I wasn't able to reproduce the deadlock, but from the reported callstack, the following lock inversion happens:
* EditorSurfaceDataSystemComponent::OnCatalogLoaded locked the AssetCatalogRequestBus mutex by calling EnumerateAssets, and then locked m_assetMutex inside GetAsset->FindOrCreateAsset inside the enumerate callback.
* Loading threads would lock m_assetMutex in AssetManager::ValidateAndRegisterAssetLoading, then lock the AssetCatalogRequestBus inside the Asset<T> copy constructor when calling UpdateDebugStatus when the constructor calls SetData->UpgradeAssetInfo->UpdateAssetInfo->AssetCatalogRequestBus::GetAssetInfoById
This should solve the lock inversion on both sides of the problem:
* UpdateDebugStatus now takes in a const ref instead of a copy, so the copy constructor isn't called.
* EditorSurfaceDataSystemComponent::OnCatalogLoaded is rewritten to call GetAsset outside of the enumeration call.
As a bonus, this also removes the blocking load call. The rest of the code already supports asynchronous refreshes as the list assets are added / modified / removed, so this code was changed to leverage the asynchronous refreshes as well.
* removed the script rule from the Editor, now will only be supported via a script or JSON manual edits
* Mesh Serialization - scriptProcessorRule doesn't save with field empty, but produces no error
* added a test to make sure Script Processor Rule operates with an empty filename
Jira: https://jira.agscollab.com/browse/ATOM-14889
Tests: Launched the Editor to removed the script rule from the Editor
Esteban Papp
Mike Balfour
jackalbe
alexpete
mbalfour
jackalbe