xpcom/base/MemoryTelemetry.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_MemoryTelemetry_h
   8 #define mozilla_MemoryTelemetry_h
   9
  10 #include "mozilla/TimeStamp.h"
  11 #include "mozilla/Maybe.h"
  12 #include "mozilla/Result.h"
  13 #include "nsIObserver.h"
  14 #include "nsITimer.h"
  15 #include "nsTArray.h"
  16 #include "nsWeakReference.h"
  17
  18 #include <functional>
  19
  20 class nsIEventTarget;
  21
  22 namespace mozilla {
  23
  24 namespace ipc {
  25 enum class ResponseRejectReason;
  26 }
  27
  28 /**
  29  * Periodically gathers memory usage metrics after cycle collection, and
  30  * populates telemetry histograms with their values.
  31  */
  32 class MemoryTelemetry final : public nsIObserver,
  33                               public nsSupportsWeakReference {
  34  public:
  35   NS_DECL_ISUPPORTS
  36   NS_DECL_NSIOBSERVER
  37
  38   static MemoryTelemetry& Get();
  39
  40   nsresult GatherReports(
  41       const std::function<void()>& aCompletionCallback = nullptr);
  42
  43   /**
  44    * Called to signal that we can begin collecting telemetry.
  45    */
  46   void DelayedInit();
  47
  48   /**
  49    * Notify that the browser is active and telemetry should be recorded soon.
  50    */
  51   void Poke();
  52
  53   nsresult Shutdown();
  54
  55  private:
  56   MemoryTelemetry();
  57
  58   ~MemoryTelemetry() = default;
  59
  60   void Init();
  61
  62   static Result<uint32_t, nsresult> GetOpenTabsCount();
  63
  64   void GatherTotalMemory();
  65   nsresult FinishGatheringTotalMemory(Maybe<int64_t> aTotalMemory,
  66                                       const nsTArray<int64_t>& aChildSizes);
  67
  68   nsCOMPtr<nsIEventTarget> mThreadPool;
  69
  70   bool mGatheringTotalMemory = false;
  71
  72   TimeStamp mLastRun{};
  73   TimeStamp mLastPoke{};
  74   nsCOMPtr<nsITimer> mTimer;
  75
  76   // True if startup is finished and it's okay to start gathering telemetry.
  77   bool mCanRun = false;
  78 };
  79
  80 }  // namespace mozilla
  81
  82 #endif  // defined mozilla_MemoryTelemetry_h