tools/performance/PerfStats.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 PerfStats_h
   8 #define PerfStats_h
   9
  10 #include "mozilla/TimeStamp.h"
  11 #include "mozilla/StaticMutex.h"
  12 #include "mozilla/StaticPtr.h"
  13 #include "mozilla/MozPromise.h"
  14 #include <memory>
  15 #include <string>
  16 #include <limits>
  17
  18 namespace mozilla {
  19
  20 class PerfStats {
  21  public:
  22   typedef MozPromise<nsCString, bool, true> PerfStatsPromise;
  23
  24   enum class Metric : uint32_t {
  25     DisplayListBuilding = 0,
  26     Rasterizing,
  27     LayerBuilding,
  28     LayerTransactions,
  29     Compositing,
  30     Reflowing,
  31     Styling,
  32     Max
  33   };
  34
  35   // MetricMask is a bitmask based on 'Metric', i.e. Metric::LayerBuilding (2)
  36   // is synonymous to 1 << 2 in MetricMask.
  37   using MetricMask = uint64_t;
  38
  39   static void RecordMeasurementStart(Metric aMetric) {
  40     if (!(sCollectionMask & (1 << static_cast<uint64_t>(aMetric)))) {
  41       return;
  42     }
  43     RecordMeasurementStartInternal(aMetric);
  44   }
  45
  46   static void RecordMeasurementEnd(Metric aMetric) {
  47     if (!(sCollectionMask & (1 << static_cast<uint64_t>(aMetric)))) {
  48       return;
  49     }
  50     RecordMeasurementEndInternal(aMetric);
  51   }
  52
  53   template <Metric N>
  54   class AutoMetricRecording {
  55    public:
  56     AutoMetricRecording() { PerfStats::RecordMeasurementStart(N); }
  57     ~AutoMetricRecording() { PerfStats::RecordMeasurementEnd(N); }
  58   };
  59
  60   static void SetCollectionMask(MetricMask aMask);
  61
  62   static RefPtr<PerfStatsPromise> CollectPerfStatsJSON() {
  63     return GetSingleton()->CollectPerfStatsJSONInternal();
  64   }
  65
  66   static nsCString CollectLocalPerfStatsJSON() {
  67     return GetSingleton()->CollectLocalPerfStatsJSONInternal();
  68   }
  69
  70  private:
  71   static PerfStats* GetSingleton();
  72   static void RecordMeasurementStartInternal(Metric aMetric);
  73   static void RecordMeasurementEndInternal(Metric aMetric);
  74
  75   RefPtr<PerfStatsPromise> CollectPerfStatsJSONInternal();
  76   nsCString CollectLocalPerfStatsJSONInternal();
  77
  78   static MetricMask sCollectionMask;
  79   static StaticMutex sMutex;
  80   static StaticAutoPtr<PerfStats> sSingleton;
  81   TimeStamp mRecordedStarts[static_cast<size_t>(Metric::Max)];
  82   double mRecordedTimes[static_cast<size_t>(Metric::Max)];
  83 };
  84
  85 static_assert(1 << (static_cast<uint64_t>(PerfStats::Metric::Max) - 1) <=
  86                   std::numeric_limits<PerfStats::MetricMask>::max(),
  87               "More metrics than can fit into sCollectionMask bitmask");
  88
  89 }  // namespace mozilla
  90
  91 #endif  // PerfStats_h