Method WaitForLoaded

Source/Engine/Content/Asset.cpp:450–512

}

bool Asset::WaitForLoaded(double timeoutInMilliseconds) const
{
    // This function is used many time when some parts of the engine need to wait for asset loading end (it may fail but has to end).
    // But it cannot be just a simple active-wait loop.
    // Imagine following situation:
    // Content Pool has 2 loading threads.
    // Both start to load layered materials which need to be recompiled (Material Generator work).
    // Every of these materials is made of a few layers.
    // To load child layer Material Generator is requesting Content Pool to load it fully.
    // However this cannot be done because Pool has limited threads and all of them may requesting more loads to be done.
    //
    // To solve that problem we have different solutions:
    // 1) add more loading threads (bad idea)
    // 2) content loading could use thread pool to enqueue single tasks (still risky due to many tasks queued and limited Thread Pool size (need to build graph of dependencies?))
    // 3) content loading could detect asset load calls from content loader threads and load requested asset without stalls
    // 4) every asset could expose dependencies and content system could load required dependencies earlier
    //
    // 3) and 4) are good solutions. 4) would require more work but will be needed in future for building system to gather assets for game packages.
    // But WaitForLoaded could detect if is called from the Loading Thead and manually load dependent asset. It's fairly easy to do and will work out.

    // Early out if asset has been already loaded
    if (IsLoaded())
    {
        // If running on a main thread we can flush asset `Loaded` event
        if (IsInMainThread())
        {
            Content::tryCallOnLoaded((Asset*)this);
        }

        return false;
    }

    // Check if loading failed
    Platform::MemoryBarrier();
    if (LastLoadFailed())
        return true;

    // Check if has missing loading task
    Platform::MemoryBarrier();
    const auto loadingTask = (ContentLoadTask*)Platform::AtomicRead(&_loadingTask);
    if (loadingTask == nullptr)
    {
        if (IsLoaded())
            return false;
        LOG(Warning, "WaitForLoaded asset \'{0}\' failed. No loading task attached and asset is not loaded.", ToString());
        return true;
    }

    PROFILE_CPU();
    ZoneColor(TracyWaitZoneColor);
    const StringView path(GetPath());
    ZoneText(*path, path.Length());

    Content::WaitForTask(loadingTask, timeoutInMilliseconds);

    // If running on a main thread we can flush asset `Loaded` event
    if (IsInMainThread() && IsLoaded())
    {