Support EventSource/event pipe in shared libraries

[MichalStrehovsky]

When EventSourceSupport MSBuild property is set to true, the build currently errors out. It is possible to bypass this by setting _SuppressNativeLibEventSourceError property to true but there are known issues. It is not recommended to ship native libraries like this unless one can make sure no other native library (or a CoreCLR instance) with EventSourceSupport gets loaded into the process. Users might consider shipping two versions of their native library DLL and only use the one with EventSourceSupport enabled when troubleshooting a specific issue.

This is a tracking uber issue that groups the known existing problems:

• [ ] https://github.com/dotnet/runtime/issues/88087
• [ ] (Windows only) https://github.com/dotnet/runtime/issues/89346

Our guidance for EventSource/EventPipe with native AOT shared libraries is as follows,

• Only use the EventSourceSupport enabled when troubleshooting a specific issue related to shared libraries.
• Any native AOT console with EventSourceSupport enabled will always win even if the process has other native AOT shared libraries with EventSourceSupport enabled.
• If there are multiple native AOT shared libraries present in a single process, then the first shared library that gets loaded will win to emit traces. Traces from other libraries will not be seen.
• [Windows] When collecting tracing in a shared library, collection should stop earlier in the application (only collect for a specific time period or use the ctrl-C option with a tool like dotnet-trace when the interesting traces are collected). Specifically, in windows, the image unload event for a shared library (or at process exit), will not make a call to shut down the EventPipe in an orderly manner, causing a corrupted trace file.

Given these challenges, it's probably best to keep the current warnings we have for shared library around EventSource support.

[ghost]

Tagging subscribers to this area: @agocke, @MichalStrehovsky, @jkotas See info in area-owners.md if you want to be subscribed.

Issue Details

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When `EventSourceSupport` MSBuild property is set to true, the build currently errors out. It is possible to bypass this by setting `_SuppressNativeLibEventSourceError` property to true but there are known issues. It is not recommended to ship native libraries like this unless one can make sure no other native library (or a CoreCLR instance) with EventSourceSupport gets loaded into the process. Users might consider shipping two versions of their native library DLL and only use the one with EventSourceSupport enabled when troubleshooting a specific issue. This is a tracking uber issue that groups the known existing problems: - [ ] https://github.com/dotnet/runtime/issues/88087 - [ ] (Windows only) https://github.com/dotnet/runtime/issues/89346

Author:	MichalStrehovsky
Assignees:	-
Labels:	`area-NativeAOT-coreclr`
Milestone:	Future