Shutdown if Parent Process Shuts Down

[cdietrich]

LS does not exit if the parent process is not alive
see eclipse-archived/xtext-core#552

[spoenemann]

How could this be solved generically in LSP4J? I think it's the responsibility of the Xtext language server to take care of this.

[cdietrich]

i think lsp4j should provide a facilitly to make this a oneliner in every implementer of ILanguageServer or even should provide default method. since the wait loop is done in lsp4j anyway. that would be the point to check and shutdown.

[cdietrich]

maybe @akosyakov can give some hints how he implemented that in real world scenarios.

[spoenemann]

The code is here:

https://github.com/eclipse/lsp4j/blob/a78806c809d5daadd34403b32833d163443a3cce/org.eclipse.lsp4j.services/src/main/java/org/eclipse/lsp4j/services/transport/server/LanguageServerEndpoint.xtend#L83-L92

That was taken from the old LS-API implementation. It does not work anymore with the LSP4J code structure because the general JSON-RPC implementation in org.eclipse.lsp4j.jsonrpc does not depend on the actual protocol in org.eclipse.lsp4j (but the other way around). And I'm against adding a default implementation to the LanguageServer interface, since that would be overridden by existing implementations anyway.

[spoenemann]

We could add a utility class that can be used by the LanguageServer implementations.

[gorkem]

On jdt.ls we ended up implementing a parent process check that would activate only after a period of inactivity because windows users were not happy with the constant resource consumption.
eclipse-jdtls/eclipse.jdt.ls@8654474

[spoenemann]

I implemented a utility class in #164. However, it works only for Unix-type systems. We should't add new API that supports only some of the relevant operating systems.

If anyone is eager to solve this, feel free to extend my solution in #164 so it also supports Windows.

[georgewfraser]

I have had success by simply exiting when System.in closes: georgewfraser/kotlin-language-server@0c9e2d0