diff options
Diffstat (limited to 'vendor/google.golang.org/grpc/clientconn.go')
| -rw-r--r-- | vendor/google.golang.org/grpc/clientconn.go | 573 |
1 files changed, 113 insertions, 460 deletions
diff --git a/vendor/google.golang.org/grpc/clientconn.go b/vendor/google.golang.org/grpc/clientconn.go index 84ba9e5..d74b8bf 100644 --- a/vendor/google.golang.org/grpc/clientconn.go +++ b/vendor/google.golang.org/grpc/clientconn.go @@ -26,6 +26,7 @@ import ( "reflect" "strings" "sync" + "sync/atomic" "time" "golang.org/x/net/context" @@ -36,16 +37,14 @@ import ( "google.golang.org/grpc/connectivity" "google.golang.org/grpc/credentials" "google.golang.org/grpc/grpclog" - "google.golang.org/grpc/internal" "google.golang.org/grpc/internal/backoff" "google.golang.org/grpc/internal/channelz" + "google.golang.org/grpc/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/stats" "google.golang.org/grpc/status" - "google.golang.org/grpc/transport" ) const ( @@ -94,33 +93,12 @@ var ( errNetworkIO = errors.New("grpc: failed with network I/O error") ) -// dialOptions configure a Dial call. dialOptions are set by the DialOption -// values passed to Dial. -type dialOptions struct { - unaryInt UnaryClientInterceptor - streamInt StreamClientInterceptor - cp Compressor - dc Decompressor - bs backoff.Strategy - block bool - insecure bool - timeout time.Duration - scChan <-chan ServiceConfig - copts transport.ConnectOptions - callOptions []CallOption - // This is used by v1 balancer dial option WithBalancer to support v1 - // balancer, and also by WithBalancerName dial option. - balancerBuilder balancer.Builder - // This is to support grpclb. - resolverBuilder resolver.Builder - waitForHandshake bool - channelzParentID int64 - disableServiceConfig bool -} - const ( defaultClientMaxReceiveMessageSize = 1024 * 1024 * 4 defaultClientMaxSendMessageSize = math.MaxInt32 + // http2IOBufSize specifies the buffer size for sending frames. + defaultWriteBufSize = 32 * 1024 + defaultReadBufSize = 32 * 1024 ) // RegisterChannelz turns on channelz service. @@ -129,312 +107,6 @@ func RegisterChannelz() { channelz.TurnOn() } -// DialOption configures how we set up the connection. -type DialOption func(*dialOptions) - -// WithWaitForHandshake blocks until the initial settings frame is received from the -// server before assigning RPCs to the connection. -// Experimental API. -func WithWaitForHandshake() DialOption { - return func(o *dialOptions) { - o.waitForHandshake = true - } -} - -// WithWriteBufferSize lets you set the size of write buffer, this determines how much data can be batched -// before doing a write on the wire. -func WithWriteBufferSize(s int) DialOption { - return func(o *dialOptions) { - o.copts.WriteBufferSize = s - } -} - -// WithReadBufferSize lets you set the size of read buffer, this determines how much data can be read at most -// for each read syscall. -func WithReadBufferSize(s int) DialOption { - return func(o *dialOptions) { - o.copts.ReadBufferSize = s - } -} - -// WithInitialWindowSize returns a DialOption which sets the value for initial window size on a stream. -// The lower bound for window size is 64K and any value smaller than that will be ignored. -func WithInitialWindowSize(s int32) DialOption { - return func(o *dialOptions) { - o.copts.InitialWindowSize = s - } -} - -// WithInitialConnWindowSize returns a DialOption which sets the value for initial window size on a connection. -// The lower bound for window size is 64K and any value smaller than that will be ignored. -func WithInitialConnWindowSize(s int32) DialOption { - return func(o *dialOptions) { - o.copts.InitialConnWindowSize = s - } -} - -// WithMaxMsgSize returns a DialOption which sets the maximum message size the client can receive. -// -// Deprecated: use WithDefaultCallOptions(MaxCallRecvMsgSize(s)) instead. -func WithMaxMsgSize(s int) DialOption { - return WithDefaultCallOptions(MaxCallRecvMsgSize(s)) -} - -// WithDefaultCallOptions returns a DialOption which sets the default CallOptions for calls over the connection. -func WithDefaultCallOptions(cos ...CallOption) DialOption { - return func(o *dialOptions) { - o.callOptions = append(o.callOptions, cos...) - } -} - -// WithCodec returns a DialOption which sets a codec for message marshaling and unmarshaling. -// -// Deprecated: use WithDefaultCallOptions(CallCustomCodec(c)) instead. -func WithCodec(c Codec) DialOption { - return WithDefaultCallOptions(CallCustomCodec(c)) -} - -// WithCompressor returns a DialOption which sets a Compressor to use for -// message compression. It has lower priority than the compressor set by -// the UseCompressor CallOption. -// -// Deprecated: use UseCompressor instead. -func WithCompressor(cp Compressor) DialOption { - return func(o *dialOptions) { - o.cp = cp - } -} - -// WithDecompressor returns a DialOption which sets a Decompressor to use for -// incoming message decompression. If incoming response messages are encoded -// using the decompressor's Type(), it will be used. Otherwise, the message -// encoding will be used to look up the compressor registered via -// encoding.RegisterCompressor, which will then be used to decompress the -// message. If no compressor is registered for the encoding, an Unimplemented -// status error will be returned. -// -// Deprecated: use encoding.RegisterCompressor instead. -func WithDecompressor(dc Decompressor) DialOption { - return func(o *dialOptions) { - o.dc = dc - } -} - -// WithBalancer returns a DialOption which sets a load balancer with the v1 API. -// Name resolver will be ignored if this DialOption is specified. -// -// Deprecated: use the new balancer APIs in balancer package and WithBalancerName. -func WithBalancer(b Balancer) DialOption { - return func(o *dialOptions) { - o.balancerBuilder = &balancerWrapperBuilder{ - b: b, - } - } -} - -// WithBalancerName sets the balancer that the ClientConn will be initialized -// with. Balancer registered with balancerName will be used. This function -// panics if no balancer was registered by balancerName. -// -// The balancer cannot be overridden by balancer option specified by service -// config. -// -// This is an EXPERIMENTAL API. -func WithBalancerName(balancerName string) DialOption { - builder := balancer.Get(balancerName) - if builder == nil { - panic(fmt.Sprintf("grpc.WithBalancerName: no balancer is registered for name %v", balancerName)) - } - return func(o *dialOptions) { - o.balancerBuilder = builder - } -} - -// withResolverBuilder is only for grpclb. -func withResolverBuilder(b resolver.Builder) DialOption { - return func(o *dialOptions) { - o.resolverBuilder = b - } -} - -// WithServiceConfig returns a DialOption which has a channel to read the service configuration. -// -// Deprecated: service config should be received through name resolver, as specified here. -// https://github.com/grpc/grpc/blob/master/doc/service_config.md -func WithServiceConfig(c <-chan ServiceConfig) DialOption { - return func(o *dialOptions) { - o.scChan = c - } -} - -// WithBackoffMaxDelay configures the dialer to use the provided maximum delay -// when backing off after failed connection attempts. -func WithBackoffMaxDelay(md time.Duration) DialOption { - return WithBackoffConfig(BackoffConfig{MaxDelay: md}) -} - -// WithBackoffConfig configures the dialer to use the provided backoff -// parameters after connection failures. -// -// Use WithBackoffMaxDelay until more parameters on BackoffConfig are opened up -// for use. -func WithBackoffConfig(b BackoffConfig) DialOption { - - return withBackoff(backoff.Exponential{ - MaxDelay: b.MaxDelay, - }) -} - -// withBackoff sets the backoff strategy used for connectRetryNum after a -// failed connection attempt. -// -// This can be exported if arbitrary backoff strategies are allowed by gRPC. -func withBackoff(bs backoff.Strategy) DialOption { - return func(o *dialOptions) { - o.bs = bs - } -} - -// WithBlock returns a DialOption which makes caller of Dial blocks until the underlying -// connection is up. Without this, Dial returns immediately and connecting the server -// happens in background. -func WithBlock() DialOption { - return func(o *dialOptions) { - o.block = true - } -} - -// WithInsecure returns a DialOption which disables transport security for this ClientConn. -// Note that transport security is required unless WithInsecure is set. -func WithInsecure() DialOption { - return func(o *dialOptions) { - o.insecure = true - } -} - -// WithTransportCredentials returns a DialOption which configures a -// connection level security credentials (e.g., TLS/SSL). -func WithTransportCredentials(creds credentials.TransportCredentials) DialOption { - return func(o *dialOptions) { - o.copts.TransportCredentials = creds - } -} - -// WithPerRPCCredentials returns a DialOption which sets -// credentials and places auth state on each outbound RPC. -func WithPerRPCCredentials(creds credentials.PerRPCCredentials) DialOption { - return func(o *dialOptions) { - o.copts.PerRPCCredentials = append(o.copts.PerRPCCredentials, creds) - } -} - -// WithTimeout returns a DialOption that configures a timeout for dialing a ClientConn -// initially. This is valid if and only if WithBlock() is present. -// -// Deprecated: use DialContext and context.WithTimeout instead. -func WithTimeout(d time.Duration) DialOption { - return func(o *dialOptions) { - o.timeout = d - } -} - -func withContextDialer(f func(context.Context, string) (net.Conn, error)) DialOption { - return func(o *dialOptions) { - o.copts.Dialer = f - } -} - -func init() { - internal.WithContextDialer = withContextDialer - internal.WithResolverBuilder = withResolverBuilder -} - -// WithDialer returns a DialOption that specifies a function to use for dialing network addresses. -// If FailOnNonTempDialError() is set to true, and an error is returned by f, gRPC checks the error's -// Temporary() method to decide if it should try to reconnect to the network address. -func WithDialer(f func(string, time.Duration) (net.Conn, error)) DialOption { - return withContextDialer( - func(ctx context.Context, addr string) (net.Conn, error) { - if deadline, ok := ctx.Deadline(); ok { - return f(addr, deadline.Sub(time.Now())) - } - return f(addr, 0) - }) -} - -// WithStatsHandler returns a DialOption that specifies the stats handler -// for all the RPCs and underlying network connections in this ClientConn. -func WithStatsHandler(h stats.Handler) DialOption { - return func(o *dialOptions) { - o.copts.StatsHandler = h - } -} - -// FailOnNonTempDialError returns a DialOption that specifies if gRPC fails on non-temporary dial errors. -// If f is true, and dialer returns a non-temporary error, gRPC will fail the connection to the network -// address and won't try to reconnect. -// The default value of FailOnNonTempDialError is false. -// This is an EXPERIMENTAL API. -func FailOnNonTempDialError(f bool) DialOption { - return func(o *dialOptions) { - o.copts.FailOnNonTempDialError = f - } -} - -// WithUserAgent returns a DialOption that specifies a user agent string for all the RPCs. -func WithUserAgent(s string) DialOption { - return func(o *dialOptions) { - o.copts.UserAgent = s - } -} - -// WithKeepaliveParams returns a DialOption that specifies keepalive parameters for the client transport. -func WithKeepaliveParams(kp keepalive.ClientParameters) DialOption { - return func(o *dialOptions) { - o.copts.KeepaliveParams = kp - } -} - -// WithUnaryInterceptor returns a DialOption that specifies the interceptor for unary RPCs. -func WithUnaryInterceptor(f UnaryClientInterceptor) DialOption { - return func(o *dialOptions) { - o.unaryInt = f - } -} - -// WithStreamInterceptor returns a DialOption that specifies the interceptor for streaming RPCs. -func WithStreamInterceptor(f StreamClientInterceptor) DialOption { - return func(o *dialOptions) { - o.streamInt = f - } -} - -// WithAuthority returns a DialOption that specifies the value to be used as -// the :authority pseudo-header. This value only works with WithInsecure and -// has no effect if TransportCredentials are present. -func WithAuthority(a string) DialOption { - return func(o *dialOptions) { - o.copts.Authority = a - } -} - -// WithChannelzParentID returns a DialOption that specifies the channelz ID of current ClientConn's -// parent. This function is used in nested channel creation (e.g. grpclb dial). -func WithChannelzParentID(id int64) DialOption { - return func(o *dialOptions) { - o.channelzParentID = id - } -} - -// WithDisableServiceConfig returns a DialOption that causes grpc to ignore any -// service config provided by the resolver and provides a hint to the resolver -// to not fetch service configs. -func WithDisableServiceConfig() DialOption { - return func(o *dialOptions) { - o.disableServiceConfig = true - } -} - // Dial creates a client connection to the given target. func Dial(target string, opts ...DialOption) (*ClientConn, error) { return DialContext(context.Background(), target, opts...) @@ -458,23 +130,25 @@ func Dial(target string, opts ...DialOption) (*ClientConn, error) { // 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{}), - + 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(&cc.dopts) + opt.apply(&cc.dopts) } if channelz.IsOn() { if cc.dopts.channelzParentID != 0 { - cc.channelzID = channelz.RegisterChannel(cc, cc.dopts.channelzParentID, target) + cc.channelzID = channelz.RegisterChannel(&channelzChannel{cc}, cc.dopts.channelzParentID, target) } else { - cc.channelzID = channelz.RegisterChannel(cc, 0, target) + cc.channelzID = channelz.RegisterChannel(&channelzChannel{cc}, 0, target) } } @@ -567,8 +241,8 @@ func DialContext(ctx context.Context, target string, opts ...DialOption) (conn * 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 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. @@ -699,13 +373,10 @@ type ClientConn struct { preBalancerName string // previous balancer name. curAddresses []resolver.Address balancerWrapper *ccBalancerWrapper + retryThrottler atomic.Value - channelzID int64 // channelz unique identification number - czmu sync.RWMutex - callsStarted int64 - callsSucceeded int64 - callsFailed int64 - lastCallStartedTime time.Time + channelzID int64 // channelz unique identification number + czData *channelzData } // WaitForStateChange waits until the connectivity.State of ClientConn changes from sourceState or @@ -830,8 +501,6 @@ func (cc *ClientConn) switchBalancer(name string) { if cc.balancerWrapper != nil { cc.balancerWrapper.close() } - // Clear all stickiness state. - cc.blockingpicker.clearStickinessState() builder := balancer.Get(name) if builder == nil { @@ -860,9 +529,10 @@ func (cc *ClientConn) handleSubConnStateChange(sc balancer.SubConn, s connectivi // 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, + 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. @@ -892,40 +562,34 @@ func (cc *ClientConn) removeAddrConn(ac *addrConn, err error) { ac.tearDown(err) } -// ChannelzMetric returns ChannelInternalMetric of current ClientConn. -// This is an EXPERIMENTAL API. -func (cc *ClientConn) ChannelzMetric() *channelz.ChannelInternalMetric { - state := cc.GetState() - cc.czmu.RLock() - defer cc.czmu.RUnlock() +func (cc *ClientConn) channelzMetric() *channelz.ChannelInternalMetric { return &channelz.ChannelInternalMetric{ - State: state, + State: cc.GetState(), Target: cc.target, - CallsStarted: cc.callsStarted, - CallsSucceeded: cc.callsSucceeded, - CallsFailed: cc.callsFailed, - LastCallStartedTimestamp: cc.lastCallStartedTime, + 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() { - cc.czmu.Lock() - cc.callsStarted++ - // TODO(yuxuanli): will make this a time.Time pointer improve performance? - cc.lastCallStartedTime = time.Now() - cc.czmu.Unlock() + atomic.AddInt64(&cc.czData.callsStarted, 1) + atomic.StoreInt64(&cc.czData.lastCallStartedTime, time.Now().UnixNano()) } func (cc *ClientConn) incrCallsSucceeded() { - cc.czmu.Lock() - cc.callsSucceeded++ - cc.czmu.Unlock() + atomic.AddInt64(&cc.czData.callsSucceeded, 1) } func (cc *ClientConn) incrCallsFailed() { - cc.czmu.Lock() - cc.callsFailed++ - cc.czmu.Unlock() + atomic.AddInt64(&cc.czData.callsFailed, 1) } // connect starts to creating transport and also starts the transport monitor @@ -1012,8 +676,10 @@ func (cc *ClientConn) GetMethodConfig(method string) MethodConfig { 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{}) +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) } @@ -1033,6 +699,19 @@ func (cc *ClientConn) handleServiceConfig(js string) error { 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 @@ -1047,17 +726,6 @@ func (cc *ClientConn) handleServiceConfig(js string) error { } } - if envConfigStickinessOn { - var newStickinessMDKey string - if sc.stickinessMetadataKey != nil && *sc.stickinessMetadataKey != "" { - newStickinessMDKey = *sc.stickinessMetadataKey - } - // newStickinessMDKey is "" if one of the following happens: - // - stickinessMetadataKey is set to "" - // - stickinessMetadataKey field doesn't exist in service config - cc.blockingpicker.updateStickinessMDKey(strings.ToLower(newStickinessMDKey)) - } - cc.mu.Unlock() return nil } @@ -1140,12 +808,8 @@ type addrConn struct { // negotiations must complete. connectDeadline time.Time - channelzID int64 // channelz unique identification number - czmu sync.RWMutex - callsStarted int64 - callsSucceeded int64 - callsFailed int64 - lastCallStartedTime time.Time + channelzID int64 // channelz unique identification number + czData *channelzData } // adjustParams updates parameters used to create transports upon @@ -1311,7 +975,7 @@ func (ac *addrConn) createTransport(connectRetryNum, ridx int, backoffDeadline, // 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 + continue case <-ac.ctx.Done(): } } @@ -1447,46 +1111,6 @@ func (ac *addrConn) transportMonitor() { } } -// wait blocks until i) the new transport is up or ii) ctx is done or iii) ac is closed or -// iv) transport is in connectivity.TransientFailure and there is a balancer/failfast is true. -func (ac *addrConn) wait(ctx context.Context, hasBalancer, failfast bool) (transport.ClientTransport, error) { - for { - ac.mu.Lock() - switch { - case ac.state == connectivity.Shutdown: - if failfast || !hasBalancer { - // RPC is failfast or balancer is nil. This RPC should fail with ac.tearDownErr. - err := ac.tearDownErr - ac.mu.Unlock() - return nil, err - } - ac.mu.Unlock() - return nil, errConnClosing - case ac.state == connectivity.Ready: - ct := ac.transport - ac.mu.Unlock() - return ct, nil - case ac.state == connectivity.TransientFailure: - if failfast || hasBalancer { - ac.mu.Unlock() - return nil, errConnUnavailable - } - } - ready := ac.ready - if ready == nil { - ready = make(chan struct{}) - ac.ready = ready - } - ac.mu.Unlock() - select { - case <-ctx.Done(): - return nil, toRPCErr(ctx.Err()) - // Wait until the new transport is ready or failed. - case <-ready: - } - } -} - // getReadyTransport returns the transport if ac's state is READY. // Otherwise it returns nil, false. // If ac's state is IDLE, it will trigger ac to connect. @@ -1551,47 +1175,76 @@ func (ac *addrConn) getState() connectivity.State { return ac.state } -func (ac *addrConn) getCurAddr() (ret resolver.Address) { - ac.mu.Lock() - ret = ac.curAddr - ac.mu.Unlock() - return -} - func (ac *addrConn) ChannelzMetric() *channelz.ChannelInternalMetric { ac.mu.Lock() addr := ac.curAddr.Addr ac.mu.Unlock() - state := ac.getState() - ac.czmu.RLock() - defer ac.czmu.RUnlock() return &channelz.ChannelInternalMetric{ - State: state, + State: ac.getState(), Target: addr, - CallsStarted: ac.callsStarted, - CallsSucceeded: ac.callsSucceeded, - CallsFailed: ac.callsFailed, - LastCallStartedTimestamp: ac.lastCallStartedTime, + 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() { - ac.czmu.Lock() - ac.callsStarted++ - ac.lastCallStartedTime = time.Now() - ac.czmu.Unlock() + atomic.AddInt64(&ac.czData.callsStarted, 1) + atomic.StoreInt64(&ac.czData.lastCallStartedTime, time.Now().UnixNano()) } func (ac *addrConn) incrCallsSucceeded() { - ac.czmu.Lock() - ac.callsSucceeded++ - ac.czmu.Unlock() + atomic.AddInt64(&ac.czData.callsSucceeded, 1) } func (ac *addrConn) incrCallsFailed() { - ac.czmu.Lock() - ac.callsFailed++ - ac.czmu.Unlock() + 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 |