balancer/pickfirst/pickfirst_test.go - external/github.com/grpc/grpc-go - Git at Google

 /*
  *
  * Copyright 2024 gRPC authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  *
  */

 package pickfirst

 import (
 	"context"
 	"errors"
 	"fmt"
 	"testing"
 	"time"

 	"google.golang.org/grpc/attributes"
 	"google.golang.org/grpc/balancer"
 	"google.golang.org/grpc/connectivity"
 	"google.golang.org/grpc/internal/grpctest"
 	"google.golang.org/grpc/internal/testutils"
 	"google.golang.org/grpc/resolver"
 )

 const (
 	// Default timeout for tests in this package.
 	defaultTestTimeout = 10 * time.Second
 	// Default short timeout, to be used when waiting for events which are not
 	// expected to happen.
 	defaultTestShortTimeout = 100 * time.Millisecond
 )

 type s struct {
 	grpctest.Tester
 }

 func Test(t *testing.T) {
 	grpctest.RunSubTests(t, s{})
 }

 // TestPickFirst_InitialResolverError sends a resolver error to the balancer
 // before a valid resolver update. It verifies that the clientconn state is
 // updated to TRANSIENT_FAILURE.
 func (s) TestPickFirst_InitialResolverError(t *testing.T) {
 	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
 	defer cancel()
 	cc := testutils.NewBalancerClientConn(t)
 	bal := balancer.Get(Name).Build(cc, balancer.BuildOptions{})
 	defer bal.Close()
 	bal.ResolverError(errors.New("resolution failed: test error"))

 	if err := cc.WaitForConnectivityState(ctx, connectivity.TransientFailure); err != nil {
 		t.Fatalf("cc.WaitForConnectivityState(%v) returned error: %v", connectivity.TransientFailure, err)
 	}

 	// After sending a valid update, the LB policy should report CONNECTING.
 	ccState := balancer.ClientConnState{
 		ResolverState: resolver.State{
 			Endpoints: []resolver.Endpoint{
 				{Addresses: []resolver.Address{{Addr: "1.1.1.1:1"}}},
 				{Addresses: []resolver.Address{{Addr: "2.2.2.2:2"}}},
 			},
 		},
 	}
 	if err := bal.UpdateClientConnState(ccState); err != nil {
 		t.Fatalf("UpdateClientConnState(%v) returned error: %v", ccState, err)
 	}

 	if err := cc.WaitForConnectivityState(ctx, connectivity.Connecting); err != nil {
 		t.Fatalf("cc.WaitForConnectivityState(%v) returned error: %v", connectivity.Connecting, err)
 	}
 }

 // TestPickFirst_ResolverErrorinTF sends a resolver error to the balancer
 // before when it's attempting to connect to a SubConn TRANSIENT_FAILURE. It
 // verifies that the picker is updated and the SubConn is not closed.
 func (s) TestPickFirst_ResolverErrorinTF(t *testing.T) {
 	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
 	defer cancel()
 	cc := testutils.NewBalancerClientConn(t)
 	bal := balancer.Get(Name).Build(cc, balancer.BuildOptions{})
 	defer bal.Close()

 	// After sending a valid update, the LB policy should report CONNECTING.
 	ccState := balancer.ClientConnState{
 		ResolverState: resolver.State{
 			Endpoints: []resolver.Endpoint{
 				{Addresses: []resolver.Address{{Addr: "1.1.1.1:1"}}},
 			},
 		},
 	}

 	if err := bal.UpdateClientConnState(ccState); err != nil {
 		t.Fatalf("UpdateClientConnState(%v) returned error: %v", ccState, err)
 	}

 	sc1 := <-cc.NewSubConnCh
 	if err := cc.WaitForConnectivityState(ctx, connectivity.Connecting); err != nil {
 		t.Fatalf("cc.WaitForConnectivityState(%v) returned error: %v", connectivity.Connecting, err)
 	}

 	scErr := fmt.Errorf("test error: connection refused")
 	sc1.UpdateState(balancer.SubConnState{
 		ConnectivityState: connectivity.TransientFailure,
 		ConnectionError:   scErr,
 	})

 	if err := cc.WaitForPickerWithErr(ctx, scErr); err != nil {
 		t.Fatalf("cc.WaitForPickerWithErr(%v) returned error: %v", scErr, err)
 	}

 	bal.ResolverError(errors.New("resolution failed: test error"))
 	if err := cc.WaitForErrPicker(ctx); err != nil {
 		t.Fatalf("cc.WaitForPickerWithErr() returned error: %v", err)
 	}

 	select {
 	case <-time.After(defaultTestShortTimeout):
 	case sc := <-cc.ShutdownSubConnCh:
 		t.Fatalf("Unexpected SubConn shutdown: %v", sc)
 	}
 }

 // TestAddressList_Iteration verifies the behaviour of the addressList while
 // iterating through the entries.
 func (s) TestAddressList_Iteration(t *testing.T) {
 	addrs := []resolver.Address{
 		{
 			Addr:               "192.168.1.1",
 			ServerName:         "test-host-1",
 			Attributes:         attributes.New("key-1", "val-1"),
 			BalancerAttributes: attributes.New("bal-key-1", "bal-val-1"),
 		},
 		{
 			Addr:               "192.168.1.2",
 			ServerName:         "test-host-2",
 			Attributes:         attributes.New("key-2", "val-2"),
 			BalancerAttributes: attributes.New("bal-key-2", "bal-val-2"),
 		},
 		{
 			Addr:               "192.168.1.3",
 			ServerName:         "test-host-3",
 			Attributes:         attributes.New("key-3", "val-3"),
 			BalancerAttributes: attributes.New("bal-key-3", "bal-val-3"),
 		},
 	}

 	addressList := addressList{}
 	addressList.updateAddrs(addrs)

 	for i := 0; i < len(addrs); i++ {
 		if got, want := addressList.isValid(), true; got != want {
 			t.Fatalf("addressList.isValid() = %t, want %t", got, want)
 		}
 		if got, want := addressList.currentAddress(), addrs[i]; !want.Equal(got) {
 			t.Errorf("addressList.currentAddress() = %v, want %v", got, want)
 		}
 		if got, want := addressList.increment(), i+1 < len(addrs); got != want {
 			t.Fatalf("addressList.increment() = %t, want %t", got, want)
 		}
 	}

 	if got, want := addressList.isValid(), false; got != want {
 		t.Fatalf("addressList.isValid() = %t, want %t", got, want)
 	}

 	// increment an invalid address list.
 	if got, want := addressList.increment(), false; got != want {
 		t.Errorf("addressList.increment() = %t, want %t", got, want)
 	}

 	if got, want := addressList.isValid(), false; got != want {
 		t.Errorf("addressList.isValid() = %t, want %t", got, want)
 	}

 	addressList.reset()
 	for i := 0; i < len(addrs); i++ {
 		if got, want := addressList.isValid(), true; got != want {
 			t.Fatalf("addressList.isValid() = %t, want %t", got, want)
 		}
 		if got, want := addressList.currentAddress(), addrs[i]; !want.Equal(got) {
 			t.Errorf("addressList.currentAddress() = %v, want %v", got, want)
 		}
 		if got, want := addressList.increment(), i+1 < len(addrs); got != want {
 			t.Fatalf("addressList.increment() = %t, want %t", got, want)
 		}
 	}
 }

 // TestAddressList_SeekTo verifies the behaviour of addressList.seekTo.
 func (s) TestAddressList_SeekTo(t *testing.T) {
 	addrs := []resolver.Address{
 		{
 			Addr:               "192.168.1.1",
 			ServerName:         "test-host-1",
 			Attributes:         attributes.New("key-1", "val-1"),
 			BalancerAttributes: attributes.New("bal-key-1", "bal-val-1"),
 		},
 		{
 			Addr:               "192.168.1.2",
 			ServerName:         "test-host-2",
 			Attributes:         attributes.New("key-2", "val-2"),
 			BalancerAttributes: attributes.New("bal-key-2", "bal-val-2"),
 		},
 		{
 			Addr:               "192.168.1.3",
 			ServerName:         "test-host-3",
 			Attributes:         attributes.New("key-3", "val-3"),
 			BalancerAttributes: attributes.New("bal-key-3", "bal-val-3"),
 		},
 	}

 	addressList := addressList{}
 	addressList.updateAddrs(addrs)

 	// Try finding an address in the list.
 	key := resolver.Address{
 		Addr:               "192.168.1.2",
 		ServerName:         "test-host-2",
 		Attributes:         attributes.New("key-2", "val-2"),
 		BalancerAttributes: attributes.New("ignored", "bal-val-2"),
 	}

 	if got, want := addressList.seekTo(key), true; got != want {
 		t.Errorf("addressList.seekTo(%v) = %t, want %t", key, got, want)
 	}

 	// It should be possible to increment once more now that the pointer has advanced.
 	if got, want := addressList.increment(), true; got != want {
 		t.Errorf("addressList.increment() = %t, want %t", got, want)
 	}

 	if got, want := addressList.increment(), false; got != want {
 		t.Errorf("addressList.increment() = %t, want %t", got, want)
 	}

 	// Seek to the key again, it is behind the pointer now.
 	if got, want := addressList.seekTo(key), true; got != want {
 		t.Errorf("addressList.seekTo(%v) = %t, want %t", key, got, want)
 	}

 	// Seek to a key not in the list.
 	key = resolver.Address{
 		Addr:               "192.168.1.5",
 		ServerName:         "test-host-5",
 		Attributes:         attributes.New("key-5", "val-5"),
 		BalancerAttributes: attributes.New("ignored", "bal-val-5"),
 	}

 	if got, want := addressList.seekTo(key), false; got != want {
 		t.Errorf("addressList.seekTo(%v) = %t, want %t", key, got, want)
 	}

 	// It should be possible to increment once more since the pointer has not advanced.
 	if got, want := addressList.increment(), true; got != want {
 		t.Errorf("addressList.increment() = %t, want %t", got, want)
 	}

 	if got, want := addressList.increment(), false; got != want {
 		t.Errorf("addressList.increment() = %t, want %t", got, want)
 	}
 }

 // TestPickFirstLeaf_TFPickerUpdate sends TRANSIENT_FAILURE SubConn state updates
 // for each SubConn managed by a pickfirst balancer. It verifies that the picker
 // is updated with the expected frequency.
 func (s) TestPickFirstLeaf_TFPickerUpdate(t *testing.T) {
 	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
 	defer cancel()
 	cc := testutils.NewBalancerClientConn(t)
 	bal := pickfirstBuilder{}.Build(cc, balancer.BuildOptions{})
 	defer bal.Close()
 	ccState := balancer.ClientConnState{
 		ResolverState: resolver.State{
 			Endpoints: []resolver.Endpoint{
 				{Addresses: []resolver.Address{{Addr: "1.1.1.1:1"}}},
 				{Addresses: []resolver.Address{{Addr: "1.1.1.1:1"}}}, // duplicate, should be ignored.
 				{Addresses: []resolver.Address{{Addr: "2.2.2.2:2"}}},
 				{Addresses: []resolver.Address{{Addr: "1.1.1.1:1"}}}, // duplicate, should be ignored.
 			},
 		},
 	}
 	if err := bal.UpdateClientConnState(ccState); err != nil {
 		t.Fatalf("UpdateClientConnState(%v) returned error: %v", ccState, err)
 	}

 	// PF should report TRANSIENT_FAILURE only once all the sunbconns have failed
 	// once.
 	tfErr := fmt.Errorf("test err: connection refused")
 	sc1 := <-cc.NewSubConnCh
 	select {
 	case <-sc1.ConnectCh:
 	case <-ctx.Done():
 		t.Fatal("Context timed out waiting for Connect() to be called on sc1.")
 	}
 	sc1.UpdateState(balancer.SubConnState{ConnectivityState: connectivity.Connecting})
 	sc1.UpdateState(balancer.SubConnState{ConnectivityState: connectivity.TransientFailure, ConnectionError: tfErr})

 	// Move the subconn back to IDLE, it should not be re-connected until the
 	// first pass is complete.
 	shortCtx, shortCancel := context.WithTimeout(ctx, defaultTestShortTimeout)
 	defer shortCancel()
 	sc1.UpdateState(balancer.SubConnState{ConnectivityState: connectivity.Idle})
 	select {
 	case <-sc1.ConnectCh:
 		t.Fatal("Connect() unexpectedly called on sc1.")
 	case <-shortCtx.Done():
 	}

 	if err := cc.WaitForPickerWithErr(ctx, balancer.ErrNoSubConnAvailable); err != nil {
 		t.Fatalf("cc.WaitForPickerWithErr(%v) returned error: %v", balancer.ErrNoSubConnAvailable, err)
 	}

 	sc2 := <-cc.NewSubConnCh
 	select {
 	case <-sc2.ConnectCh:
 	case <-ctx.Done():
 		t.Fatal("Context timed out waiting for Connect() to be called on sc2.")
 	}
 	sc2.UpdateState(balancer.SubConnState{ConnectivityState: connectivity.Connecting})
 	sc2.UpdateState(balancer.SubConnState{ConnectivityState: connectivity.TransientFailure, ConnectionError: tfErr})

 	if err := cc.WaitForPickerWithErr(ctx, tfErr); err != nil {
 		t.Fatalf("cc.WaitForPickerWithErr(%v) returned error: %v", tfErr, err)
 	}

 	// Subsequent TRANSIENT_FAILUREs should be reported only after seeing "# of SubConns"
 	// TRANSIENT_FAILUREs.

 	// Both the subconns should be connected in parallel.
 	select {
 	case <-sc1.ConnectCh:
 	case <-ctx.Done():
 		t.Fatal("Context timed out waiting for Connect() to be called on sc1.")
 	}

 	shortCtx, shortCancel = context.WithTimeout(ctx, defaultTestShortTimeout)
 	defer shortCancel()
 	select {
 	case <-sc2.ConnectCh:
 		t.Fatal("Connect() called on sc2 before it completed backing-off.")
 	case <-shortCtx.Done():
 	}

 	sc2.UpdateState(balancer.SubConnState{ConnectivityState: connectivity.Idle})
 	select {
 	case <-sc2.ConnectCh:
 	case <-ctx.Done():
 		t.Fatal("Context timed out waiting for Connect() to be called on sc2.")
 	}

 	newTfErr := fmt.Errorf("test err: unreachable")
 	sc2.UpdateState(balancer.SubConnState{ConnectivityState: connectivity.TransientFailure, ConnectionError: newTfErr})
 	select {
 	case <-time.After(defaultTestShortTimeout):
 	case p := <-cc.NewPickerCh:
 		sc, err := p.Pick(balancer.PickInfo{})
 		t.Fatalf("Unexpected picker update: %v, %v", sc, err)
 	}

 	sc2.UpdateState(balancer.SubConnState{ConnectivityState: connectivity.TransientFailure, ConnectionError: newTfErr})
 	if err := cc.WaitForPickerWithErr(ctx, newTfErr); err != nil {
 		t.Fatalf("cc.WaitForPickerWithErr(%v) returned error: %v", newTfErr, err)
 	}
 }
	/*
	*
	* Copyright 2024 gRPC authors.
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*
	*/

	package pickfirst

	import (
	"context"
	"errors"
	"fmt"
	"testing"
	"time"

	"google.golang.org/grpc/attributes"
	"google.golang.org/grpc/balancer"
	"google.golang.org/grpc/connectivity"
	"google.golang.org/grpc/internal/grpctest"
	"google.golang.org/grpc/internal/testutils"
	"google.golang.org/grpc/resolver"
	)

	const (
	// Default timeout for tests in this package.
	defaultTestTimeout = 10 * time.Second
	// Default short timeout, to be used when waiting for events which are not
	// expected to happen.
	defaultTestShortTimeout = 100 * time.Millisecond
	)

	type s struct {
	grpctest.Tester
	}

	func Test(t *testing.T) {
	grpctest.RunSubTests(t, s{})
	}

	// TestPickFirst_InitialResolverError sends a resolver error to the balancer
	// before a valid resolver update. It verifies that the clientconn state is
	// updated to TRANSIENT_FAILURE.
	func (s) TestPickFirst_InitialResolverError(t *testing.T) {
	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
	defer cancel()
	cc := testutils.NewBalancerClientConn(t)
	bal := balancer.Get(Name).Build(cc, balancer.BuildOptions{})
	defer bal.Close()
	bal.ResolverError(errors.New("resolution failed: test error"))

	if err := cc.WaitForConnectivityState(ctx, connectivity.TransientFailure); err != nil {
	t.Fatalf("cc.WaitForConnectivityState(%v) returned error: %v", connectivity.TransientFailure, err)
	}

	// After sending a valid update, the LB policy should report CONNECTING.
	ccState := balancer.ClientConnState{
	ResolverState: resolver.State{
	Endpoints: []resolver.Endpoint{
	{Addresses: []resolver.Address{{Addr: "1.1.1.1:1"}}},
	{Addresses: []resolver.Address{{Addr: "2.2.2.2:2"}}},
	},
	},
	}
	if err := bal.UpdateClientConnState(ccState); err != nil {
	t.Fatalf("UpdateClientConnState(%v) returned error: %v", ccState, err)
	}

	if err := cc.WaitForConnectivityState(ctx, connectivity.Connecting); err != nil {
	t.Fatalf("cc.WaitForConnectivityState(%v) returned error: %v", connectivity.Connecting, err)
	}
	}

	// TestPickFirst_ResolverErrorinTF sends a resolver error to the balancer
	// before when it's attempting to connect to a SubConn TRANSIENT_FAILURE. It
	// verifies that the picker is updated and the SubConn is not closed.
	func (s) TestPickFirst_ResolverErrorinTF(t *testing.T) {
	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
	defer cancel()
	cc := testutils.NewBalancerClientConn(t)
	bal := balancer.Get(Name).Build(cc, balancer.BuildOptions{})
	defer bal.Close()

	// After sending a valid update, the LB policy should report CONNECTING.
	ccState := balancer.ClientConnState{
	ResolverState: resolver.State{
	Endpoints: []resolver.Endpoint{
	{Addresses: []resolver.Address{{Addr: "1.1.1.1:1"}}},
	},
	},
	}

	if err := bal.UpdateClientConnState(ccState); err != nil {
	t.Fatalf("UpdateClientConnState(%v) returned error: %v", ccState, err)
	}

	sc1 := <-cc.NewSubConnCh
	if err := cc.WaitForConnectivityState(ctx, connectivity.Connecting); err != nil {
	t.Fatalf("cc.WaitForConnectivityState(%v) returned error: %v", connectivity.Connecting, err)
	}

	scErr := fmt.Errorf("test error: connection refused")
	sc1.UpdateState(balancer.SubConnState{
	ConnectivityState: connectivity.TransientFailure,
	ConnectionError: scErr,
	})

	if err := cc.WaitForPickerWithErr(ctx, scErr); err != nil {
	t.Fatalf("cc.WaitForPickerWithErr(%v) returned error: %v", scErr, err)
	}

	bal.ResolverError(errors.New("resolution failed: test error"))
	if err := cc.WaitForErrPicker(ctx); err != nil {
	t.Fatalf("cc.WaitForPickerWithErr() returned error: %v", err)
	}

	select {
	case <-time.After(defaultTestShortTimeout):
	case sc := <-cc.ShutdownSubConnCh:
	t.Fatalf("Unexpected SubConn shutdown: %v", sc)
	}
	}

	// TestAddressList_Iteration verifies the behaviour of the addressList while
	// iterating through the entries.
	func (s) TestAddressList_Iteration(t *testing.T) {
	addrs := []resolver.Address{
	{
	Addr: "192.168.1.1",
	ServerName: "test-host-1",
	Attributes: attributes.New("key-1", "val-1"),
	BalancerAttributes: attributes.New("bal-key-1", "bal-val-1"),
	},
	{
	Addr: "192.168.1.2",
	ServerName: "test-host-2",
	Attributes: attributes.New("key-2", "val-2"),
	BalancerAttributes: attributes.New("bal-key-2", "bal-val-2"),
	},
	{
	Addr: "192.168.1.3",
	ServerName: "test-host-3",
	Attributes: attributes.New("key-3", "val-3"),
	BalancerAttributes: attributes.New("bal-key-3", "bal-val-3"),
	},
	}

	addressList := addressList{}
	addressList.updateAddrs(addrs)

	for i := 0; i < len(addrs); i++ {
	if got, want := addressList.isValid(), true; got != want {
	t.Fatalf("addressList.isValid() = %t, want %t", got, want)
	}
	if got, want := addressList.currentAddress(), addrs[i]; !want.Equal(got) {
	t.Errorf("addressList.currentAddress() = %v, want %v", got, want)
	}
	if got, want := addressList.increment(), i+1 < len(addrs); got != want {
	t.Fatalf("addressList.increment() = %t, want %t", got, want)
	}
	}

	if got, want := addressList.isValid(), false; got != want {
	t.Fatalf("addressList.isValid() = %t, want %t", got, want)
	}

	// increment an invalid address list.
	if got, want := addressList.increment(), false; got != want {
	t.Errorf("addressList.increment() = %t, want %t", got, want)
	}

	if got, want := addressList.isValid(), false; got != want {
	t.Errorf("addressList.isValid() = %t, want %t", got, want)
	}

	addressList.reset()
	for i := 0; i < len(addrs); i++ {
	if got, want := addressList.isValid(), true; got != want {
	t.Fatalf("addressList.isValid() = %t, want %t", got, want)
	}
	if got, want := addressList.currentAddress(), addrs[i]; !want.Equal(got) {
	t.Errorf("addressList.currentAddress() = %v, want %v", got, want)
	}
	if got, want := addressList.increment(), i+1 < len(addrs); got != want {
	t.Fatalf("addressList.increment() = %t, want %t", got, want)
	}
	}
	}

	// TestAddressList_SeekTo verifies the behaviour of addressList.seekTo.
	func (s) TestAddressList_SeekTo(t *testing.T) {
	addrs := []resolver.Address{
	{
	Addr: "192.168.1.1",
	ServerName: "test-host-1",
	Attributes: attributes.New("key-1", "val-1"),
	BalancerAttributes: attributes.New("bal-key-1", "bal-val-1"),
	},
	{
	Addr: "192.168.1.2",
	ServerName: "test-host-2",
	Attributes: attributes.New("key-2", "val-2"),
	BalancerAttributes: attributes.New("bal-key-2", "bal-val-2"),
	},
	{
	Addr: "192.168.1.3",
	ServerName: "test-host-3",
	Attributes: attributes.New("key-3", "val-3"),
	BalancerAttributes: attributes.New("bal-key-3", "bal-val-3"),
	},
	}

	addressList := addressList{}
	addressList.updateAddrs(addrs)

	// Try finding an address in the list.
	key := resolver.Address{
	Addr: "192.168.1.2",
	ServerName: "test-host-2",
	Attributes: attributes.New("key-2", "val-2"),
	BalancerAttributes: attributes.New("ignored", "bal-val-2"),
	}

	if got, want := addressList.seekTo(key), true; got != want {
	t.Errorf("addressList.seekTo(%v) = %t, want %t", key, got, want)
	}

	// It should be possible to increment once more now that the pointer has advanced.
	if got, want := addressList.increment(), true; got != want {
	t.Errorf("addressList.increment() = %t, want %t", got, want)
	}

	if got, want := addressList.increment(), false; got != want {
	t.Errorf("addressList.increment() = %t, want %t", got, want)
	}

	// Seek to the key again, it is behind the pointer now.
	if got, want := addressList.seekTo(key), true; got != want {
	t.Errorf("addressList.seekTo(%v) = %t, want %t", key, got, want)
	}

	// Seek to a key not in the list.
	key = resolver.Address{
	Addr: "192.168.1.5",
	ServerName: "test-host-5",
	Attributes: attributes.New("key-5", "val-5"),
	BalancerAttributes: attributes.New("ignored", "bal-val-5"),
	}

	if got, want := addressList.seekTo(key), false; got != want {
	t.Errorf("addressList.seekTo(%v) = %t, want %t", key, got, want)
	}

	// It should be possible to increment once more since the pointer has not advanced.
	if got, want := addressList.increment(), true; got != want {
	t.Errorf("addressList.increment() = %t, want %t", got, want)
	}

	if got, want := addressList.increment(), false; got != want {
	t.Errorf("addressList.increment() = %t, want %t", got, want)
	}
	}

	// TestPickFirstLeaf_TFPickerUpdate sends TRANSIENT_FAILURE SubConn state updates
	// for each SubConn managed by a pickfirst balancer. It verifies that the picker
	// is updated with the expected frequency.
	func (s) TestPickFirstLeaf_TFPickerUpdate(t *testing.T) {
	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
	defer cancel()
	cc := testutils.NewBalancerClientConn(t)
	bal := pickfirstBuilder{}.Build(cc, balancer.BuildOptions{})
	defer bal.Close()
	ccState := balancer.ClientConnState{
	ResolverState: resolver.State{
	Endpoints: []resolver.Endpoint{
	{Addresses: []resolver.Address{{Addr: "1.1.1.1:1"}}},
	{Addresses: []resolver.Address{{Addr: "1.1.1.1:1"}}}, // duplicate, should be ignored.
	{Addresses: []resolver.Address{{Addr: "2.2.2.2:2"}}},
	{Addresses: []resolver.Address{{Addr: "1.1.1.1:1"}}}, // duplicate, should be ignored.
	},
	},
	}
	if err := bal.UpdateClientConnState(ccState); err != nil {
	t.Fatalf("UpdateClientConnState(%v) returned error: %v", ccState, err)
	}

	// PF should report TRANSIENT_FAILURE only once all the sunbconns have failed
	// once.
	tfErr := fmt.Errorf("test err: connection refused")
	sc1 := <-cc.NewSubConnCh
	select {
	case <-sc1.ConnectCh:
	case <-ctx.Done():
	t.Fatal("Context timed out waiting for Connect() to be called on sc1.")
	}
	sc1.UpdateState(balancer.SubConnState{ConnectivityState: connectivity.Connecting})
	sc1.UpdateState(balancer.SubConnState{ConnectivityState: connectivity.TransientFailure, ConnectionError: tfErr})

	// Move the subconn back to IDLE, it should not be re-connected until the
	// first pass is complete.
	shortCtx, shortCancel := context.WithTimeout(ctx, defaultTestShortTimeout)
	defer shortCancel()
	sc1.UpdateState(balancer.SubConnState{ConnectivityState: connectivity.Idle})
	select {
	case <-sc1.ConnectCh:
	t.Fatal("Connect() unexpectedly called on sc1.")
	case <-shortCtx.Done():
	}

	if err := cc.WaitForPickerWithErr(ctx, balancer.ErrNoSubConnAvailable); err != nil {
	t.Fatalf("cc.WaitForPickerWithErr(%v) returned error: %v", balancer.ErrNoSubConnAvailable, err)
	}

	sc2 := <-cc.NewSubConnCh
	select {
	case <-sc2.ConnectCh:
	case <-ctx.Done():
	t.Fatal("Context timed out waiting for Connect() to be called on sc2.")
	}
	sc2.UpdateState(balancer.SubConnState{ConnectivityState: connectivity.Connecting})
	sc2.UpdateState(balancer.SubConnState{ConnectivityState: connectivity.TransientFailure, ConnectionError: tfErr})

	if err := cc.WaitForPickerWithErr(ctx, tfErr); err != nil {
	t.Fatalf("cc.WaitForPickerWithErr(%v) returned error: %v", tfErr, err)
	}

	// Subsequent TRANSIENT_FAILUREs should be reported only after seeing "# of SubConns"
	// TRANSIENT_FAILUREs.

	// Both the subconns should be connected in parallel.
	select {
	case <-sc1.ConnectCh:
	case <-ctx.Done():
	t.Fatal("Context timed out waiting for Connect() to be called on sc1.")
	}

	shortCtx, shortCancel = context.WithTimeout(ctx, defaultTestShortTimeout)
	defer shortCancel()
	select {
	case <-sc2.ConnectCh:
	t.Fatal("Connect() called on sc2 before it completed backing-off.")
	case <-shortCtx.Done():
	}

	sc2.UpdateState(balancer.SubConnState{ConnectivityState: connectivity.Idle})
	select {
	case <-sc2.ConnectCh:
	case <-ctx.Done():
	t.Fatal("Context timed out waiting for Connect() to be called on sc2.")
	}

	newTfErr := fmt.Errorf("test err: unreachable")
	sc2.UpdateState(balancer.SubConnState{ConnectivityState: connectivity.TransientFailure, ConnectionError: newTfErr})
	select {
	case <-time.After(defaultTestShortTimeout):
	case p := <-cc.NewPickerCh:
	sc, err := p.Pick(balancer.PickInfo{})
	t.Fatalf("Unexpected picker update: %v, %v", sc, err)
	}

	sc2.UpdateState(balancer.SubConnState{ConnectivityState: connectivity.TransientFailure, ConnectionError: newTfErr})
	if err := cc.WaitForPickerWithErr(ctx, newTfErr); err != nil {
	t.Fatalf("cc.WaitForPickerWithErr(%v) returned error: %v", newTfErr, err)
	}
	}