Solution to https://community.cesium.com/t/it-took-more-than-ten-seconds-to-exit/23354 problem

[newpeople123]

Dear Cesium Official Team,

Hello!

This pull request primarily addresses the issue discussed on the Cesium forum regarding this link It took more than ten seconds to exit.

The approach is as follows: it tracks all pending requests made by the UnrealAssetAccessor class, and when a UCesiumRasterOverlay or Cesium3DTileset instance is destroyed, it simultaneously cancels all pending requests associated with that instance.

Its limitation: for Cesium Ion map resources, it determines this in a hard-coded manner (e.g., for Bing Maps or Cesium World Terrain).

For a large open-source repository, this code is not particularly perfect. I do not have high expectations for the acceptance of this pull request, but I hope my approach is helpful to you, and I hope you will pay attention to this issue. This would make it more friendly for developers in regions with poor network conditions or those facing network instability.

Best regards.

[kring]

Thanks @newpeople123! Do we have a signed Contributor License Agreement from you already? https://github.com/CesiumGS/community/tree/main/CLAs

[newpeople123]

Thanks @newpeople123! Do we have a signed Contributor License Agreement from you already? https://github.com/CesiumGS/community/tree/main/CLAs

Sorry for the delay — I was on May Day holiday the past few days and just got back to work today. I’ve now signed the individual CLA. Please take a look at my pull request when you have a chance (not necessarily to merge, but at least as a reference).