Revert of [profiler] Implement POC Sampling Heap Profiler

include/v8-profiler.h

 // 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 <vector>
 #include "v8.h"  // NOLINT(build/include)
 
@@ skipping 401 matching lines @@
   virtual ~ActivityControl() {}
   /**
    * Notify about current progress. The activity can be stopped by
    * returning kAbort as the callback result.
    */
   virtual ControlOption ReportProgressValue(int done, int total) = 0;
 };
 
 
 /**
- * AllocationProfile is a sampled profile of allocations done by the program.
- * This is structured as a call-graph.
- */
-class V8_EXPORT AllocationProfile {
- public:
-  struct Allocation {
-    /**
-     * Size of the sampled allocation object.
-     */
-    size_t size;
-
-    /**
-     * The number of objects of such size that were sampled.
-     */
-    unsigned int count;
-  };
-
-  /**
-   * Represents a node in the call-graph.
-   */
-  struct Node {
-    /**
-     * Name of the function. May be empty for anonymous functions or if the
-     * script corresponding to this function has been unloaded.
-     */
-    Local<String> name;
-
-    /**
-     * Name of the script containing the function. May be empty if the script
-     * name is not available, or if the script has been unloaded.
-     */
-    Local<String> script_name;
-
-    /**
-     * id of the script where the function is located. May be equal to
-     * v8::UnboundScript::kNoScriptId in cases where the script doesn't exist.
-     */
-    int script_id;
-
-    /**
-     * Start position of the function in the script.
-     */
-    int start_position;
-
-    /**
-     * 1-indexed line number where the function starts. May be
-     * kNoLineNumberInfo if no line number information is available.
-     */
-    int line_number;
-
-    /**
-     * 1-indexed column number where the function starts. May be
-     * kNoColumnNumberInfo if no line number information is available.
-     */
-    int column_number;
-
-    /**
-     * List of callees called from this node for which we have sampled
-     * allocations. The lifetime of the children is scoped to the containing
-     * AllocationProfile.
-     */
-    std::vector<Node*> children;
-
-    /**
-     * List of self allocations done by this node in the call-graph.
-     */
-    std::vector<Allocation> allocations;
-  };
-
-  /**
-   * Returns the root node of the call-graph. The root node corresponds to an
-   * empty JS call-stack. The lifetime of the returned Node* is scoped to the
-   * containing AllocationProfile.
-   */
-  virtual Node* GetRootNode() = 0;
-
-  virtual ~AllocationProfile() {}
-
-  static const int kNoLineNumberInfo = Message::kNoLineNumberInfo;
-  static const int kNoColumnNumberInfo = Message::kNoColumnInfo;
-};
-
-
-/**
  * Interface for controlling heap profiling. Instance of the
  * profiler can be retrieved using v8::Isolate::GetHeapProfiler.
  */
 class V8_EXPORT HeapProfiler {
  public:
   /**
    * Callback function invoked for obtaining RetainedObjectInfo for
    * the given JavaScript wrapper object. It is prohibited to enter V8
    * while the callback is running: only getters on the handle and
    * GetPointerFromInternalField on the objects are allowed.
@@ skipping 83 matching lines @@
                                 int64_t* timestamp_us = NULL);
 
   /**
    * Stops tracking of heap objects population statistics, cleans up all
    * collected data. StartHeapObjectsTracking must be called again prior to
    * calling GetHeapStats next time.
    */
   void StopTrackingHeapObjects();
 
   /**
-   * Starts gathering a sampling heap profile. A sampling heap profile is
-   * similar to tcmalloc's heap profiler and Go's mprof. It samples object
-   * allocations and builds an online 'sampling' heap profile. At any point in
-   * time, this profile is expected to be a representative sample of objects
-   * currently live in the system. Each sampled allocation includes the stack
-   * trace at the time of allocation, which makes this really useful for memory
-   * leak detection.
-   *
-   * This mechanism is intended to be cheap enough that it can be used in
-   * production with minimal performance overhead.
-   *
-   * Allocations are sampled using a randomized Poisson process. On average, one
-   * allocation will be sampled every |sample_interval| bytes allocated. The
-   * |stack_depth| parameter controls the maximum number of stack frames to be
-   * captured on each allocation.
-   *
-   * NOTE: This is a proof-of-concept at this point. Right now we only sample
-   * newspace allocations. Support for paged space allocation (e.g. pre-tenured
-   * objects, large objects, code objects, etc.) and native allocations
-   * doesn't exist yet, but is anticipated in the future.
-   *
-   * Objects allocated before the sampling is started will not be included in
-   * the profile.
-   *
-   * Returns false if a sampling heap profiler is already running.
-   */
-  bool StartSamplingHeapProfiler(uint64_t sample_interval = 512 * 1024,
-                                 int stack_depth = 16);
-
-  /**
-   * Stops the sampling heap profile and discards the current profile.
-   */
-  void StopSamplingHeapProfiler();
-
-  /**
-   * Returns the sampled profile of allocations allocated (and still live) since
-   * StartSamplingHeapProfiler was called. The ownership of the pointer is
-   * transfered to the caller. Returns nullptr if sampling heap profiler is not
-   * active.
-   */
-  AllocationProfile* GetAllocationProfile();
-
-  /**
    * Deletes all snapshots taken. All previously returned pointers to
    * snapshots and their contents become invalid after this call.
    */
   void DeleteAllHeapSnapshots();
 
   /** Binds a callback to embedder's class ID. */
   void SetWrapperClassInfoProvider(
       uint16_t class_id,
       WrapperInfoCallback callback);
 
@@ skipping 104 matching lines @@
   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_