fix: trace git command correctly (#39520)

Help  #39410

modules/git/gitcmd/command.go

@@ -49,8 +49,8 @@ type Command struct {
 	cmd *process.Cmd
 
 	cmdCtx       context.Context
-	cmdCancel    process.CancelCauseFunc
-	cmdFinished  process.FinishedFunc
+	cmdCtxCancel process.CancelCauseFunc
+	cmdFinished  func()
 	cmdStartTime time.Time
 
 	pipelineFunc func(Context) error
@@ -428,19 +428,24 @@ func (c *Command) Start(ctx context.Context) (retErr error) {
 	if c.callerInfo == "" {
 		c.WithParentCallerInfo()
 	}
+
 	// these logs are for debugging purposes only, so no guarantee of correctness or stability
 	desc := fmt.Sprintf("git.Run(by:%s, repo:%s): %s", c.callerInfo, logArgSanitize(c.gitDir), cmdLogString)
 	log.Debug("git.Command: %s", desc)
 
 	_, span := gtprof.GetTracer().Start(ctx, gtprof.TraceSpanGitRun)
-	defer span.End()
 	span.SetAttributeString(gtprof.TraceAttrFuncCaller, c.callerInfo)
 	span.SetAttributeString(gtprof.TraceAttrGitCommand, cmdLogString)
 
+	var cmdCtxFinished func()
 	if c.cmdTimeout <= 0 {
-		c.cmdCtx, c.cmdCancel, c.cmdFinished = process.GetManager().AddContext(ctx, desc)
+		c.cmdCtx, c.cmdCtxCancel, cmdCtxFinished = process.GetManager().AddContext(ctx, desc)
 	} else {
-		c.cmdCtx, c.cmdCancel, c.cmdFinished = process.GetManager().AddContextTimeout(ctx, c.cmdTimeout, desc)
+		c.cmdCtx, c.cmdCtxCancel, cmdCtxFinished = process.GetManager().AddContextTimeout(ctx, c.cmdTimeout, desc)
+	}
+	c.cmdFinished = func() {
+		cmdCtxFinished()
+		span.End()
 	}
 
 	c.cmdStartTime = time.Now()

modules/git/gitcmd/context.go

@@ -27,6 +27,6 @@ func (c *cmdContext) CancelPipeline(err error) error {
 	// * context canceled by pipeline caller with/without error (normal cancellation)
 	// * context canceled by parent context (still context.Canceled error)
 	// * other causes
-	c.cmd.cmdCancel(pipelineError{err})
+	c.cmd.cmdCtxCancel(pipelineError{err})
 	return err
 }

modules/gtprof/trace.go

@@ -122,6 +122,8 @@ func (t *Tracer) Start(ctx context.Context, spanName string) (context.Context, *
 		ts.parent = parentSpan
 	}
 
+	// FIXME: this ctx handling is not right. The returned ctx should inherit the ctx passed in, but not from span's internal contexts
+	// The returned ctx only needs to inherit the values of the internal contexts of spans
 	parentCtx := ctx
 	for internalSpanIdx, tsp := range starters {
 		var internalSpan traceSpanInternal

modules/gtprof/trace_const.go

@@ -6,14 +6,17 @@ package gtprof
 // Some interesting names could be found in https://github.com/open-telemetry/opentelemetry-go/tree/main/semconv
 
 const (
+	TraceSpanContext  = "context"
 	TraceSpanHTTP     = "http"
 	TraceSpanGitRun   = "git-run"
 	TraceSpanDatabase = "database"
 )
 
 const (
-	TraceAttrFuncCaller = "func.caller"
-	TraceAttrDbSQL      = "db.sql"
-	TraceAttrGitCommand = "git.command"
-	TraceAttrHTTPRoute  = "http.route"
+	TraceAttrGeneralName = "general.name"
+	TraceAttrGeneralDesc = "general.desc"
+	TraceAttrFuncCaller  = "func.caller"
+	TraceAttrDbSQL       = "db.sql"
+	TraceAttrGitCommand  = "git.command"
+	TraceAttrHTTPRoute   = "http.route"
 )