diff options
Diffstat (limited to 'vendor/google.golang.org/grpc/clientconn.go')
| -rw-r--r-- | vendor/google.golang.org/grpc/clientconn.go | 1255 |
1 files changed, 0 insertions, 1255 deletions
diff --git a/vendor/google.golang.org/grpc/clientconn.go b/vendor/google.golang.org/grpc/clientconn.go deleted file mode 100644 index d74b8bf..0000000 --- a/vendor/google.golang.org/grpc/clientconn.go +++ /dev/null @@ -1,1255 +0,0 @@ -/* - * - * Copyright 2014 gRPC authors. - * - * Licensed under the Apache License, Version 2.0 (the "License"); - * you may not use this file except in compliance with the License. - * You may obtain a copy of the License at - * - * http://www.apache.org/licenses/LICENSE-2.0 - * - * Unless required by applicable law or agreed to in writing, software - * distributed under the License is distributed on an "AS IS" BASIS, - * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - * See the License for the specific language governing permissions and - * limitations under the License. - * - */ - -package grpc - -import ( - "errors" - "fmt" - "math" - "net" - "reflect" - "strings" - "sync" - "sync/atomic" - "time" - - "golang.org/x/net/context" - "golang.org/x/net/trace" - "google.golang.org/grpc/balancer" - _ "google.golang.org/grpc/balancer/roundrobin" // To register roundrobin. - "google.golang.org/grpc/codes" - "google.golang.org/grpc/connectivity" - "google.golang.org/grpc/credentials" - "google.golang.org/grpc/grpclog" - "google.golang.org/grpc/internal/backoff" - "google.golang.org/grpc/internal/channelz" - "google.golang.org/grpc/internal/transport" - "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/status" -) - -const ( - // minimum time to give a connection to complete - minConnectTimeout = 20 * time.Second - // must match grpclbName in grpclb/grpclb.go - grpclbName = "grpclb" -) - -var ( - // ErrClientConnClosing indicates that the operation is illegal because - // the ClientConn is closing. - // - // Deprecated: this error should not be relied upon by users; use the status - // code of Canceled instead. - ErrClientConnClosing = status.Error(codes.Canceled, "grpc: the client connection is closing") - // errConnDrain indicates that the connection starts to be drained and does not accept any new RPCs. - errConnDrain = errors.New("grpc: the connection is drained") - // errConnClosing indicates that the connection is closing. - errConnClosing = errors.New("grpc: the connection is closing") - // errConnUnavailable indicates that the connection is unavailable. - errConnUnavailable = errors.New("grpc: the connection is unavailable") - // errBalancerClosed indicates that the balancer is closed. - errBalancerClosed = errors.New("grpc: balancer is closed") - // We use an accessor so that minConnectTimeout can be - // atomically read and updated while testing. - getMinConnectTimeout = func() time.Duration { - return minConnectTimeout - } -) - -// The following errors are returned from Dial and DialContext -var ( - // errNoTransportSecurity indicates that there is no transport security - // being set for ClientConn. Users should either set one or explicitly - // call WithInsecure DialOption to disable security. - errNoTransportSecurity = errors.New("grpc: no transport security set (use grpc.WithInsecure() explicitly or set credentials)") - // errTransportCredentialsMissing indicates that users want to transmit security - // information (e.g., oauth2 token) which requires secure connection on an insecure - // connection. - errTransportCredentialsMissing = errors.New("grpc: the credentials require transport level security (use grpc.WithTransportCredentials() to set)") - // errCredentialsConflict indicates that grpc.WithTransportCredentials() - // and grpc.WithInsecure() are both called for a connection. - errCredentialsConflict = errors.New("grpc: transport credentials are set for an insecure connection (grpc.WithTransportCredentials() and grpc.WithInsecure() are both called)") - // errNetworkIO indicates that the connection is down due to some network I/O error. - errNetworkIO = errors.New("grpc: failed with network I/O error") -) - -const ( - defaultClientMaxReceiveMessageSize = 1024 * 1024 * 4 - defaultClientMaxSendMessageSize = math.MaxInt32 - // http2IOBufSize specifies the buffer size for sending frames. - defaultWriteBufSize = 32 * 1024 - defaultReadBufSize = 32 * 1024 -) - -// RegisterChannelz turns on channelz service. -// This is an EXPERIMENTAL API. -func RegisterChannelz() { - channelz.TurnOn() -} - -// 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), - } - cc.retryThrottler.Store((*retryThrottler)(nil)) - cc.ctx, cc.cancel = context.WithCancel(context.Background()) - - for _, opt := range opts { - opt.apply(&cc.dopts) - } - - if channelz.IsOn() { - if cc.dopts.channelzParentID != 0 { - cc.channelzID = channelz.RegisterChannel(&channelzChannel{cc}, cc.dopts.channelzParentID, target) - } else { - cc.channelzID = channelz.RegisterChannel(&channelzChannel{cc}, 0, target) - } - } - - if !cc.dopts.insecure { - if cc.dopts.copts.TransportCredentials == nil { - return nil, errNoTransportSecurity - } - } else { - if cc.dopts.copts.TransportCredentials != nil { - return nil, errCredentialsConflict - } - for _, cd := range cc.dopts.copts.PerRPCCredentials { - if cd.RequireTransportSecurity() { - return nil, errTransportCredentialsMissing - } - } - } - - cc.mkp = cc.dopts.copts.KeepaliveParams - - if cc.dopts.copts.Dialer == nil { - cc.dopts.copts.Dialer = newProxyDialer( - func(ctx context.Context, addr string) (net.Conn, error) { - network, addr := parseDialTarget(addr) - return dialContext(ctx, network, addr) - }, - ) - } - - if cc.dopts.copts.UserAgent != "" { - cc.dopts.copts.UserAgent += " " + grpcUA - } else { - cc.dopts.copts.UserAgent = grpcUA - } - - if cc.dopts.timeout > 0 { - var cancel context.CancelFunc - ctx, cancel = context.WithTimeout(ctx, cc.dopts.timeout) - defer cancel() - } - - defer func() { - select { - case <-ctx.Done(): - conn, err = nil, ctx.Err() - default: - } - - if err != nil { - cc.Close() - } - }() - - scSet := false - if cc.dopts.scChan != nil { - // Try to get an initial service config. - select { - case sc, ok := <-cc.dopts.scChan: - if ok { - cc.sc = sc - scSet = true - } - default: - } - } - if cc.dopts.bs == nil { - cc.dopts.bs = backoff.Exponential{ - MaxDelay: DefaultBackoffConfig.MaxDelay, - } - } - if cc.dopts.resolverBuilder == nil { - // Only try to parse target when resolver builder is not already set. - cc.parsedTarget = parseTarget(cc.target) - grpclog.Infof("parsed scheme: %q", cc.parsedTarget.Scheme) - cc.dopts.resolverBuilder = resolver.Get(cc.parsedTarget.Scheme) - if cc.dopts.resolverBuilder == nil { - // If resolver builder is still nil, the parse target's scheme is - // not registered. Fallback to default resolver and set Endpoint to - // the original unparsed target. - grpclog.Infof("scheme %q not registered, fallback to default scheme", cc.parsedTarget.Scheme) - cc.parsedTarget = resolver.Target{ - Scheme: resolver.GetDefaultScheme(), - Endpoint: target, - } - cc.dopts.resolverBuilder = resolver.Get(cc.parsedTarget.Scheme) - } - } else { - cc.parsedTarget = resolver.Target{Endpoint: target} - } - creds := cc.dopts.copts.TransportCredentials - if creds != nil && creds.Info().ServerName != "" { - cc.authority = creds.Info().ServerName - } else if cc.dopts.insecure && cc.dopts.authority != "" { - cc.authority = cc.dopts.authority - } else { - // Use endpoint from "scheme://authority/endpoint" as the default - // authority for ClientConn. - cc.authority = cc.parsedTarget.Endpoint - } - - if cc.dopts.scChan != nil && !scSet { - // Blocking wait for the initial service config. - select { - case sc, ok := <-cc.dopts.scChan: - if ok { - cc.sc = sc - } - case <-ctx.Done(): - return nil, ctx.Err() - } - } - if cc.dopts.scChan != nil { - go cc.scWatcher() - } - - var credsClone credentials.TransportCredentials - if creds := cc.dopts.copts.TransportCredentials; creds != nil { - credsClone = creds.Clone() - } - cc.balancerBuildOpts = balancer.BuildOptions{ - DialCreds: credsClone, - Dialer: cc.dopts.copts.Dialer, - ChannelzParentID: cc.channelzID, - } - - // Build the resolver. - cc.resolverWrapper, err = newCCResolverWrapper(cc) - if err != nil { - return nil, fmt.Errorf("failed to build resolver: %v", err) - } - // Start the resolver wrapper goroutine after resolverWrapper is created. - // - // If the goroutine is started before resolverWrapper is ready, the - // following may happen: The goroutine sends updates to cc. cc forwards - // those to balancer. Balancer creates new addrConn. addrConn fails to - // connect, and calls resolveNow(). resolveNow() tries to use the non-ready - // resolverWrapper. - cc.resolverWrapper.start() - - // A blocking dial blocks until the clientConn is ready. - if cc.dopts.block { - for { - s := cc.GetState() - if s == connectivity.Ready { - break - } - if !cc.WaitForStateChange(ctx, s) { - // ctx got timeout or canceled. - return nil, ctx.Err() - } - } - } - - return cc, nil -} - -// connectivityStateManager keeps the connectivity.State of ClientConn. -// This struct will eventually be exported so the balancers can access it. -type connectivityStateManager struct { - mu sync.Mutex - state connectivity.State - notifyChan chan struct{} -} - -// updateState updates the connectivity.State of ClientConn. -// If there's a change it notifies goroutines waiting on state change to -// happen. -func (csm *connectivityStateManager) updateState(state connectivity.State) { - csm.mu.Lock() - defer csm.mu.Unlock() - if csm.state == connectivity.Shutdown { - return - } - if csm.state == state { - return - } - csm.state = state - if csm.notifyChan != nil { - // There are other goroutines waiting on this channel. - close(csm.notifyChan) - csm.notifyChan = nil - } -} - -func (csm *connectivityStateManager) getState() connectivity.State { - csm.mu.Lock() - defer csm.mu.Unlock() - return csm.state -} - -func (csm *connectivityStateManager) getNotifyChan() <-chan struct{} { - csm.mu.Lock() - defer csm.mu.Unlock() - if csm.notifyChan == nil { - csm.notifyChan = make(chan struct{}) - } - return csm.notifyChan -} - -// ClientConn represents a client connection to an RPC server. -type ClientConn struct { - ctx context.Context - cancel context.CancelFunc - - target string - parsedTarget resolver.Target - authority string - dopts dialOptions - csMgr *connectivityStateManager - - balancerBuildOpts balancer.BuildOptions - resolverWrapper *ccResolverWrapper - blockingpicker *pickerWrapper - - mu sync.RWMutex - sc ServiceConfig - scRaw string - conns map[*addrConn]struct{} - // Keepalive parameter can be updated if a GoAway is received. - mkp keepalive.ClientParameters - curBalancerName string - preBalancerName string // previous balancer name. - curAddresses []resolver.Address - balancerWrapper *ccBalancerWrapper - retryThrottler atomic.Value - - channelzID int64 // channelz unique identification number - czData *channelzData -} - -// WaitForStateChange waits until the connectivity.State of ClientConn changes from sourceState or -// ctx expires. A true value is returned in former case and false in latter. -// This is an EXPERIMENTAL API. -func (cc *ClientConn) WaitForStateChange(ctx context.Context, sourceState connectivity.State) bool { - ch := cc.csMgr.getNotifyChan() - if cc.csMgr.getState() != sourceState { - return true - } - select { - case <-ctx.Done(): - return false - case <-ch: - return true - } -} - -// GetState returns the connectivity.State of ClientConn. -// This is an EXPERIMENTAL API. -func (cc *ClientConn) GetState() connectivity.State { - return cc.csMgr.getState() -} - -func (cc *ClientConn) scWatcher() { - for { - select { - case sc, ok := <-cc.dopts.scChan: - if !ok { - return - } - cc.mu.Lock() - // TODO: load balance policy runtime change is ignored. - // We may revist this decision in the future. - cc.sc = sc - cc.scRaw = "" - cc.mu.Unlock() - case <-cc.ctx.Done(): - return - } - } -} - -func (cc *ClientConn) handleResolvedAddrs(addrs []resolver.Address, err error) { - cc.mu.Lock() - defer cc.mu.Unlock() - if cc.conns == nil { - // cc was closed. - return - } - - if reflect.DeepEqual(cc.curAddresses, addrs) { - return - } - - cc.curAddresses = addrs - - if cc.dopts.balancerBuilder == nil { - // Only look at balancer types and switch balancer if balancer dial - // option is not set. - var isGRPCLB bool - for _, a := range addrs { - if a.Type == resolver.GRPCLB { - isGRPCLB = true - break - } - } - var newBalancerName string - if isGRPCLB { - newBalancerName = grpclbName - } else { - // Address list doesn't contain grpclb address. Try to pick a - // non-grpclb balancer. - newBalancerName = cc.curBalancerName - // If current balancer is grpclb, switch to the previous one. - if newBalancerName == grpclbName { - newBalancerName = cc.preBalancerName - } - // The following could be true in two cases: - // - the first time handling resolved addresses - // (curBalancerName="") - // - the first time handling non-grpclb addresses - // (curBalancerName="grpclb", preBalancerName="") - if newBalancerName == "" { - newBalancerName = PickFirstBalancerName - } - } - cc.switchBalancer(newBalancerName) - } else if cc.balancerWrapper == nil { - // Balancer dial option was set, and this is the first time handling - // resolved addresses. Build a balancer with dopts.balancerBuilder. - cc.balancerWrapper = newCCBalancerWrapper(cc, cc.dopts.balancerBuilder, cc.balancerBuildOpts) - } - - cc.balancerWrapper.handleResolvedAddrs(addrs, nil) -} - -// switchBalancer starts the switching from current balancer to the balancer -// with the given name. -// -// It will NOT send the current address list to the new balancer. If needed, -// caller of this function should send address list to the new balancer after -// this function returns. -// -// Caller must hold cc.mu. -func (cc *ClientConn) switchBalancer(name string) { - if cc.conns == nil { - return - } - - if strings.ToLower(cc.curBalancerName) == strings.ToLower(name) { - return - } - - grpclog.Infof("ClientConn switching balancer to %q", name) - if cc.dopts.balancerBuilder != nil { - grpclog.Infoln("ignoring balancer switching: Balancer DialOption used instead") - return - } - // TODO(bar switching) change this to two steps: drain and close. - // Keep track of sc in wrapper. - if cc.balancerWrapper != nil { - cc.balancerWrapper.close() - } - - 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, - czData: new(channelzData), - } - ac.ctx, ac.cancel = context.WithCancel(cc.ctx) - // Track ac in cc. This needs to be done before any getTransport(...) is called. - cc.mu.Lock() - if cc.conns == nil { - cc.mu.Unlock() - return nil, ErrClientConnClosing - } - if channelz.IsOn() { - ac.channelzID = channelz.RegisterSubChannel(ac, cc.channelzID, "") - } - cc.conns[ac] = struct{}{} - cc.mu.Unlock() - return ac, nil -} - -// removeAddrConn removes the addrConn in the subConn from clientConn. -// It also tears down the ac with the given error. -func (cc *ClientConn) removeAddrConn(ac *addrConn, err error) { - cc.mu.Lock() - if cc.conns == nil { - cc.mu.Unlock() - return - } - delete(cc.conns, ac) - cc.mu.Unlock() - ac.tearDown(err) -} - -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. -// This is an EXPERIMENTAL API. -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 to creating transport and also starts the transport monitor -// goroutine for this ac. -// It does nothing if the ac is not IDLE. -// TODO(bar) Move this to the addrConn section. -// This was part of resetAddrConn, keep it here to make the diff look clean. -func (ac *addrConn) connect() error { - ac.mu.Lock() - if ac.state == connectivity.Shutdown { - ac.mu.Unlock() - return errConnClosing - } - if ac.state != connectivity.Idle { - ac.mu.Unlock() - return nil - } - ac.state = connectivity.Connecting - ac.cc.handleSubConnStateChange(ac.acbw, ac.state) - ac.mu.Unlock() - - // Start a goroutine connecting to the server asynchronously. - go func() { - if err := ac.resetTransport(); err != nil { - grpclog.Warningf("Failed to dial %s: %v; please retry.", ac.addrs[0].Addr, err) - if err != errConnClosing { - // Keep this ac in cc.conns, to get the reason it's torn down. - ac.tearDown(err) - } - return - } - ac.transportMonitor() - }() - return nil -} - -// tryUpdateAddrs tries to update ac.addrs with the new addresses list. -// -// It checks whether current connected address of ac is in the new addrs list. -// - If true, it updates ac.addrs and returns true. The ac will keep using -// the existing connection. -// - If false, it does nothing and returns false. -func (ac *addrConn) tryUpdateAddrs(addrs []resolver.Address) bool { - ac.mu.Lock() - defer ac.mu.Unlock() - grpclog.Infof("addrConn: tryUpdateAddrs curAddr: %v, addrs: %v", ac.curAddr, addrs) - if ac.state == connectivity.Shutdown { - ac.addrs = addrs - return true - } - - var curAddrFound bool - for _, a := range addrs { - if reflect.DeepEqual(ac.curAddr, a) { - curAddrFound = true - break - } - } - grpclog.Infof("addrConn: tryUpdateAddrs curAddrFound: %v", curAddrFound) - if curAddrFound { - ac.addrs = addrs - ac.reconnectIdx = 0 // Start reconnecting from beginning in the new list. - } - - return curAddrFound -} - -// GetMethodConfig gets the method config of the input method. -// If there's an exact match for input method (i.e. /service/method), we return -// the corresponding MethodConfig. -// If there isn't an exact match for the input method, we look for the default config -// under the service (i.e /service/). If there is a default MethodConfig for -// the service, we return it. -// Otherwise, we return an empty MethodConfig. -func (cc *ClientConn) GetMethodConfig(method string) MethodConfig { - // TODO: Avoid the locking here. - cc.mu.RLock() - defer cc.mu.RUnlock() - m, ok := cc.sc.Methods[method] - if !ok { - i := strings.LastIndex(method, "/") - m = cc.sc.Methods[method[:i+1]] - } - return m -} - -func (cc *ClientConn) getTransport(ctx context.Context, failfast bool, method string) (transport.ClientTransport, func(balancer.DoneInfo), error) { - t, done, err := cc.blockingpicker.pick(ctx, failfast, balancer.PickOptions{ - FullMethodName: method, - }) - if err != nil { - return nil, nil, toRPCErr(err) - } - return t, done, nil -} - -// handleServiceConfig parses the service config string in JSON format to Go native -// struct ServiceConfig, and store both the struct and the JSON string in ClientConn. -func (cc *ClientConn) handleServiceConfig(js string) error { - if cc.dopts.disableServiceConfig { - return nil - } - sc, err := parseServiceConfig(js) - if err != nil { - return err - } - cc.mu.Lock() - cc.scRaw = js - cc.sc = sc - - if sc.retryThrottling != nil { - newThrottler := &retryThrottler{ - tokens: sc.retryThrottling.MaxTokens, - max: sc.retryThrottling.MaxTokens, - thresh: sc.retryThrottling.MaxTokens / 2, - ratio: sc.retryThrottling.TokenRatio, - } - cc.retryThrottler.Store(newThrottler) - } else { - cc.retryThrottler.Store((*retryThrottler)(nil)) - } - - 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) - } - } - - cc.mu.Unlock() - return nil -} - -func (cc *ClientConn) resolveNow(o resolver.ResolveNowOption) { - cc.mu.RLock() - r := cc.resolverWrapper - cc.mu.RUnlock() - if r == nil { - return - } - go r.resolveNow(o) -} - -// Close tears down the ClientConn and all underlying connections. -func (cc *ClientConn) Close() error { - defer cc.cancel() - - cc.mu.Lock() - if cc.conns == nil { - cc.mu.Unlock() - return ErrClientConnClosing - } - conns := cc.conns - cc.conns = nil - cc.csMgr.updateState(connectivity.Shutdown) - - rWrapper := cc.resolverWrapper - cc.resolverWrapper = nil - bWrapper := cc.balancerWrapper - cc.balancerWrapper = nil - cc.mu.Unlock() - - cc.blockingpicker.close() - - if rWrapper != nil { - rWrapper.close() - } - if bWrapper != nil { - bWrapper.close() - } - - for ac := range conns { - ac.tearDown(ErrClientConnClosing) - } - if channelz.IsOn() { - channelz.RemoveEntry(cc.channelzID) - } - return nil -} - -// addrConn is a network connection to a given address. -type addrConn struct { - ctx context.Context - cancel context.CancelFunc - - cc *ClientConn - addrs []resolver.Address - dopts dialOptions - events trace.EventLog - acbw balancer.SubConn - - mu sync.Mutex - curAddr resolver.Address - reconnectIdx int // The index in addrs list to start reconnecting from. - state connectivity.State - // ready is closed and becomes nil when a new transport is up or failed - // due to timeout. - ready chan struct{} - transport transport.ClientTransport - - // The reason this addrConn is torn down. - tearDownErr error - - connectRetryNum int - // backoffDeadline is the time until which resetTransport needs to - // wait before increasing connectRetryNum count. - backoffDeadline time.Time - // connectDeadline is the time by which all connection - // negotiations must complete. - connectDeadline time.Time - - channelzID int64 // channelz unique identification number - czData *channelzData -} - -// adjustParams updates parameters used to create transports upon -// receiving a GoAway. -func (ac *addrConn) adjustParams(r transport.GoAwayReason) { - switch r { - case transport.GoAwayTooManyPings: - v := 2 * ac.dopts.copts.KeepaliveParams.Time - ac.cc.mu.Lock() - if v > ac.cc.mkp.Time { - ac.cc.mkp.Time = v - } - ac.cc.mu.Unlock() - } -} - -// printf records an event in ac's event log, unless ac has been closed. -// REQUIRES ac.mu is held. -func (ac *addrConn) printf(format string, a ...interface{}) { - if ac.events != nil { - ac.events.Printf(format, a...) - } -} - -// errorf records an error in ac's event log, unless ac has been closed. -// REQUIRES ac.mu is held. -func (ac *addrConn) errorf(format string, a ...interface{}) { - if ac.events != nil { - ac.events.Errorf(format, a...) - } -} - -// resetTransport recreates a transport to the address for ac. The old -// transport will close itself on error or when the clientconn is closed. -// The created transport must receive initial settings frame from the server. -// In case that doesn't happen, transportMonitor will kill the newly created -// transport after connectDeadline has expired. -// In case there was an error on the transport before the settings frame was -// received, resetTransport resumes connecting to backends after the one that -// was previously connected to. In case end of the list is reached, resetTransport -// backs off until the original deadline. -// If the DialOption WithWaitForHandshake was set, resetTrasport returns -// successfully only after server settings are received. -// -// TODO(bar) make sure all state transitions are valid. -func (ac *addrConn) resetTransport() error { - ac.mu.Lock() - if ac.state == connectivity.Shutdown { - ac.mu.Unlock() - return errConnClosing - } - if ac.ready != nil { - close(ac.ready) - ac.ready = nil - } - ac.transport = nil - ridx := ac.reconnectIdx - ac.mu.Unlock() - ac.cc.mu.RLock() - ac.dopts.copts.KeepaliveParams = ac.cc.mkp - ac.cc.mu.RUnlock() - var backoffDeadline, connectDeadline time.Time - for connectRetryNum := 0; ; connectRetryNum++ { - ac.mu.Lock() - if ac.backoffDeadline.IsZero() { - // This means either a successful HTTP2 connection was established - // or this is the first time this addrConn is trying to establish a - // connection. - backoffFor := ac.dopts.bs.Backoff(connectRetryNum) // time.Duration. - // This will be the duration that dial gets to finish. - dialDuration := getMinConnectTimeout() - if backoffFor > dialDuration { - // Give dial more time as we keep failing to connect. - dialDuration = backoffFor - } - start := time.Now() - backoffDeadline = start.Add(backoffFor) - connectDeadline = start.Add(dialDuration) - ridx = 0 // Start connecting from the beginning. - } else { - // Continue trying to connect with the same deadlines. - connectRetryNum = ac.connectRetryNum - backoffDeadline = ac.backoffDeadline - connectDeadline = ac.connectDeadline - ac.backoffDeadline = time.Time{} - ac.connectDeadline = time.Time{} - ac.connectRetryNum = 0 - } - if ac.state == connectivity.Shutdown { - ac.mu.Unlock() - return errConnClosing - } - ac.printf("connecting") - if ac.state != connectivity.Connecting { - ac.state = connectivity.Connecting - ac.cc.handleSubConnStateChange(ac.acbw, ac.state) - } - // copy ac.addrs in case of race - addrsIter := make([]resolver.Address, len(ac.addrs)) - copy(addrsIter, ac.addrs) - copts := ac.dopts.copts - ac.mu.Unlock() - connected, err := ac.createTransport(connectRetryNum, ridx, backoffDeadline, connectDeadline, addrsIter, copts) - if err != nil { - return err - } - if connected { - return nil - } - } -} - -// createTransport creates a connection to one of the backends in addrs. -// It returns true if a connection was established. -func (ac *addrConn) createTransport(connectRetryNum, ridx int, backoffDeadline, connectDeadline time.Time, addrs []resolver.Address, copts transport.ConnectOptions) (bool, error) { - for i := ridx; i < len(addrs); i++ { - addr := addrs[i] - target := transport.TargetInfo{ - Addr: addr.Addr, - Metadata: addr.Metadata, - Authority: ac.cc.authority, - } - done := make(chan struct{}) - onPrefaceReceipt := func() { - ac.mu.Lock() - close(done) - if !ac.backoffDeadline.IsZero() { - // If we haven't already started reconnecting to - // other backends. - // Note, this can happen when writer notices an error - // and triggers resetTransport while at the same time - // reader receives the preface and invokes this closure. - ac.backoffDeadline = time.Time{} - ac.connectDeadline = time.Time{} - ac.connectRetryNum = 0 - } - ac.mu.Unlock() - } - // Do not cancel in the success path because of - // this issue in Go1.6: https://github.com/golang/go/issues/15078. - connectCtx, cancel := context.WithDeadline(ac.ctx, connectDeadline) - if channelz.IsOn() { - copts.ChannelzParentID = ac.channelzID - } - newTr, err := transport.NewClientTransport(connectCtx, ac.cc.ctx, target, copts, onPrefaceReceipt) - if err != nil { - cancel() - ac.cc.blockingpicker.updateConnectionError(err) - ac.mu.Lock() - if ac.state == connectivity.Shutdown { - // ac.tearDown(...) has been invoked. - ac.mu.Unlock() - return false, errConnClosing - } - ac.mu.Unlock() - grpclog.Warningf("grpc: addrConn.createTransport failed to connect to %v. Err :%v. Reconnecting...", addr, err) - continue - } - if ac.dopts.waitForHandshake { - select { - case <-done: - case <-connectCtx.Done(): - // Didn't receive server preface, must kill this new transport now. - grpclog.Warningf("grpc: addrConn.createTransport failed to receive server preface before deadline.") - newTr.Close() - continue - case <-ac.ctx.Done(): - } - } - ac.mu.Lock() - if ac.state == connectivity.Shutdown { - ac.mu.Unlock() - // ac.tearDonn(...) has been invoked. - newTr.Close() - return false, errConnClosing - } - ac.printf("ready") - ac.state = connectivity.Ready - ac.cc.handleSubConnStateChange(ac.acbw, ac.state) - ac.transport = newTr - ac.curAddr = addr - if ac.ready != nil { - close(ac.ready) - ac.ready = nil - } - select { - case <-done: - // If the server has responded back with preface already, - // don't set the reconnect parameters. - default: - ac.connectRetryNum = connectRetryNum - ac.backoffDeadline = backoffDeadline - ac.connectDeadline = connectDeadline - ac.reconnectIdx = i + 1 // Start reconnecting from the next backend in the list. - } - ac.mu.Unlock() - return true, nil - } - ac.mu.Lock() - if ac.state == connectivity.Shutdown { - ac.mu.Unlock() - return false, errConnClosing - } - ac.state = connectivity.TransientFailure - ac.cc.handleSubConnStateChange(ac.acbw, ac.state) - ac.cc.resolveNow(resolver.ResolveNowOption{}) - if ac.ready != nil { - close(ac.ready) - ac.ready = nil - } - ac.mu.Unlock() - timer := time.NewTimer(backoffDeadline.Sub(time.Now())) - select { - case <-timer.C: - case <-ac.ctx.Done(): - timer.Stop() - return false, ac.ctx.Err() - } - return false, nil -} - -// Run in a goroutine to track the error in transport and create the -// new transport if an error happens. It returns when the channel is closing. -func (ac *addrConn) transportMonitor() { - for { - var timer *time.Timer - var cdeadline <-chan time.Time - ac.mu.Lock() - t := ac.transport - if !ac.connectDeadline.IsZero() { - timer = time.NewTimer(ac.connectDeadline.Sub(time.Now())) - cdeadline = timer.C - } - ac.mu.Unlock() - // Block until we receive a goaway or an error occurs. - select { - case <-t.GoAway(): - done := t.Error() - cleanup := t.Close - // Since this transport will be orphaned (won't have a transportMonitor) - // we need to launch a goroutine to keep track of clientConn.Close() - // happening since it might not be noticed by any other goroutine for a while. - go func() { - <-done - cleanup() - }() - case <-t.Error(): - // In case this is triggered because clientConn.Close() - // was called, we want to immeditately close the transport - // since no other goroutine might notice it for a while. - t.Close() - case <-cdeadline: - ac.mu.Lock() - // This implies that client received server preface. - if ac.backoffDeadline.IsZero() { - ac.mu.Unlock() - continue - } - ac.mu.Unlock() - timer = nil - // No server preface received until deadline. - // Kill the connection. - grpclog.Warningf("grpc: addrConn.transportMonitor didn't get server preface after waiting. Closing the new transport now.") - t.Close() - } - if timer != nil { - timer.Stop() - } - // If a GoAway happened, regardless of error, adjust our keepalive - // parameters as appropriate. - select { - case <-t.GoAway(): - ac.adjustParams(t.GetGoAwayReason()) - default: - } - ac.mu.Lock() - if ac.state == connectivity.Shutdown { - ac.mu.Unlock() - return - } - // Set connectivity state to TransientFailure before calling - // resetTransport. Transition READY->CONNECTING is not valid. - ac.state = connectivity.TransientFailure - ac.cc.handleSubConnStateChange(ac.acbw, ac.state) - ac.cc.resolveNow(resolver.ResolveNowOption{}) - ac.curAddr = resolver.Address{} - ac.mu.Unlock() - if err := ac.resetTransport(); err != nil { - ac.mu.Lock() - ac.printf("transport exiting: %v", err) - ac.mu.Unlock() - grpclog.Warningf("grpc: addrConn.transportMonitor exits due to: %v", err) - if err != errConnClosing { - // Keep this ac in cc.conns, to get the reason it's torn down. - ac.tearDown(err) - } - return - } - } -} - -// getReadyTransport returns the transport if ac's state is READY. -// Otherwise it returns nil, false. -// If ac's state is IDLE, it will trigger ac to connect. -func (ac *addrConn) getReadyTransport() (transport.ClientTransport, bool) { - ac.mu.Lock() - if ac.state == connectivity.Ready { - t := ac.transport - ac.mu.Unlock() - return t, true - } - var idle bool - if ac.state == connectivity.Idle { - idle = true - } - ac.mu.Unlock() - // Trigger idle ac to connect. - if idle { - ac.connect() - } - return nil, false -} - -// tearDown starts to tear down the addrConn. -// TODO(zhaoq): Make this synchronous to avoid unbounded memory consumption in -// some edge cases (e.g., the caller opens and closes many addrConn's in a -// tight loop. -// tearDown doesn't remove ac from ac.cc.conns. -func (ac *addrConn) tearDown(err error) { - ac.cancel() - ac.mu.Lock() - defer ac.mu.Unlock() - if ac.state == connectivity.Shutdown { - return - } - ac.curAddr = resolver.Address{} - if err == errConnDrain && ac.transport != nil { - // GracefulClose(...) may be executed multiple times when - // i) receiving multiple GoAway frames from the server; or - // ii) there are concurrent name resolver/Balancer triggered - // address removal and GoAway. - ac.transport.GracefulClose() - } - ac.state = connectivity.Shutdown - ac.tearDownErr = err - ac.cc.handleSubConnStateChange(ac.acbw, ac.state) - if ac.events != nil { - ac.events.Finish() - ac.events = nil - } - if ac.ready != nil { - close(ac.ready) - ac.ready = nil - } - if channelz.IsOn() { - channelz.RemoveEntry(ac.channelzID) - } -} - -func (ac *addrConn) getState() connectivity.State { - ac.mu.Lock() - defer ac.mu.Unlock() - return ac.state -} - -func (ac *addrConn) 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") |