C# plugin hangs and cause high CPU usage while opening a big project

Issue Description

Since C# plugin 1.21.13, the C# plugin seems to hang when I open a project with more than 700 files. There is also a side effect that causes extensionHosts to max out a single CPU core. It can be reproduced 100% of the time and I have not experience the hang to finish at any point.

**EDIT: ** My project is a Unity project

1.21.12 was the last version that was working properly for me.

Steps to Reproduce

1. Open my project with C# plugin 1.21.13 or 1.21.14 installed
2. Observe OmniSharp log to stop at a point
3. Observe extensionHosts using nearly 100 unit of CPU

Expected Behavior

Project loads properly (Omnisharp prints “solution initialized”) in about a minute, Code Lens and jump to declaration works properly.

Actual Behavior

Project does not finish loading, Reference Code Lens does not appear and jump to declaration does not work.

Logs

OmniSharp log

The log contains file names to an already-live project, so I am hesitant to share. In summary, the log stops at the same line of text every time when the issue occurs.

C# log

None

Environment information

VSCode version: 1.43.0 C# Extension: 1.21.13

Mono Information

OmniSharp using global mono :6.8.0

Dotnet Information

.NET Core SDK (reflecting any global.json): Version: 3.0.101 Commit: bc5f8df0f5

Runtime Environment: OS Name: Mac OS X OS Version: 10.15 OS Platform: Darwin RID: osx.10.15-x64 Base Path: /usr/local/share/dotnet/sdk/3.0.101/

Host (useful for support): Version: 3.0.1 Commit: 32085cbc72

.NET Core SDKs installed: 2.1.103 [/usr/local/share/dotnet/sdk] 2.1.505 [/usr/local/share/dotnet/sdk] 3.0.101 [/usr/local/share/dotnet/sdk]

.NET Core runtimes installed: Microsoft.AspNetCore.All 2.1.9 [/usr/local/share/dotnet/shared/Microsoft.AspNetCore.All] Microsoft.AspNetCore.App 2.1.9 [/usr/local/share/dotnet/shared/Microsoft.AspNetCore.App] Microsoft.AspNetCore.App 3.0.1 [/usr/local/share/dotnet/shared/Microsoft.AspNetCore.App] Microsoft.NETCore.App 1.0.0-rc2-3002702 [/usr/local/share/dotnet/shared/Microsoft.NETCore.App] Microsoft.NETCore.App 1.0.0 [/usr/local/share/dotnet/shared/Microsoft.NETCore.App] Microsoft.NETCore.App 1.0.2 [/usr/local/share/dotnet/shared/Microsoft.NETCore.App] Microsoft.NETCore.App 2.0.6 [/usr/local/share/dotnet/shared/Microsoft.NETCore.App] Microsoft.NETCore.App 2.1.9 [/usr/local/share/dotnet/shared/Microsoft.NETCore.App] Microsoft.NETCore.App 2.1.14 [/usr/local/share/dotnet/shared/Microsoft.NETCore.App] Microsoft.NETCore.App 3.0.1 [/usr/local/share/dotnet/shared/Microsoft.NETCore.App]

To install additional .NET Core runtimes or SDKs: https://aka.ms/dotnet-download

Visual Studio Code Extensions

Extension	Author	Version
cpptools	ms-vscode	0.26.3
csharp	ms-dotnettools	1.21.13
FlatUI	lkytal	1.4.9
theme-bluloco-light	uloco	3.0.1
theme-flatui	danibram	3.1.0
theme-karyfoundation-themes	karyfoundation	20.0.3
vscode-antlr4	mike-lischke	2.2.3
vscode-clang	mitaki28	0.2.3
vscode-icons	vscode-icons-team	10.0.0
xcode-default-theme	smockle	2.0.21

[NTaylorMullen]

@NTaylorMullen I believe this glob is chewing up the CPU for users with large node_modules. https://github.com/OmniSharp/omnisharp-vscode/pull/3593/files#diff-8c9691b11e7b8efdf4865f5653a295c5R175

Oh goodness! Wow that’s awful, i’ll absolutely take a stab at making that code more targeted instead of diving the whole directory.

[JoeRobich]

@mdowais Thank you so much for your investigation. I was looking through the changes in 1.21.13 and I think you hit on it being the node_modules folder.

@NTaylorMullen I believe this glob is chewing up the CPU for users with large node_modules. https://github.com/OmniSharp/omnisharp-vscode/pull/3593/files#diff-8c9691b11e7b8efdf4865f5653a295c5R175

We’ve had several users share .cpuprofiles which showed a large amount of time in the glob package, but I didn’t give it much weight since I know the heavy lifting is done in .NET.