High CPU usage when working with cgo

[RadhiFadlillah]

As title said, I'm experiencing high CPU usage when working with a cgo project. This problem happened everytime I type a character which can be seen here.

Here are my vscode-go settings :

"go.formatTool": "goimports",
"go.autocompleteUnimportedPackages": false,
"go.installDependenciesWhenBuilding": false,
"go.useCodeSnippetsOnFunctionSuggestWithoutType": true,
"go.buildOnSave": "off",

[ramya-rao-a]

Thanks for reporting @RadhiFadlillah

@stamblerre Based on the settings shared above, the only tool that the Go extension calls on each letter being typed is your fork of gocode. Is it also responsible for the calls to gcc, go list etc?

@RadhiFadlillah Can you try the new language server feature we have? That will avoid calling gocode for completion feature.

[RadhiFadlillah]

Hi @ramya-rao-a, thanks for the response.

Can you try the new language server feature we have? That will avoid calling gocode for completion feature.

Yes, I've already tried the language server. Unfortunately, it doesn't work any better, as can be seen here. After I enabled the language server and reload the window, the CPU usage started to spike even before I type anything. Soon after, gopls crashed.

... the only tool that the Go extension calls on each letter being typed is your fork of gocode. Is it also responsible for the calls to gcc, go list etc?

Yes, that's also my first thought, and I was planned to submit this issue in @stamblerre repository. However, when I checked the source code for gocode, I didn't see any call to go list -compiled=true command. Hence why I decided to post this issue here.

[RadhiFadlillah]

After looking around, I found out that while gocode doesn't call go list by itself, it depends on golang.org/x/tools/go/packages which uses go list.

Since gocode uses go/packages with LoadSyntax mode, the go/packages end up using go list with -compiled flag set to true, which lead to high CPU usage in cgo project.

The same thing also happened with gopls, because it uses go/packages with NeedCompiledGoFiles mode, which lead to high CPU usage as well.

With that said, I guess the problem is not from vscode-go, gocode or gopls, but instead from go/packages.

[ramya-rao-a]

Thanks for the follow up @RadhiFadlillah!

Can you log an issue with your findings at https://github.com/golang/go/ and provide a link here?

cc @stamblerre, @ianthehat

[stamblerre]

@RadhiFadlillah are you using go1.12? There were some issues with cgo and go/packages that should have been improved in go1.12.

[RadhiFadlillah]

@ramya-rao-a sorry for late response, I've opened it in go#32821.

@stamblerre I'm using Go 1.12.5. Both gocode and go/packages have been updated to latest commit as well.

[stamblerre]

@RadhiFadlillah: Is this still an issue for you? gopls should work better for cgo than gocode does, if you are interested in trying that out as an alternative.

[vscodebot]

This issue has been closed automatically because it needs more information and has not had recent activity. Thank you for your contributions.