netwerk/ipc/ChannelEventQueue.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  * vim: set sw=2 ts=8 et tw=80 :
   3  */
   4 /* This Source Code Form is subject to the terms of the Mozilla Public
   5  * License, v. 2.0. If a copy of the MPL was not distributed with this
   6  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   7
   8 #include "nsISupports.h"
   9 #include "mozilla/net/ChannelEventQueue.h"
  10 #include "nsThreadUtils.h"
  11
  12 namespace mozilla {
  13 namespace net {
  14
  15 void
  16 ChannelEventQueue::FlushQueue()
  17 {
  18   // Events flushed could include destruction of channel (and our own
  19   // destructor) unless we make sure its refcount doesn't drop to 0 while this
  20   // method is running.
  21   nsCOMPtr<nsISupports> kungFuDeathGrip(mOwner);
  22
  23   // Prevent flushed events from flushing the queue recursively
  24   mFlushing = true;
  25
  26   uint32_t i;
  27   for (i = 0; i < mEventQueue.Length(); i++) {
  28     mEventQueue[i]->Run();
  29     if (mSuspended)
  30       break;
  31   }
  32
  33   // We will always want to remove at least one finished callback.
  34   if (i < mEventQueue.Length())
  35     i++;
  36
  37   // It is possible for new callbacks to be enqueued as we are
  38   // flushing the queue, so the queue must not be cleared until
  39   // all callbacks have run.
  40   mEventQueue.RemoveElementsAt(0, i);
  41
  42   mFlushing = false;
  43 }
  44
  45 void
  46 ChannelEventQueue::Resume()
  47 {
  48   // Resuming w/o suspend: error in debug mode, ignore in build
  49   MOZ_ASSERT(mSuspendCount > 0);
  50   if (mSuspendCount <= 0) {
  51     return;
  52   }
  53
  54   if (!--mSuspendCount) {
  55     nsRefPtr<nsRunnableMethod<ChannelEventQueue> > event =
  56       NS_NewRunnableMethod(this, &ChannelEventQueue::CompleteResume);
  57     if (mTargetThread) {
  58       mTargetThread->Dispatch(event, NS_DISPATCH_NORMAL);
  59     } else {
  60       MOZ_RELEASE_ASSERT(NS_IsMainThread());
  61       NS_DispatchToCurrentThread(event);
  62     }
  63   }
  64 }
  65
  66 nsresult
  67 ChannelEventQueue::RetargetDeliveryTo(nsIEventTarget* aTargetThread)
  68 {
  69   MOZ_RELEASE_ASSERT(NS_IsMainThread());
  70   MOZ_RELEASE_ASSERT(!mTargetThread);
  71   MOZ_RELEASE_ASSERT(aTargetThread);
  72
  73   mTargetThread = do_QueryInterface(aTargetThread);
  74   MOZ_RELEASE_ASSERT(mTargetThread);
  75
  76   return NS_OK;
  77 }
  78
  79 }
  80 }