base/trace_event/process_memory_dump.h

// Copyright 2015 The Chromium 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 BASE_TRACE_EVENT_PROCESS_MEMORY_DUMP_H_
#define BASE_TRACE_EVENT_PROCESS_MEMORY_DUMP_H_

#include "base/base_export.h"
#include "base/containers/hash_tables.h"
#include "base/containers/small_map.h"
#include "base/memory/ref_counted.h"
#include "base/memory/scoped_vector.h"
#include "base/trace_event/memory_allocator_dump.h"
#include "base/trace_event/memory_dump_session_state.h"
#include "base/trace_event/process_memory_maps.h"
#include "base/trace_event/process_memory_totals.h"

namespace base {
namespace trace_event {

class ConvertableToTraceFormat;
class MemoryDumpManager;
class MemoryDumpSessionState;

// ProcessMemoryDump is as a strongly typed container which enforces the data
// model for each memory dump and holds the dumps produced by the
// MemoryDumpProvider(s) for a specific process.
// At trace generation time (i.e. when AsValue() is called), ProcessMemoryDump
// will compose a key-value dictionary of the various dumps obtained at trace
// dump point time.
class BASE_EXPORT ProcessMemoryDump {
 public:
  // Maps allocator dumps absolute names (allocator_name/heap/subheap) to
  // MemoryAllocatorDump instances.
  using AllocatorDumpsMap =
      SmallMap<hash_map<std::string, MemoryAllocatorDump*>>;

  ProcessMemoryDump(const scoped_refptr<MemoryDumpSessionState>& session_state);
  ~ProcessMemoryDump();

  // Called at trace generation time to populate the TracedValue.
  void AsValueInto(TracedValue* value) const;

  ProcessMemoryTotals* process_totals() { return &process_totals_; }
  bool has_process_totals() const { return has_process_totals_; }
  void set_has_process_totals() { has_process_totals_ = true; }

  ProcessMemoryMaps* process_mmaps() { return &process_mmaps_; }
  bool has_process_mmaps() const { return has_process_mmaps_; }
  void set_has_process_mmaps() { has_process_mmaps_ = true; }

  // Creates a new MemoryAllocatorDump with the given name and returns the
  // empty object back to the caller.
  // Arguments:
  //   absolute_name: a name that uniquely identifies allocator dumps produced
  //       by this provider. It is possible to specify nesting by using a
  //       path-like string (e.g., v8/isolate1/heap1, v8/isolate1/heap2).
  //       Leading or trailing slashes are not allowed.
  // ProcessMemoryDump handles the memory ownership of its MemoryAllocatorDumps.
  MemoryAllocatorDump* CreateAllocatorDump(const std::string& absolute_name);

  // Looks up a MemoryAllocatorDump given its allocator and heap names, or
  // nullptr if not found.
  MemoryAllocatorDump* GetAllocatorDump(const std::string& absolute_name) const;

  // Returns the map of the MemoryAllocatorDumps added to this dump.
  const AllocatorDumpsMap& allocator_dumps() const { return allocator_dumps_; }

  const scoped_refptr<MemoryDumpSessionState>& session_state() const {
    return session_state_;
  }

 private:
  ProcessMemoryTotals process_totals_;
  bool has_process_totals_;

  ProcessMemoryMaps process_mmaps_;
  bool has_process_mmaps_;

  AllocatorDumpsMap allocator_dumps_;

  // ProcessMemoryDump handles the memory ownership of all its belongings.
  ScopedVector<MemoryAllocatorDump> allocator_dumps_storage_;

  // State shared among all PMDs instances created in a given trace session.
  scoped_refptr<MemoryDumpSessionState> session_state_;

  DISALLOW_COPY_AND_ASSIGN(ProcessMemoryDump);
};

}  // namespace trace_event
}  // namespace base

#endif  // BASE_TRACE_EVENT_PROCESS_MEMORY_DUMP_H_