replace zxq.co/ripple/hanayo

vendor/gopkg.in/redis.v5/internal/pool/bench_test.go

@@ -0,0 +1,70 @@
+package pool_test
+
+import (
+	"errors"
+	"testing"
+	"time"
+
+	"gopkg.in/redis.v5/internal/pool"
+)
+
+func benchmarkPoolGetPut(b *testing.B, poolSize int) {
+	connPool := pool.NewConnPool(dummyDialer, poolSize, time.Second, time.Hour, time.Hour)
+
+	b.ResetTimer()
+
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			cn, _, err := connPool.Get()
+			if err != nil {
+				b.Fatal(err)
+			}
+			if err = connPool.Put(cn); err != nil {
+				b.Fatal(err)
+			}
+		}
+	})
+}
+
+func BenchmarkPoolGetPut10Conns(b *testing.B) {
+	benchmarkPoolGetPut(b, 10)
+}
+
+func BenchmarkPoolGetPut100Conns(b *testing.B) {
+	benchmarkPoolGetPut(b, 100)
+}
+
+func BenchmarkPoolGetPut1000Conns(b *testing.B) {
+	benchmarkPoolGetPut(b, 1000)
+}
+
+func benchmarkPoolGetRemove(b *testing.B, poolSize int) {
+	connPool := pool.NewConnPool(dummyDialer, poolSize, time.Second, time.Hour, time.Hour)
+	removeReason := errors.New("benchmark")
+
+	b.ResetTimer()
+
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			cn, _, err := connPool.Get()
+			if err != nil {
+				b.Fatal(err)
+			}
+			if err := connPool.Remove(cn, removeReason); err != nil {
+				b.Fatal(err)
+			}
+		}
+	})
+}
+
+func BenchmarkPoolGetRemove10Conns(b *testing.B) {
+	benchmarkPoolGetRemove(b, 10)
+}
+
+func BenchmarkPoolGetRemove100Conns(b *testing.B) {
+	benchmarkPoolGetRemove(b, 100)
+}
+
+func BenchmarkPoolGetRemove1000Conns(b *testing.B) {
+	benchmarkPoolGetRemove(b, 1000)
+}

vendor/gopkg.in/redis.v5/internal/pool/conn.go

@@ -0,0 +1,78 @@
+package pool
+
+import (
+	"net"
+	"sync/atomic"
+	"time"
+
+	"gopkg.in/redis.v5/internal/proto"
+)
+
+var noDeadline = time.Time{}
+
+type Conn struct {
+	netConn net.Conn
+
+	Rd *proto.Reader
+	Wb *proto.WriteBuffer
+
+	Inited bool
+	usedAt atomic.Value
+}
+
+func NewConn(netConn net.Conn) *Conn {
+	cn := &Conn{
+		netConn: netConn,
+		Wb:      proto.NewWriteBuffer(),
+	}
+	cn.Rd = proto.NewReader(cn.netConn)
+	cn.SetUsedAt(time.Now())
+	return cn
+}
+
+func (cn *Conn) UsedAt() time.Time {
+	return cn.usedAt.Load().(time.Time)
+}
+
+func (cn *Conn) SetUsedAt(tm time.Time) {
+	cn.usedAt.Store(tm)
+}
+
+func (cn *Conn) SetNetConn(netConn net.Conn) {
+	cn.netConn = netConn
+	cn.Rd.Reset(netConn)
+}
+
+func (cn *Conn) IsStale(timeout time.Duration) bool {
+	return timeout > 0 && time.Since(cn.UsedAt()) > timeout
+}
+
+func (cn *Conn) SetReadTimeout(timeout time.Duration) error {
+	now := time.Now()
+	cn.SetUsedAt(now)
+	if timeout > 0 {
+		return cn.netConn.SetReadDeadline(now.Add(timeout))
+	}
+	return cn.netConn.SetReadDeadline(noDeadline)
+}
+
+func (cn *Conn) SetWriteTimeout(timeout time.Duration) error {
+	now := time.Now()
+	cn.SetUsedAt(now)
+	if timeout > 0 {
+		return cn.netConn.SetWriteDeadline(now.Add(timeout))
+	}
+	return cn.netConn.SetWriteDeadline(noDeadline)
+}
+
+func (cn *Conn) Write(b []byte) (int, error) {
+	return cn.netConn.Write(b)
+}
+
+func (cn *Conn) RemoteAddr() net.Addr {
+	return cn.netConn.RemoteAddr()
+}
+
+func (cn *Conn) Close() error {
+	return cn.netConn.Close()
+}

vendor/gopkg.in/redis.v5/internal/pool/main_test.go

@@ -0,0 +1,35 @@
+package pool_test
+
+import (
+	"net"
+	"sync"
+	"testing"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+func TestGinkgoSuite(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "pool")
+}
+
+func perform(n int, cbs ...func(int)) {
+	var wg sync.WaitGroup
+	for _, cb := range cbs {
+		for i := 0; i < n; i++ {
+			wg.Add(1)
+			go func(cb func(int), i int) {
+				defer GinkgoRecover()
+				defer wg.Done()
+
+				cb(i)
+			}(cb, i)
+		}
+	}
+	wg.Wait()
+}
+
+func dummyDialer() (net.Conn, error) {
+	return &net.TCPConn{}, nil
+}

vendor/gopkg.in/redis.v5/internal/pool/pool.go

@@ -0,0 +1,354 @@
+package pool
+
+import (
+	"errors"
+	"fmt"
+	"net"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"gopkg.in/redis.v5/internal"
+)
+
+var (
+	ErrClosed      = errors.New("redis: client is closed")
+	ErrPoolTimeout = errors.New("redis: connection pool timeout")
+	errConnStale   = errors.New("connection is stale")
+)
+
+var timers = sync.Pool{
+	New: func() interface{} {
+		t := time.NewTimer(time.Hour)
+		t.Stop()
+		return t
+	},
+}
+
+// Stats contains pool state information and accumulated stats.
+type Stats struct {
+	Requests uint32 // number of times a connection was requested by the pool
+	Hits     uint32 // number of times free connection was found in the pool
+	Timeouts uint32 // number of times a wait timeout occurred
+
+	TotalConns uint32 // the number of total connections in the pool
+	FreeConns  uint32 // the number of free connections in the pool
+}
+
+type Pooler interface {
+	Get() (*Conn, bool, error)
+	Put(*Conn) error
+	Remove(*Conn, error) error
+	Len() int
+	FreeLen() int
+	Stats() *Stats
+	Close() error
+}
+
+type dialer func() (net.Conn, error)
+
+type ConnPool struct {
+	dial    dialer
+	OnClose func(*Conn) error
+
+	poolTimeout time.Duration
+	idleTimeout time.Duration
+
+	queue chan struct{}
+
+	connsMu sync.Mutex
+	conns   []*Conn
+
+	freeConnsMu sync.Mutex
+	freeConns   []*Conn
+
+	stats Stats
+
+	_closed int32 // atomic
+	lastErr atomic.Value
+}
+
+var _ Pooler = (*ConnPool)(nil)
+
+func NewConnPool(dial dialer, poolSize int, poolTimeout, idleTimeout, idleCheckFrequency time.Duration) *ConnPool {
+	p := &ConnPool{
+		dial: dial,
+
+		poolTimeout: poolTimeout,
+		idleTimeout: idleTimeout,
+
+		queue:     make(chan struct{}, poolSize),
+		conns:     make([]*Conn, 0, poolSize),
+		freeConns: make([]*Conn, 0, poolSize),
+	}
+	if idleTimeout > 0 && idleCheckFrequency > 0 {
+		go p.reaper(idleCheckFrequency)
+	}
+	return p
+}
+
+func (p *ConnPool) NewConn() (*Conn, error) {
+	netConn, err := p.dial()
+	if err != nil {
+		return nil, err
+	}
+	return NewConn(netConn), nil
+}
+
+func (p *ConnPool) PopFree() *Conn {
+	timer := timers.Get().(*time.Timer)
+	timer.Reset(p.poolTimeout)
+
+	select {
+	case p.queue <- struct{}{}:
+		if !timer.Stop() {
+			<-timer.C
+		}
+		timers.Put(timer)
+	case <-timer.C:
+		timers.Put(timer)
+		atomic.AddUint32(&p.stats.Timeouts, 1)
+		return nil
+	}
+
+	p.freeConnsMu.Lock()
+	cn := p.popFree()
+	p.freeConnsMu.Unlock()
+
+	if cn == nil {
+		<-p.queue
+	}
+	return cn
+}
+
+func (p *ConnPool) popFree() *Conn {
+	if len(p.freeConns) == 0 {
+		return nil
+	}
+
+	idx := len(p.freeConns) - 1
+	cn := p.freeConns[idx]
+	p.freeConns = p.freeConns[:idx]
+	return cn
+}
+
+// Get returns existed connection from the pool or creates a new one.
+func (p *ConnPool) Get() (*Conn, bool, error) {
+	if p.closed() {
+		return nil, false, ErrClosed
+	}
+
+	atomic.AddUint32(&p.stats.Requests, 1)
+
+	timer := timers.Get().(*time.Timer)
+	timer.Reset(p.poolTimeout)
+
+	select {
+	case p.queue <- struct{}{}:
+		if !timer.Stop() {
+			<-timer.C
+		}
+		timers.Put(timer)
+	case <-timer.C:
+		timers.Put(timer)
+		atomic.AddUint32(&p.stats.Timeouts, 1)
+		return nil, false, ErrPoolTimeout
+	}
+
+	for {
+		p.freeConnsMu.Lock()
+		cn := p.popFree()
+		p.freeConnsMu.Unlock()
+
+		if cn == nil {
+			break
+		}
+
+		if cn.IsStale(p.idleTimeout) {
+			p.remove(cn, errConnStale)
+			continue
+		}
+
+		atomic.AddUint32(&p.stats.Hits, 1)
+		return cn, false, nil
+	}
+
+	newcn, err := p.NewConn()
+	if err != nil {
+		<-p.queue
+		return nil, false, err
+	}
+
+	p.connsMu.Lock()
+	p.conns = append(p.conns, newcn)
+	p.connsMu.Unlock()
+
+	return newcn, true, nil
+}
+
+func (p *ConnPool) Put(cn *Conn) error {
+	if data := cn.Rd.PeekBuffered(); data != nil {
+		err := fmt.Errorf("connection has unread data: %q", data)
+		internal.Logf(err.Error())
+		return p.Remove(cn, err)
+	}
+	p.freeConnsMu.Lock()
+	p.freeConns = append(p.freeConns, cn)
+	p.freeConnsMu.Unlock()
+	<-p.queue
+	return nil
+}
+
+func (p *ConnPool) Remove(cn *Conn, reason error) error {
+	p.remove(cn, reason)
+	<-p.queue
+	return nil
+}
+
+func (p *ConnPool) remove(cn *Conn, reason error) {
+	_ = p.closeConn(cn, reason)
+
+	p.connsMu.Lock()
+	for i, c := range p.conns {
+		if c == cn {
+			p.conns = append(p.conns[:i], p.conns[i+1:]...)
+			break
+		}
+	}
+	p.connsMu.Unlock()
+}
+
+// Len returns total number of connections.
+func (p *ConnPool) Len() int {
+	p.connsMu.Lock()
+	l := len(p.conns)
+	p.connsMu.Unlock()
+	return l
+}
+
+// FreeLen returns number of free connections.
+func (p *ConnPool) FreeLen() int {
+	p.freeConnsMu.Lock()
+	l := len(p.freeConns)
+	p.freeConnsMu.Unlock()
+	return l
+}
+
+func (p *ConnPool) Stats() *Stats {
+	return &Stats{
+		Requests:   atomic.LoadUint32(&p.stats.Requests),
+		Hits:       atomic.LoadUint32(&p.stats.Hits),
+		Timeouts:   atomic.LoadUint32(&p.stats.Timeouts),
+		TotalConns: uint32(p.Len()),
+		FreeConns:  uint32(p.FreeLen()),
+	}
+}
+
+func (p *ConnPool) closed() bool {
+	return atomic.LoadInt32(&p._closed) == 1
+}
+
+func (p *ConnPool) Close() error {
+	if !atomic.CompareAndSwapInt32(&p._closed, 0, 1) {
+		return ErrClosed
+	}
+
+	p.connsMu.Lock()
+	var firstErr error
+	for _, cn := range p.conns {
+		if cn == nil {
+			continue
+		}
+		if err := p.closeConn(cn, ErrClosed); err != nil && firstErr == nil {
+			firstErr = err
+		}
+	}
+	p.conns = nil
+	p.connsMu.Unlock()
+
+	p.freeConnsMu.Lock()
+	p.freeConns = nil
+	p.freeConnsMu.Unlock()
+
+	return firstErr
+}
+
+func (p *ConnPool) closeConn(cn *Conn, reason error) error {
+	if p.OnClose != nil {
+		_ = p.OnClose(cn)
+	}
+	return cn.Close()
+}
+
+func (p *ConnPool) reapStaleConn() bool {
+	if len(p.freeConns) == 0 {
+		return false
+	}
+
+	cn := p.freeConns[0]
+	if !cn.IsStale(p.idleTimeout) {
+		return false
+	}
+
+	p.remove(cn, errConnStale)
+	p.freeConns = append(p.freeConns[:0], p.freeConns[1:]...)
+
+	return true
+}
+
+func (p *ConnPool) ReapStaleConns() (int, error) {
+	var n int
+	for {
+		p.queue <- struct{}{}
+		p.freeConnsMu.Lock()
+
+		reaped := p.reapStaleConn()
+
+		p.freeConnsMu.Unlock()
+		<-p.queue
+
+		if reaped {
+			n++
+		} else {
+			break
+		}
+	}
+	return n, nil
+}
+
+func (p *ConnPool) reaper(frequency time.Duration) {
+	ticker := time.NewTicker(frequency)
+	defer ticker.Stop()
+
+	for _ = range ticker.C {
+		if p.closed() {
+			break
+		}
+		n, err := p.ReapStaleConns()
+		if err != nil {
+			internal.Logf("ReapStaleConns failed: %s", err)
+			continue
+		}
+		s := p.Stats()
+		internal.Logf(
+			"reaper: removed %d stale conns (TotalConns=%d FreeConns=%d Requests=%d Hits=%d Timeouts=%d)",
+			n, s.TotalConns, s.FreeConns, s.Requests, s.Hits, s.Timeouts,
+		)
+	}
+}
+
+//------------------------------------------------------------------------------
+
+var idleCheckFrequency atomic.Value
+
+func SetIdleCheckFrequency(d time.Duration) {
+	idleCheckFrequency.Store(d)
+}
+
+func getIdleCheckFrequency() time.Duration {
+	v := idleCheckFrequency.Load()
+	if v == nil {
+		return time.Minute
+	}
+	return v.(time.Duration)
+}

vendor/gopkg.in/redis.v5/internal/pool/pool_single.go

@@ -0,0 +1,47 @@
+package pool
+
+type SingleConnPool struct {
+	cn *Conn
+}
+
+var _ Pooler = (*SingleConnPool)(nil)
+
+func NewSingleConnPool(cn *Conn) *SingleConnPool {
+	return &SingleConnPool{
+		cn: cn,
+	}
+}
+
+func (p *SingleConnPool) Get() (*Conn, bool, error) {
+	return p.cn, false, nil
+}
+
+func (p *SingleConnPool) Put(cn *Conn) error {
+	if p.cn != cn {
+		panic("p.cn != cn")
+	}
+	return nil
+}
+
+func (p *SingleConnPool) Remove(cn *Conn, _ error) error {
+	if p.cn != cn {
+		panic("p.cn != cn")
+	}
+	return nil
+}
+
+func (p *SingleConnPool) Len() int {
+	return 1
+}
+
+func (p *SingleConnPool) FreeLen() int {
+	return 0
+}
+
+func (p *SingleConnPool) Stats() *Stats {
+	return nil
+}
+
+func (p *SingleConnPool) Close() error {
+	return nil
+}

vendor/gopkg.in/redis.v5/internal/pool/pool_sticky.go

@@ -0,0 +1,119 @@
+package pool
+
+import (
+	"errors"
+	"sync"
+)
+
+type StickyConnPool struct {
+	pool     *ConnPool
+	reusable bool
+
+	cn     *Conn
+	closed bool
+	mu     sync.Mutex
+}
+
+var _ Pooler = (*StickyConnPool)(nil)
+
+func NewStickyConnPool(pool *ConnPool, reusable bool) *StickyConnPool {
+	return &StickyConnPool{
+		pool:     pool,
+		reusable: reusable,
+	}
+}
+
+func (p *StickyConnPool) Get() (*Conn, bool, error) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+
+	if p.closed {
+		return nil, false, ErrClosed
+	}
+	if p.cn != nil {
+		return p.cn, false, nil
+	}
+
+	cn, _, err := p.pool.Get()
+	if err != nil {
+		return nil, false, err
+	}
+	p.cn = cn
+	return cn, true, nil
+}
+
+func (p *StickyConnPool) putUpstream() (err error) {
+	err = p.pool.Put(p.cn)
+	p.cn = nil
+	return err
+}
+
+func (p *StickyConnPool) Put(cn *Conn) error {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+
+	if p.closed {
+		return ErrClosed
+	}
+	return nil
+}
+
+func (p *StickyConnPool) removeUpstream(reason error) error {
+	err := p.pool.Remove(p.cn, reason)
+	p.cn = nil
+	return err
+}
+
+func (p *StickyConnPool) Remove(cn *Conn, reason error) error {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+
+	if p.closed {
+		return nil
+	}
+	return p.removeUpstream(reason)
+}
+
+func (p *StickyConnPool) Len() int {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+
+	if p.cn == nil {
+		return 0
+	}
+	return 1
+}
+
+func (p *StickyConnPool) FreeLen() int {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+
+	if p.cn == nil {
+		return 1
+	}
+	return 0
+}
+
+func (p *StickyConnPool) Stats() *Stats {
+	return nil
+}
+
+func (p *StickyConnPool) Close() error {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+
+	if p.closed {
+		return ErrClosed
+	}
+	p.closed = true
+	var err error
+	if p.cn != nil {
+		if p.reusable {
+			err = p.putUpstream()
+		} else {
+			reason := errors.New("redis: unreusable sticky connection")
+			err = p.removeUpstream(reason)
+		}
+	}
+	return err
+}

vendor/gopkg.in/redis.v5/internal/pool/pool_test.go

@@ -0,0 +1,247 @@
+package pool_test
+
+import (
+	"errors"
+	"testing"
+	"time"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+
+	"gopkg.in/redis.v5/internal/pool"
+)
+
+var _ = Describe("ConnPool", func() {
+	var connPool *pool.ConnPool
+
+	BeforeEach(func() {
+		connPool = pool.NewConnPool(
+			dummyDialer, 10, time.Hour, time.Millisecond, time.Millisecond)
+	})
+
+	AfterEach(func() {
+		connPool.Close()
+	})
+
+	It("should unblock client when conn is removed", func() {
+		// Reserve one connection.
+		cn, _, err := connPool.Get()
+		Expect(err).NotTo(HaveOccurred())
+
+		// Reserve all other connections.
+		var cns []*pool.Conn
+		for i := 0; i < 9; i++ {
+			cn, _, err := connPool.Get()
+			Expect(err).NotTo(HaveOccurred())
+			cns = append(cns, cn)
+		}
+
+		started := make(chan bool, 1)
+		done := make(chan bool, 1)
+		go func() {
+			defer GinkgoRecover()
+
+			started <- true
+			_, _, err := connPool.Get()
+			Expect(err).NotTo(HaveOccurred())
+			done <- true
+
+			err = connPool.Put(cn)
+			Expect(err).NotTo(HaveOccurred())
+		}()
+		<-started
+
+		// Check that Get is blocked.
+		select {
+		case <-done:
+			Fail("Get is not blocked")
+		default:
+			// ok
+		}
+
+		err = connPool.Remove(cn, errors.New("test"))
+		Expect(err).NotTo(HaveOccurred())
+
+		// Check that Ping is unblocked.
+		select {
+		case <-done:
+			// ok
+		case <-time.After(time.Second):
+			Fail("Get is not unblocked")
+		}
+
+		for _, cn := range cns {
+			err = connPool.Put(cn)
+			Expect(err).NotTo(HaveOccurred())
+		}
+	})
+})
+
+var _ = Describe("conns reaper", func() {
+	const idleTimeout = time.Minute
+
+	var connPool *pool.ConnPool
+	var conns, idleConns, closedConns []*pool.Conn
+
+	BeforeEach(func() {
+		connPool = pool.NewConnPool(
+			dummyDialer, 10, time.Second, idleTimeout, time.Hour)
+
+		closedConns = nil
+		connPool.OnClose = func(cn *pool.Conn) error {
+			closedConns = append(closedConns, cn)
+			return nil
+		}
+
+		conns = nil
+
+		// add stale connections
+		idleConns = nil
+		for i := 0; i < 3; i++ {
+			cn, _, err := connPool.Get()
+			Expect(err).NotTo(HaveOccurred())
+			cn.SetUsedAt(time.Now().Add(-2 * idleTimeout))
+			conns = append(conns, cn)
+			idleConns = append(idleConns, cn)
+		}
+
+		// add fresh connections
+		for i := 0; i < 3; i++ {
+			cn, _, err := connPool.Get()
+			Expect(err).NotTo(HaveOccurred())
+			conns = append(conns, cn)
+		}
+
+		for _, cn := range conns {
+			Expect(connPool.Put(cn)).NotTo(HaveOccurred())
+		}
+
+		Expect(connPool.Len()).To(Equal(6))
+		Expect(connPool.FreeLen()).To(Equal(6))
+
+		n, err := connPool.ReapStaleConns()
+		Expect(err).NotTo(HaveOccurred())
+		Expect(n).To(Equal(3))
+	})
+
+	AfterEach(func() {
+		_ = connPool.Close()
+		Expect(connPool.Len()).To(Equal(0))
+		Expect(connPool.FreeLen()).To(Equal(0))
+		Expect(len(closedConns)).To(Equal(len(conns)))
+		Expect(closedConns).To(ConsistOf(conns))
+	})
+
+	It("reaps stale connections", func() {
+		Expect(connPool.Len()).To(Equal(3))
+		Expect(connPool.FreeLen()).To(Equal(3))
+	})
+
+	It("does not reap fresh connections", func() {
+		n, err := connPool.ReapStaleConns()
+		Expect(err).NotTo(HaveOccurred())
+		Expect(n).To(Equal(0))
+	})
+
+	It("stale connections are closed", func() {
+		Expect(len(closedConns)).To(Equal(len(idleConns)))
+		Expect(closedConns).To(ConsistOf(idleConns))
+	})
+
+	It("pool is functional", func() {
+		for j := 0; j < 3; j++ {
+			var freeCns []*pool.Conn
+			for i := 0; i < 3; i++ {
+				cn, _, err := connPool.Get()
+				Expect(err).NotTo(HaveOccurred())
+				Expect(cn).NotTo(BeNil())
+				freeCns = append(freeCns, cn)
+			}
+
+			Expect(connPool.Len()).To(Equal(3))
+			Expect(connPool.FreeLen()).To(Equal(0))
+
+			cn, _, err := connPool.Get()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(cn).NotTo(BeNil())
+			conns = append(conns, cn)
+
+			Expect(connPool.Len()).To(Equal(4))
+			Expect(connPool.FreeLen()).To(Equal(0))
+
+			err = connPool.Remove(cn, errors.New("test"))
+			Expect(err).NotTo(HaveOccurred())
+
+			Expect(connPool.Len()).To(Equal(3))
+			Expect(connPool.FreeLen()).To(Equal(0))
+
+			for _, cn := range freeCns {
+				err := connPool.Put(cn)
+				Expect(err).NotTo(HaveOccurred())
+			}
+
+			Expect(connPool.Len()).To(Equal(3))
+			Expect(connPool.FreeLen()).To(Equal(3))
+		}
+	})
+})
+
+var _ = Describe("race", func() {
+	var connPool *pool.ConnPool
+	var C, N int
+
+	BeforeEach(func() {
+		C, N = 10, 1000
+		if testing.Short() {
+			C = 4
+			N = 100
+		}
+	})
+
+	AfterEach(func() {
+		connPool.Close()
+	})
+
+	It("does not happen on Get, Put, and Remove", func() {
+		connPool = pool.NewConnPool(
+			dummyDialer, 10, time.Minute, time.Millisecond, time.Millisecond)
+
+		perform(C, func(id int) {
+			for i := 0; i < N; i++ {
+				cn, _, err := connPool.Get()
+				Expect(err).NotTo(HaveOccurred())
+				if err == nil {
+					Expect(connPool.Put(cn)).NotTo(HaveOccurred())
+				}
+			}
+		}, func(id int) {
+			for i := 0; i < N; i++ {
+				cn, _, err := connPool.Get()
+				Expect(err).NotTo(HaveOccurred())
+				if err == nil {
+					Expect(connPool.Remove(cn, errors.New("test"))).NotTo(HaveOccurred())
+				}
+			}
+		})
+	})
+
+	It("does not happen on Get and PopFree", func() {
+		connPool = pool.NewConnPool(
+			dummyDialer, 10, time.Minute, time.Second, time.Millisecond)
+
+		perform(C, func(id int) {
+			for i := 0; i < N; i++ {
+				cn, _, err := connPool.Get()
+				Expect(err).NotTo(HaveOccurred())
+				if err == nil {
+					Expect(connPool.Put(cn)).NotTo(HaveOccurred())
+				}
+
+				cn = connPool.PopFree()
+				if cn != nil {
+					Expect(connPool.Put(cn)).NotTo(HaveOccurred())
+				}
+			}
+		})
+	})
+})