Поправил логику

thread.go

@@ -16,12 +16,8 @@ type Manager struct {
 func (m *Manager) Start(f func()) {
 	m.stopped = make(chan bool, 1)
 	for {
-		if m.runningCount.Load() >= m.Count {
-			continue
-		}
-
 		if m.stop {
-			if m.runningCount.Load() <= 1 {
+			if m.runningCount.Load() < 1 {
 				gol.Debug("thread manager stopped")
 				m.stopped <- true
 				break
@@ -30,7 +26,12 @@ func (m *Manager) Start(f func()) {
 			continue
 		}
 
+		if m.runningCount.Load() >= m.Count {
+			continue
+		}
+
 		if m.runningCount.Add(1) > m.Count {
+			m.runningCount.Add(-1)
 			gol.Debug("thread manager atomic skip")
 			continue
 		}