tools/profiler/ThreadResponsiveness.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "ThreadResponsiveness.h"
   7 #include "platform.h"
   8 #include "nsComponentManagerUtils.h"
   9 #include "nsThreadUtils.h"
  10 #include "nsITimer.h"
  11 #include "mozilla/Monitor.h"
  12 #include "ProfileEntry.h"
  13
  14 using mozilla::Monitor;
  15 using mozilla::MonitorAutoLock;
  16 using mozilla::TimeStamp;
  17
  18 class CheckResponsivenessTask : public nsRunnable,
  19                                 public nsITimerCallback {
  20 public:
  21   CheckResponsivenessTask()
  22     : mLastTracerTime(TimeStamp::Now())
  23     , mMonitor("CheckResponsivenessTask")
  24     , mTimer(nullptr)
  25     , mStop(false)
  26   {
  27     MOZ_COUNT_CTOR(CheckResponsivenessTask);
  28   }
  29
  30 protected:
  31   ~CheckResponsivenessTask()
  32   {
  33     MOZ_COUNT_DTOR(CheckResponsivenessTask);
  34   }
  35
  36 public:
  37   NS_IMETHOD Run()
  38   {
  39     MonitorAutoLock mon(mMonitor);
  40     if (mStop)
  41       return NS_OK;
  42
  43     // This is raced on because we might pause the thread here
  44     // for profiling so if we tried to use a monitor to protect
  45     // mLastTracerTime we could deadlock. We're risking seeing
  46     // a partial write which will show up as an outlier in our
  47     // performance data.
  48     mLastTracerTime = TimeStamp::Now();
  49     if (!mTimer) {
  50       mTimer = do_CreateInstance("@mozilla.org/timer;1");
  51     }
  52     mTimer->InitWithCallback(this, 16, nsITimer::TYPE_ONE_SHOT);
  53
  54     return NS_OK;
  55   }
  56
  57   NS_IMETHODIMP Notify(nsITimer* aTimer) MOZ_FINAL
  58   {
  59     NS_DispatchToMainThread(this);
  60     return NS_OK;
  61   }
  62
  63   void Terminate() {
  64     MonitorAutoLock mon(mMonitor);
  65     mStop = true;
  66   }
  67
  68   const TimeStamp& GetLastTracerTime() const {
  69     return mLastTracerTime;
  70   }
  71
  72   NS_DECL_ISUPPORTS_INHERITED
  73
  74 private:
  75   TimeStamp mLastTracerTime;
  76   Monitor mMonitor;
  77   nsCOMPtr<nsITimer> mTimer;
  78   bool mStop;
  79 };
  80
  81 NS_IMPL_ISUPPORTS_INHERITED(CheckResponsivenessTask, nsRunnable, nsITimerCallback)
  82
  83 ThreadResponsiveness::ThreadResponsiveness(ThreadProfile *aThreadProfile)
  84   : mThreadProfile(aThreadProfile)
  85   , mActiveTracerEvent(nullptr)
  86 {
  87   MOZ_COUNT_CTOR(ThreadResponsiveness);
  88 }
  89
  90 ThreadResponsiveness::~ThreadResponsiveness()
  91 {
  92   MOZ_COUNT_DTOR(ThreadResponsiveness);
  93   if (mActiveTracerEvent) {
  94     mActiveTracerEvent->Terminate();
  95   }
  96 }
  97
  98 void
  99 ThreadResponsiveness::Update()
 100 {
 101   return;
 102   if (!mActiveTracerEvent) {
 103     if (mThreadProfile->GetThreadInfo()->IsMainThread()) {
 104       mActiveTracerEvent = new CheckResponsivenessTask();
 105       NS_DispatchToMainThread(mActiveTracerEvent);
 106     } else if (mThreadProfile->GetThreadInfo()->GetThread()) {
 107       mActiveTracerEvent = new CheckResponsivenessTask();
 108       mThreadProfile->GetThreadInfo()->
 109         GetThread()->Dispatch(mActiveTracerEvent, NS_DISPATCH_NORMAL);
 110     }
 111   }
 112
 113   if (mActiveTracerEvent) {
 114     mLastTracerTime = mActiveTracerEvent->GetLastTracerTime();
 115   }
 116 }
 117