Try fix EventRoute weak memory leak

[lindexi]

Fixes #9467

Reference #6700 and #9460

Description

See #9467

After #6700 , to reduce allocations when tracing routed events, we'll use _traceArguments field to store the trace arguments which cause #9467 issues.

I try clear the reference from _traceArguments after call the TraceRoutedEvent.Trace.

And this pr is a patch, and I think #9460 will be better. Thank you @kasperk81

Customer Impact

See #9467

The memory will still be freed, albeit at a slower pace. Even if this issue is not addressed, it won't have a significant impact. There are two reasons for this. Firstly, the memory will still be freed, it just can't be released immediately. Secondly, this issue only affects those who have enabled Trace, which normal users typically do not do.

Regression

Reference #6700

And Cc @bgrainger

Testing

CI Only.

Risk

Middling

Microsoft Reviewers: Open in CodeFlow

[kasperk81]

duplicate of dotnet/runtime#9460

[lindexi]

And I think the #9460 is better than this. This pr is the patch.

[kasperk81]

i've closed mine.

your fix still has chance of race, when multiple threads are updating the variable. make the variable local? correctness > performance

[dipeshmsft]

@lindexi , @h3xds1nz this PR and #9468 are doing the same thing right, the difference being that here we are clearing out the array, whereas in the other PR we have replaced the array with ReadOnlySpan. Is there something more to it that I have missed ?

[lindexi]

@dipeshmsft You are right. My PR #9463 just simple fix. @h3xds1nz 's #9468 can do more improve. I expected this PR to be incorporated into the official release as a way to fix the patch, so I decided to make minimal changes.

[dipeshmsft]

I expected this PR to be incorporated into the official release as a way to fix the patch, so I decided to make minimal changes.

I completely agree with this. I was thinking of taking this for .NET 9 as this is minimal and solves the problem and will be easier to get approved for servicing.

[h3xds1nz]

I completely agree with this. I was thinking of taking this for .NET 9 as this is minimal and solves the problem and will be easier to get approved for servicing.

@dipeshmsft That was basically "our" intention with @lindexi.

[dipeshmsft]

In that case, @lindexi can you retarget this PR to release/9.0 branch.

[lindexi]

@dipeshmsft Done.

[dipeshmsft]

Thanks a lot @lindexi for taking a stab at this issue.