📝Optimize the logic when cleaning up expired workers

pool.go

@@ -68,7 +68,7 @@ func (p *Pool) periodicallyPurge() {
 	heartbeat := time.NewTicker(p.expiryDuration)
 	defer heartbeat.Stop()
 
-	var purgeWorkers []*Worker
+	var expiredWorkers []*Worker
 	for range heartbeat.C {
 		if CLOSED == atomic.LoadInt32(&p.release) {
 			break
@@ -81,7 +81,7 @@ func (p *Pool) periodicallyPurge() {
 		for i < n && currentTime.Sub(idleWorkers[i].recycleTime) > p.expiryDuration {
 			i++
 		}
-		purgeWorkers = append(purgeWorkers[:0], idleWorkers[:i]...)
+		expiredWorkers = append(expiredWorkers[:0], idleWorkers[:i]...)
 		if i > 0 {
 			m := copy(idleWorkers, idleWorkers[i:])
 			for i = m; i < n; i++ {
@@ -95,9 +95,9 @@ func (p *Pool) periodicallyPurge() {
 		// This notification must be outside the p.lock, since w.task
 		// may be blocking and may consume a lot of time if many workers
 		// are located on non-local CPUs.
-		for i, w := range purgeWorkers {
+		for i, w := range expiredWorkers {
 			w.task <- nil
-			purgeWorkers[i] = nil
+			expiredWorkers[i] = nil
 		}
 	}
 }

pool_func.go

@@ -71,6 +71,7 @@ func (p *PoolWithFunc) periodicallyPurge() {
 	heartbeat := time.NewTicker(p.expiryDuration)
 	defer heartbeat.Stop()
 
+	var expiredWorkers []*Worker
 	for range heartbeat.C {
 		if CLOSED == atomic.LoadInt32(&p.release) {
 			break
@@ -78,23 +79,29 @@ func (p *PoolWithFunc) periodicallyPurge() {
 		currentTime := time.Now()
 		p.lock.Lock()
 		idleWorkers := p.workers
-		n := -1
+		n := len(idleWorkers)
-		for i, w := range idleWorkers {
+		i := 0
-			if currentTime.Sub(w.recycleTime) <= p.expiryDuration {
+		for i < n && currentTime.Sub(idleWorkers[i].recycleTime) > p.expiryDuration {
-				break
+			i++
 		}
-			n = i
+		expiredWorkers = append(expiredWorkers[:0], idleWorkers[:i]...)
-			w.args <- nil
+		if i > 0 {
+			m := copy(idleWorkers, idleWorkers[i:])
+			for i = m; i < n; i++ {
 				idleWorkers[i] = nil
 			}
-		if n > -1 {
+			p.workers = idleWorkers[:m]
-			if n >= len(idleWorkers)-1 {
-				p.workers = idleWorkers[:0]
-			} else {
-				p.workers = idleWorkers[n+1:]
-			}
 		}
 		p.lock.Unlock()
+
+		// Notify obsolete workers to stop.
+		// This notification must be outside the p.lock, since w.task
+		// may be blocking and may consume a lot of time if many workers
+		// are located on non-local CPUs.
+		for i, w := range expiredWorkers {
+			w.args <- nil
+			expiredWorkers[i] = nil
+		}
 	}
 }