Visual Studio 2017 RC hangs on closing VF# solution

[forki]

Nearly every time I close the VF# solution (sln from this repo here) in VS2017 RC the VS hangs forever on unloading project 50 from 64.

Same happens when switching branches.

[cartermp]

I haven't encountered this before - neither on my desktop nor my laptop. Do you have similar behavior in other F# projects with a fair amount of .fsprojs?

[forki]

No. I only tried with this solution and it's always project 50. Unfortunately it doesn't say which project that is. Am 16.12.2016 06:56 schrieb "Phillip Carter" <notifications@github.com>:

…

I haven't encountered this before - neither on my desktop nor my laptop. Do you have similar behavior in other F# projects with a fair amount of .fsprojs? — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#2022 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AADgNBrKcpQ9-XP_izAIr4KYOOyT5rrTks5rIigWgaJpZM4LObKL> .

[cartermp]

@forki have you noticed this lately? I still haven't encountered it.

[forki]

Yes still there

[cartermp]

FYI I was able to repro this on a VM. It's inconsistent (could never repro it on my desktop nor my laptop after multiple installations), but now that we have a VM with this repro-ing we can try and get a fix. Unfortunately we're going to have to punt this one for now, but we're calling it out as a known regression ...and thus it has a high priority for us to fix.

[cartermp]

Just an update: I've been seeing this pretty consistently now with RC3 + VSIX installed. Not sure how that "helped" by making it more common, but at least it's something we can pin down pretty reliably.

[vasily-kirichenko]

Yes, I see it now on RC3. This is what dotTrace shows:

Leaving alone the huge portion on native code, Microsoft.CodeAnalysis.Workspace.OnDocumentContextUpdated is actively doing something in a background thread. I'm not sure if it's our issue or Roslyn's. Note that VS loads one CPU code forever.

[vasily-kirichenko]

[vasily-kirichenko]

Looks like Roslyn is waiting SemaphoreSlim here http://source.roslyn.io/#Microsoft.CodeAnalysis.Workspaces/Workspace/Workspace_Editor.cs,347
This semaphore can be locked in any of 34 places where it's used :(

@Pilchie @CyrusNajmabadi any ideas how to investigate it further?

[CyrusNajmabadi]

Is this just a dupe of dotnet/roslyn#14479 ? If so, @dpoeschl has submitted a fix here: dotnet/roslyn#16889

[vasily-kirichenko]

@CyrusNajmabadi yes, looks like it's the same bug. And it looks like the fix is going to RTM?

[CyrusNajmabadi]

Yup. The fix is going into RTM.

[forki]

Cool. Would have been a real paint point otherwise. Thanks