v8/include/v8-profiler.h

// Copyright 2010 the V8 project authors. All rights reserved.
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#ifndef V8_V8_PROFILER_H_
#define V8_V8_PROFILER_H_

#include "v8.h"

#ifdef _WIN32
// Setup for Windows DLL export/import. See v8.h in this directory for
// information on how to build/use V8 as a DLL.
#if defined(BUILDING_V8_SHARED) && defined(USING_V8_SHARED)
#error both BUILDING_V8_SHARED and USING_V8_SHARED are set - please check the\
  build configuration to ensure that at most one of these is set
#endif

#ifdef BUILDING_V8_SHARED
#define V8EXPORT __declspec(dllexport)
#elif USING_V8_SHARED
#define V8EXPORT __declspec(dllimport)
#else
#define V8EXPORT
#endif

#else  // _WIN32

// Setup for Linux shared library export. See v8.h in this directory for
// information on how to build/use V8 as shared library.
#if defined(__GNUC__) && (__GNUC__ >= 4) && defined(V8_SHARED)
#define V8EXPORT __attribute__ ((visibility("default")))
#else  // defined(__GNUC__) && (__GNUC__ >= 4)
#define V8EXPORT
#endif  // defined(__GNUC__) && (__GNUC__ >= 4)

#endif  // _WIN32


/**
 * Profiler support for the V8 JavaScript engine.
 */
namespace v8 {


/**
 * CpuProfileNode represents a node in a call graph.
 */
class V8EXPORT CpuProfileNode {
 public:
  /** Returns function name (empty string for anonymous functions.) */
  Handle<String> GetFunctionName() const;

  /** Returns resource name for script from where the function originates. */
  Handle<String> GetScriptResourceName() const;

  /**
   * Returns the number, 1-based, of the line where the function originates.
   * kNoLineNumberInfo if no line number information is available.
   */
  int GetLineNumber() const;

  /**
   * Returns total (self + children) execution time of the function,
   * in milliseconds, estimated by samples count.
   */
  double GetTotalTime() const;

  /**
   * Returns self execution time of the function, in milliseconds,
   * estimated by samples count.
   */
  double GetSelfTime() const;

  /** Returns the count of samples where function exists. */
  double GetTotalSamplesCount() const;

  /** Returns the count of samples where function was currently executing. */
  double GetSelfSamplesCount() const;

  /** Returns function entry UID. */
  unsigned GetCallUid() const;

  /** Returns child nodes count of the node. */
  int GetChildrenCount() const;

  /** Retrieves a child node by index. */
  const CpuProfileNode* GetChild(int index) const;

  static const int kNoLineNumberInfo = Message::kNoLineNumberInfo;
};


/**
 * CpuProfile contains a CPU profile in a form of two call trees:
 *  - top-down (from main() down to functions that do all the work);
 *  - bottom-up call graph (in backward direction).
 */
class V8EXPORT CpuProfile {
 public:
  /** Returns CPU profile UID (assigned by the profiler.) */
  unsigned GetUid() const;

  /** Returns CPU profile title. */
  Handle<String> GetTitle() const;

  /** Returns the root node of the bottom up call tree. */
  const CpuProfileNode* GetBottomUpRoot() const;

  /** Returns the root node of the top down call tree. */
  const CpuProfileNode* GetTopDownRoot() const;
};


/**
 * Interface for controlling CPU profiling.
 */
class V8EXPORT CpuProfiler {
 public:
  /**
   * A note on security tokens usage. As scripts from different
   * origins can run inside a single V8 instance, it is possible to
   * have functions from different security contexts intermixed in a
   * single CPU profile. To avoid exposing function names belonging to
   * other contexts, filtering by security token is performed while
   * obtaining profiling results.
   */

  /**
   * Returns the number of profiles collected (doesn't include
   * profiles that are being collected at the moment of call.)
   */
  static int GetProfilesCount();

  /** Returns a profile by index. */
  static const CpuProfile* GetProfile(
      int index,
      Handle<Value> security_token = Handle<Value>());

  /** Returns a profile by uid. */
  static const CpuProfile* FindProfile(
      unsigned uid,
      Handle<Value> security_token = Handle<Value>());

  /**
   * Starts collecting CPU profile. Title may be an empty string. It
   * is allowed to have several profiles being collected at
   * once. Attempts to start collecting several profiles with the same
   * title are silently ignored. While collecting a profile, functions
   * from all security contexts are included in it. The token-based
   * filtering is only performed when querying for a profile.
   */
  static void StartProfiling(Handle<String> title);

  /**
   * Stops collecting CPU profile with a given title and returns it.
   * If the title given is empty, finishes the last profile started.
   */
  static const CpuProfile* StopProfiling(
      Handle<String> title,
      Handle<Value> security_token = Handle<Value>());
};


}  // namespace v8


#undef V8EXPORT


#endif  // V8_V8_PROFILER_H_