diff --git a/pool.go b/pool.go
index 5f6ce63..f3d931c 100644
--- a/pool.go
+++ b/pool.go
@@ -184,6 +184,7 @@ func (p *Pool) getWorker() *Worker {
 	waiting := false
 
 	p.lock.Lock()
+	defer p.lock.Unlock()
 	idleWorkers := p.workers
 	n := len(idleWorkers) - 1
 	if n < 0 {
@@ -193,14 +194,11 @@ func (p *Pool) getWorker() *Worker {
 		idleWorkers[n] = nil
 		p.workers = idleWorkers[:n]
 	}
-	p.lock.Unlock()
 
 	if waiting {
-		p.lock.Lock()
 		p.cond.Wait()
 		l := len(p.workers) - 1
 		w = p.workers[l]
-		p.lock.Unlock()
 	} else if w == nil {
 		w = &Worker{
 			pool: p,
@@ -217,7 +215,7 @@ func (p *Pool) putWorker(worker *Worker) {
 	worker.recycleTime = time.Now()
 	p.lock.Lock()
 	p.workers = append(p.workers, worker)
-	p.lock.Unlock()
 	//通知有一个空闲的worker
 	p.cond.Signal()
+	p.lock.Unlock()
 }
diff --git a/pool_func.go b/pool_func.go
index 6051117..d1ed757 100644
--- a/pool_func.go
+++ b/pool_func.go
@@ -50,7 +50,7 @@ type PoolWithFunc struct {
 
 	// lock for synchronous operation.
 	lock sync.Mutex
-
+	cond *sync.Cond
 	// pf is the function for processing tasks.
 	poolFunc pf
 
@@ -107,6 +107,7 @@ func NewTimingPoolWithFunc(size, expiry int, f pf) (*PoolWithFunc, error) {
 		expiryDuration: time.Duration(expiry) * time.Second,
 		poolFunc:       f,
 	}
+	p.cond = sync.NewCond(&p.lock)
 	go p.periodicallyPurge()
 	return p, nil
 }
@@ -185,6 +186,7 @@ func (p *PoolWithFunc) getWorker() *WorkerWithFunc {
 	waiting := false
 
 	p.lock.Lock()
+	defer p.lock.Unlock()
 	idleWorkers := p.workers
 	n := len(idleWorkers) - 1
 	if n < 0 {
@@ -194,23 +196,11 @@ func (p *PoolWithFunc) getWorker() *WorkerWithFunc {
 		idleWorkers[n] = nil
 		p.workers = idleWorkers[:n]
 	}
-	p.lock.Unlock()
 
 	if waiting {
-		for {
-			p.lock.Lock()
-			idleWorkers = p.workers
-			l := len(idleWorkers) - 1
-			if l < 0 {
-				p.lock.Unlock()
-				continue
-			}
-			w = idleWorkers[l]
-			idleWorkers[l] = nil
-			p.workers = idleWorkers[:l]
-			p.lock.Unlock()
-			break
-		}
+		p.cond.Wait()
+		l := len(p.workers) - 1
+		w = p.workers[l]
 	} else if w == nil {
 		w = &WorkerWithFunc{
 			pool: p,
@@ -227,5 +217,7 @@ func (p *PoolWithFunc) putWorker(worker *WorkerWithFunc) {
 	worker.recycleTime = time.Now()
 	p.lock.Lock()
 	p.workers = append(p.workers, worker)
+	//通知有一个空闲的worker
+	p.cond.Signal()
 	p.lock.Unlock()
 }