x/tools/cmd/gopls: locks up with "no room in queue" error

[stamblerre]

There have been numerous reports of users seeing gopls freeze up, fail all request, and log "no room in queue". This seems to be a symptom of some larger gopls failure, likely a deadlock in the process of type-checking. It has been mentioned in discussions on #32360 and #31977.

[as]

This seems to happen because the defaultMessageBufferSize is set to 20 and RejectIfOverloaded is set to true for both client and server conns in jsonrpc2.

https://github.com/golang/tools/blob/master/internal/lsp/protocol/protocol.go#L14
https://github.com/golang/tools/blob/master/internal/jsonrpc2/jsonrpc2.go#L28

I think increasing the default to a more-reasonable 128, or just disabling RejectIfOverloaded should fix this issue.

[as]

After a bit of discussion, it seems reasonable to point out that this will not fix any request that happens to wedge the server, it would only fix a congestion issue that isn't a result of deadlock.

[k1ng440]

yes this issue exists for few days/weeks. gopls is being unable to use in windows or WSL

[tonyghita]

Chiming in with a bit of data... I'm now seeing this issue after the latest release

[Error - 11:23:07 AM] Request textDocument/documentLink failed.
  Message: no room in queue
  Code: -32000 
[Error - 11:23:07 AM] Request textDocument/codeAction failed.
  Message: no room in queue
  Code: -32000 
[Error - 11:23:07 AM] Request textDocument/documentSymbol failed.
  Message: no room in queue
  Code: -32000 
[Error - 11:23:07 AM] Request textDocument/codeAction failed.
  Message: no room in queue
  Code: -32000 

My build information

[Info  - 10:55:10 AM] Build info
----------
version v0.0.1-20190607+alpha, built in $GOPATH mode
Go info
-------
go version go1.12.5 darwin/amd64

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/1.12.5/libexec"
GOTMPDIR=""
GOTOOLDIR="/usr/local/Cellar/go/1.12.5/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-build209673958=/tmp/go-build -gno-record-gcc-switches -fno-common"

[VojtechVitek]

The "no room in queue" bug was crashing my gopls golangserver in VSCode every couple minutes since 2-3 weeks ago.

Finally, I lost my patience today and switched to "bingo". Hope this helps someone:

go get -u github.com/saibing/bingo

  "go.useLanguageServer": true,
  "go.alternateTools": {
    "go-langserver": "bingo",
    "gopls": "bingo"
  },
  "go.languageServerFlags": [
    "--diagnostics-style=instant",
    "--enhance-signature-help",
    "--format-style=goimports",
    "--goimports-prefix='github.com/pressly'", // enter your own here
  ],
  "go.languageServerExperimentalFeatures": {
    "autoComplete": true,
    "documentSymbols": true,
    "findReferences": true,
    "format": true,
    "goToDefinition": true,
    "goToTypeDefinition": true,
    "hover": true,
    "signatureHelp": true,
    "rename": true,
    "workspaceSymbols": true,
  },

[stamblerre]

@VojtechVitek: What version of gopls were you using (gopls version)? This bug is not entirely resolved, but those error messages should not have been appearing as of https://go-review.googlesource.com/c/tools/+/182458.

[VojtechVitek]

@stamblerre

$ gopls version
version v0.1.0-cmd.gopls, built in $GOPATH mode

[gopherbot]

Change https://golang.org/cl/183718 mentions this issue: internal/jsonrpc2: change the concurrency strategy