gopls: enable telemetry uploading only with 'serve'

Fixes golang/go#64425

Change-Id: Ic27115a7034020313109f8268b4656f8fef66fb1
Reviewed-on: https://go-review.googlesource.com/c/tools/+/545475
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
Reviewed-by: Robert Findley <rfindley@google.com>
Auto-Submit: Hyang-Ah Hana Kim <hyangah@gmail.com>
Commit-Queue: Hyang-Ah Hana Kim <hyangah@gmail.com>

gopls/internal/cmd/serve.go

@@ -18,6 +18,7 @@ import (
 	"golang.org/x/tools/gopls/internal/lsp/debug"
 	"golang.org/x/tools/gopls/internal/lsp/lsprpc"
 	"golang.org/x/tools/gopls/internal/lsp/protocol"
+	"golang.org/x/tools/gopls/internal/telemetry"
 	"golang.org/x/tools/internal/fakenet"
 	"golang.org/x/tools/internal/jsonrpc2"
 	"golang.org/x/tools/internal/tool"
@@ -77,6 +78,8 @@ func (s *Serve) remoteArgs(network, address string) []string {
 // Run configures a server based on the flags, and then runs it.
 // It blocks until the server shuts down.
 func (s *Serve) Run(ctx context.Context, args ...string) error {
+	telemetry.Upload()
+
 	if len(args) > 0 {
 		return tool.CommandLineErrorf("server does not take arguments, got %v", args)
 	}

gopls/internal/telemetry/telemetry.go

@@ -26,10 +26,8 @@ func SetMode(mode string) error {
 	return telemetry.SetMode(mode)
 }
 
-// Start starts telemetry instrumentation.
-func Start() {
-	counter.Open()
-	// upload only once at startup, hoping that users restart gopls often.
+// Upload starts a goroutine for telemetry upload.
+func Upload() {
 	go upload.Run(nil)
 }
 

gopls/internal/telemetry/telemetry_go118.go

@@ -17,7 +17,7 @@ func SetMode(mode string) error {
 	return nil
 }
 
-func Start() {
+func Upload() {
 }
 
 func RecordClientInfo(params *protocol.ParamInitialize) {

gopls/main.go

@@ -17,14 +17,14 @@ import (
 	"context"
 	"os"
 
+	"golang.org/x/telemetry/counter"
 	"golang.org/x/tools/gopls/internal/cmd"
 	"golang.org/x/tools/gopls/internal/hooks"
-	"golang.org/x/tools/gopls/internal/telemetry"
 	"golang.org/x/tools/internal/tool"
 )
 
 func main() {
-	telemetry.Start()
+	counter.Open() // Enable telemetry counter writing.
 	ctx := context.Background()
 	tool.Main(ctx, cmd.New("gopls", "", nil, hooks.Options), os.Args[1:])
 }