Files
UnrealEngineUWP/Engine/Source/Runtime/PakFile
Wojciech Krywult d1baf24722 AsyncIO: Fixed incorrect handling of the STAT_AsyncFileMemory stat.
I've reviewed all code using async requests and we had multiple places incorrectly handling the stat: some placed failed to decrease the counter, while others would decrease it when they shouldn't. The main cause was the fact that when we create an async request and pass nullptr as the target memory, the request allocates the memory itself and increases the STAT_AsyncFileMemory. However, when we call GetReadResults() on such requests, the responsibility is on the caller to balance the calls and decrease the stat, which is not very obvious and leads to the mentioned bugs. On top of that, when we call GetReadResults() we may not have the knowledge as to whether the returned memory was allocated by the request or not (which may affect whether we should touch the stat at all).

Resolved by adding IAsyncReadRequest::ReleaseMemoryOwnershipImpl member, which may be used by request implementations to do the proper clean up (balance the stat). This way requests take the full responsibility for their changes and users of the requests don't need to know their implementation details.

#preflight none
#rb Patrick.Laflamme
#jira UE-185064

[CL 25664733 by Wojciech Krywult in ue5-main branch]
2023-05-29 12:11:37 -04:00
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