fix: race condition in reporter between RunDaemon and Close (#796)

## Summary

- Fix data race on `r.closed` between `RunDaemon()` and `Close()` by protecting it with the existing `stateMu` — `closed` is part of the reporter state. `RunDaemon()` reads it under `stateMu.RLock()`, `Close()` sets it inside the existing `stateMu.Lock()` block
- `ReportState` now has a parameter to not report results from runDaemon even if set, from now on `Close` reports the result
- `Close` waits for `RunDaemon()` to signal exit via a closed channel `daemon` before reporting the final logs and state with result, unless something really wrong happens it does not time out
- Add `TestReporter_EphemeralRunnerDeletion` which reproduces the exact scenario from #793: RunDaemon's `ReportState` racing with `Close`, causing the ephemeral runner to be deleted before final logs are sent
- Add `TestReporter_RunDaemonClose_Race` which exercises `RunDaemon()` and `Close()` concurrently to verify no data race on `r.closed` under `go test -race`
- Enable `-race` flag in `make test` so CI catches data races going forward

Based on #794, with fixes for the remaining unprotected `r.closed` reads that the race detector catches.

Fixes #793

---------

Co-authored-by: Christopher Homberger <christopher.homberger@web.de>
Co-authored-by: ChristopherHX <christopher.homberger@web.de>
Co-authored-by: rmawatson <rmawatson@hotmail.com>
Reviewed-on: https://gitea.com/gitea/act_runner/pulls/796
Reviewed-by: ChristopherHX <christopherhx@noreply.gitea.com>
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: silverwind <me@silverwind.io>
Co-committed-by: silverwind <me@silverwind.io>

internal/pkg/report/reporter.go

@@ -5,6 +5,7 @@ package report
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"regexp"
 	"strings"
@@ -37,6 +38,7 @@ type Reporter struct {
 	state   *runnerv1.TaskState
 	stateMu sync.RWMutex
 	outputs sync.Map
+	daemon  chan struct{}
 
 	debugOutputEnabled  bool
 	stopCommandEndToken string
@@ -63,6 +65,7 @@ func NewReporter(ctx context.Context, cancel context.CancelFunc, client client.C
 		state: &runnerv1.TaskState{
 			Id: task.Id,
 		},
+		daemon: make(chan struct{}),
 	}
 
 	if task.Secrets["ACTIONS_STEP_DEBUG"] == "true" {
@@ -109,6 +112,7 @@ func (r *Reporter) Fire(entry *log.Entry) error {
 	if stage != "Main" {
 		if v, ok := entry.Data["jobResult"]; ok {
 			if jobResult, ok := r.parseResult(v); ok {
+				// We need to ensure log upload before this upload
 				r.state.Result = jobResult
 				r.state.StoppedAt = timestamppb.New(timestamp)
 				for _, s := range r.state.Steps {
@@ -176,15 +180,17 @@ func (r *Reporter) Fire(entry *log.Entry) error {
 }
 
 func (r *Reporter) RunDaemon() {
-	if r.closed {
-		return
-	}
-	if r.ctx.Err() != nil {
+	r.stateMu.RLock()
+	closed := r.closed
+	r.stateMu.RUnlock()
+	if closed || r.ctx.Err() != nil {
+		// Acknowledge close
+		close(r.daemon)
 		return
 	}
 
 	_ = r.ReportLog(false)
-	_ = r.ReportState()
+	_ = r.ReportState(false)
 
 	time.AfterFunc(time.Second, r.RunDaemon)
 }
@@ -226,9 +232,8 @@ func (r *Reporter) SetOutputs(outputs map[string]string) {
 }
 
 func (r *Reporter) Close(lastWords string) error {
-	r.closed = true
-
 	r.stateMu.Lock()
+	r.closed = true
 	if r.state.Result == runnerv1.Result_RESULT_UNSPECIFIED {
 		if lastWords == "" {
 			lastWords = "Early termination"
@@ -251,13 +256,23 @@ func (r *Reporter) Close(lastWords string) error {
 		})
 	}
 	r.stateMu.Unlock()
+	// Wait for Acknowledge
+	select {
+	case <-r.daemon:
+	case <-time.After(60 * time.Second):
+		close(r.daemon)
+		log.Error("No Response from RunDaemon for 60s, continue best effort")
+	}
 
-	return retry.Do(func() error {
-		if err := r.ReportLog(true); err != nil {
-			return err
-		}
-		return r.ReportState()
-	}, retry.Context(r.ctx))
+	// Report the job outcome even when all log upload retry attempts have been exhausted
+	return errors.Join(
+		retry.Do(func() error {
+			return r.ReportLog(true)
+		}, retry.Context(r.ctx)),
+		retry.Do(func() error {
+			return r.ReportState(true)
+		}, retry.Context(r.ctx)),
+	)
 }
 
 func (r *Reporter) ReportLog(noMore bool) error {
@@ -285,17 +300,20 @@ func (r *Reporter) ReportLog(noMore bool) error {
 
 	r.stateMu.Lock()
 	r.logRows = r.logRows[ack-r.logOffset:]
+	submitted := r.logOffset + len(rows)
 	r.logOffset = ack
 	r.stateMu.Unlock()
 
-	if noMore && ack < r.logOffset+len(rows) {
+	if noMore && ack < submitted {
 		return fmt.Errorf("not all logs are submitted")
 	}
 
 	return nil
 }
 
-func (r *Reporter) ReportState() error {
+// ReportState only reports the job result if reportResult is true
+// RunDaemon never reports results even if result is set
+func (r *Reporter) ReportState(reportResult bool) error {
 	r.clientM.Lock()
 	defer r.clientM.Unlock()
 
@@ -303,6 +321,11 @@ func (r *Reporter) ReportState() error {
 	state := proto.Clone(r.state).(*runnerv1.TaskState)
 	r.stateMu.RUnlock()
 
+	// Only report result from Close to reliable sent logs
+	if !reportResult {
+		state.Result = runnerv1.Result_RESULT_UNSPECIFIED
+	}
+
 	outputs := make(map[string]string)
 	r.outputs.Range(func(k, v interface{}) bool {
 		if val, ok := v.(string); ok {