Extension causes high cpu load

[tonyghita]

• Issue Type: Performance
• Extension Name: Go
• Extension Version: 0.10.0
• OS Version: Darwin x64 17.7.0
• VSCode version: 1.33.1

ms-vscode.Go-unresponsive.cpuprofile.txt

[tonyghita]

$ go env
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/tonyghita/Library/Caches/go-build"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/tonyghita/go"
GOPROXY=""
GORACE=""
GOROOT="/usr/local/Cellar/go/1.12.4/libexec"
GOTMPDIR=""
GOTOOLDIR="/usr/local/Cellar/go/1.12.4/libexec/pkg/tool/darwin_amd64"
GCCGO="gccgo"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD=""
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/gv/vdmq3_l541b_0lq_ds37xslnzgdpkw/T/go-build045906030=/tmp/go-build -gno-record-gcc-switches -fno-common"

[tonyghita]

The Go portion of settings.json:

{
    "go.formatTool": "goimports",
    "go.installDependenciesWhenBuilding": false,
    "go.useLanguageServer": true,
    "go.vetOnSave": "off",
    "go.lintTool": "staticcheck",
    "go.lintOnSave": "file"
}

[tonyghita]

The settings I had don't seem to make sense. I read through the installation instructions of gopls, ensured gopls was installed, and replaced my existing configuration with the provided configuration.

"go.useLanguageServer": true,
"go.alternateTools": {
     "go-langserver": "gopls"
},
"go.languageServerExperimentalFeatures": {
    "format": true,
    "autoComplete": true,
    "diagnostics": true,
    "goToDefinition": true,
    "hover": true,
    "signatureHelp": true,
    "goToTypeDefinition": true,
    "documentSymbols": true,
},
"go.buildOnSave": "off",
"go.vetOnSave": "off",
"[go]": {
    "editor.snippetSuggestions": "none",
    "editor.formatOnSave": true,
    "editor.codeActionsOnSave": {
        "source.organizeImports": true
    },
},
"gopls": {
    "enablePlaceholders": true, // add parameter placeholders when completing a function
    "enhancedHover": true,      // experimental to improve quality of hover (will be on by default soon)
}

The editor and plugin seem to be pretty happy now.

[ramya-rao-a]

Thanks for that note @tonyghita

With the latest version of the extension most of the above are not needed.
Can you try removing all the above except "go.useLanguageServer": true, reload your VS Code window and see if you see high CPU usage?

[tonyke-bot]

I have the same issue with "go.useLanguageServer": true
If I disable languaguServer, everything is good except those go modules project. I highly doubt that this feature is causing the crash.

FYI


ms-vscode.Go-unresponsive.cpuprofile.txt

[lloiser]

I had the same problem. Even copying the recommended settings from https://github.com/golang/go/wiki/gopls#editors-instructions did not work.

Eventually I fixed it by:

• set "go.useLanguageServer": false
• reload vscode
• get prompt to install and use the gopls language server
• reload vscode

I have not installed gopls previously, so maybe there is an issue with the detection of gopls?

[ramya-rao-a]

Thanks for sharing what worked @lloiser

@THaGKI9 Can you try the steps that @lloiser shared above and see if that helps?

@lloiser and anyone else who are able to fix the situation with the above steps:
Can you describe what the status of your settings were before the high cpu usage problem?
I'd like to replicate the scenario to come up with a fix, because it looks like multiple users are seeing the issue after the latest update

[tonyke-bot]

@ramya-rao-a

Following @lloiser 's instructions,
I set "go.useLanguageServer": false and reload the vscode.
But I don't get prompt to install the gopls language server and I try to manually install gopls with

$ go get -u -v golang.org/x/tools/cmd/gopls

After installing gopls, I restart vscode with goLanguageServer enabled and the problem is fixed

[lloiser]

@ramya-rao-a these are my settings that worked very well with the previous version 0.9:

{
    "go.autocompleteUnimportedPackages": true,
    "go.useCodeSnippetsOnFunctionSuggest": true,
    "go.toolsGopath": "/Users/lloiser/go_tools",
    "go.lintFlags": [
        "--config=${workspaceRoot}/scripts/revive.toml"
    ],
    "go.lintTool": "revive",
    "go.useLanguageServer": false,
    "go.vetOnSave": "off"
}

After updating to 0.10 I only changed

    "go.useLanguageServer": true,

which resulted in the high cpu...

I did not have gopls or any other language server installed previously.

[tonyghita]

@ramya-rao-a

With the latest version of the extension most of the above are not needed.
Can you try removing all the above except "go.useLanguageServer": true, reload your VS Code window and see if you see high CPU usage?

I removed all go-related settings except "go.useLanguageServer": true, and everything seems to work fine. I do not get the high-CPU issue.

At this point I wonder if the issue was actually that gopls was not yet installed (I happened to be working off a fresh installation of MacOS). I was not prompted by the extension to install any tools. I installed gopls via go get.

[ramya-rao-a]

Thanks for the sequence of steps @lloiser, I was able to replicate the issue
@tonyghita Your notes helped as well

I have pushed a fix and released an update (0.10.1) which will have the fix.

Thanks for reporting and your patience and for helping me figure out the issue!

[tonyghita]

@ramya-rao-a very much appreciate your leadership on this plugin, thank you!