git subrepo clone (merge) https://github.com/kubernetes-incubator/metrics-server.git metrics-server
subrepo:
subdir: "metrics-server"
merged: "92d8412"
upstream:
origin: "https://github.com/kubernetes-incubator/metrics-server.git"
branch: "master"
commit: "92d8412"
git-subrepo:
version: "0.4.0"
origin: "???"
commit: "???"
diff --git a/metrics-server/vendor/google.golang.org/grpc/clientconn.go b/metrics-server/vendor/google.golang.org/grpc/clientconn.go
new file mode 100644
index 0000000..84ba9e5
--- /dev/null
+++ b/metrics-server/vendor/google.golang.org/grpc/clientconn.go
@@ -0,0 +1,1602 @@
+/*
+ *
+ * Copyright 2014 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 grpc
+
+import (
+ "errors"
+ "fmt"
+ "math"
+ "net"
+ "reflect"
+ "strings"
+ "sync"
+ "time"
+
+ "golang.org/x/net/context"
+ "golang.org/x/net/trace"
+ "google.golang.org/grpc/balancer"
+ _ "google.golang.org/grpc/balancer/roundrobin" // To register roundrobin.
+ "google.golang.org/grpc/codes"
+ "google.golang.org/grpc/connectivity"
+ "google.golang.org/grpc/credentials"
+ "google.golang.org/grpc/grpclog"
+ "google.golang.org/grpc/internal"
+ "google.golang.org/grpc/internal/backoff"
+ "google.golang.org/grpc/internal/channelz"
+ "google.golang.org/grpc/keepalive"
+ "google.golang.org/grpc/resolver"
+ _ "google.golang.org/grpc/resolver/dns" // To register dns resolver.
+ _ "google.golang.org/grpc/resolver/passthrough" // To register passthrough resolver.
+ "google.golang.org/grpc/stats"
+ "google.golang.org/grpc/status"
+ "google.golang.org/grpc/transport"
+)
+
+const (
+ // minimum time to give a connection to complete
+ minConnectTimeout = 20 * time.Second
+ // must match grpclbName in grpclb/grpclb.go
+ grpclbName = "grpclb"
+)
+
+var (
+ // ErrClientConnClosing indicates that the operation is illegal because
+ // the ClientConn is closing.
+ //
+ // Deprecated: this error should not be relied upon by users; use the status
+ // code of Canceled instead.
+ ErrClientConnClosing = status.Error(codes.Canceled, "grpc: the client connection is closing")
+ // errConnDrain indicates that the connection starts to be drained and does not accept any new RPCs.
+ errConnDrain = errors.New("grpc: the connection is drained")
+ // errConnClosing indicates that the connection is closing.
+ errConnClosing = errors.New("grpc: the connection is closing")
+ // errConnUnavailable indicates that the connection is unavailable.
+ errConnUnavailable = errors.New("grpc: the connection is unavailable")
+ // errBalancerClosed indicates that the balancer is closed.
+ errBalancerClosed = errors.New("grpc: balancer is closed")
+ // We use an accessor so that minConnectTimeout can be
+ // atomically read and updated while testing.
+ getMinConnectTimeout = func() time.Duration {
+ return minConnectTimeout
+ }
+)
+
+// The following errors are returned from Dial and DialContext
+var (
+ // errNoTransportSecurity indicates that there is no transport security
+ // being set for ClientConn. Users should either set one or explicitly
+ // call WithInsecure DialOption to disable security.
+ errNoTransportSecurity = errors.New("grpc: no transport security set (use grpc.WithInsecure() explicitly or set credentials)")
+ // errTransportCredentialsMissing indicates that users want to transmit security
+ // information (e.g., oauth2 token) which requires secure connection on an insecure
+ // connection.
+ errTransportCredentialsMissing = errors.New("grpc: the credentials require transport level security (use grpc.WithTransportCredentials() to set)")
+ // errCredentialsConflict indicates that grpc.WithTransportCredentials()
+ // and grpc.WithInsecure() are both called for a connection.
+ errCredentialsConflict = errors.New("grpc: transport credentials are set for an insecure connection (grpc.WithTransportCredentials() and grpc.WithInsecure() are both called)")
+ // errNetworkIO indicates that the connection is down due to some network I/O error.
+ errNetworkIO = errors.New("grpc: failed with network I/O error")
+)
+
+// dialOptions configure a Dial call. dialOptions are set by the DialOption
+// values passed to Dial.
+type dialOptions struct {
+ unaryInt UnaryClientInterceptor
+ streamInt StreamClientInterceptor
+ cp Compressor
+ dc Decompressor
+ bs backoff.Strategy
+ block bool
+ insecure bool
+ timeout time.Duration
+ scChan <-chan ServiceConfig
+ copts transport.ConnectOptions
+ callOptions []CallOption
+ // This is used by v1 balancer dial option WithBalancer to support v1
+ // balancer, and also by WithBalancerName dial option.
+ balancerBuilder balancer.Builder
+ // This is to support grpclb.
+ resolverBuilder resolver.Builder
+ waitForHandshake bool
+ channelzParentID int64
+ disableServiceConfig bool
+}
+
+const (
+ defaultClientMaxReceiveMessageSize = 1024 * 1024 * 4
+ defaultClientMaxSendMessageSize = math.MaxInt32
+)
+
+// RegisterChannelz turns on channelz service.
+// This is an EXPERIMENTAL API.
+func RegisterChannelz() {
+ channelz.TurnOn()
+}
+
+// DialOption configures how we set up the connection.
+type DialOption func(*dialOptions)
+
+// WithWaitForHandshake blocks until the initial settings frame is received from the
+// server before assigning RPCs to the connection.
+// Experimental API.
+func WithWaitForHandshake() DialOption {
+ return func(o *dialOptions) {
+ o.waitForHandshake = true
+ }
+}
+
+// WithWriteBufferSize lets you set the size of write buffer, this determines how much data can be batched
+// before doing a write on the wire.
+func WithWriteBufferSize(s int) DialOption {
+ return func(o *dialOptions) {
+ o.copts.WriteBufferSize = s
+ }
+}
+
+// WithReadBufferSize lets you set the size of read buffer, this determines how much data can be read at most
+// for each read syscall.
+func WithReadBufferSize(s int) DialOption {
+ return func(o *dialOptions) {
+ o.copts.ReadBufferSize = s
+ }
+}
+
+// WithInitialWindowSize returns a DialOption which sets the value for initial window size on a stream.
+// The lower bound for window size is 64K and any value smaller than that will be ignored.
+func WithInitialWindowSize(s int32) DialOption {
+ return func(o *dialOptions) {
+ o.copts.InitialWindowSize = s
+ }
+}
+
+// WithInitialConnWindowSize returns a DialOption which sets the value for initial window size on a connection.
+// The lower bound for window size is 64K and any value smaller than that will be ignored.
+func WithInitialConnWindowSize(s int32) DialOption {
+ return func(o *dialOptions) {
+ o.copts.InitialConnWindowSize = s
+ }
+}
+
+// WithMaxMsgSize returns a DialOption which sets the maximum message size the client can receive.
+//
+// Deprecated: use WithDefaultCallOptions(MaxCallRecvMsgSize(s)) instead.
+func WithMaxMsgSize(s int) DialOption {
+ return WithDefaultCallOptions(MaxCallRecvMsgSize(s))
+}
+
+// WithDefaultCallOptions returns a DialOption which sets the default CallOptions for calls over the connection.
+func WithDefaultCallOptions(cos ...CallOption) DialOption {
+ return func(o *dialOptions) {
+ o.callOptions = append(o.callOptions, cos...)
+ }
+}
+
+// WithCodec returns a DialOption which sets a codec for message marshaling and unmarshaling.
+//
+// Deprecated: use WithDefaultCallOptions(CallCustomCodec(c)) instead.
+func WithCodec(c Codec) DialOption {
+ return WithDefaultCallOptions(CallCustomCodec(c))
+}
+
+// WithCompressor returns a DialOption which sets a Compressor to use for
+// message compression. It has lower priority than the compressor set by
+// the UseCompressor CallOption.
+//
+// Deprecated: use UseCompressor instead.
+func WithCompressor(cp Compressor) DialOption {
+ return func(o *dialOptions) {
+ o.cp = cp
+ }
+}
+
+// WithDecompressor returns a DialOption which sets a Decompressor to use for
+// incoming message decompression. If incoming response messages are encoded
+// using the decompressor's Type(), it will be used. Otherwise, the message
+// encoding will be used to look up the compressor registered via
+// encoding.RegisterCompressor, which will then be used to decompress the
+// message. If no compressor is registered for the encoding, an Unimplemented
+// status error will be returned.
+//
+// Deprecated: use encoding.RegisterCompressor instead.
+func WithDecompressor(dc Decompressor) DialOption {
+ return func(o *dialOptions) {
+ o.dc = dc
+ }
+}
+
+// WithBalancer returns a DialOption which sets a load balancer with the v1 API.
+// Name resolver will be ignored if this DialOption is specified.
+//
+// Deprecated: use the new balancer APIs in balancer package and WithBalancerName.
+func WithBalancer(b Balancer) DialOption {
+ return func(o *dialOptions) {
+ o.balancerBuilder = &balancerWrapperBuilder{
+ b: b,
+ }
+ }
+}
+
+// WithBalancerName sets the balancer that the ClientConn will be initialized
+// with. Balancer registered with balancerName will be used. This function
+// panics if no balancer was registered by balancerName.
+//
+// The balancer cannot be overridden by balancer option specified by service
+// config.
+//
+// This is an EXPERIMENTAL API.
+func WithBalancerName(balancerName string) DialOption {
+ builder := balancer.Get(balancerName)
+ if builder == nil {
+ panic(fmt.Sprintf("grpc.WithBalancerName: no balancer is registered for name %v", balancerName))
+ }
+ return func(o *dialOptions) {
+ o.balancerBuilder = builder
+ }
+}
+
+// withResolverBuilder is only for grpclb.
+func withResolverBuilder(b resolver.Builder) DialOption {
+ return func(o *dialOptions) {
+ o.resolverBuilder = b
+ }
+}
+
+// WithServiceConfig returns a DialOption which has a channel to read the service configuration.
+//
+// Deprecated: service config should be received through name resolver, as specified here.
+// https://github.com/grpc/grpc/blob/master/doc/service_config.md
+func WithServiceConfig(c <-chan ServiceConfig) DialOption {
+ return func(o *dialOptions) {
+ o.scChan = c
+ }
+}
+
+// WithBackoffMaxDelay configures the dialer to use the provided maximum delay
+// when backing off after failed connection attempts.
+func WithBackoffMaxDelay(md time.Duration) DialOption {
+ return WithBackoffConfig(BackoffConfig{MaxDelay: md})
+}
+
+// WithBackoffConfig configures the dialer to use the provided backoff
+// parameters after connection failures.
+//
+// Use WithBackoffMaxDelay until more parameters on BackoffConfig are opened up
+// for use.
+func WithBackoffConfig(b BackoffConfig) DialOption {
+
+ return withBackoff(backoff.Exponential{
+ MaxDelay: b.MaxDelay,
+ })
+}
+
+// withBackoff sets the backoff strategy used for connectRetryNum after a
+// failed connection attempt.
+//
+// This can be exported if arbitrary backoff strategies are allowed by gRPC.
+func withBackoff(bs backoff.Strategy) DialOption {
+ return func(o *dialOptions) {
+ o.bs = bs
+ }
+}
+
+// WithBlock returns a DialOption which makes caller of Dial blocks until the underlying
+// connection is up. Without this, Dial returns immediately and connecting the server
+// happens in background.
+func WithBlock() DialOption {
+ return func(o *dialOptions) {
+ o.block = true
+ }
+}
+
+// WithInsecure returns a DialOption which disables transport security for this ClientConn.
+// Note that transport security is required unless WithInsecure is set.
+func WithInsecure() DialOption {
+ return func(o *dialOptions) {
+ o.insecure = true
+ }
+}
+
+// WithTransportCredentials returns a DialOption which configures a
+// connection level security credentials (e.g., TLS/SSL).
+func WithTransportCredentials(creds credentials.TransportCredentials) DialOption {
+ return func(o *dialOptions) {
+ o.copts.TransportCredentials = creds
+ }
+}
+
+// WithPerRPCCredentials returns a DialOption which sets
+// credentials and places auth state on each outbound RPC.
+func WithPerRPCCredentials(creds credentials.PerRPCCredentials) DialOption {
+ return func(o *dialOptions) {
+ o.copts.PerRPCCredentials = append(o.copts.PerRPCCredentials, creds)
+ }
+}
+
+// WithTimeout returns a DialOption that configures a timeout for dialing a ClientConn
+// initially. This is valid if and only if WithBlock() is present.
+//
+// Deprecated: use DialContext and context.WithTimeout instead.
+func WithTimeout(d time.Duration) DialOption {
+ return func(o *dialOptions) {
+ o.timeout = d
+ }
+}
+
+func withContextDialer(f func(context.Context, string) (net.Conn, error)) DialOption {
+ return func(o *dialOptions) {
+ o.copts.Dialer = f
+ }
+}
+
+func init() {
+ internal.WithContextDialer = withContextDialer
+ internal.WithResolverBuilder = withResolverBuilder
+}
+
+// WithDialer returns a DialOption that specifies a function to use for dialing network addresses.
+// If FailOnNonTempDialError() is set to true, and an error is returned by f, gRPC checks the error's
+// Temporary() method to decide if it should try to reconnect to the network address.
+func WithDialer(f func(string, time.Duration) (net.Conn, error)) DialOption {
+ return withContextDialer(
+ func(ctx context.Context, addr string) (net.Conn, error) {
+ if deadline, ok := ctx.Deadline(); ok {
+ return f(addr, deadline.Sub(time.Now()))
+ }
+ return f(addr, 0)
+ })
+}
+
+// WithStatsHandler returns a DialOption that specifies the stats handler
+// for all the RPCs and underlying network connections in this ClientConn.
+func WithStatsHandler(h stats.Handler) DialOption {
+ return func(o *dialOptions) {
+ o.copts.StatsHandler = h
+ }
+}
+
+// FailOnNonTempDialError returns a DialOption that specifies if gRPC fails on non-temporary dial errors.
+// If f is true, and dialer returns a non-temporary error, gRPC will fail the connection to the network
+// address and won't try to reconnect.
+// The default value of FailOnNonTempDialError is false.
+// This is an EXPERIMENTAL API.
+func FailOnNonTempDialError(f bool) DialOption {
+ return func(o *dialOptions) {
+ o.copts.FailOnNonTempDialError = f
+ }
+}
+
+// WithUserAgent returns a DialOption that specifies a user agent string for all the RPCs.
+func WithUserAgent(s string) DialOption {
+ return func(o *dialOptions) {
+ o.copts.UserAgent = s
+ }
+}
+
+// WithKeepaliveParams returns a DialOption that specifies keepalive parameters for the client transport.
+func WithKeepaliveParams(kp keepalive.ClientParameters) DialOption {
+ return func(o *dialOptions) {
+ o.copts.KeepaliveParams = kp
+ }
+}
+
+// WithUnaryInterceptor returns a DialOption that specifies the interceptor for unary RPCs.
+func WithUnaryInterceptor(f UnaryClientInterceptor) DialOption {
+ return func(o *dialOptions) {
+ o.unaryInt = f
+ }
+}
+
+// WithStreamInterceptor returns a DialOption that specifies the interceptor for streaming RPCs.
+func WithStreamInterceptor(f StreamClientInterceptor) DialOption {
+ return func(o *dialOptions) {
+ o.streamInt = f
+ }
+}
+
+// WithAuthority returns a DialOption that specifies the value to be used as
+// the :authority pseudo-header. This value only works with WithInsecure and
+// has no effect if TransportCredentials are present.
+func WithAuthority(a string) DialOption {
+ return func(o *dialOptions) {
+ o.copts.Authority = a
+ }
+}
+
+// WithChannelzParentID returns a DialOption that specifies the channelz ID of current ClientConn's
+// parent. This function is used in nested channel creation (e.g. grpclb dial).
+func WithChannelzParentID(id int64) DialOption {
+ return func(o *dialOptions) {
+ o.channelzParentID = id
+ }
+}
+
+// WithDisableServiceConfig returns a DialOption that causes grpc to ignore any
+// service config provided by the resolver and provides a hint to the resolver
+// to not fetch service configs.
+func WithDisableServiceConfig() DialOption {
+ return func(o *dialOptions) {
+ o.disableServiceConfig = true
+ }
+}
+
+// Dial creates a client connection to the given target.
+func Dial(target string, opts ...DialOption) (*ClientConn, error) {
+ return DialContext(context.Background(), target, opts...)
+}
+
+// DialContext creates a client connection to the given target. By default, it's
+// a non-blocking dial (the function won't wait for connections to be
+// established, and connecting happens in the background). To make it a blocking
+// dial, use WithBlock() dial option.
+//
+// In the non-blocking case, the ctx does not act against the connection. It
+// only controls the setup steps.
+//
+// In the blocking case, ctx can be used to cancel or expire the pending
+// connection. Once this function returns, the cancellation and expiration of
+// ctx will be noop. Users should call ClientConn.Close to terminate all the
+// pending operations after this function returns.
+//
+// The target name syntax is defined in
+// https://github.com/grpc/grpc/blob/master/doc/naming.md.
+// e.g. to use dns resolver, a "dns:///" prefix should be applied to the target.
+func DialContext(ctx context.Context, target string, opts ...DialOption) (conn *ClientConn, err error) {
+ cc := &ClientConn{
+ target: target,
+ csMgr: &connectivityStateManager{},
+ conns: make(map[*addrConn]struct{}),
+
+ blockingpicker: newPickerWrapper(),
+ }
+ cc.ctx, cc.cancel = context.WithCancel(context.Background())
+
+ for _, opt := range opts {
+ opt(&cc.dopts)
+ }
+
+ if channelz.IsOn() {
+ if cc.dopts.channelzParentID != 0 {
+ cc.channelzID = channelz.RegisterChannel(cc, cc.dopts.channelzParentID, target)
+ } else {
+ cc.channelzID = channelz.RegisterChannel(cc, 0, target)
+ }
+ }
+
+ if !cc.dopts.insecure {
+ if cc.dopts.copts.TransportCredentials == nil {
+ return nil, errNoTransportSecurity
+ }
+ } else {
+ if cc.dopts.copts.TransportCredentials != nil {
+ return nil, errCredentialsConflict
+ }
+ for _, cd := range cc.dopts.copts.PerRPCCredentials {
+ if cd.RequireTransportSecurity() {
+ return nil, errTransportCredentialsMissing
+ }
+ }
+ }
+
+ cc.mkp = cc.dopts.copts.KeepaliveParams
+
+ if cc.dopts.copts.Dialer == nil {
+ cc.dopts.copts.Dialer = newProxyDialer(
+ func(ctx context.Context, addr string) (net.Conn, error) {
+ network, addr := parseDialTarget(addr)
+ return dialContext(ctx, network, addr)
+ },
+ )
+ }
+
+ if cc.dopts.copts.UserAgent != "" {
+ cc.dopts.copts.UserAgent += " " + grpcUA
+ } else {
+ cc.dopts.copts.UserAgent = grpcUA
+ }
+
+ if cc.dopts.timeout > 0 {
+ var cancel context.CancelFunc
+ ctx, cancel = context.WithTimeout(ctx, cc.dopts.timeout)
+ defer cancel()
+ }
+
+ defer func() {
+ select {
+ case <-ctx.Done():
+ conn, err = nil, ctx.Err()
+ default:
+ }
+
+ if err != nil {
+ cc.Close()
+ }
+ }()
+
+ scSet := false
+ if cc.dopts.scChan != nil {
+ // Try to get an initial service config.
+ select {
+ case sc, ok := <-cc.dopts.scChan:
+ if ok {
+ cc.sc = sc
+ scSet = true
+ }
+ default:
+ }
+ }
+ if cc.dopts.bs == nil {
+ cc.dopts.bs = backoff.Exponential{
+ MaxDelay: DefaultBackoffConfig.MaxDelay,
+ }
+ }
+ if cc.dopts.resolverBuilder == nil {
+ // Only try to parse target when resolver builder is not already set.
+ cc.parsedTarget = parseTarget(cc.target)
+ grpclog.Infof("parsed scheme: %q", cc.parsedTarget.Scheme)
+ cc.dopts.resolverBuilder = resolver.Get(cc.parsedTarget.Scheme)
+ if cc.dopts.resolverBuilder == nil {
+ // If resolver builder is still nil, the parse target's scheme is
+ // not registered. Fallback to default resolver and set Endpoint to
+ // the original unparsed target.
+ grpclog.Infof("scheme %q not registered, fallback to default scheme", cc.parsedTarget.Scheme)
+ cc.parsedTarget = resolver.Target{
+ Scheme: resolver.GetDefaultScheme(),
+ Endpoint: target,
+ }
+ cc.dopts.resolverBuilder = resolver.Get(cc.parsedTarget.Scheme)
+ }
+ } else {
+ cc.parsedTarget = resolver.Target{Endpoint: target}
+ }
+ creds := cc.dopts.copts.TransportCredentials
+ if creds != nil && creds.Info().ServerName != "" {
+ cc.authority = creds.Info().ServerName
+ } else if cc.dopts.insecure && cc.dopts.copts.Authority != "" {
+ cc.authority = cc.dopts.copts.Authority
+ } else {
+ // Use endpoint from "scheme://authority/endpoint" as the default
+ // authority for ClientConn.
+ cc.authority = cc.parsedTarget.Endpoint
+ }
+
+ if cc.dopts.scChan != nil && !scSet {
+ // Blocking wait for the initial service config.
+ select {
+ case sc, ok := <-cc.dopts.scChan:
+ if ok {
+ cc.sc = sc
+ }
+ case <-ctx.Done():
+ return nil, ctx.Err()
+ }
+ }
+ if cc.dopts.scChan != nil {
+ go cc.scWatcher()
+ }
+
+ var credsClone credentials.TransportCredentials
+ if creds := cc.dopts.copts.TransportCredentials; creds != nil {
+ credsClone = creds.Clone()
+ }
+ cc.balancerBuildOpts = balancer.BuildOptions{
+ DialCreds: credsClone,
+ Dialer: cc.dopts.copts.Dialer,
+ ChannelzParentID: cc.channelzID,
+ }
+
+ // Build the resolver.
+ cc.resolverWrapper, err = newCCResolverWrapper(cc)
+ if err != nil {
+ return nil, fmt.Errorf("failed to build resolver: %v", err)
+ }
+ // Start the resolver wrapper goroutine after resolverWrapper is created.
+ //
+ // If the goroutine is started before resolverWrapper is ready, the
+ // following may happen: The goroutine sends updates to cc. cc forwards
+ // those to balancer. Balancer creates new addrConn. addrConn fails to
+ // connect, and calls resolveNow(). resolveNow() tries to use the non-ready
+ // resolverWrapper.
+ cc.resolverWrapper.start()
+
+ // A blocking dial blocks until the clientConn is ready.
+ if cc.dopts.block {
+ for {
+ s := cc.GetState()
+ if s == connectivity.Ready {
+ break
+ }
+ if !cc.WaitForStateChange(ctx, s) {
+ // ctx got timeout or canceled.
+ return nil, ctx.Err()
+ }
+ }
+ }
+
+ return cc, nil
+}
+
+// connectivityStateManager keeps the connectivity.State of ClientConn.
+// This struct will eventually be exported so the balancers can access it.
+type connectivityStateManager struct {
+ mu sync.Mutex
+ state connectivity.State
+ notifyChan chan struct{}
+}
+
+// updateState updates the connectivity.State of ClientConn.
+// If there's a change it notifies goroutines waiting on state change to
+// happen.
+func (csm *connectivityStateManager) updateState(state connectivity.State) {
+ csm.mu.Lock()
+ defer csm.mu.Unlock()
+ if csm.state == connectivity.Shutdown {
+ return
+ }
+ if csm.state == state {
+ return
+ }
+ csm.state = state
+ if csm.notifyChan != nil {
+ // There are other goroutines waiting on this channel.
+ close(csm.notifyChan)
+ csm.notifyChan = nil
+ }
+}
+
+func (csm *connectivityStateManager) getState() connectivity.State {
+ csm.mu.Lock()
+ defer csm.mu.Unlock()
+ return csm.state
+}
+
+func (csm *connectivityStateManager) getNotifyChan() <-chan struct{} {
+ csm.mu.Lock()
+ defer csm.mu.Unlock()
+ if csm.notifyChan == nil {
+ csm.notifyChan = make(chan struct{})
+ }
+ return csm.notifyChan
+}
+
+// ClientConn represents a client connection to an RPC server.
+type ClientConn struct {
+ ctx context.Context
+ cancel context.CancelFunc
+
+ target string
+ parsedTarget resolver.Target
+ authority string
+ dopts dialOptions
+ csMgr *connectivityStateManager
+
+ balancerBuildOpts balancer.BuildOptions
+ resolverWrapper *ccResolverWrapper
+ blockingpicker *pickerWrapper
+
+ mu sync.RWMutex
+ sc ServiceConfig
+ scRaw string
+ conns map[*addrConn]struct{}
+ // Keepalive parameter can be updated if a GoAway is received.
+ mkp keepalive.ClientParameters
+ curBalancerName string
+ preBalancerName string // previous balancer name.
+ curAddresses []resolver.Address
+ balancerWrapper *ccBalancerWrapper
+
+ channelzID int64 // channelz unique identification number
+ czmu sync.RWMutex
+ callsStarted int64
+ callsSucceeded int64
+ callsFailed int64
+ lastCallStartedTime time.Time
+}
+
+// WaitForStateChange waits until the connectivity.State of ClientConn changes from sourceState or
+// ctx expires. A true value is returned in former case and false in latter.
+// This is an EXPERIMENTAL API.
+func (cc *ClientConn) WaitForStateChange(ctx context.Context, sourceState connectivity.State) bool {
+ ch := cc.csMgr.getNotifyChan()
+ if cc.csMgr.getState() != sourceState {
+ return true
+ }
+ select {
+ case <-ctx.Done():
+ return false
+ case <-ch:
+ return true
+ }
+}
+
+// GetState returns the connectivity.State of ClientConn.
+// This is an EXPERIMENTAL API.
+func (cc *ClientConn) GetState() connectivity.State {
+ return cc.csMgr.getState()
+}
+
+func (cc *ClientConn) scWatcher() {
+ for {
+ select {
+ case sc, ok := <-cc.dopts.scChan:
+ if !ok {
+ return
+ }
+ cc.mu.Lock()
+ // TODO: load balance policy runtime change is ignored.
+ // We may revist this decision in the future.
+ cc.sc = sc
+ cc.scRaw = ""
+ cc.mu.Unlock()
+ case <-cc.ctx.Done():
+ return
+ }
+ }
+}
+
+func (cc *ClientConn) handleResolvedAddrs(addrs []resolver.Address, err error) {
+ cc.mu.Lock()
+ defer cc.mu.Unlock()
+ if cc.conns == nil {
+ // cc was closed.
+ return
+ }
+
+ if reflect.DeepEqual(cc.curAddresses, addrs) {
+ return
+ }
+
+ cc.curAddresses = addrs
+
+ if cc.dopts.balancerBuilder == nil {
+ // Only look at balancer types and switch balancer if balancer dial
+ // option is not set.
+ var isGRPCLB bool
+ for _, a := range addrs {
+ if a.Type == resolver.GRPCLB {
+ isGRPCLB = true
+ break
+ }
+ }
+ var newBalancerName string
+ if isGRPCLB {
+ newBalancerName = grpclbName
+ } else {
+ // Address list doesn't contain grpclb address. Try to pick a
+ // non-grpclb balancer.
+ newBalancerName = cc.curBalancerName
+ // If current balancer is grpclb, switch to the previous one.
+ if newBalancerName == grpclbName {
+ newBalancerName = cc.preBalancerName
+ }
+ // The following could be true in two cases:
+ // - the first time handling resolved addresses
+ // (curBalancerName="")
+ // - the first time handling non-grpclb addresses
+ // (curBalancerName="grpclb", preBalancerName="")
+ if newBalancerName == "" {
+ newBalancerName = PickFirstBalancerName
+ }
+ }
+ cc.switchBalancer(newBalancerName)
+ } else if cc.balancerWrapper == nil {
+ // Balancer dial option was set, and this is the first time handling
+ // resolved addresses. Build a balancer with dopts.balancerBuilder.
+ cc.balancerWrapper = newCCBalancerWrapper(cc, cc.dopts.balancerBuilder, cc.balancerBuildOpts)
+ }
+
+ cc.balancerWrapper.handleResolvedAddrs(addrs, nil)
+}
+
+// switchBalancer starts the switching from current balancer to the balancer
+// with the given name.
+//
+// It will NOT send the current address list to the new balancer. If needed,
+// caller of this function should send address list to the new balancer after
+// this function returns.
+//
+// Caller must hold cc.mu.
+func (cc *ClientConn) switchBalancer(name string) {
+ if cc.conns == nil {
+ return
+ }
+
+ if strings.ToLower(cc.curBalancerName) == strings.ToLower(name) {
+ return
+ }
+
+ grpclog.Infof("ClientConn switching balancer to %q", name)
+ if cc.dopts.balancerBuilder != nil {
+ grpclog.Infoln("ignoring balancer switching: Balancer DialOption used instead")
+ return
+ }
+ // TODO(bar switching) change this to two steps: drain and close.
+ // Keep track of sc in wrapper.
+ if cc.balancerWrapper != nil {
+ cc.balancerWrapper.close()
+ }
+ // Clear all stickiness state.
+ cc.blockingpicker.clearStickinessState()
+
+ builder := balancer.Get(name)
+ if builder == nil {
+ grpclog.Infof("failed to get balancer builder for: %v, using pick_first instead", name)
+ builder = newPickfirstBuilder()
+ }
+ cc.preBalancerName = cc.curBalancerName
+ cc.curBalancerName = builder.Name()
+ cc.balancerWrapper = newCCBalancerWrapper(cc, builder, cc.balancerBuildOpts)
+}
+
+func (cc *ClientConn) handleSubConnStateChange(sc balancer.SubConn, s connectivity.State) {
+ cc.mu.Lock()
+ if cc.conns == nil {
+ cc.mu.Unlock()
+ return
+ }
+ // TODO(bar switching) send updates to all balancer wrappers when balancer
+ // gracefully switching is supported.
+ cc.balancerWrapper.handleSubConnStateChange(sc, s)
+ cc.mu.Unlock()
+}
+
+// newAddrConn creates an addrConn for addrs and adds it to cc.conns.
+//
+// Caller needs to make sure len(addrs) > 0.
+func (cc *ClientConn) newAddrConn(addrs []resolver.Address) (*addrConn, error) {
+ ac := &addrConn{
+ cc: cc,
+ addrs: addrs,
+ dopts: cc.dopts,
+ }
+ ac.ctx, ac.cancel = context.WithCancel(cc.ctx)
+ // Track ac in cc. This needs to be done before any getTransport(...) is called.
+ cc.mu.Lock()
+ if cc.conns == nil {
+ cc.mu.Unlock()
+ return nil, ErrClientConnClosing
+ }
+ if channelz.IsOn() {
+ ac.channelzID = channelz.RegisterSubChannel(ac, cc.channelzID, "")
+ }
+ cc.conns[ac] = struct{}{}
+ cc.mu.Unlock()
+ return ac, nil
+}
+
+// removeAddrConn removes the addrConn in the subConn from clientConn.
+// It also tears down the ac with the given error.
+func (cc *ClientConn) removeAddrConn(ac *addrConn, err error) {
+ cc.mu.Lock()
+ if cc.conns == nil {
+ cc.mu.Unlock()
+ return
+ }
+ delete(cc.conns, ac)
+ cc.mu.Unlock()
+ ac.tearDown(err)
+}
+
+// ChannelzMetric returns ChannelInternalMetric of current ClientConn.
+// This is an EXPERIMENTAL API.
+func (cc *ClientConn) ChannelzMetric() *channelz.ChannelInternalMetric {
+ state := cc.GetState()
+ cc.czmu.RLock()
+ defer cc.czmu.RUnlock()
+ return &channelz.ChannelInternalMetric{
+ State: state,
+ Target: cc.target,
+ CallsStarted: cc.callsStarted,
+ CallsSucceeded: cc.callsSucceeded,
+ CallsFailed: cc.callsFailed,
+ LastCallStartedTimestamp: cc.lastCallStartedTime,
+ }
+}
+
+func (cc *ClientConn) incrCallsStarted() {
+ cc.czmu.Lock()
+ cc.callsStarted++
+ // TODO(yuxuanli): will make this a time.Time pointer improve performance?
+ cc.lastCallStartedTime = time.Now()
+ cc.czmu.Unlock()
+}
+
+func (cc *ClientConn) incrCallsSucceeded() {
+ cc.czmu.Lock()
+ cc.callsSucceeded++
+ cc.czmu.Unlock()
+}
+
+func (cc *ClientConn) incrCallsFailed() {
+ cc.czmu.Lock()
+ cc.callsFailed++
+ cc.czmu.Unlock()
+}
+
+// connect starts to creating transport and also starts the transport monitor
+// goroutine for this ac.
+// It does nothing if the ac is not IDLE.
+// TODO(bar) Move this to the addrConn section.
+// This was part of resetAddrConn, keep it here to make the diff look clean.
+func (ac *addrConn) connect() error {
+ ac.mu.Lock()
+ if ac.state == connectivity.Shutdown {
+ ac.mu.Unlock()
+ return errConnClosing
+ }
+ if ac.state != connectivity.Idle {
+ ac.mu.Unlock()
+ return nil
+ }
+ ac.state = connectivity.Connecting
+ ac.cc.handleSubConnStateChange(ac.acbw, ac.state)
+ ac.mu.Unlock()
+
+ // Start a goroutine connecting to the server asynchronously.
+ go func() {
+ if err := ac.resetTransport(); err != nil {
+ grpclog.Warningf("Failed to dial %s: %v; please retry.", ac.addrs[0].Addr, err)
+ if err != errConnClosing {
+ // Keep this ac in cc.conns, to get the reason it's torn down.
+ ac.tearDown(err)
+ }
+ return
+ }
+ ac.transportMonitor()
+ }()
+ return nil
+}
+
+// tryUpdateAddrs tries to update ac.addrs with the new addresses list.
+//
+// It checks whether current connected address of ac is in the new addrs list.
+// - If true, it updates ac.addrs and returns true. The ac will keep using
+// the existing connection.
+// - If false, it does nothing and returns false.
+func (ac *addrConn) tryUpdateAddrs(addrs []resolver.Address) bool {
+ ac.mu.Lock()
+ defer ac.mu.Unlock()
+ grpclog.Infof("addrConn: tryUpdateAddrs curAddr: %v, addrs: %v", ac.curAddr, addrs)
+ if ac.state == connectivity.Shutdown {
+ ac.addrs = addrs
+ return true
+ }
+
+ var curAddrFound bool
+ for _, a := range addrs {
+ if reflect.DeepEqual(ac.curAddr, a) {
+ curAddrFound = true
+ break
+ }
+ }
+ grpclog.Infof("addrConn: tryUpdateAddrs curAddrFound: %v", curAddrFound)
+ if curAddrFound {
+ ac.addrs = addrs
+ ac.reconnectIdx = 0 // Start reconnecting from beginning in the new list.
+ }
+
+ return curAddrFound
+}
+
+// GetMethodConfig gets the method config of the input method.
+// If there's an exact match for input method (i.e. /service/method), we return
+// the corresponding MethodConfig.
+// If there isn't an exact match for the input method, we look for the default config
+// under the service (i.e /service/). If there is a default MethodConfig for
+// the service, we return it.
+// Otherwise, we return an empty MethodConfig.
+func (cc *ClientConn) GetMethodConfig(method string) MethodConfig {
+ // TODO: Avoid the locking here.
+ cc.mu.RLock()
+ defer cc.mu.RUnlock()
+ m, ok := cc.sc.Methods[method]
+ if !ok {
+ i := strings.LastIndex(method, "/")
+ m = cc.sc.Methods[method[:i+1]]
+ }
+ return m
+}
+
+func (cc *ClientConn) getTransport(ctx context.Context, failfast bool) (transport.ClientTransport, func(balancer.DoneInfo), error) {
+ t, done, err := cc.blockingpicker.pick(ctx, failfast, balancer.PickOptions{})
+ if err != nil {
+ return nil, nil, toRPCErr(err)
+ }
+ return t, done, nil
+}
+
+// handleServiceConfig parses the service config string in JSON format to Go native
+// struct ServiceConfig, and store both the struct and the JSON string in ClientConn.
+func (cc *ClientConn) handleServiceConfig(js string) error {
+ if cc.dopts.disableServiceConfig {
+ return nil
+ }
+ sc, err := parseServiceConfig(js)
+ if err != nil {
+ return err
+ }
+ cc.mu.Lock()
+ cc.scRaw = js
+ cc.sc = sc
+ if sc.LB != nil && *sc.LB != grpclbName { // "grpclb" is not a valid balancer option in service config.
+ if cc.curBalancerName == grpclbName {
+ // If current balancer is grpclb, there's at least one grpclb
+ // balancer address in the resolved list. Don't switch the balancer,
+ // but change the previous balancer name, so if a new resolved
+ // address list doesn't contain grpclb address, balancer will be
+ // switched to *sc.LB.
+ cc.preBalancerName = *sc.LB
+ } else {
+ cc.switchBalancer(*sc.LB)
+ cc.balancerWrapper.handleResolvedAddrs(cc.curAddresses, nil)
+ }
+ }
+
+ if envConfigStickinessOn {
+ var newStickinessMDKey string
+ if sc.stickinessMetadataKey != nil && *sc.stickinessMetadataKey != "" {
+ newStickinessMDKey = *sc.stickinessMetadataKey
+ }
+ // newStickinessMDKey is "" if one of the following happens:
+ // - stickinessMetadataKey is set to ""
+ // - stickinessMetadataKey field doesn't exist in service config
+ cc.blockingpicker.updateStickinessMDKey(strings.ToLower(newStickinessMDKey))
+ }
+
+ cc.mu.Unlock()
+ return nil
+}
+
+func (cc *ClientConn) resolveNow(o resolver.ResolveNowOption) {
+ cc.mu.RLock()
+ r := cc.resolverWrapper
+ cc.mu.RUnlock()
+ if r == nil {
+ return
+ }
+ go r.resolveNow(o)
+}
+
+// Close tears down the ClientConn and all underlying connections.
+func (cc *ClientConn) Close() error {
+ defer cc.cancel()
+
+ cc.mu.Lock()
+ if cc.conns == nil {
+ cc.mu.Unlock()
+ return ErrClientConnClosing
+ }
+ conns := cc.conns
+ cc.conns = nil
+ cc.csMgr.updateState(connectivity.Shutdown)
+
+ rWrapper := cc.resolverWrapper
+ cc.resolverWrapper = nil
+ bWrapper := cc.balancerWrapper
+ cc.balancerWrapper = nil
+ cc.mu.Unlock()
+
+ cc.blockingpicker.close()
+
+ if rWrapper != nil {
+ rWrapper.close()
+ }
+ if bWrapper != nil {
+ bWrapper.close()
+ }
+
+ for ac := range conns {
+ ac.tearDown(ErrClientConnClosing)
+ }
+ if channelz.IsOn() {
+ channelz.RemoveEntry(cc.channelzID)
+ }
+ return nil
+}
+
+// addrConn is a network connection to a given address.
+type addrConn struct {
+ ctx context.Context
+ cancel context.CancelFunc
+
+ cc *ClientConn
+ addrs []resolver.Address
+ dopts dialOptions
+ events trace.EventLog
+ acbw balancer.SubConn
+
+ mu sync.Mutex
+ curAddr resolver.Address
+ reconnectIdx int // The index in addrs list to start reconnecting from.
+ state connectivity.State
+ // ready is closed and becomes nil when a new transport is up or failed
+ // due to timeout.
+ ready chan struct{}
+ transport transport.ClientTransport
+
+ // The reason this addrConn is torn down.
+ tearDownErr error
+
+ connectRetryNum int
+ // backoffDeadline is the time until which resetTransport needs to
+ // wait before increasing connectRetryNum count.
+ backoffDeadline time.Time
+ // connectDeadline is the time by which all connection
+ // negotiations must complete.
+ connectDeadline time.Time
+
+ channelzID int64 // channelz unique identification number
+ czmu sync.RWMutex
+ callsStarted int64
+ callsSucceeded int64
+ callsFailed int64
+ lastCallStartedTime time.Time
+}
+
+// adjustParams updates parameters used to create transports upon
+// receiving a GoAway.
+func (ac *addrConn) adjustParams(r transport.GoAwayReason) {
+ switch r {
+ case transport.GoAwayTooManyPings:
+ v := 2 * ac.dopts.copts.KeepaliveParams.Time
+ ac.cc.mu.Lock()
+ if v > ac.cc.mkp.Time {
+ ac.cc.mkp.Time = v
+ }
+ ac.cc.mu.Unlock()
+ }
+}
+
+// printf records an event in ac's event log, unless ac has been closed.
+// REQUIRES ac.mu is held.
+func (ac *addrConn) printf(format string, a ...interface{}) {
+ if ac.events != nil {
+ ac.events.Printf(format, a...)
+ }
+}
+
+// errorf records an error in ac's event log, unless ac has been closed.
+// REQUIRES ac.mu is held.
+func (ac *addrConn) errorf(format string, a ...interface{}) {
+ if ac.events != nil {
+ ac.events.Errorf(format, a...)
+ }
+}
+
+// resetTransport recreates a transport to the address for ac. The old
+// transport will close itself on error or when the clientconn is closed.
+// The created transport must receive initial settings frame from the server.
+// In case that doesn't happen, transportMonitor will kill the newly created
+// transport after connectDeadline has expired.
+// In case there was an error on the transport before the settings frame was
+// received, resetTransport resumes connecting to backends after the one that
+// was previously connected to. In case end of the list is reached, resetTransport
+// backs off until the original deadline.
+// If the DialOption WithWaitForHandshake was set, resetTrasport returns
+// successfully only after server settings are received.
+//
+// TODO(bar) make sure all state transitions are valid.
+func (ac *addrConn) resetTransport() error {
+ ac.mu.Lock()
+ if ac.state == connectivity.Shutdown {
+ ac.mu.Unlock()
+ return errConnClosing
+ }
+ if ac.ready != nil {
+ close(ac.ready)
+ ac.ready = nil
+ }
+ ac.transport = nil
+ ridx := ac.reconnectIdx
+ ac.mu.Unlock()
+ ac.cc.mu.RLock()
+ ac.dopts.copts.KeepaliveParams = ac.cc.mkp
+ ac.cc.mu.RUnlock()
+ var backoffDeadline, connectDeadline time.Time
+ for connectRetryNum := 0; ; connectRetryNum++ {
+ ac.mu.Lock()
+ if ac.backoffDeadline.IsZero() {
+ // This means either a successful HTTP2 connection was established
+ // or this is the first time this addrConn is trying to establish a
+ // connection.
+ backoffFor := ac.dopts.bs.Backoff(connectRetryNum) // time.Duration.
+ // This will be the duration that dial gets to finish.
+ dialDuration := getMinConnectTimeout()
+ if backoffFor > dialDuration {
+ // Give dial more time as we keep failing to connect.
+ dialDuration = backoffFor
+ }
+ start := time.Now()
+ backoffDeadline = start.Add(backoffFor)
+ connectDeadline = start.Add(dialDuration)
+ ridx = 0 // Start connecting from the beginning.
+ } else {
+ // Continue trying to connect with the same deadlines.
+ connectRetryNum = ac.connectRetryNum
+ backoffDeadline = ac.backoffDeadline
+ connectDeadline = ac.connectDeadline
+ ac.backoffDeadline = time.Time{}
+ ac.connectDeadline = time.Time{}
+ ac.connectRetryNum = 0
+ }
+ if ac.state == connectivity.Shutdown {
+ ac.mu.Unlock()
+ return errConnClosing
+ }
+ ac.printf("connecting")
+ if ac.state != connectivity.Connecting {
+ ac.state = connectivity.Connecting
+ ac.cc.handleSubConnStateChange(ac.acbw, ac.state)
+ }
+ // copy ac.addrs in case of race
+ addrsIter := make([]resolver.Address, len(ac.addrs))
+ copy(addrsIter, ac.addrs)
+ copts := ac.dopts.copts
+ ac.mu.Unlock()
+ connected, err := ac.createTransport(connectRetryNum, ridx, backoffDeadline, connectDeadline, addrsIter, copts)
+ if err != nil {
+ return err
+ }
+ if connected {
+ return nil
+ }
+ }
+}
+
+// createTransport creates a connection to one of the backends in addrs.
+// It returns true if a connection was established.
+func (ac *addrConn) createTransport(connectRetryNum, ridx int, backoffDeadline, connectDeadline time.Time, addrs []resolver.Address, copts transport.ConnectOptions) (bool, error) {
+ for i := ridx; i < len(addrs); i++ {
+ addr := addrs[i]
+ target := transport.TargetInfo{
+ Addr: addr.Addr,
+ Metadata: addr.Metadata,
+ Authority: ac.cc.authority,
+ }
+ done := make(chan struct{})
+ onPrefaceReceipt := func() {
+ ac.mu.Lock()
+ close(done)
+ if !ac.backoffDeadline.IsZero() {
+ // If we haven't already started reconnecting to
+ // other backends.
+ // Note, this can happen when writer notices an error
+ // and triggers resetTransport while at the same time
+ // reader receives the preface and invokes this closure.
+ ac.backoffDeadline = time.Time{}
+ ac.connectDeadline = time.Time{}
+ ac.connectRetryNum = 0
+ }
+ ac.mu.Unlock()
+ }
+ // Do not cancel in the success path because of
+ // this issue in Go1.6: https://github.com/golang/go/issues/15078.
+ connectCtx, cancel := context.WithDeadline(ac.ctx, connectDeadline)
+ if channelz.IsOn() {
+ copts.ChannelzParentID = ac.channelzID
+ }
+ newTr, err := transport.NewClientTransport(connectCtx, ac.cc.ctx, target, copts, onPrefaceReceipt)
+ if err != nil {
+ cancel()
+ ac.cc.blockingpicker.updateConnectionError(err)
+ ac.mu.Lock()
+ if ac.state == connectivity.Shutdown {
+ // ac.tearDown(...) has been invoked.
+ ac.mu.Unlock()
+ return false, errConnClosing
+ }
+ ac.mu.Unlock()
+ grpclog.Warningf("grpc: addrConn.createTransport failed to connect to %v. Err :%v. Reconnecting...", addr, err)
+ continue
+ }
+ if ac.dopts.waitForHandshake {
+ select {
+ case <-done:
+ case <-connectCtx.Done():
+ // Didn't receive server preface, must kill this new transport now.
+ grpclog.Warningf("grpc: addrConn.createTransport failed to receive server preface before deadline.")
+ newTr.Close()
+ break
+ case <-ac.ctx.Done():
+ }
+ }
+ ac.mu.Lock()
+ if ac.state == connectivity.Shutdown {
+ ac.mu.Unlock()
+ // ac.tearDonn(...) has been invoked.
+ newTr.Close()
+ return false, errConnClosing
+ }
+ ac.printf("ready")
+ ac.state = connectivity.Ready
+ ac.cc.handleSubConnStateChange(ac.acbw, ac.state)
+ ac.transport = newTr
+ ac.curAddr = addr
+ if ac.ready != nil {
+ close(ac.ready)
+ ac.ready = nil
+ }
+ select {
+ case <-done:
+ // If the server has responded back with preface already,
+ // don't set the reconnect parameters.
+ default:
+ ac.connectRetryNum = connectRetryNum
+ ac.backoffDeadline = backoffDeadline
+ ac.connectDeadline = connectDeadline
+ ac.reconnectIdx = i + 1 // Start reconnecting from the next backend in the list.
+ }
+ ac.mu.Unlock()
+ return true, nil
+ }
+ ac.mu.Lock()
+ if ac.state == connectivity.Shutdown {
+ ac.mu.Unlock()
+ return false, errConnClosing
+ }
+ ac.state = connectivity.TransientFailure
+ ac.cc.handleSubConnStateChange(ac.acbw, ac.state)
+ ac.cc.resolveNow(resolver.ResolveNowOption{})
+ if ac.ready != nil {
+ close(ac.ready)
+ ac.ready = nil
+ }
+ ac.mu.Unlock()
+ timer := time.NewTimer(backoffDeadline.Sub(time.Now()))
+ select {
+ case <-timer.C:
+ case <-ac.ctx.Done():
+ timer.Stop()
+ return false, ac.ctx.Err()
+ }
+ return false, nil
+}
+
+// Run in a goroutine to track the error in transport and create the
+// new transport if an error happens. It returns when the channel is closing.
+func (ac *addrConn) transportMonitor() {
+ for {
+ var timer *time.Timer
+ var cdeadline <-chan time.Time
+ ac.mu.Lock()
+ t := ac.transport
+ if !ac.connectDeadline.IsZero() {
+ timer = time.NewTimer(ac.connectDeadline.Sub(time.Now()))
+ cdeadline = timer.C
+ }
+ ac.mu.Unlock()
+ // Block until we receive a goaway or an error occurs.
+ select {
+ case <-t.GoAway():
+ done := t.Error()
+ cleanup := t.Close
+ // Since this transport will be orphaned (won't have a transportMonitor)
+ // we need to launch a goroutine to keep track of clientConn.Close()
+ // happening since it might not be noticed by any other goroutine for a while.
+ go func() {
+ <-done
+ cleanup()
+ }()
+ case <-t.Error():
+ // In case this is triggered because clientConn.Close()
+ // was called, we want to immeditately close the transport
+ // since no other goroutine might notice it for a while.
+ t.Close()
+ case <-cdeadline:
+ ac.mu.Lock()
+ // This implies that client received server preface.
+ if ac.backoffDeadline.IsZero() {
+ ac.mu.Unlock()
+ continue
+ }
+ ac.mu.Unlock()
+ timer = nil
+ // No server preface received until deadline.
+ // Kill the connection.
+ grpclog.Warningf("grpc: addrConn.transportMonitor didn't get server preface after waiting. Closing the new transport now.")
+ t.Close()
+ }
+ if timer != nil {
+ timer.Stop()
+ }
+ // If a GoAway happened, regardless of error, adjust our keepalive
+ // parameters as appropriate.
+ select {
+ case <-t.GoAway():
+ ac.adjustParams(t.GetGoAwayReason())
+ default:
+ }
+ ac.mu.Lock()
+ if ac.state == connectivity.Shutdown {
+ ac.mu.Unlock()
+ return
+ }
+ // Set connectivity state to TransientFailure before calling
+ // resetTransport. Transition READY->CONNECTING is not valid.
+ ac.state = connectivity.TransientFailure
+ ac.cc.handleSubConnStateChange(ac.acbw, ac.state)
+ ac.cc.resolveNow(resolver.ResolveNowOption{})
+ ac.curAddr = resolver.Address{}
+ ac.mu.Unlock()
+ if err := ac.resetTransport(); err != nil {
+ ac.mu.Lock()
+ ac.printf("transport exiting: %v", err)
+ ac.mu.Unlock()
+ grpclog.Warningf("grpc: addrConn.transportMonitor exits due to: %v", err)
+ if err != errConnClosing {
+ // Keep this ac in cc.conns, to get the reason it's torn down.
+ ac.tearDown(err)
+ }
+ return
+ }
+ }
+}
+
+// wait blocks until i) the new transport is up or ii) ctx is done or iii) ac is closed or
+// iv) transport is in connectivity.TransientFailure and there is a balancer/failfast is true.
+func (ac *addrConn) wait(ctx context.Context, hasBalancer, failfast bool) (transport.ClientTransport, error) {
+ for {
+ ac.mu.Lock()
+ switch {
+ case ac.state == connectivity.Shutdown:
+ if failfast || !hasBalancer {
+ // RPC is failfast or balancer is nil. This RPC should fail with ac.tearDownErr.
+ err := ac.tearDownErr
+ ac.mu.Unlock()
+ return nil, err
+ }
+ ac.mu.Unlock()
+ return nil, errConnClosing
+ case ac.state == connectivity.Ready:
+ ct := ac.transport
+ ac.mu.Unlock()
+ return ct, nil
+ case ac.state == connectivity.TransientFailure:
+ if failfast || hasBalancer {
+ ac.mu.Unlock()
+ return nil, errConnUnavailable
+ }
+ }
+ ready := ac.ready
+ if ready == nil {
+ ready = make(chan struct{})
+ ac.ready = ready
+ }
+ ac.mu.Unlock()
+ select {
+ case <-ctx.Done():
+ return nil, toRPCErr(ctx.Err())
+ // Wait until the new transport is ready or failed.
+ case <-ready:
+ }
+ }
+}
+
+// getReadyTransport returns the transport if ac's state is READY.
+// Otherwise it returns nil, false.
+// If ac's state is IDLE, it will trigger ac to connect.
+func (ac *addrConn) getReadyTransport() (transport.ClientTransport, bool) {
+ ac.mu.Lock()
+ if ac.state == connectivity.Ready {
+ t := ac.transport
+ ac.mu.Unlock()
+ return t, true
+ }
+ var idle bool
+ if ac.state == connectivity.Idle {
+ idle = true
+ }
+ ac.mu.Unlock()
+ // Trigger idle ac to connect.
+ if idle {
+ ac.connect()
+ }
+ return nil, false
+}
+
+// tearDown starts to tear down the addrConn.
+// TODO(zhaoq): Make this synchronous to avoid unbounded memory consumption in
+// some edge cases (e.g., the caller opens and closes many addrConn's in a
+// tight loop.
+// tearDown doesn't remove ac from ac.cc.conns.
+func (ac *addrConn) tearDown(err error) {
+ ac.cancel()
+ ac.mu.Lock()
+ defer ac.mu.Unlock()
+ if ac.state == connectivity.Shutdown {
+ return
+ }
+ ac.curAddr = resolver.Address{}
+ if err == errConnDrain && ac.transport != nil {
+ // GracefulClose(...) may be executed multiple times when
+ // i) receiving multiple GoAway frames from the server; or
+ // ii) there are concurrent name resolver/Balancer triggered
+ // address removal and GoAway.
+ ac.transport.GracefulClose()
+ }
+ ac.state = connectivity.Shutdown
+ ac.tearDownErr = err
+ ac.cc.handleSubConnStateChange(ac.acbw, ac.state)
+ if ac.events != nil {
+ ac.events.Finish()
+ ac.events = nil
+ }
+ if ac.ready != nil {
+ close(ac.ready)
+ ac.ready = nil
+ }
+ if channelz.IsOn() {
+ channelz.RemoveEntry(ac.channelzID)
+ }
+}
+
+func (ac *addrConn) getState() connectivity.State {
+ ac.mu.Lock()
+ defer ac.mu.Unlock()
+ return ac.state
+}
+
+func (ac *addrConn) getCurAddr() (ret resolver.Address) {
+ ac.mu.Lock()
+ ret = ac.curAddr
+ ac.mu.Unlock()
+ return
+}
+
+func (ac *addrConn) ChannelzMetric() *channelz.ChannelInternalMetric {
+ ac.mu.Lock()
+ addr := ac.curAddr.Addr
+ ac.mu.Unlock()
+ state := ac.getState()
+ ac.czmu.RLock()
+ defer ac.czmu.RUnlock()
+ return &channelz.ChannelInternalMetric{
+ State: state,
+ Target: addr,
+ CallsStarted: ac.callsStarted,
+ CallsSucceeded: ac.callsSucceeded,
+ CallsFailed: ac.callsFailed,
+ LastCallStartedTimestamp: ac.lastCallStartedTime,
+ }
+}
+
+func (ac *addrConn) incrCallsStarted() {
+ ac.czmu.Lock()
+ ac.callsStarted++
+ ac.lastCallStartedTime = time.Now()
+ ac.czmu.Unlock()
+}
+
+func (ac *addrConn) incrCallsSucceeded() {
+ ac.czmu.Lock()
+ ac.callsSucceeded++
+ ac.czmu.Unlock()
+}
+
+func (ac *addrConn) incrCallsFailed() {
+ ac.czmu.Lock()
+ ac.callsFailed++
+ ac.czmu.Unlock()
+}
+
+// ErrClientConnTimeout indicates that the ClientConn cannot establish the
+// underlying connections within the specified timeout.
+//
+// Deprecated: This error is never returned by grpc and should not be
+// referenced by users.
+var ErrClientConnTimeout = errors.New("grpc: timed out when dialing")