotObjectId GetId() const;
 
  size_t GetShallowSize() const;
 
  int GetChildrenCount() const;
 
  const HeapGraphEdge* GetChild(int index) const;
};
 
 
class V8_EXPORT OutputStream {  // NOLINT
 public:
  enum WriteResult {
    kContinue = 0,
    kAbort = 1
  };
  virtual ~OutputStream() {}
  virtual void EndOfStream() = 0;
  virtual int GetChunkSize() { return 1024; }
  virtual WriteResult WriteAsciiChunk(char* data, int size) = 0;
  virtual WriteResult WriteHeapStatsChunk(HeapStatsUpdate* data, int count) {
    return kAbort;
  }
};
 
 
class V8_EXPORT HeapSnapshot {
 public:
  enum SerializationFormat {
    kJSON = 0  // See format description near 'Serialize' method.
  };
 
  const HeapGraphNode* GetRoot() const;
 
  const HeapGraphNode* GetNodeById(SnapshotObjectId id) const;
 
  int GetNodesCount() const;
 
  const HeapGraphNode* GetNode(int index) const;
 
  SnapshotObjectId GetMaxSnapshotJSObjectId() const;
 
  void Delete();
 
  void Serialize(OutputStream* stream,
                 SerializationFormat format = kJSON) const;
};
 
 
class V8_EXPORT ActivityControl {  // NOLINT
 public:
  enum ControlOption {
    kContinue = 0,
    kAbort = 1
  };
  virtual ~ActivityControl() {}
  virtual ControlOption ReportProgressValue(int done, int total) = 0;
};
 
 
class V8_EXPORT AllocationProfile {
 public:
  struct Allocation {
    size_t size;
 
    unsigned int count;
  };
 
  struct Node {
    Local<String> name;
 
    Local<String> script_name;
 
    int script_id;
 
    int start_position;
 
    int line_number;
 
    int column_number;
 
    std::vector<Node*> children;
 
    std::vector<Allocation> allocations;
  };
 
  virtual Node* GetRootNode() = 0;
 
  virtual ~AllocationProfile() {}
 
  static const int kNoLineNumberInfo = Message::kNoLineNumberInfo;
  static const int kNoColumnNumberInfo = Message::kNoColumnInfo;
};
 
 
class V8_EXPORT HeapProfiler {
 public:
  enum SamplingFlags {
    kSamplingNoFlags = 0,
    kSamplingForceGC = 1 << 0,
  };
 
  typedef std::unordered_set<const v8::PersistentBase<v8::Value>*>
      RetainerChildren;
  typedef std::vector<std::pair<v8::RetainedObjectInfo*, RetainerChildren>>
      RetainerGroups;
  typedef std::vector<std::pair<const v8::PersistentBase<v8::Value>*,
                                const v8::PersistentBase<v8::Value>*>>
      RetainerEdges;
 
  struct RetainerInfos {
    RetainerGroups groups;
    RetainerEdges edges;
  };
 
  typedef RetainerInfos (*GetRetainerInfosCallback)(v8::Isolate* isolate);
 
  typedef RetainedObjectInfo* (*WrapperInfoCallback)(uint16_t class_id,
                                                     Local<Value> wrapper);
 
  int GetSnapshotCount();
 
  const HeapSnapshot* GetHeapSnapshot(int index);
 
  SnapshotObjectId GetObjectId(Local<Value> value);
 
  Local<Value> FindObjectById(SnapshotObjectId id);
 
  void ClearObjectIds();
 
  static const SnapshotObjectId kUnknownObjectId = 0;
 
  class ObjectNameResolver {
   public:
    virtual const char* GetName(Local<Object> object) = 0;
 
   protected:
    virtual ~ObjectNameResolver() {}
  };
 
  const HeapSnapshot* TakeHeapSnapshot(
      ActivityControl* control = NULL,
      ObjectNameResolver* global_object_name_resolver = NULL);
 
  void StartTrackingHeapObjects(bool track_allocations = false);
 
  SnapshotObjectId GetHeapStats(OutputStream* stream,
                                int64_t* timestamp_us = NULL);
 
  void StopTrackingHeapObjects();
 
  bool StartSamplingHeapProfiler(uint64_t sample_interval = 512 * 1024,
                                 int stack_depth = 16,
                                 SamplingFlags flags = kSamplingNoFlags);
 
  void StopSamplingHeapProfiler();
 
  AllocationProfile* GetAllocationProfile();
 
  void DeleteAllHeapSnapshots();
 
  void SetWrapperClassInfoProvider(
      uint16_t class_id,
      WrapperInfoCallback callback);
 
  void SetGetRetainerInfosCallback(GetRetainerInfosCallback callback);
 
  static const uint16_t kPersistentHandleNoClassId = 0;
 
 private:
  HeapProfiler();
  ~HeapProfiler();
  HeapProfiler(const HeapProfiler&);
  HeapProfiler& operator=(const HeapProfiler&);
};
 
class V8_EXPORT RetainedObjectInfo {  // NOLINT
 public:
  virtual void Dispose() = 0;
 
  virtual bool IsEquivalent(RetainedObjectInfo* other) = 0;
 
  virtual intptr_t GetHash() = 0;
 
  virtual const char* GetLabel() = 0;
 
  virtual const char* GetGroupLabel() { return GetLabel(); }
 
  virtual intptr_t GetElementCount() { return -1; }
 
  virtual intptr_t GetSizeInBytes() { return -1; }
 
 protected:
  RetainedObjectInfo() {}
  virtual ~RetainedObjectInfo() {}
 
 private:
  RetainedObjectInfo(const RetainedObjectInfo&);
  RetainedObjectInfo& operator=(const RetainedObjectInfo&);
};
 
 
struct HeapStatsUpdate {
  HeapStatsUpdate(uint32_t index, uint32_t count, uint32_t size)
    : index(index), count(count), size(size) { }
  uint32_t index;  // Index of the time interval that was changed.
  uint32_t count;  // New value of count field for the interval with this index.
  uint32_t size;  // New value of size field for the interval with this index.
};
 
 
}  // namespace v8
 
 
#endif  // V8_V8_PROFILER_H_