dom/gamepad/ipc/GamepadEventChannelChild.cpp
author Nicholas Nethercote <nnethercote@mozilla.com>
Fri, 02 Sep 2016 17:12:24 +1000
changeset 312898 177f41cecedb422d7a11156091ee718ec919c643
parent 302813 342068569153f7399dbf141c6c2b36bce71888fb
child 322738 39ac4382a2c019178604b90acd816753fe142908
permissions -rw-r--r--
Bug 1299384 - Use MOZ_MUST_USE with NS_warn_if_impl(). r=erahm. This change avoids lots of false positives for Coverity's CHECKED_RETURN warning, caused by NS_WARN_IF's current use in both statement-style and expression-style. In the case where the code within the NS_WARN_IF has side-effects, I made the following change. > NS_WARN_IF(NS_FAILED(FunctionWithSideEffects())); > --> > Unused << NS_WARN_IF(NS_FAILED(FunctionWithSideEffects())); In the case where the code within the NS_WARN_IF lacks side-effects, I made the following change. > NS_WARN_IF(!condWithoutSideEffects); > --> > NS_WARNING_ASSERTION(condWithoutSideEffects, "msg"); This has two improvements. - The condition is not evaluated in non-debug builds. - The sense of the condition is inverted to the familiar "this condition should be true" sense used in assertions. A common variation on the side-effect-free case is the following. > nsresult rv = Fn(); > NS_WARN_IF_(NS_FAILED(rv)); > --> > DebugOnly<nsresult rv> = Fn(); > NS_WARNING_ASSERTION(NS_SUCCEEDED(rv), "Fn failed");

/* 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 "GamepadEventChannelChild.h"
#include "mozilla/dom/GamepadManager.h"

namespace mozilla {
namespace dom{

namespace {

class GamepadUpdateRunnable final : public Runnable
{
 public:
  explicit GamepadUpdateRunnable(const GamepadChangeEvent& aGamepadEvent)
             : mEvent(aGamepadEvent) {}
  NS_IMETHOD Run() override
  {
    RefPtr<GamepadManager> svc(GamepadManager::GetService());
    if (svc) {
      svc->Update(mEvent);
    }
    return NS_OK;
  }
 protected:
  GamepadChangeEvent mEvent;
};

} // namespace

bool
GamepadEventChannelChild::RecvGamepadUpdate(
                                       const GamepadChangeEvent& aGamepadEvent)
{
  DebugOnly<nsresult> rv =
    NS_DispatchToMainThread(new GamepadUpdateRunnable(aGamepadEvent));
  NS_WARNING_ASSERTION(NS_SUCCEEDED(rv), "NS_DispatchToMainThread failed");
  return true;
}

} // namespace dom
} // namespace mozilla