fix: prevent mutex deadlock on panic in config watcher

commit: 200ec03cdfacac1a547f7a06c7013ea8bf021b03
author: brice · 9mo ago · 2026-01-24 16:36 UTC
parent: 677e3c0
signature: GPG VerifiedCD88F9E564E0102646FB6077A1A07C7C7C3E349D · arch-gpg Verified for the committer email

1 file · +11 -2

M internal/infrastructure/config/watcher.go +11 -2


@@ -24,6 +24,14 @@ func (m *Manager) Watch() error {
24	24		// Acquire write lock before reload (reload modifies m.config)
25	25		m.mu.Lock()
26	26
	27	+	// Track whether notifyCallbacksLocked will handle the unlock
	28	+	willNotify := false
	29	+	defer func() {
	30	+	if !willNotify {
	31	+	m.mu.Unlock()
	32	+	}
	33	+	}()
	34	+
27	35		// Skip reload if this was triggered by our own Save() - the in-memory
28	36		// config is already correct and viper may have stale cached data
29	37		if m.skipNextReload {

@@ -34,6 +42,7 @@ func (m *Manager) Watch() error {
34	42		log.Warn().Err(err).Msg("failed to sync viper config after Save")
35	43		// Continue anyway - in-memory config is correct, just viper internal state is off
36	44		}
	45	+	willNotify = true
37	46		m.notifyCallbacksLocked()
38	47		return
39	48		}

@@ -41,9 +50,9 @@ func (m *Manager) Watch() error {
41	50		log.Debug().Msg("reloading config from external change")
42	51		if err := m.reload(); err != nil {
43	52		log.Warn().Err(err).Msg("failed to reload config")
44		-	m.mu.Unlock()
45		-	return
	53	+	return // defer will unlock
46	54		}
	55	+	willNotify = true
47	56		m.notifyCallbacksLocked()
48	57		})
49	58

 		// Acquire write lock before reload (reload modifies m.config)
 		m.mu.Lock()
+		// Track whether notifyCallbacksLocked will handle the unlock
+		willNotify := false
+		defer func() {
+			if !willNotify {
+				m.mu.Unlock()
+			}
+		}()
 		// Skip reload if this was triggered by our own Save() - the in-memory
 		// config is already correct and viper may have stale cached data
 		if m.skipNextReload {
 				log.Warn().Err(err).Msg("failed to sync viper config after Save")
 				// Continue anyway - in-memory config is correct, just viper internal state is off
 			}
+			willNotify = true
 			m.notifyCallbacksLocked()
 			return
 		}
 		log.Debug().Msg("reloading config from external change")
 		if err := m.reload(); err != nil {
 			log.Warn().Err(err).Msg("failed to reload config")
-			m.mu.Unlock()
+			return // defer will unlock
-			return
 		}
+		willNotify = true
 		m.notifyCallbacksLocked()
 	})