lambda.cpp

// lambda BASED
bool
WorkerPrivate::AddHolder(WorkerHolder* aHolder, WorkerStatus aFailStatus)
{
  return mWorkerThreadAccessible.Access(
    [this, aHolder, aFailStatus] (WorkerThreadAccessible& aData) {
      {
        MutexAutoLock lock(mMutex);

        if (mStatus >= aFailStatus) {
          return false;
        }
      }

      MOZ_ASSERT(!mHolders.Contains(aHolder), "Already know about this one!");

      if (aHolder->GetBehavior() == WorkerHolder::PreventIdleShutdownStart) {
        if (!aData.mNumHoldersPreventingShutdownStart && !ModifyBusyCountFromWorker(true)) {
          return false;
        }
        aData.mNumHoldersPreventingShutdownStart += 1;
      }

      mHolders.AppendElement(aHolder);
      return true;
    });
}

RAII-based.cpp

// RAII BASED
bool
WorkerPrivate::AddHolder(WorkerHolder* aHolder, WorkerStatus aFailStatus)
{
  auto data = mWorkerThreadAccessible.Access();

  {
    MutexAutoLock lock(mMutex);

    if (mStatus >= aFailStatus) {
      return false;
    }
  }

  MOZ_ASSERT(!mHolders.Contains(aHolder), "Already know about this one!");

  if (aHolder->GetBehavior() == WorkerHolder::PreventIdleShutdownStart) {
    if (!data->mNumHoldersPreventingShutdownStart && !ModifyBusyCountFromWorker(true)) {
      return false;
    }
    data->mNumHoldersPreventingShutdownStart += 1;
  }

  mHolders.AppendElement(aHolder);

  return true;
}