diff --git a/ants.go b/ants.go
index 8844460..d116067 100644
--- a/ants.go
+++ b/ants.go
@@ -28,42 +28,42 @@ import (
 )
 
 const (
-	// DefaultAntsPoolSize is the default capacity for a default goroutine pool
+	// DefaultAntsPoolSize is the default capacity for a default goroutine pool.
 	DefaultAntsPoolSize = math.MaxInt32
 
-	// DefaultCleanIntervalTime is the interval time to clean up goroutines
+	// DefaultCleanIntervalTime is the interval time to clean up goroutines.
 	DefaultCleanIntervalTime = 10
 )
 
-// Init a instance pool when importing ants
+// Init a instance pool when importing ants.
 var defaultAntsPool, _ = NewPool(DefaultAntsPoolSize)
 
-// Submit submit a task to pool
+// Submit submits a task to pool.
 func Submit(task f) error {
 	return defaultAntsPool.Submit(task)
 }
 
-// Running returns the number of the currently running goroutines
+// Running returns the number of the currently running goroutines.
 func Running() int {
 	return defaultAntsPool.Running()
 }
 
-// Cap returns the capacity of this default pool
+// Cap returns the capacity of this default pool.
 func Cap() int {
 	return defaultAntsPool.Cap()
 }
 
-// Free returns the available goroutines to work
+// Free returns the available goroutines to work.
 func Free() int {
 	return defaultAntsPool.Free()
 }
 
-// Release Closed the default pool
+// Release Closes the default pool.
 func Release() {
 	defaultAntsPool.Release()
 }
 
-// Errors for the Ants API
+// Errors for the Ants API.
 var (
 	ErrInvalidPoolSize   = errors.New("invalid size for pool")
 	ErrInvalidPoolExpiry = errors.New("invalid expiry for pool")
diff --git a/pool.go b/pool.go
index 8f0abba..4e93a36 100644
--- a/pool.go
+++ b/pool.go
@@ -50,12 +50,12 @@ type Pool struct {
 	// release is used to notice the pool to closed itself.
 	release chan sig
 
-	// lock for synchronous operation
+	// lock for synchronous operation.
 	lock sync.Mutex
 
 	once sync.Once
 }
-
+// clear expired workers periodically.
 func (p *Pool) periodicallyPurge() {
 	heartbeat := time.NewTicker(p.expiryDuration)
 	for range heartbeat.C {
@@ -83,12 +83,12 @@ func (p *Pool) periodicallyPurge() {
 	}
 }
 
-// NewPool generates a instance of ants pool
+// NewPool generates an instance of ants pool.
 func NewPool(size int) (*Pool, error) {
 	return NewTimingPool(size, DefaultCleanIntervalTime)
 }
 
-// NewTimingPool generates a instance of ants pool with a custom timed task
+// NewTimingPool generates an instance of ants pool with a custom timed task.
 func NewTimingPool(size, expiry int) (*Pool, error) {
 	if size <= 0 {
 		return nil, ErrInvalidPoolSize
@@ -107,7 +107,7 @@ func NewTimingPool(size, expiry int) (*Pool, error) {
 
 //-------------------------------------------------------------------------
 
-// Submit submit a task to pool
+// Submit submits a task to this pool.
 func (p *Pool) Submit(task f) error {
 	if len(p.release) > 0 {
 		return ErrPoolClosed
@@ -116,22 +116,22 @@ func (p *Pool) Submit(task f) error {
 	return nil
 }
 
-// Running returns the number of the currently running goroutines
+// Running returns the number of the currently running goroutines.
 func (p *Pool) Running() int {
 	return int(atomic.LoadInt32(&p.running))
 }
 
-// Free returns the available goroutines to work
+// Free returns the available goroutines to work.
 func (p *Pool) Free() int {
 	return int(atomic.LoadInt32(&p.capacity) - atomic.LoadInt32(&p.running))
 }
 
-// Cap returns the capacity of this pool
+// Cap returns the capacity of this pool.
 func (p *Pool) Cap() int {
 	return int(atomic.LoadInt32(&p.capacity))
 }
 
-// ReSize change the capacity of this pool
+// ReSize changes the capacity of this pool.
 func (p *Pool) ReSize(size int) {
 	if size == p.Cap() {
 		return
@@ -145,7 +145,7 @@ func (p *Pool) ReSize(size int) {
 	}
 }
 
-// Release Closed this pool
+// Release Closes this pool.
 func (p *Pool) Release() error {
 	p.once.Do(func() {
 		p.release <- sig{}
@@ -163,12 +163,12 @@ func (p *Pool) Release() error {
 
 //-------------------------------------------------------------------------
 
-// incRunning increases the number of the currently running goroutines
+// incRunning increases the number of the currently running goroutines.
 func (p *Pool) incRunning() {
 	atomic.AddInt32(&p.running, 1)
 }
 
-// decRunning decreases the number of the currently running goroutines
+// decRunning decreases the number of the currently running goroutines.
 func (p *Pool) decRunning() {
 	atomic.AddInt32(&p.running, -1)
 }
diff --git a/pool_func.go b/pool_func.go
index 890e7be..944a6ba 100644
--- a/pool_func.go
+++ b/pool_func.go
@@ -48,15 +48,16 @@ type PoolWithFunc struct {
 	// release is used to notice the pool to closed itself.
 	release chan sig
 
-	// lock for synchronous operation
+	// lock for synchronous operation.
 	lock sync.Mutex
 
-	// pf is the function for processing tasks
+	// pf is the function for processing tasks.
 	poolFunc pf
 
 	once sync.Once
 }
 
+// clear expired workers periodically.
 func (p *PoolWithFunc) periodicallyPurge() {
 	heartbeat := time.NewTicker(p.expiryDuration)
 	for range heartbeat.C {
@@ -84,12 +85,12 @@ func (p *PoolWithFunc) periodicallyPurge() {
 	}
 }
 
-// NewPoolWithFunc generates a instance of ants pool with a specific function
+// NewPoolWithFunc generates an instance of ants pool with a specific function.
 func NewPoolWithFunc(size int, f pf) (*PoolWithFunc, error) {
 	return NewTimingPoolWithFunc(size, DefaultCleanIntervalTime, f)
 }
 
-// NewTimingPoolWithFunc generates a instance of ants pool with a specific function and a custom timed task
+// NewTimingPoolWithFunc generates an instance of ants pool with a specific function and a custom timed task.
 func NewTimingPoolWithFunc(size, expiry int, f pf) (*PoolWithFunc, error) {
 	if size <= 0 {
 		return nil, ErrInvalidPoolSize
@@ -109,11 +110,8 @@ func NewTimingPoolWithFunc(size, expiry int, f pf) (*PoolWithFunc, error) {
 
 //-------------------------------------------------------------------------
 
-// Serve submit a task to pool
+// Serve submits a task to pool.
 func (p *PoolWithFunc) Serve(args interface{}) error {
-	//if atomic.LoadInt32(&p.closed) == 1 {
-	//	return ErrPoolClosed
-	//}
 	if len(p.release) > 0 {
 		return ErrPoolClosed
 	}
@@ -121,22 +119,22 @@ func (p *PoolWithFunc) Serve(args interface{}) error {
 	return nil
 }
 
-// Running returns the number of the currently running goroutines
+// Running returns the number of the currently running goroutines.
 func (p *PoolWithFunc) Running() int {
 	return int(atomic.LoadInt32(&p.running))
 }
 
-// Free returns the available goroutines to work
+// Free returns a available goroutines to work.
 func (p *PoolWithFunc) Free() int {
 	return int(atomic.LoadInt32(&p.capacity) - atomic.LoadInt32(&p.running))
 }
 
-// Cap returns the capacity of this pool
+// Cap returns the capacity of this pool.
 func (p *PoolWithFunc) Cap() int {
 	return int(atomic.LoadInt32(&p.capacity))
 }
 
-// ReSize change the capacity of this pool
+// ReSize change the capacity of this pool.
 func (p *PoolWithFunc) ReSize(size int) {
 	if size == p.Cap() {
 		return
@@ -150,7 +148,7 @@ func (p *PoolWithFunc) ReSize(size int) {
 	}
 }
 
-// Release Closed this pool
+// Release Closed this pool.
 func (p *PoolWithFunc) Release() error {
 	p.once.Do(func() {
 		p.release <- sig{}
@@ -168,12 +166,12 @@ func (p *PoolWithFunc) Release() error {
 
 //-------------------------------------------------------------------------
 
-// incRunning increases the number of the currently running goroutines
+// incRunning increases the number of the currently running goroutines.
 func (p *PoolWithFunc) incRunning() {
 	atomic.AddInt32(&p.running, 1)
 }
 
-// decRunning decreases the number of the currently running goroutines
+// decRunning decreases the number of the currently running goroutines.
 func (p *PoolWithFunc) decRunning() {
 	atomic.AddInt32(&p.running, -1)
 }