TSServer High CPU Usage

[mjbvz]

Moving microsoft/vscode#21442 over to the TypeScript side.

@atian25 provided a bunch of logs to help with the investigation but it as not clear to me what is going wrong. Here's the TSServer log:

-----------------------------------------------
Open files: 
/Users/tz/Workspaces/eggjs/common-bin/test/fixtures/my-bin/lib/my_program.js
Info 34   event: {"seq":0,"type":"event","event":"configFileDiag","body":{"triggerFile":"/Users/tz/Workspaces/eggjs/common-bin/test/fixtures/my-bin/lib/my_program.js","diagnostics":[]}}
Perf 35   6::open: async elapsed time (in milliseconds) 1780.4235
Info 36   request: {"seq":7,"type":"request","command":"geterr","arguments":{"delay":0,"files":["/Users/tz/Workspaces/eggjs/common-bin/test/fixtures/my-bin/lib/my_program.js"]}}
Perf 37   7::geterr: async elapsed time (in milliseconds) 1.7650
Info 38   event: {"seq":0,"type":"event","event":"syntaxDiag","body":{"file":"/Users/tz/Workspaces/eggjs/common-bin/test/fixtures/my-bin/lib/my_program.js","diagnostics":[]}}
Info 39   /Users/tz/ti-6176.log is not tsconfig.json
Info 40   /Users/tz/ti-6176.log is not tsconfig.json
Info 41   /Users/tz/ti-6176.log is not tsconfig.json
Info 42   /Users/tz/ti-6176.log is not tsconfig.json
Info 43   /Users/tz/ti-6176.log is not tsconfig.json
Info 44   /Users/tz/ti-6176.log is not tsconfig.json
Info 45   event: {"seq":0,"type":"event","event":"semanticDiag","body":{"file":"/Users/tz/Workspaces/eggjs/common-bin/test/fixtures/my-bin/lib/my_program.js","diagnostics":[]}}
Info 46   Sending request: {"projectName":"/dev/null/inferredProject1*","fileNames":["/Applications/Visual Studio Code.app/Contents/Resources/app/extensions/typescript/node_modules/typescript/lib/lib.es6.d.ts","/Users/tz/Workspaces/eggjs/common-bin/lib/run.js","/Users/tz/Workspaces/eggjs/common-bin/lib/program.js","/Users/tz/Workspaces/eggjs/common-bin/lib/helper.js","/Users/tz/Workspaces/eggjs/common-bin/lib/command.js","/Users/tz/Workspaces/eggjs/common-bin/index.js","/Users/tz/Workspaces/eggjs/common-bin/test/fixtures/my-bin/lib/my_program.js"],"compilerOptions":{"module":1,"target":2,"allowSyntheticDefaultImports":true,"allowNonTsExtensions":true,"allowJs":true,"jsx":1,"noEmitForJsFiles":true},"typeAcquisition":{"enable":true,"include":[],"exclude":[]},"unresolvedImports":["assert","child_process","child_process","crypto","events","fs","http","net","path","path","readline","stream","tls"],"projectRootPath":"","kind":"discover"}
Info 47   /Users/tz/ti-6176.log is not tsconfig.json
Info 48   /Users/tz/.zsh_history.LOCK is not tsconfig.json
Info 49   /Users/tz/.zsh_history.LOCK is not tsconfig.json
Info 50   /Users/tz/.zsh_history.LOCK is not tsconfig.json
Info 51   /Users/tz/.zsh_history.LOCK is not tsconfig.json
Info 52   /Users/tz/.zsh_history.LOCK is not tsconfig.json
Info 53   /Users/tz/.zsh_history.LOCK is not tsconfig.json
Info 54   /Users/tz/.zsh_history.LOCK is not tsconfig.json
Info 55   /Users/tz/.zsh_history.LOCK is not tsconfig.json

microsoft/vscode#21442 contains some other logs that may be useful for the investigation. I was unable to repo the problem on my local machine

[mhegazy]

@sheetalkamat can you take a look at this one as well.