xpcom/threads/DelayedRunnable.cpp

   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 #include "DelayedRunnable.h"
   8
   9 #include "mozilla/ProfilerRunnable.h"
  10
  11 namespace mozilla {
  12
  13 DelayedRunnable::DelayedRunnable(already_AddRefed<nsIEventTarget> aTarget,
  14                                  already_AddRefed<nsIRunnable> aRunnable,
  15                                  uint32_t aDelay)
  16     : mozilla::Runnable("DelayedRunnable"),
  17       mTarget(aTarget),
  18       mObserver(do_QueryInterface(mTarget)),
  19       mWrappedRunnable(aRunnable),
  20       mDelayedFrom(TimeStamp::NowLoRes()),
  21       mDelay(aDelay) {
  22   MOZ_DIAGNOSTIC_ASSERT(mObserver,
  23                         "Target must implement nsIDelayedRunnableObserver");
  24 }
  25
  26 nsresult DelayedRunnable::Init() {
  27   mObserver->OnDelayedRunnableCreated(this);
  28   return NS_NewTimerWithCallback(getter_AddRefs(mTimer), this, mDelay,
  29                                  nsITimer::TYPE_ONE_SHOT, mTarget);
  30 }
  31
  32 void DelayedRunnable::CancelTimer() {
  33   MOZ_ASSERT(mTarget->IsOnCurrentThread());
  34   mTimer->Cancel();
  35 }
  36
  37 NS_IMETHODIMP DelayedRunnable::Run() {
  38   MOZ_ASSERT(mTimer, "DelayedRunnable without Init?");
  39
  40   // Already ran?
  41   if (!mWrappedRunnable) {
  42     return NS_OK;
  43   }
  44
  45   // Are we too early?
  46   if ((mozilla::TimeStamp::NowLoRes() - mDelayedFrom).ToMilliseconds() <
  47       mDelay) {
  48     if (mObserver) {
  49       mObserver->OnDelayedRunnableScheduled(this);
  50     }
  51     return NS_OK;  // Let the nsITimer run us.
  52   }
  53
  54   mTimer->Cancel();
  55   return DoRun();
  56 }
  57
  58 NS_IMETHODIMP DelayedRunnable::Notify(nsITimer* aTimer) {
  59   // If we already ran, the timer should have been canceled.
  60   MOZ_ASSERT(mWrappedRunnable);
  61
  62   if (mObserver) {
  63     mObserver->OnDelayedRunnableRan(this);
  64   }
  65   return DoRun();
  66 }
  67
  68 nsresult DelayedRunnable::DoRun() {
  69   nsCOMPtr<nsIRunnable> r = std::move(mWrappedRunnable);
  70   AUTO_PROFILE_FOLLOWING_RUNNABLE(r);
  71   return r->Run();
  72 }
  73
  74 NS_IMPL_ISUPPORTS_INHERITED(DelayedRunnable, Runnable, nsITimerCallback)
  75
  76 }  // namespace mozilla