import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

netwerk/ipc/ChannelEventQueue.cpp

@@ -0,0 +1,98 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set sw=2 ts=8 et tw=80 :
+ */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.h"
+#include "mozilla/net/ChannelEventQueue.h"
+#include "mozilla/Unused.h"
+#include "nsThreadUtils.h"
+#include "mozilla/Unused.h"
+
+namespace mozilla {
+namespace net {
+
+ChannelEvent*
+ChannelEventQueue::TakeEvent()
+{
+  MutexAutoLock lock(mMutex);
+  MOZ_ASSERT(mFlushing);
+
+  if (mSuspended || mEventQueue.IsEmpty()) {
+    return nullptr;
+  }
+
+  UniquePtr<ChannelEvent> event(Move(mEventQueue[0]));
+  mEventQueue.RemoveElementAt(0);
+
+  return event.release();
+}
+
+void
+ChannelEventQueue::FlushQueue()
+{
+  // Events flushed could include destruction of channel (and our own
+  // destructor) unless we make sure its refcount doesn't drop to 0 while this
+  // method is running.
+  nsCOMPtr<nsISupports> kungFuDeathGrip(mOwner);
+  mozilla::Unused << kungFuDeathGrip; // Not used in this function
+
+  // Prevent flushed events from flushing the queue recursively
+  {
+    MutexAutoLock lock(mMutex);
+    mFlushing = true;
+  }
+
+  while (true) {
+    UniquePtr<ChannelEvent> event(TakeEvent());
+    if (!event) {
+      break;
+    }
+
+    event->Run();
+  }
+
+  MutexAutoLock lock(mMutex);
+  mFlushing = false;
+}
+
+void
+ChannelEventQueue::Resume()
+{
+  MutexAutoLock lock(mMutex);
+
+  // Resuming w/o suspend: error in debug mode, ignore in build
+  MOZ_ASSERT(mSuspendCount > 0);
+  if (mSuspendCount <= 0) {
+    return;
+  }
+
+  if (!--mSuspendCount) {
+    RefPtr<Runnable> event =
+      NewRunnableMethod(this, &ChannelEventQueue::CompleteResume);
+    if (mTargetThread) {
+      mTargetThread->Dispatch(event.forget(), NS_DISPATCH_NORMAL);
+    } else {
+      MOZ_RELEASE_ASSERT(NS_IsMainThread());
+      Unused << NS_WARN_IF(NS_FAILED(NS_DispatchToCurrentThread(event.forget())));
+    }
+  }
+}
+
+nsresult
+ChannelEventQueue::RetargetDeliveryTo(nsIEventTarget* aTargetThread)
+{
+  MOZ_RELEASE_ASSERT(NS_IsMainThread());
+  MOZ_RELEASE_ASSERT(!mTargetThread);
+  MOZ_RELEASE_ASSERT(aTargetThread);
+
+  mTargetThread = do_QueryInterface(aTargetThread);
+  MOZ_RELEASE_ASSERT(mTargetThread);
+
+  return NS_OK;
+}
+
+} // namespace net
+} // namespace mozilla