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-rw-r--r--vendor/google.golang.org/grpc/clientconn.go1571
1 files changed, 1571 insertions, 0 deletions
diff --git a/vendor/google.golang.org/grpc/clientconn.go b/vendor/google.golang.org/grpc/clientconn.go
new file mode 100644
index 000000000..cbd671a85
--- /dev/null
+++ b/vendor/google.golang.org/grpc/clientconn.go
@@ -0,0 +1,1571 @@
+/*
+ *
+ * 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 (
+ "context"
+ "errors"
+ "fmt"
+ "math"
+ "net"
+ "reflect"
+ "strings"
+ "sync"
+ "sync/atomic"
+ "time"
+
+ "google.golang.org/grpc/balancer"
+ "google.golang.org/grpc/balancer/base"
+ "google.golang.org/grpc/codes"
+ "google.golang.org/grpc/connectivity"
+ "google.golang.org/grpc/credentials"
+ "google.golang.org/grpc/internal/backoff"
+ "google.golang.org/grpc/internal/channelz"
+ "google.golang.org/grpc/internal/grpcsync"
+ "google.golang.org/grpc/internal/grpcutil"
+ "google.golang.org/grpc/internal/transport"
+ "google.golang.org/grpc/keepalive"
+ "google.golang.org/grpc/resolver"
+ "google.golang.org/grpc/serviceconfig"
+ "google.golang.org/grpc/status"
+
+ _ "google.golang.org/grpc/balancer/roundrobin" // To register roundrobin.
+ _ "google.golang.org/grpc/internal/resolver/dns" // To register dns resolver.
+ _ "google.golang.org/grpc/internal/resolver/passthrough" // To register passthrough resolver.
+)
+
+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")
+ // invalidDefaultServiceConfigErrPrefix is used to prefix the json parsing error for the default
+ // service config.
+ invalidDefaultServiceConfigErrPrefix = "grpc: the provided default service config is invalid"
+)
+
+// 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)")
+ // errTransportCredsAndBundle indicates that creds bundle is used together
+ // with other individual Transport Credentials.
+ errTransportCredsAndBundle = errors.New("grpc: credentials.Bundle may not be used with individual TransportCredentials")
+ // 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)")
+)
+
+const (
+ defaultClientMaxReceiveMessageSize = 1024 * 1024 * 4
+ defaultClientMaxSendMessageSize = math.MaxInt32
+ // http2IOBufSize specifies the buffer size for sending frames.
+ defaultWriteBufSize = 32 * 1024
+ defaultReadBufSize = 32 * 1024
+)
+
+// 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{}),
+ dopts: defaultDialOptions(),
+ blockingpicker: newPickerWrapper(),
+ czData: new(channelzData),
+ firstResolveEvent: grpcsync.NewEvent(),
+ }
+ cc.retryThrottler.Store((*retryThrottler)(nil))
+ cc.ctx, cc.cancel = context.WithCancel(context.Background())
+
+ for _, opt := range opts {
+ opt.apply(&cc.dopts)
+ }
+
+ chainUnaryClientInterceptors(cc)
+ chainStreamClientInterceptors(cc)
+
+ defer func() {
+ if err != nil {
+ cc.Close()
+ }
+ }()
+
+ if channelz.IsOn() {
+ if cc.dopts.channelzParentID != 0 {
+ cc.channelzID = channelz.RegisterChannel(&channelzChannel{cc}, cc.dopts.channelzParentID, target)
+ channelz.AddTraceEvent(logger, cc.channelzID, 0, &channelz.TraceEventDesc{
+ Desc: "Channel Created",
+ Severity: channelz.CtInfo,
+ Parent: &channelz.TraceEventDesc{
+ Desc: fmt.Sprintf("Nested Channel(id:%d) created", cc.channelzID),
+ Severity: channelz.CtInfo,
+ },
+ })
+ } else {
+ cc.channelzID = channelz.RegisterChannel(&channelzChannel{cc}, 0, target)
+ channelz.Info(logger, cc.channelzID, "Channel Created")
+ }
+ cc.csMgr.channelzID = cc.channelzID
+ }
+
+ if !cc.dopts.insecure {
+ if cc.dopts.copts.TransportCredentials == nil && cc.dopts.copts.CredsBundle == nil {
+ return nil, errNoTransportSecurity
+ }
+ if cc.dopts.copts.TransportCredentials != nil && cc.dopts.copts.CredsBundle != nil {
+ return nil, errTransportCredsAndBundle
+ }
+ } else {
+ if cc.dopts.copts.TransportCredentials != nil || cc.dopts.copts.CredsBundle != nil {
+ return nil, errCredentialsConflict
+ }
+ for _, cd := range cc.dopts.copts.PerRPCCredentials {
+ if cd.RequireTransportSecurity() {
+ return nil, errTransportCredentialsMissing
+ }
+ }
+ }
+
+ if cc.dopts.defaultServiceConfigRawJSON != nil {
+ scpr := parseServiceConfig(*cc.dopts.defaultServiceConfigRawJSON)
+ if scpr.Err != nil {
+ return nil, fmt.Errorf("%s: %v", invalidDefaultServiceConfigErrPrefix, scpr.Err)
+ }
+ cc.dopts.defaultServiceConfig, _ = scpr.Config.(*ServiceConfig)
+ }
+ cc.mkp = cc.dopts.copts.KeepaliveParams
+
+ if cc.dopts.copts.Dialer == nil {
+ cc.dopts.copts.Dialer = func(ctx context.Context, addr string) (net.Conn, error) {
+ network, addr := parseDialTarget(addr)
+ return (&net.Dialer{}).DialContext(ctx, network, addr)
+ }
+ if cc.dopts.withProxy {
+ cc.dopts.copts.Dialer = newProxyDialer(cc.dopts.copts.Dialer)
+ }
+ }
+
+ 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():
+ switch {
+ case ctx.Err() == err:
+ conn = nil
+ case err == nil || !cc.dopts.returnLastError:
+ conn, err = nil, ctx.Err()
+ default:
+ conn, err = nil, fmt.Errorf("%v: %v", ctx.Err(), err)
+ }
+ default:
+ }
+ }()
+
+ 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.DefaultExponential
+ }
+
+ // Determine the resolver to use.
+ cc.parsedTarget = grpcutil.ParseTarget(cc.target)
+ unixScheme := strings.HasPrefix(cc.target, "unix:")
+ channelz.Infof(logger, cc.channelzID, "parsed scheme: %q", cc.parsedTarget.Scheme)
+ resolverBuilder := cc.getResolver(cc.parsedTarget.Scheme)
+ if resolverBuilder == nil {
+ // If resolver builder is still nil, the parsed target's scheme is
+ // not registered. Fallback to default resolver and set Endpoint to
+ // the original target.
+ channelz.Infof(logger, cc.channelzID, "scheme %q not registered, fallback to default scheme", cc.parsedTarget.Scheme)
+ cc.parsedTarget = resolver.Target{
+ Scheme: resolver.GetDefaultScheme(),
+ Endpoint: target,
+ }
+ resolverBuilder = cc.getResolver(cc.parsedTarget.Scheme)
+ if resolverBuilder == nil {
+ return nil, fmt.Errorf("could not get resolver for default scheme: %q", cc.parsedTarget.Scheme)
+ }
+ }
+
+ creds := cc.dopts.copts.TransportCredentials
+ if creds != nil && creds.Info().ServerName != "" {
+ cc.authority = creds.Info().ServerName
+ } else if cc.dopts.insecure && cc.dopts.authority != "" {
+ cc.authority = cc.dopts.authority
+ } else if unixScheme {
+ cc.authority = "localhost"
+ } 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,
+ CredsBundle: cc.dopts.copts.CredsBundle,
+ Dialer: cc.dopts.copts.Dialer,
+ ChannelzParentID: cc.channelzID,
+ Target: cc.parsedTarget,
+ }
+
+ // Build the resolver.
+ rWrapper, err := newCCResolverWrapper(cc, resolverBuilder)
+ if err != nil {
+ return nil, fmt.Errorf("failed to build resolver: %v", err)
+ }
+ cc.mu.Lock()
+ cc.resolverWrapper = rWrapper
+ cc.mu.Unlock()
+
+ // A blocking dial blocks until the clientConn is ready.
+ if cc.dopts.block {
+ for {
+ s := cc.GetState()
+ if s == connectivity.Ready {
+ break
+ } else if cc.dopts.copts.FailOnNonTempDialError && s == connectivity.TransientFailure {
+ if err = cc.connectionError(); err != nil {
+ terr, ok := err.(interface {
+ Temporary() bool
+ })
+ if ok && !terr.Temporary() {
+ return nil, err
+ }
+ }
+ }
+ if !cc.WaitForStateChange(ctx, s) {
+ // ctx got timeout or canceled.
+ if err = cc.connectionError(); err != nil && cc.dopts.returnLastError {
+ return nil, err
+ }
+ return nil, ctx.Err()
+ }
+ }
+ }
+
+ return cc, nil
+}
+
+// chainUnaryClientInterceptors chains all unary client interceptors into one.
+func chainUnaryClientInterceptors(cc *ClientConn) {
+ interceptors := cc.dopts.chainUnaryInts
+ // Prepend dopts.unaryInt to the chaining interceptors if it exists, since unaryInt will
+ // be executed before any other chained interceptors.
+ if cc.dopts.unaryInt != nil {
+ interceptors = append([]UnaryClientInterceptor{cc.dopts.unaryInt}, interceptors...)
+ }
+ var chainedInt UnaryClientInterceptor
+ if len(interceptors) == 0 {
+ chainedInt = nil
+ } else if len(interceptors) == 1 {
+ chainedInt = interceptors[0]
+ } else {
+ chainedInt = func(ctx context.Context, method string, req, reply interface{}, cc *ClientConn, invoker UnaryInvoker, opts ...CallOption) error {
+ return interceptors[0](ctx, method, req, reply, cc, getChainUnaryInvoker(interceptors, 0, invoker), opts...)
+ }
+ }
+ cc.dopts.unaryInt = chainedInt
+}
+
+// getChainUnaryInvoker recursively generate the chained unary invoker.
+func getChainUnaryInvoker(interceptors []UnaryClientInterceptor, curr int, finalInvoker UnaryInvoker) UnaryInvoker {
+ if curr == len(interceptors)-1 {
+ return finalInvoker
+ }
+ return func(ctx context.Context, method string, req, reply interface{}, cc *ClientConn, opts ...CallOption) error {
+ return interceptors[curr+1](ctx, method, req, reply, cc, getChainUnaryInvoker(interceptors, curr+1, finalInvoker), opts...)
+ }
+}
+
+// chainStreamClientInterceptors chains all stream client interceptors into one.
+func chainStreamClientInterceptors(cc *ClientConn) {
+ interceptors := cc.dopts.chainStreamInts
+ // Prepend dopts.streamInt to the chaining interceptors if it exists, since streamInt will
+ // be executed before any other chained interceptors.
+ if cc.dopts.streamInt != nil {
+ interceptors = append([]StreamClientInterceptor{cc.dopts.streamInt}, interceptors...)
+ }
+ var chainedInt StreamClientInterceptor
+ if len(interceptors) == 0 {
+ chainedInt = nil
+ } else if len(interceptors) == 1 {
+ chainedInt = interceptors[0]
+ } else {
+ chainedInt = func(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, streamer Streamer, opts ...CallOption) (ClientStream, error) {
+ return interceptors[0](ctx, desc, cc, method, getChainStreamer(interceptors, 0, streamer), opts...)
+ }
+ }
+ cc.dopts.streamInt = chainedInt
+}
+
+// getChainStreamer recursively generate the chained client stream constructor.
+func getChainStreamer(interceptors []StreamClientInterceptor, curr int, finalStreamer Streamer) Streamer {
+ if curr == len(interceptors)-1 {
+ return finalStreamer
+ }
+ return func(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, opts ...CallOption) (ClientStream, error) {
+ return interceptors[curr+1](ctx, desc, cc, method, getChainStreamer(interceptors, curr+1, finalStreamer), opts...)
+ }
+}
+
+// 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{}
+ channelzID int64
+}
+
+// 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
+ channelz.Infof(logger, csm.channelzID, "Channel Connectivity change to %v", 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
+}
+
+// ClientConnInterface defines the functions clients need to perform unary and
+// streaming RPCs. It is implemented by *ClientConn, and is only intended to
+// be referenced by generated code.
+type ClientConnInterface interface {
+ // Invoke performs a unary RPC and returns after the response is received
+ // into reply.
+ Invoke(ctx context.Context, method string, args interface{}, reply interface{}, opts ...CallOption) error
+ // NewStream begins a streaming RPC.
+ NewStream(ctx context.Context, desc *StreamDesc, method string, opts ...CallOption) (ClientStream, error)
+}
+
+// Assert *ClientConn implements ClientConnInterface.
+var _ ClientConnInterface = (*ClientConn)(nil)
+
+// ClientConn represents a virtual connection to a conceptual endpoint, to
+// perform RPCs.
+//
+// A ClientConn is free to have zero or more actual connections to the endpoint
+// based on configuration, load, etc. It is also free to determine which actual
+// endpoints to use and may change it every RPC, permitting client-side load
+// balancing.
+//
+// A ClientConn encapsulates a range of functionality including name
+// resolution, TCP connection establishment (with retries and backoff) and TLS
+// handshakes. It also handles errors on established connections by
+// re-resolving the name and reconnecting.
+type ClientConn struct {
+ ctx context.Context
+ cancel context.CancelFunc
+
+ target string
+ parsedTarget resolver.Target
+ authority string
+ dopts dialOptions
+ csMgr *connectivityStateManager
+
+ balancerBuildOpts balancer.BuildOptions
+ blockingpicker *pickerWrapper
+
+ mu sync.RWMutex
+ resolverWrapper *ccResolverWrapper
+ sc *ServiceConfig
+ conns map[*addrConn]struct{}
+ // Keepalive parameter can be updated if a GoAway is received.
+ mkp keepalive.ClientParameters
+ curBalancerName string
+ balancerWrapper *ccBalancerWrapper
+ retryThrottler atomic.Value
+
+ firstResolveEvent *grpcsync.Event
+
+ channelzID int64 // channelz unique identification number
+ czData *channelzData
+
+ lceMu sync.Mutex // protects lastConnectionError
+ lastConnectionError error
+}
+
+// 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.
+//
+// Experimental
+//
+// Notice: This API is EXPERIMENTAL and may be changed or removed in a
+// later release.
+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.
+//
+// Experimental
+//
+// Notice: This API is EXPERIMENTAL and may be changed or removed in a
+// later release.
+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 revisit this decision in the future.
+ cc.sc = &sc
+ cc.mu.Unlock()
+ case <-cc.ctx.Done():
+ return
+ }
+ }
+}
+
+// waitForResolvedAddrs blocks until the resolver has provided addresses or the
+// context expires. Returns nil unless the context expires first; otherwise
+// returns a status error based on the context.
+func (cc *ClientConn) waitForResolvedAddrs(ctx context.Context) error {
+ // This is on the RPC path, so we use a fast path to avoid the
+ // more-expensive "select" below after the resolver has returned once.
+ if cc.firstResolveEvent.HasFired() {
+ return nil
+ }
+ select {
+ case <-cc.firstResolveEvent.Done():
+ return nil
+ case <-ctx.Done():
+ return status.FromContextError(ctx.Err()).Err()
+ case <-cc.ctx.Done():
+ return ErrClientConnClosing
+ }
+}
+
+var emptyServiceConfig *ServiceConfig
+
+func init() {
+ cfg := parseServiceConfig("{}")
+ if cfg.Err != nil {
+ panic(fmt.Sprintf("impossible error parsing empty service config: %v", cfg.Err))
+ }
+ emptyServiceConfig = cfg.Config.(*ServiceConfig)
+}
+
+func (cc *ClientConn) maybeApplyDefaultServiceConfig(addrs []resolver.Address) {
+ if cc.sc != nil {
+ cc.applyServiceConfigAndBalancer(cc.sc, addrs)
+ return
+ }
+ if cc.dopts.defaultServiceConfig != nil {
+ cc.applyServiceConfigAndBalancer(cc.dopts.defaultServiceConfig, addrs)
+ } else {
+ cc.applyServiceConfigAndBalancer(emptyServiceConfig, addrs)
+ }
+}
+
+func (cc *ClientConn) updateResolverState(s resolver.State, err error) error {
+ defer cc.firstResolveEvent.Fire()
+ cc.mu.Lock()
+ // Check if the ClientConn is already closed. Some fields (e.g.
+ // balancerWrapper) are set to nil when closing the ClientConn, and could
+ // cause nil pointer panic if we don't have this check.
+ if cc.conns == nil {
+ cc.mu.Unlock()
+ return nil
+ }
+
+ if err != nil {
+ // May need to apply the initial service config in case the resolver
+ // doesn't support service configs, or doesn't provide a service config
+ // with the new addresses.
+ cc.maybeApplyDefaultServiceConfig(nil)
+
+ if cc.balancerWrapper != nil {
+ cc.balancerWrapper.resolverError(err)
+ }
+
+ // No addresses are valid with err set; return early.
+ cc.mu.Unlock()
+ return balancer.ErrBadResolverState
+ }
+
+ var ret error
+ if cc.dopts.disableServiceConfig || s.ServiceConfig == nil {
+ cc.maybeApplyDefaultServiceConfig(s.Addresses)
+ // TODO: do we need to apply a failing LB policy if there is no
+ // default, per the error handling design?
+ } else {
+ if sc, ok := s.ServiceConfig.Config.(*ServiceConfig); s.ServiceConfig.Err == nil && ok {
+ cc.applyServiceConfigAndBalancer(sc, s.Addresses)
+ } else {
+ ret = balancer.ErrBadResolverState
+ if cc.balancerWrapper == nil {
+ var err error
+ if s.ServiceConfig.Err != nil {
+ err = status.Errorf(codes.Unavailable, "error parsing service config: %v", s.ServiceConfig.Err)
+ } else {
+ err = status.Errorf(codes.Unavailable, "illegal service config type: %T", s.ServiceConfig.Config)
+ }
+ cc.blockingpicker.updatePicker(base.NewErrPicker(err))
+ cc.csMgr.updateState(connectivity.TransientFailure)
+ cc.mu.Unlock()
+ return ret
+ }
+ }
+ }
+
+ var balCfg serviceconfig.LoadBalancingConfig
+ if cc.dopts.balancerBuilder == nil && cc.sc != nil && cc.sc.lbConfig != nil {
+ balCfg = cc.sc.lbConfig.cfg
+ }
+
+ cbn := cc.curBalancerName
+ bw := cc.balancerWrapper
+ cc.mu.Unlock()
+ if cbn != grpclbName {
+ // Filter any grpclb addresses since we don't have the grpclb balancer.
+ for i := 0; i < len(s.Addresses); {
+ if s.Addresses[i].Type == resolver.GRPCLB {
+ copy(s.Addresses[i:], s.Addresses[i+1:])
+ s.Addresses = s.Addresses[:len(s.Addresses)-1]
+ continue
+ }
+ i++
+ }
+ }
+ uccsErr := bw.updateClientConnState(&balancer.ClientConnState{ResolverState: s, BalancerConfig: balCfg})
+ if ret == nil {
+ ret = uccsErr // prefer ErrBadResolver state since any other error is
+ // currently meaningless to the caller.
+ }
+ return ret
+}
+
+// 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 strings.EqualFold(cc.curBalancerName, name) {
+ return
+ }
+
+ channelz.Infof(logger, cc.channelzID, "ClientConn switching balancer to %q", name)
+ if cc.dopts.balancerBuilder != nil {
+ channelz.Info(logger, cc.channelzID, "ignoring balancer switching: Balancer DialOption used instead")
+ return
+ }
+ if cc.balancerWrapper != nil {
+ cc.balancerWrapper.close()
+ }
+
+ builder := balancer.Get(name)
+ if builder == nil {
+ channelz.Warningf(logger, cc.channelzID, "Channel switches to new LB policy %q due to fallback from invalid balancer name", PickFirstBalancerName)
+ channelz.Infof(logger, cc.channelzID, "failed to get balancer builder for: %v, using pick_first instead", name)
+ builder = newPickfirstBuilder()
+ } else {
+ channelz.Infof(logger, cc.channelzID, "Channel switches to new LB policy %q", name)
+ }
+
+ cc.curBalancerName = builder.Name()
+ cc.balancerWrapper = newCCBalancerWrapper(cc, builder, cc.balancerBuildOpts)
+}
+
+func (cc *ClientConn) handleSubConnStateChange(sc balancer.SubConn, s connectivity.State, err error) {
+ 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, err)
+ 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, opts balancer.NewSubConnOptions) (*addrConn, error) {
+ ac := &addrConn{
+ state: connectivity.Idle,
+ cc: cc,
+ addrs: addrs,
+ scopts: opts,
+ dopts: cc.dopts,
+ czData: new(channelzData),
+ resetBackoff: make(chan struct{}),
+ }
+ 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, "")
+ channelz.AddTraceEvent(logger, ac.channelzID, 0, &channelz.TraceEventDesc{
+ Desc: "Subchannel Created",
+ Severity: channelz.CtInfo,
+ Parent: &channelz.TraceEventDesc{
+ Desc: fmt.Sprintf("Subchannel(id:%d) created", ac.channelzID),
+ Severity: channelz.CtInfo,
+ },
+ })
+ }
+ 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)
+}
+
+func (cc *ClientConn) channelzMetric() *channelz.ChannelInternalMetric {
+ return &channelz.ChannelInternalMetric{
+ State: cc.GetState(),
+ Target: cc.target,
+ CallsStarted: atomic.LoadInt64(&cc.czData.callsStarted),
+ CallsSucceeded: atomic.LoadInt64(&cc.czData.callsSucceeded),
+ CallsFailed: atomic.LoadInt64(&cc.czData.callsFailed),
+ LastCallStartedTimestamp: time.Unix(0, atomic.LoadInt64(&cc.czData.lastCallStartedTime)),
+ }
+}
+
+// Target returns the target string of the ClientConn.
+//
+// Experimental
+//
+// Notice: This API is EXPERIMENTAL and may be changed or removed in a
+// later release.
+func (cc *ClientConn) Target() string {
+ return cc.target
+}
+
+func (cc *ClientConn) incrCallsStarted() {
+ atomic.AddInt64(&cc.czData.callsStarted, 1)
+ atomic.StoreInt64(&cc.czData.lastCallStartedTime, time.Now().UnixNano())
+}
+
+func (cc *ClientConn) incrCallsSucceeded() {
+ atomic.AddInt64(&cc.czData.callsSucceeded, 1)
+}
+
+func (cc *ClientConn) incrCallsFailed() {
+ atomic.AddInt64(&cc.czData.callsFailed, 1)
+}
+
+// connect starts creating a transport.
+// It does nothing if the ac is not IDLE.
+// TODO(bar) Move this to the addrConn section.
+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
+ }
+ // Update connectivity state within the lock to prevent subsequent or
+ // concurrent calls from resetting the transport more than once.
+ ac.updateConnectivityState(connectivity.Connecting, nil)
+ ac.mu.Unlock()
+
+ // Start a goroutine connecting to the server asynchronously.
+ go ac.resetTransport()
+ return nil
+}
+
+// tryUpdateAddrs tries to update ac.addrs with the new addresses list.
+//
+// If ac is Connecting, it returns false. The caller should tear down the ac and
+// create a new one. Note that the backoff will be reset when this happens.
+//
+// If ac is TransientFailure, it updates ac.addrs and returns true. The updated
+// addresses will be picked up by retry in the next iteration after backoff.
+//
+// If ac is Shutdown or Idle, it updates ac.addrs and returns true.
+//
+// If ac is Ready, 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()
+ channelz.Infof(logger, ac.channelzID, "addrConn: tryUpdateAddrs curAddr: %v, addrs: %v", ac.curAddr, addrs)
+ if ac.state == connectivity.Shutdown ||
+ ac.state == connectivity.TransientFailure ||
+ ac.state == connectivity.Idle {
+ ac.addrs = addrs
+ return true
+ }
+
+ if ac.state == connectivity.Connecting {
+ return false
+ }
+
+ // ac.state is Ready, try to find the connected address.
+ var curAddrFound bool
+ for _, a := range addrs {
+ if reflect.DeepEqual(ac.curAddr, a) {
+ curAddrFound = true
+ break
+ }
+ }
+ channelz.Infof(logger, ac.channelzID, "addrConn: tryUpdateAddrs curAddrFound: %v", curAddrFound)
+ if curAddrFound {
+ ac.addrs = addrs
+ }
+
+ 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 service's default
+// config under the service (i.e /service/) and then for the default for all services (empty string).
+//
+// 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()
+ if cc.sc == nil {
+ return MethodConfig{}
+ }
+ if m, ok := cc.sc.Methods[method]; ok {
+ return m
+ }
+ i := strings.LastIndex(method, "/")
+ if m, ok := cc.sc.Methods[method[:i+1]]; ok {
+ return m
+ }
+ return cc.sc.Methods[""]
+}
+
+func (cc *ClientConn) healthCheckConfig() *healthCheckConfig {
+ cc.mu.RLock()
+ defer cc.mu.RUnlock()
+ if cc.sc == nil {
+ return nil
+ }
+ return cc.sc.healthCheckConfig
+}
+
+func (cc *ClientConn) getTransport(ctx context.Context, failfast bool, method string) (transport.ClientTransport, func(balancer.DoneInfo), error) {
+ t, done, err := cc.blockingpicker.pick(ctx, failfast, balancer.PickInfo{
+ Ctx: ctx,
+ FullMethodName: method,
+ })
+ if err != nil {
+ return nil, nil, toRPCErr(err)
+ }
+ return t, done, nil
+}
+
+func (cc *ClientConn) applyServiceConfigAndBalancer(sc *ServiceConfig, addrs []resolver.Address) {
+ if sc == nil {
+ // should never reach here.
+ return
+ }
+ cc.sc = sc
+
+ if cc.sc.retryThrottling != nil {
+ newThrottler := &retryThrottler{
+ tokens: cc.sc.retryThrottling.MaxTokens,
+ max: cc.sc.retryThrottling.MaxTokens,
+ thresh: cc.sc.retryThrottling.MaxTokens / 2,
+ ratio: cc.sc.retryThrottling.TokenRatio,
+ }
+ cc.retryThrottler.Store(newThrottler)
+ } else {
+ cc.retryThrottler.Store((*retryThrottler)(nil))
+ }
+
+ if cc.dopts.balancerBuilder == nil {
+ // Only look at balancer types and switch balancer if balancer dial
+ // option is not set.
+ var newBalancerName string
+ if cc.sc != nil && cc.sc.lbConfig != nil {
+ newBalancerName = cc.sc.lbConfig.name
+ } else {
+ var isGRPCLB bool
+ for _, a := range addrs {
+ if a.Type == resolver.GRPCLB {
+ isGRPCLB = true
+ break
+ }
+ }
+ if isGRPCLB {
+ newBalancerName = grpclbName
+ } else if cc.sc != nil && cc.sc.LB != nil {
+ newBalancerName = *cc.sc.LB
+ } else {
+ 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.curBalancerName = cc.dopts.balancerBuilder.Name()
+ cc.balancerWrapper = newCCBalancerWrapper(cc, cc.dopts.balancerBuilder, cc.balancerBuildOpts)
+ }
+}
+
+func (cc *ClientConn) resolveNow(o resolver.ResolveNowOptions) {
+ cc.mu.RLock()
+ r := cc.resolverWrapper
+ cc.mu.RUnlock()
+ if r == nil {
+ return
+ }
+ go r.resolveNow(o)
+}
+
+// ResetConnectBackoff wakes up all subchannels in transient failure and causes
+// them to attempt another connection immediately. It also resets the backoff
+// times used for subsequent attempts regardless of the current state.
+//
+// In general, this function should not be used. Typical service or network
+// outages result in a reasonable client reconnection strategy by default.
+// However, if a previously unavailable network becomes available, this may be
+// used to trigger an immediate reconnect.
+//
+// Experimental
+//
+// Notice: This API is EXPERIMENTAL and may be changed or removed in a
+// later release.
+func (cc *ClientConn) ResetConnectBackoff() {
+ cc.mu.Lock()
+ conns := cc.conns
+ cc.mu.Unlock()
+ for ac := range conns {
+ ac.resetConnectBackoff()
+ }
+}
+
+// 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() {
+ ted := &channelz.TraceEventDesc{
+ Desc: "Channel Deleted",
+ Severity: channelz.CtInfo,
+ }
+ if cc.dopts.channelzParentID != 0 {
+ ted.Parent = &channelz.TraceEventDesc{
+ Desc: fmt.Sprintf("Nested channel(id:%d) deleted", cc.channelzID),
+ Severity: channelz.CtInfo,
+ }
+ }
+ channelz.AddTraceEvent(logger, cc.channelzID, 0, ted)
+ // TraceEvent needs to be called before RemoveEntry, as TraceEvent may add trace reference to
+ // the entity being deleted, and thus prevent it from being deleted right away.
+ 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
+ dopts dialOptions
+ acbw balancer.SubConn
+ scopts balancer.NewSubConnOptions
+
+ // transport is set when there's a viable transport (note: ac state may not be READY as LB channel
+ // health checking may require server to report healthy to set ac to READY), and is reset
+ // to nil when the current transport should no longer be used to create a stream (e.g. after GoAway
+ // is received, transport is closed, ac has been torn down).
+ transport transport.ClientTransport // The current transport.
+
+ mu sync.Mutex
+ curAddr resolver.Address // The current address.
+ addrs []resolver.Address // All addresses that the resolver resolved to.
+
+ // Use updateConnectivityState for updating addrConn's connectivity state.
+ state connectivity.State
+
+ backoffIdx int // Needs to be stateful for resetConnectBackoff.
+ resetBackoff chan struct{}
+
+ channelzID int64 // channelz unique identification number.
+ czData *channelzData
+}
+
+// Note: this requires a lock on ac.mu.
+func (ac *addrConn) updateConnectivityState(s connectivity.State, lastErr error) {
+ if ac.state == s {
+ return
+ }
+ ac.state = s
+ channelz.Infof(logger, ac.channelzID, "Subchannel Connectivity change to %v", s)
+ ac.cc.handleSubConnStateChange(ac.acbw, s, lastErr)
+}
+
+// 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()
+ }
+}
+
+func (ac *addrConn) resetTransport() {
+ for i := 0; ; i++ {
+ if i > 0 {
+ ac.cc.resolveNow(resolver.ResolveNowOptions{})
+ }
+
+ ac.mu.Lock()
+ if ac.state == connectivity.Shutdown {
+ ac.mu.Unlock()
+ return
+ }
+
+ addrs := ac.addrs
+ backoffFor := ac.dopts.bs.Backoff(ac.backoffIdx)
+ // This will be the duration that dial gets to finish.
+ dialDuration := minConnectTimeout
+ if ac.dopts.minConnectTimeout != nil {
+ dialDuration = ac.dopts.minConnectTimeout()
+ }
+
+ if dialDuration < backoffFor {
+ // Give dial more time as we keep failing to connect.
+ dialDuration = backoffFor
+ }
+ // We can potentially spend all the time trying the first address, and
+ // if the server accepts the connection and then hangs, the following
+ // addresses will never be tried.
+ //
+ // The spec doesn't mention what should be done for multiple addresses.
+ // https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md#proposed-backoff-algorithm
+ connectDeadline := time.Now().Add(dialDuration)
+
+ ac.updateConnectivityState(connectivity.Connecting, nil)
+ ac.transport = nil
+ ac.mu.Unlock()
+
+ newTr, addr, reconnect, err := ac.tryAllAddrs(addrs, connectDeadline)
+ if err != nil {
+ // After exhausting all addresses, the addrConn enters
+ // TRANSIENT_FAILURE.
+ ac.mu.Lock()
+ if ac.state == connectivity.Shutdown {
+ ac.mu.Unlock()
+ return
+ }
+ ac.updateConnectivityState(connectivity.TransientFailure, err)
+
+ // Backoff.
+ b := ac.resetBackoff
+ ac.mu.Unlock()
+
+ timer := time.NewTimer(backoffFor)
+ select {
+ case <-timer.C:
+ ac.mu.Lock()
+ ac.backoffIdx++
+ ac.mu.Unlock()
+ case <-b:
+ timer.Stop()
+ case <-ac.ctx.Done():
+ timer.Stop()
+ return
+ }
+ continue
+ }
+
+ ac.mu.Lock()
+ if ac.state == connectivity.Shutdown {
+ ac.mu.Unlock()
+ newTr.Close()
+ return
+ }
+ ac.curAddr = addr
+ ac.transport = newTr
+ ac.backoffIdx = 0
+
+ hctx, hcancel := context.WithCancel(ac.ctx)
+ ac.startHealthCheck(hctx)
+ ac.mu.Unlock()
+
+ // Block until the created transport is down. And when this happens,
+ // we restart from the top of the addr list.
+ <-reconnect.Done()
+ hcancel()
+ // restart connecting - the top of the loop will set state to
+ // CONNECTING. This is against the current connectivity semantics doc,
+ // however it allows for graceful behavior for RPCs not yet dispatched
+ // - unfortunate timing would otherwise lead to the RPC failing even
+ // though the TRANSIENT_FAILURE state (called for by the doc) would be
+ // instantaneous.
+ //
+ // Ideally we should transition to Idle here and block until there is
+ // RPC activity that leads to the balancer requesting a reconnect of
+ // the associated SubConn.
+ }
+}
+
+// tryAllAddrs tries to creates a connection to the addresses, and stop when at the
+// first successful one. It returns the transport, the address and a Event in
+// the successful case. The Event fires when the returned transport disconnects.
+func (ac *addrConn) tryAllAddrs(addrs []resolver.Address, connectDeadline time.Time) (transport.ClientTransport, resolver.Address, *grpcsync.Event, error) {
+ var firstConnErr error
+ for _, addr := range addrs {
+ ac.mu.Lock()
+ if ac.state == connectivity.Shutdown {
+ ac.mu.Unlock()
+ return nil, resolver.Address{}, nil, errConnClosing
+ }
+
+ ac.cc.mu.RLock()
+ ac.dopts.copts.KeepaliveParams = ac.cc.mkp
+ ac.cc.mu.RUnlock()
+
+ copts := ac.dopts.copts
+ if ac.scopts.CredsBundle != nil {
+ copts.CredsBundle = ac.scopts.CredsBundle
+ }
+ ac.mu.Unlock()
+
+ channelz.Infof(logger, ac.channelzID, "Subchannel picks a new address %q to connect", addr.Addr)
+
+ newTr, reconnect, err := ac.createTransport(addr, copts, connectDeadline)
+ if err == nil {
+ return newTr, addr, reconnect, nil
+ }
+ if firstConnErr == nil {
+ firstConnErr = err
+ }
+ ac.cc.updateConnectionError(err)
+ }
+
+ // Couldn't connect to any address.
+ return nil, resolver.Address{}, nil, firstConnErr
+}
+
+// createTransport creates a connection to addr. It returns the transport and a
+// Event in the successful case. The Event fires when the returned transport
+// disconnects.
+func (ac *addrConn) createTransport(addr resolver.Address, copts transport.ConnectOptions, connectDeadline time.Time) (transport.ClientTransport, *grpcsync.Event, error) {
+ prefaceReceived := make(chan struct{})
+ onCloseCalled := make(chan struct{})
+ reconnect := grpcsync.NewEvent()
+
+ // addr.ServerName takes precedent over ClientConn authority, if present.
+ if addr.ServerName == "" {
+ addr.ServerName = ac.cc.authority
+ }
+
+ once := sync.Once{}
+ onGoAway := func(r transport.GoAwayReason) {
+ ac.mu.Lock()
+ ac.adjustParams(r)
+ once.Do(func() {
+ if ac.state == connectivity.Ready {
+ // Prevent this SubConn from being used for new RPCs by setting its
+ // state to Connecting.
+ //
+ // TODO: this should be Idle when grpc-go properly supports it.
+ ac.updateConnectivityState(connectivity.Connecting, nil)
+ }
+ })
+ ac.mu.Unlock()
+ reconnect.Fire()
+ }
+
+ onClose := func() {
+ ac.mu.Lock()
+ once.Do(func() {
+ if ac.state == connectivity.Ready {
+ // Prevent this SubConn from being used for new RPCs by setting its
+ // state to Connecting.
+ //
+ // TODO: this should be Idle when grpc-go properly supports it.
+ ac.updateConnectivityState(connectivity.Connecting, nil)
+ }
+ })
+ ac.mu.Unlock()
+ close(onCloseCalled)
+ reconnect.Fire()
+ }
+
+ onPrefaceReceipt := func() {
+ close(prefaceReceived)
+ }
+
+ connectCtx, cancel := context.WithDeadline(ac.ctx, connectDeadline)
+ defer cancel()
+ if channelz.IsOn() {
+ copts.ChannelzParentID = ac.channelzID
+ }
+
+ newTr, err := transport.NewClientTransport(connectCtx, ac.cc.ctx, addr, copts, onPrefaceReceipt, onGoAway, onClose)
+ if err != nil {
+ // newTr is either nil, or closed.
+ channelz.Warningf(logger, ac.channelzID, "grpc: addrConn.createTransport failed to connect to %v. Err: %v. Reconnecting...", addr, err)
+ return nil, nil, err
+ }
+
+ select {
+ case <-time.After(time.Until(connectDeadline)):
+ // We didn't get the preface in time.
+ newTr.Close()
+ channelz.Warningf(logger, ac.channelzID, "grpc: addrConn.createTransport failed to connect to %v: didn't receive server preface in time. Reconnecting...", addr)
+ return nil, nil, errors.New("timed out waiting for server handshake")
+ case <-prefaceReceived:
+ // We got the preface - huzzah! things are good.
+ case <-onCloseCalled:
+ // The transport has already closed - noop.
+ return nil, nil, errors.New("connection closed")
+ // TODO(deklerk) this should bail on ac.ctx.Done(). Add a test and fix.
+ }
+ return newTr, reconnect, nil
+}
+
+// startHealthCheck starts the health checking stream (RPC) to watch the health
+// stats of this connection if health checking is requested and configured.
+//
+// LB channel health checking is enabled when all requirements below are met:
+// 1. it is not disabled by the user with the WithDisableHealthCheck DialOption
+// 2. internal.HealthCheckFunc is set by importing the grpc/health package
+// 3. a service config with non-empty healthCheckConfig field is provided
+// 4. the load balancer requests it
+//
+// It sets addrConn to READY if the health checking stream is not started.
+//
+// Caller must hold ac.mu.
+func (ac *addrConn) startHealthCheck(ctx context.Context) {
+ var healthcheckManagingState bool
+ defer func() {
+ if !healthcheckManagingState {
+ ac.updateConnectivityState(connectivity.Ready, nil)
+ }
+ }()
+
+ if ac.cc.dopts.disableHealthCheck {
+ return
+ }
+ healthCheckConfig := ac.cc.healthCheckConfig()
+ if healthCheckConfig == nil {
+ return
+ }
+ if !ac.scopts.HealthCheckEnabled {
+ return
+ }
+ healthCheckFunc := ac.cc.dopts.healthCheckFunc
+ if healthCheckFunc == nil {
+ // The health package is not imported to set health check function.
+ //
+ // TODO: add a link to the health check doc in the error message.
+ channelz.Error(logger, ac.channelzID, "Health check is requested but health check function is not set.")
+ return
+ }
+
+ healthcheckManagingState = true
+
+ // Set up the health check helper functions.
+ currentTr := ac.transport
+ newStream := func(method string) (interface{}, error) {
+ ac.mu.Lock()
+ if ac.transport != currentTr {
+ ac.mu.Unlock()
+ return nil, status.Error(codes.Canceled, "the provided transport is no longer valid to use")
+ }
+ ac.mu.Unlock()
+ return newNonRetryClientStream(ctx, &StreamDesc{ServerStreams: true}, method, currentTr, ac)
+ }
+ setConnectivityState := func(s connectivity.State, lastErr error) {
+ ac.mu.Lock()
+ defer ac.mu.Unlock()
+ if ac.transport != currentTr {
+ return
+ }
+ ac.updateConnectivityState(s, lastErr)
+ }
+ // Start the health checking stream.
+ go func() {
+ err := ac.cc.dopts.healthCheckFunc(ctx, newStream, setConnectivityState, healthCheckConfig.ServiceName)
+ if err != nil {
+ if status.Code(err) == codes.Unimplemented {
+ channelz.Error(logger, ac.channelzID, "Subchannel health check is unimplemented at server side, thus health check is disabled")
+ } else {
+ channelz.Errorf(logger, ac.channelzID, "HealthCheckFunc exits with unexpected error %v", err)
+ }
+ }
+ }()
+}
+
+func (ac *addrConn) resetConnectBackoff() {
+ ac.mu.Lock()
+ close(ac.resetBackoff)
+ ac.backoffIdx = 0
+ ac.resetBackoff = make(chan struct{})
+ ac.mu.Unlock()
+}
+
+// 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 && ac.transport != nil {
+ 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.mu.Lock()
+ if ac.state == connectivity.Shutdown {
+ ac.mu.Unlock()
+ return
+ }
+ curTr := ac.transport
+ ac.transport = nil
+ // We have to set the state to Shutdown before anything else to prevent races
+ // between setting the state and logic that waits on context cancellation / etc.
+ ac.updateConnectivityState(connectivity.Shutdown, nil)
+ ac.cancel()
+ ac.curAddr = resolver.Address{}
+ if err == errConnDrain && curTr != 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.
+ // We have to unlock and re-lock here because GracefulClose => Close => onClose, which requires locking ac.mu.
+ ac.mu.Unlock()
+ curTr.GracefulClose()
+ ac.mu.Lock()
+ }
+ if channelz.IsOn() {
+ channelz.AddTraceEvent(logger, ac.channelzID, 0, &channelz.TraceEventDesc{
+ Desc: "Subchannel Deleted",
+ Severity: channelz.CtInfo,
+ Parent: &channelz.TraceEventDesc{
+ Desc: fmt.Sprintf("Subchanel(id:%d) deleted", ac.channelzID),
+ Severity: channelz.CtInfo,
+ },
+ })
+ // TraceEvent needs to be called before RemoveEntry, as TraceEvent may add trace reference to
+ // the entity being deleted, and thus prevent it from being deleted right away.
+ channelz.RemoveEntry(ac.channelzID)
+ }
+ ac.mu.Unlock()
+}
+
+func (ac *addrConn) getState() connectivity.State {
+ ac.mu.Lock()
+ defer ac.mu.Unlock()
+ return ac.state
+}
+
+func (ac *addrConn) ChannelzMetric() *channelz.ChannelInternalMetric {
+ ac.mu.Lock()
+ addr := ac.curAddr.Addr
+ ac.mu.Unlock()
+ return &channelz.ChannelInternalMetric{
+ State: ac.getState(),
+ Target: addr,
+ CallsStarted: atomic.LoadInt64(&ac.czData.callsStarted),
+ CallsSucceeded: atomic.LoadInt64(&ac.czData.callsSucceeded),
+ CallsFailed: atomic.LoadInt64(&ac.czData.callsFailed),
+ LastCallStartedTimestamp: time.Unix(0, atomic.LoadInt64(&ac.czData.lastCallStartedTime)),
+ }
+}
+
+func (ac *addrConn) incrCallsStarted() {
+ atomic.AddInt64(&ac.czData.callsStarted, 1)
+ atomic.StoreInt64(&ac.czData.lastCallStartedTime, time.Now().UnixNano())
+}
+
+func (ac *addrConn) incrCallsSucceeded() {
+ atomic.AddInt64(&ac.czData.callsSucceeded, 1)
+}
+
+func (ac *addrConn) incrCallsFailed() {
+ atomic.AddInt64(&ac.czData.callsFailed, 1)
+}
+
+type retryThrottler struct {
+ max float64
+ thresh float64
+ ratio float64
+
+ mu sync.Mutex
+ tokens float64 // TODO(dfawley): replace with atomic and remove lock.
+}
+
+// throttle subtracts a retry token from the pool and returns whether a retry
+// should be throttled (disallowed) based upon the retry throttling policy in
+// the service config.
+func (rt *retryThrottler) throttle() bool {
+ if rt == nil {
+ return false
+ }
+ rt.mu.Lock()
+ defer rt.mu.Unlock()
+ rt.tokens--
+ if rt.tokens < 0 {
+ rt.tokens = 0
+ }
+ return rt.tokens <= rt.thresh
+}
+
+func (rt *retryThrottler) successfulRPC() {
+ if rt == nil {
+ return
+ }
+ rt.mu.Lock()
+ defer rt.mu.Unlock()
+ rt.tokens += rt.ratio
+ if rt.tokens > rt.max {
+ rt.tokens = rt.max
+ }
+}
+
+type channelzChannel struct {
+ cc *ClientConn
+}
+
+func (c *channelzChannel) ChannelzMetric() *channelz.ChannelInternalMetric {
+ return c.cc.channelzMetric()
+}
+
+// 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")
+
+func (cc *ClientConn) getResolver(scheme string) resolver.Builder {
+ for _, rb := range cc.dopts.resolvers {
+ if scheme == rb.Scheme() {
+ return rb
+ }
+ }
+ return resolver.Get(scheme)
+}
+
+func (cc *ClientConn) updateConnectionError(err error) {
+ cc.lceMu.Lock()
+ cc.lastConnectionError = err
+ cc.lceMu.Unlock()
+}
+
+func (cc *ClientConn) connectionError() error {
+ cc.lceMu.Lock()
+ defer cc.lceMu.Unlock()
+ return cc.lastConnectionError
+}
generated by cgit v1.2.3-54-g00ecf (git 2.39.0) at 2024-10-21 06:24:23 +0000