widget/gonk/WidgetTraceEvent.cpp

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #include "mozilla/WidgetTraceEvent.h"
   6 #include "mozilla/StaticPtr.h"
   7 #include "nsThreadUtils.h"
   8 #include <mozilla/CondVar.h>
   9 #include <mozilla/Mutex.h>
  10
  11 using mozilla::CondVar;
  12 using mozilla::Mutex;
  13 using mozilla::MutexAutoLock;
  14
  15 namespace mozilla {
  16   class TracerRunnable : public nsRunnable {
  17     public:
  18       TracerRunnable() {
  19         mTracerLock = new Mutex("TracerRunnable");
  20         mTracerCondVar = new CondVar(*mTracerLock, "TracerRunnable");
  21         mMainThread = do_GetMainThread();
  22       }
  23
  24       ~TracerRunnable() {
  25         delete mTracerCondVar;
  26         delete mTracerLock;
  27         mTracerLock = nullptr;
  28         mTracerCondVar = nullptr;
  29       }
  30
  31       virtual nsresult Run() {
  32         MutexAutoLock lock(*mTracerLock);
  33         mHasRun = true;
  34         mTracerCondVar->Notify();
  35         return NS_OK;
  36       }
  37
  38       bool Fire() {
  39         if (!mTracerLock || !mTracerCondVar) {
  40           return false;
  41         }
  42
  43         MutexAutoLock lock(*mTracerLock);
  44         mHasRun = false;
  45         mMainThread->Dispatch(this, NS_DISPATCH_NORMAL);
  46         while (!mHasRun) {
  47           mTracerCondVar->Wait();
  48         }
  49         return true;
  50       }
  51
  52       void Signal() {
  53         MutexAutoLock lock(*mTracerLock);
  54         mHasRun = true;
  55         mTracerCondVar->Notify();
  56       }
  57
  58     private:
  59       Mutex* mTracerLock;
  60       CondVar* mTracerCondVar;
  61       bool mHasRun;
  62       nsCOMPtr<nsIThread> mMainThread;
  63   };
  64
  65   StaticRefPtr<TracerRunnable> sTracerRunnable;
  66
  67   bool InitWidgetTracing()
  68   {
  69     if (!sTracerRunnable) {
  70       sTracerRunnable = new TracerRunnable();
  71     }
  72     return true;
  73   }
  74
  75   void CleanUpWidgetTracing()
  76   {
  77     sTracerRunnable = nullptr;
  78   }
  79
  80   bool FireAndWaitForTracerEvent()
  81   {
  82     if (sTracerRunnable) {
  83       return sTracerRunnable->Fire();
  84     }
  85
  86     return false;
  87   }
  88
  89   void SignalTracerThread()
  90   {
  91     if (sTracerRunnable) {
  92       return sTracerRunnable->Signal();
  93     }
  94   }
  95 }  // namespace mozilla
  96