/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 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 "SameProcessMessageQueue.h"

#include "nsThreadUtils.h"

using namespace mozilla;

using namespace mozilla::dom;

SameProcessMessageQueue* SameProcessMessageQueue::sSingleton;

SameProcessMessageQueue::SameProcessMessageQueue()

{

}

SameProcessMessageQueue::~SameProcessMessageQueue()

{

  // This code should run during shutdown, and we should already have pumped the

  // event loop. So we should only see messages here if someone is sending

  // messages pretty late in shutdown.

  NS_WARNING_ASSERTION(mQueue.IsEmpty(),

                       "Shouldn't send messages during shutdown");

  sSingleton = nullptr;

}

void

SameProcessMessageQueue::Push(Runnable* aRunnable)

{

  mQueue.AppendElement(aRunnable);

  NS_DispatchToCurrentThread(aRunnable);

}

void

SameProcessMessageQueue::Flush()

{

  nsTArray<RefPtr<Runnable>> queue;

  mQueue.SwapElements(queue);

  for (size_t i = 0; i < queue.Length(); i++) {

    queue[i]->Run();

  }

}

/* static */ SameProcessMessageQueue*

SameProcessMessageQueue::Get()

{

  if (!sSingleton) {

    sSingleton = new SameProcessMessageQueue();

  }

  return sSingleton;

}

SameProcessMessageQueue::Runnable::Runnable()

 : mDispatched(false)

{

}

NS_IMPL_ISUPPORTS(SameProcessMessageQueue::Runnable, nsIRunnable)

nsresult

SameProcessMessageQueue::Runnable::Run()

{

  if (mDispatched) {

    return NS_OK;

  }

  SameProcessMessageQueue* queue = SameProcessMessageQueue::Get();

  queue->mQueue.RemoveElement(this);

  mDispatched = true;

  return HandleMessage();

}