Speed scope

[adamsitnik]

@vancem I decided to add the new argument --format to the dotnet-collect tool. IMHO output format of the collect command is more natural to me than new analysis command (we don't analyze anything here). Also the dotnet-collect has the concept of ETW/EventPipe and it was simply very easy to add it there.

If the user specifies --format speedscope I load the trace file and export it to a *.speedsope.json format. The default is just "trace" (does not change existing behavior)

Sample usage:

dotnet run -- --profile Default --format SpeedScope --config-path /Projects/SomeApp/bin/Release/netcoreapp3.0/SomeApp.eventpipeconfig --process-id 792

I added few provider names to the "default" profile. I needed to that to be able to get stack samples and symbols (rundown).

I tested it on macOS and Windows with .NET Core 3.0 and it works.

I am open to any ideas/suggestions/changes.

[sywhang]

I believe this line is throwing

EtwCollector.cs(86,36): error CS0618: 'ThreadTimeStackComputer' is obsolete: 'This is not obsolete but experimental, its interface is likely to change' 

in the CI builds :-)

[adamsitnik]

@vancem told me that a new tool (dotnet trace) will be created soon and it's going to contain this feature so I am closing this PR

[josalem]

@adamsitnik - Would it be possible to incorporate these changes into the updated dotnet-trace tool? If you don't have time, I can take up the effort if you'd be willing to outline the work necessary.

[adamsitnik]

Hi @josalem

Unfortunately, I don't have time now but I can outline the work necessary.

The logic that exports the data to a speedscope format lives in SpeedScopeStackSourceWriter.WriteStackViewAsJson which is part of the TraceEvent library (version 2.0.34+).
The method accepts a StackSource which is the provider of all profiling samples for the exporter. You can copy the code from this PR that allows for creating it from the EventPipe file.

Most probably the hardest thing will be choosing the new console argument name ;)

Please let me know if you need any help or something does not work as expected.