diff options
Diffstat (limited to 'go/vendor/google.golang.org/grpc/clientconn.go')
| -rw-r--r-- | go/vendor/google.golang.org/grpc/clientconn.go | 1338 |
1 files changed, 880 insertions, 458 deletions
diff --git a/go/vendor/google.golang.org/grpc/clientconn.go b/go/vendor/google.golang.org/grpc/clientconn.go index 146166a..bfbef36 100644 --- a/go/vendor/google.golang.org/grpc/clientconn.go +++ b/go/vendor/google.golang.org/grpc/clientconn.go @@ -1,33 +1,18 @@ /* * - * Copyright 2014, Google Inc. - * All rights reserved. + * Copyright 2014 gRPC authors. * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions are - * met: + * 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 * - * * Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * * Redistributions in binary form must reproduce the above - * copyright notice, this list of conditions and the following disclaimer - * in the documentation and/or other materials provided with the - * distribution. - * * Neither the name of Google Inc. nor the names of its - * contributors may be used to endorse or promote products derived from - * this software without specific prior written permission. + * http://www.apache.org/licenses/LICENSE-2.0 * - * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS - * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT - * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR - * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT - * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, - * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT - * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, - * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY - * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT - * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE - * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * 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. * */ @@ -36,15 +21,24 @@ 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/connectivity" "google.golang.org/grpc/credentials" "google.golang.org/grpc/grpclog" + "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/transport" ) @@ -55,10 +49,22 @@ var ( ErrClientConnClosing = errors.New("grpc: the client connection is closing") // ErrClientConnTimeout indicates that the ClientConn cannot establish the // underlying connections within the specified timeout. - // DEPRECATED: Please use context.DeadlineExceeded instead. This error will be - // removed in Q1 2017. + // DEPRECATED: Please use context.DeadlineExceeded instead. ErrClientConnTimeout = errors.New("grpc: timed out when dialing") + // 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") + // minimum time to give a connection to complete + minConnectTimeout = 20 * time.Second +) +// 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. @@ -72,37 +78,94 @@ var ( 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") - // 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") - errNoAddr = errors.New("grpc: there is no address available to dial") - // minimum time to give a connection to complete - minConnectTimeout = 20 * time.Second ) // dialOptions configure a Dial call. dialOptions are set by the DialOption // values passed to Dial. type dialOptions struct { - unaryInt UnaryClientInterceptor - streamInt StreamClientInterceptor - codec Codec - cp Compressor - dc Decompressor - bs backoffStrategy - balancer Balancer - block bool - insecure bool - timeout time.Duration - scChan <-chan ServiceConfig - copts transport.ConnectOptions + unaryInt UnaryClientInterceptor + streamInt StreamClientInterceptor + codec Codec + cp Compressor + dc Decompressor + bs backoffStrategy + 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 + // Custom user options for resolver.Build. + resolverBuildUserOptions interface{} + waitForHandshake bool } +const ( + defaultClientMaxReceiveMessageSize = 1024 * 1024 * 4 + defaultClientMaxSendMessageSize = math.MaxInt32 +) + // 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. func WithCodec(c Codec) DialOption { return func(o *dialOptions) { @@ -110,30 +173,80 @@ func WithCodec(c Codec) DialOption { } } -// WithCompressor returns a DialOption which sets a CompressorGenerator for generating message -// compressor. +// 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 DecompressorGenerator for generating -// message decompressor. +// 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. +// 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.balancer = b + 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 + } +} + +// WithResolverUserOptions returns a DialOption which sets the UserOptions +// field of resolver's BuildOption. +func WithResolverUserOptions(userOpt interface{}) DialOption { + return func(o *dialOptions) { + o.resolverBuildUserOptions = userOpt } } // 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 @@ -158,7 +271,7 @@ func WithBackoffConfig(b BackoffConfig) DialOption { return withBackoff(b) } -// withBackoff sets the backoff strategy used for retries after a +// 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. @@ -194,7 +307,7 @@ func WithTransportCredentials(creds credentials.TransportCredentials) DialOption } // WithPerRPCCredentials returns a DialOption which sets -// credentials which will place auth state on each outbound RPC. +// 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) @@ -203,24 +316,30 @@ func WithPerRPCCredentials(creds credentials.PerRPCCredentials) DialOption { // 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 + } +} + // 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 func(o *dialOptions) { - o.copts.Dialer = func(ctx context.Context, addr string) (net.Conn, error) { + 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 @@ -231,7 +350,7 @@ func WithStatsHandler(h stats.Handler) DialOption { } } -// FailOnNonTempDialError returns a DialOption that specified if gRPC fails on non-temporary dial errors. +// 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. @@ -249,6 +368,13 @@ func WithUserAgent(s string) DialOption { } } +// 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) { @@ -263,25 +389,69 @@ func WithStreamInterceptor(f StreamClientInterceptor) DialOption { } } +// 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 + } +} + // 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. ctx can be used to -// cancel or expire the pending connecting. Once this function returns, the +// 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. -// This is the EXPERIMENTAL API. func DialContext(ctx context.Context, target string, opts ...DialOption) (conn *ClientConn, err error) { cc := &ClientConn{ target: target, - conns: make(map[Address]*addrConn), + 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 !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) { + return dialContext(ctx, "tcp", 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) @@ -300,15 +470,16 @@ func DialContext(ctx context.Context, target string, opts ...DialOption) (conn * } }() + scSet := false if cc.dopts.scChan != nil { - // Wait for the initial service config. + // Try to get an initial service config. select { case sc, ok := <-cc.dopts.scChan: if ok { cc.sc = sc + scSet = true } - case <-ctx.Done(): - return nil, ctx.Err() + default: } } // Set defaults. @@ -318,110 +489,114 @@ func DialContext(ctx context.Context, target string, opts ...DialOption) (conn * if cc.dopts.bs == nil { cc.dopts.bs = DefaultBackoffConfig } + cc.parsedTarget = parseTarget(cc.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 { - colonPos := strings.LastIndex(target, ":") - if colonPos == -1 { - colonPos = len(target) - } - cc.authority = target[:colonPos] + // Use endpoint from "scheme://authority/endpoint" as the default + // authority for ClientConn. + cc.authority = cc.parsedTarget.Endpoint } - var ok bool - waitC := make(chan error, 1) - go func() { - var addrs []Address - if cc.dopts.balancer == nil && cc.sc.LB != nil { - cc.dopts.balancer = cc.sc.LB - } - if cc.dopts.balancer == nil { - // Connect to target directly if balancer is nil. - addrs = append(addrs, Address{Addr: target}) - } else { - var credsClone credentials.TransportCredentials - if creds != nil { - credsClone = creds.Clone() - } - config := BalancerConfig{ - DialCreds: credsClone, - } - if err := cc.dopts.balancer.Start(target, config); err != nil { - waitC <- err - return - } - ch := cc.dopts.balancer.Notify() - if ch == nil { - // There is no name resolver installed. - addrs = append(addrs, Address{Addr: target}) - } else { - addrs, ok = <-ch - if !ok || len(addrs) == 0 { - waitC <- errNoAddr - return - } - } - } - for _, a := range addrs { - if err := cc.resetAddrConn(a, false, nil); err != nil { - waitC <- err - return + + 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 } - } - close(waitC) - }() - select { - case <-ctx.Done(): - return nil, ctx.Err() - case err := <-waitC: - if err != nil { - return nil, err + case <-ctx.Done(): + return nil, ctx.Err() } } + if cc.dopts.scChan != nil { + go cc.scWatcher() + } - // If balancer is nil or balancer.Notify() is nil, ok will be false here. - // The lbWatcher goroutine will not be created. - if ok { - go cc.lbWatcher() + 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, } - if cc.dopts.scChan != nil { - go cc.scWatcher() + // 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 } -// ConnectivityState indicates the state of a client connection. -type ConnectivityState int +// 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{} +} -const ( - // Idle indicates the ClientConn is idle. - Idle ConnectivityState = iota - // Connecting indicates the ClienConn is connecting. - Connecting - // Ready indicates the ClientConn is ready for work. - Ready - // TransientFailure indicates the ClientConn has seen a failure but expects to recover. - TransientFailure - // Shutdown indicates the ClientConn has started shutting down. - Shutdown -) +// 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 (s ConnectivityState) String() string { - switch s { - case Idle: - return "IDLE" - case Connecting: - return "CONNECTING" - case Ready: - return "READY" - case TransientFailure: - return "TRANSIENT_FAILURE" - case Shutdown: - return "SHUTDOWN" - default: - panic(fmt.Sprintf("unknown connectivity state: %d", s)) +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. @@ -429,50 +604,50 @@ type ClientConn struct { ctx context.Context cancel context.CancelFunc - target string - authority string - dopts dialOptions + target string + parsedTarget resolver.Target + authority string + dopts dialOptions + csMgr *connectivityStateManager + + balancerBuildOpts balancer.BuildOptions + resolverWrapper *ccResolverWrapper + blockingpicker *pickerWrapper mu sync.RWMutex sc ServiceConfig - conns map[Address]*addrConn + 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 } -func (cc *ClientConn) lbWatcher() { - for addrs := range cc.dopts.balancer.Notify() { - var ( - add []Address // Addresses need to setup connections. - del []*addrConn // Connections need to tear down. - ) - cc.mu.Lock() - for _, a := range addrs { - if _, ok := cc.conns[a]; !ok { - add = append(add, a) - } - } - for k, c := range cc.conns { - var keep bool - for _, a := range addrs { - if k == a { - keep = true - break - } - } - if !keep { - del = append(del, c) - delete(cc.conns, c.addr) - } - } - cc.mu.Unlock() - for _, a := range add { - cc.resetAddrConn(a, true, nil) - } - for _, c := range del { - c.tearDown(errConnDrain) - } +// 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 { @@ -484,6 +659,7 @@ func (cc *ClientConn) scWatcher() { // 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 @@ -491,151 +667,271 @@ func (cc *ClientConn) scWatcher() { } } -// resetAddrConn creates an addrConn for addr and adds it to cc.conns. -// If there is an old addrConn for addr, it will be torn down, using tearDownErr as the reason. -// If tearDownErr is nil, errConnDrain will be used instead. -func (cc *ClientConn) resetAddrConn(addr Address, skipWait bool, tearDownErr error) error { - ac := &addrConn{ - cc: cc, - addr: addr, - dopts: cc.dopts, +func (cc *ClientConn) handleResolvedAddrs(addrs []resolver.Address, err error) { + cc.mu.Lock() + defer cc.mu.Unlock() + if cc.conns == nil { + // cc was closed. + return } - ac.ctx, ac.cancel = context.WithCancel(cc.ctx) - ac.stateCV = sync.NewCond(&ac.mu) - if EnableTracing { - ac.events = trace.NewEventLog("grpc.ClientConn", ac.addr.Addr) + + if reflect.DeepEqual(cc.curAddresses, addrs) { + return } - if !ac.dopts.insecure { - if ac.dopts.copts.TransportCredentials == nil { - return errNoTransportSecurity - } - } else { - if ac.dopts.copts.TransportCredentials != nil { - return errCredentialsConflict + + 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 + } } - for _, cd := range ac.dopts.copts.PerRPCCredentials { - if cd.RequireTransportSecurity() { - return errTransportCredentialsMissing + 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() + } + + 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 ErrClientConnClosing + return nil, ErrClientConnClosing } - stale := cc.conns[ac.addr] - cc.conns[ac.addr] = ac + cc.conns[ac] = struct{}{} cc.mu.Unlock() - if stale != nil { - // There is an addrConn alive on ac.addr already. This could be due to - // 1) a buggy Balancer notifies duplicated Addresses; - // 2) goaway was received, a new ac will replace the old ac. - // The old ac should be deleted from cc.conns, but the - // underlying transport should drain rather than close. - if tearDownErr == nil { - // tearDownErr is nil if resetAddrConn is called by - // 1) Dial - // 2) lbWatcher - // In both cases, the stale ac should drain, not close. - stale.tearDown(errConnDrain) - } else { - stale.tearDown(tearDownErr) - } + 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 } - // skipWait may overwrite the decision in ac.dopts.block. - if ac.dopts.block && !skipWait { - if err := ac.resetTransport(false); err != nil { + delete(cc.conns, ac) + cc.mu.Unlock() + ac.tearDown(err) +} + +// 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 { - // Tear down ac and delete it from cc.conns. - cc.mu.Lock() - delete(cc.conns, ac.addr) - cc.mu.Unlock() + // Keep this ac in cc.conns, to get the reason it's torn down. ac.tearDown(err) } - if e, ok := err.(transport.ConnectionError); ok && !e.Temporary() { - return e.Origin() - } - return err + return } - // Start to monitor the error status of transport. - go ac.transportMonitor() - } else { - // Start a goroutine connecting to the server asynchronously. - go func() { - if err := ac.resetTransport(false); err != nil { - grpclog.Printf("Failed to dial %s: %v; please retry.", ac.addr.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() - }() - } + ac.transportMonitor() + }() return nil } -// TODO: Avoid the locking here. -func (cc *ClientConn) getMethodConfig(method string) (m MethodConfig, ok bool) { - cc.mu.RLock() - defer cc.mu.RUnlock() - m, ok = cc.sc.Methods[method] - return -} +// 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 + } -func (cc *ClientConn) getTransport(ctx context.Context, opts BalancerGetOptions) (transport.ClientTransport, func(), error) { - var ( - ac *addrConn - ok bool - put func() - ) - if cc.dopts.balancer == nil { - // If balancer is nil, there should be only one addrConn available. - cc.mu.RLock() - if cc.conns == nil { - cc.mu.RUnlock() - return nil, nil, toRPCErr(ErrClientConnClosing) - } - for _, ac = range cc.conns { - // Break after the first iteration to get the first addrConn. - ok = true + var curAddrFound bool + for _, a := range addrs { + if reflect.DeepEqual(ac.curAddr, a) { + curAddrFound = true break } - cc.mu.RUnlock() - } else { - var ( - addr Address - err error - ) - addr, put, err = cc.dopts.balancer.Get(ctx, opts) - if err != nil { - return nil, nil, toRPCErr(err) - } - cc.mu.RLock() - if cc.conns == nil { - cc.mu.RUnlock() - return nil, nil, toRPCErr(ErrClientConnClosing) - } - ac, ok = cc.conns[addr] - cc.mu.RUnlock() } + 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 serivce, 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 { - if put != nil { - put() - } - return nil, nil, errConnClosing + i := strings.LastIndex(method, "/") + m, _ = cc.sc.Methods[method[:i+1]] } - t, err := ac.wait(ctx, cc.dopts.balancer != nil, !opts.BlockingWait) + 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 { - if put != nil { - put() + 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 { + 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) } - return nil, nil, err } - return t, put, nil + cc.mu.Unlock() + return nil +} + +func (cc *ClientConn) resolveNow(o resolver.ResolveNowOption) { + cc.mu.Lock() + r := cc.resolverWrapper + cc.mu.Unlock() + if r == nil { + return + } + go r.resolveNow(o) } // Close tears down the ClientConn and all underlying connections. @@ -649,11 +945,21 @@ func (cc *ClientConn) Close() error { } 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() - if cc.dopts.balancer != nil { - cc.dopts.balancer.Close() + cc.blockingpicker.close() + if rWrapper != nil { + rWrapper.close() + } + if bWrapper != nil { + bWrapper.close() } - for _, ac := range conns { + for ac := range conns { ac.tearDown(ErrClientConnClosing) } return nil @@ -665,14 +971,15 @@ type addrConn struct { cancel context.CancelFunc cc *ClientConn - addr Address + addrs []resolver.Address dopts dialOptions events trace.EventLog + acbw balancer.SubConn - mu sync.Mutex - state ConnectivityState - stateCV *sync.Cond - down func(error) // the handler called when a connection is down. + 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{} @@ -680,6 +987,28 @@ type addrConn struct { // 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 +} + +// 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. @@ -698,198 +1027,270 @@ func (ac *addrConn) errorf(format string, a ...interface{}) { } } -// getState returns the connectivity state of the Conn -func (ac *addrConn) getState() ConnectivityState { - ac.mu.Lock() - defer ac.mu.Unlock() - return ac.state -} - -// waitForStateChange blocks until the state changes to something other than the sourceState. -func (ac *addrConn) waitForStateChange(ctx context.Context, sourceState ConnectivityState) (ConnectivityState, error) { +// 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 doesnt 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() - defer ac.mu.Unlock() - if sourceState != ac.state { - return ac.state, nil + if ac.state == connectivity.Shutdown { + ac.mu.Unlock() + return errConnClosing } - done := make(chan struct{}) - var err error - go func() { - select { - case <-ctx.Done(): - ac.mu.Lock() - err = ctx.Err() - ac.stateCV.Broadcast() - ac.mu.Unlock() - case <-done: - } - }() - defer close(done) - for sourceState == ac.state { - ac.stateCV.Wait() - if err != nil { - return ac.state, err - } + if ac.ready != nil { + close(ac.ready) + ac.ready = nil } - return ac.state, nil -} - -func (ac *addrConn) resetTransport(closeTransport bool) error { - for retries := 0; ; retries++ { + 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() - ac.printf("connecting") - if ac.state == Shutdown { - // ac.tearDown(...) has been invoked. + 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 := minConnectTimeout + 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 conect 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 } - if ac.down != nil { - ac.down(downErrorf(false, true, "%v", errNetworkIO)) - ac.down = nil + ac.printf("connecting") + if ac.state != connectivity.Connecting { + ac.state = connectivity.Connecting + ac.cc.handleSubConnStateChange(ac.acbw, ac.state) } - ac.state = Connecting - ac.stateCV.Broadcast() - t := ac.transport + // 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() - if closeTransport && t != nil { - t.Close() + connected, err := ac.createTransport(connectRetryNum, ridx, backoffDeadline, connectDeadline, addrsIter, copts) + if err != nil { + return err } - sleepTime := ac.dopts.bs.backoff(retries) - timeout := minConnectTimeout - if timeout < sleepTime { - timeout = sleepTime + if connected { + return nil } - ctx, cancel := context.WithTimeout(ac.ctx, timeout) - connectTime := time.Now() - sinfo := transport.TargetInfo{ - Addr: ac.addr.Addr, - Metadata: ac.addr.Metadata, + } +} + +// 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, } - newTransport, err := transport.NewClientTransport(ctx, sinfo, ac.dopts.copts) + 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) + newTr, err := transport.NewClientTransport(connectCtx, ac.cc.ctx, target, copts, onPrefaceReceipt) if err != nil { cancel() - if e, ok := err.(transport.ConnectionError); ok && !e.Temporary() { - return err + ac.mu.Lock() + if ac.state != connectivity.Shutdown { + ac.state = connectivity.TransientFailure + ac.cc.handleSubConnStateChange(ac.acbw, ac.state) + } + ac.mu.Unlock() + return false, err } - grpclog.Printf("grpc: addrConn.resetTransport failed to create client transport: %v; Reconnecting to %v", err, ac.addr) ac.mu.Lock() - if ac.state == Shutdown { + if ac.state == connectivity.Shutdown { // ac.tearDown(...) has been invoked. ac.mu.Unlock() - return errConnClosing - } - ac.errorf("transient failure: %v", err) - ac.state = TransientFailure - ac.stateCV.Broadcast() - if ac.ready != nil { - close(ac.ready) - ac.ready = nil + return false, errConnClosing } ac.mu.Unlock() - closeTransport = false + grpclog.Warningf("grpc: addrConn.createTransport failed to connect to %v. Err :%v. Reconnecting...", addr, err) + continue + } + if ac.dopts.waitForHandshake { select { - case <-time.After(sleepTime - time.Since(connectTime)): + 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(): - return ac.ctx.Err() } - continue } ac.mu.Lock() - ac.printf("ready") - if ac.state == Shutdown { - // ac.tearDown(...) has been invoked. + if ac.state == connectivity.Shutdown { ac.mu.Unlock() - newTransport.Close() - return errConnClosing + // ac.tearDonn(...) has been invoked. + newTr.Close() + return false, errConnClosing } - ac.state = Ready - ac.stateCV.Broadcast() - ac.transport = newTransport + 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 } - if ac.cc.dopts.balancer != nil { - ac.down = ac.cc.dopts.balancer.Up(ac.addr) + 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 nil + return true, nil + } + ac.mu.Lock() + 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 { - // This is needed to detect the teardown when - // the addrConn is idle (i.e., no RPC in flight). - case <-ac.ctx.Done(): - select { - case <-t.Error(): - t.Close() - default: - } - return case <-t.GoAway(): - // If GoAway happens without any network I/O error, ac is closed without shutting down the - // underlying transport (the transport will be closed when all the pending RPCs finished or - // failed.). - // If GoAway and some network I/O error happen concurrently, ac and its underlying transport - // are closed. - // In both cases, a new ac is created. - select { - case <-t.Error(): - ac.cc.resetAddrConn(ac.addr, true, errNetworkIO) - default: - ac.cc.resetAddrConn(ac.addr, true, errConnDrain) - } - return case <-t.Error(): - select { - case <-ac.ctx.Done(): - t.Close() - return - case <-t.GoAway(): - ac.cc.resetAddrConn(ac.addr, true, errNetworkIO) - return - default: - } + case <-cdeadline: ac.mu.Lock() - if ac.state == Shutdown { - // ac has been shutdown. + // This implies that client received server preface. + if ac.backoffDeadline.IsZero() { ac.mu.Unlock() - return + continue } - ac.state = TransientFailure - ac.stateCV.Broadcast() ac.mu.Unlock() - if err := ac.resetTransport(true); err != nil { - ac.mu.Lock() - ac.printf("transport exiting: %v", err) - ac.mu.Unlock() - grpclog.Printf("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 + 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 TransientFailure and there is a balancer/failfast is true. +// 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 == Shutdown: + 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 @@ -898,11 +1299,11 @@ func (ac *addrConn) wait(ctx context.Context, hasBalancer, failfast bool) (trans } ac.mu.Unlock() return nil, errConnClosing - case ac.state == Ready: + case ac.state == connectivity.Ready: ct := ac.transport ac.mu.Unlock() return ct, nil - case ac.state == TransientFailure: + case ac.state == connectivity.TransientFailure: if failfast || hasBalancer { ac.mu.Unlock() return nil, errConnUnavailable @@ -923,6 +1324,28 @@ func (ac *addrConn) wait(ctx context.Context, hasBalancer, failfast bool) (trans } } +// 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 @@ -930,13 +1353,12 @@ func (ac *addrConn) wait(ctx context.Context, hasBalancer, failfast bool) (trans // 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.down != nil { - ac.down(downErrorf(false, false, "%v", err)) - ac.down = nil + 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 @@ -944,12 +1366,9 @@ func (ac *addrConn) tearDown(err error) { // address removal and GoAway. ac.transport.GracefulClose() } - if ac.state == Shutdown { - return - } - ac.state = Shutdown + ac.state = connectivity.Shutdown ac.tearDownErr = err - ac.stateCV.Broadcast() + ac.cc.handleSubConnStateChange(ac.acbw, ac.state) if ac.events != nil { ac.events.Finish() ac.events = nil @@ -958,8 +1377,11 @@ func (ac *addrConn) tearDown(err error) { close(ac.ready) ac.ready = nil } - if ac.transport != nil && err != errConnDrain { - ac.transport.Close() - } return } + +func (ac *addrConn) getState() connectivity.State { + ac.mu.Lock() + defer ac.mu.Unlock() + return ac.state +} |