diff options
Diffstat (limited to 'vendor/google.golang.org/grpc/clientconn.go')
-rw-r--r-- | vendor/google.golang.org/grpc/clientconn.go | 888 |
1 files changed, 0 insertions, 888 deletions
diff --git a/vendor/google.golang.org/grpc/clientconn.go b/vendor/google.golang.org/grpc/clientconn.go deleted file mode 100644 index 61674729a..000000000 --- a/vendor/google.golang.org/grpc/clientconn.go +++ /dev/null @@ -1,888 +0,0 @@ -/* - * - * Copyright 2014, Google Inc. - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions are - * met: - * - * * 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. - * - * 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. - * - */ - -package grpc - -import ( - "errors" - "fmt" - "net" - "strings" - "sync" - "time" - - "golang.org/x/net/context" - "golang.org/x/net/trace" - "google.golang.org/grpc/credentials" - "google.golang.org/grpc/grpclog" - "google.golang.org/grpc/transport" -) - -var ( - // ErrClientConnClosing indicates that the operation is illegal because - // the ClientConn is closing. - ErrClientConnClosing = errors.New("grpc: the client connection is closing") - // ErrClientConnTimeout indicates that the ClientConn cannot establish the - // underlying connections within the specified timeout. - ErrClientConnTimeout = errors.New("grpc: timed out when dialing") - - // 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") - // 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 - copts transport.ConnectOptions -} - -// DialOption configures how we set up the connection. -type DialOption func(*dialOptions) - -// WithCodec returns a DialOption which sets a codec for message marshaling and unmarshaling. -func WithCodec(c Codec) DialOption { - return func(o *dialOptions) { - o.codec = c - } -} - -// WithCompressor returns a DialOption which sets a CompressorGenerator for generating message -// compressor. -func WithCompressor(cp Compressor) DialOption { - return func(o *dialOptions) { - o.cp = cp - } -} - -// WithDecompressor returns a DialOption which sets a DecompressorGenerator for generating -// message decompressor. -func WithDecompressor(dc Decompressor) DialOption { - return func(o *dialOptions) { - o.dc = dc - } -} - -// WithBalancer returns a DialOption which sets a load balancer. -func WithBalancer(b Balancer) DialOption { - return func(o *dialOptions) { - o.balancer = b - } -} - -// 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 { - // Set defaults to ensure that provided BackoffConfig is valid and - // unexported fields get default values. - setDefaults(&b) - return withBackoff(b) -} - -// withBackoff sets the backoff strategy used for retries after a -// failed connection attempt. -// -// This can be exported if arbitrary backoff strategies are allowed by gRPC. -func withBackoff(bs backoffStrategy) 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 which will place 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. -func WithTimeout(d time.Duration) DialOption { - return func(o *dialOptions) { - o.timeout = d - } -} - -// WithDialer returns a DialOption that specifies a function to use for dialing network addresses. -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) { - if deadline, ok := ctx.Deadline(); ok { - return f(addr, deadline.Sub(time.Now())) - } - return f(addr, 0) - } - } -} - -// 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 - } -} - -// 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 - } -} - -// 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 -// 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), - } - cc.ctx, cc.cancel = context.WithCancel(context.Background()) - defer func() { - select { - case <-ctx.Done(): - conn, err = nil, ctx.Err() - default: - } - - if err != nil { - cc.Close() - } - }() - - for _, opt := range opts { - opt(&cc.dopts) - } - - // Set defaults. - if cc.dopts.codec == nil { - cc.dopts.codec = protoCodec{} - } - if cc.dopts.bs == nil { - cc.dopts.bs = DefaultBackoffConfig - } - creds := cc.dopts.copts.TransportCredentials - if creds != nil && creds.Info().ServerName != "" { - cc.authority = creds.Info().ServerName - } else { - colonPos := strings.LastIndex(target, ":") - if colonPos == -1 { - colonPos = len(target) - } - cc.authority = target[:colonPos] - } - var ok bool - waitC := make(chan error, 1) - go func() { - var addrs []Address - 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 - } - } - close(waitC) - }() - var timeoutCh <-chan time.Time - if cc.dopts.timeout > 0 { - timeoutCh = time.After(cc.dopts.timeout) - } - select { - case <-ctx.Done(): - return nil, ctx.Err() - case err := <-waitC: - if err != nil { - return nil, err - } - case <-timeoutCh: - return nil, ErrClientConnTimeout - } - // 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() - } - return cc, nil -} - -// ConnectivityState indicates the state of a client connection. -type ConnectivityState int - -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 -) - -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)) - } -} - -// ClientConn represents a client connection to an RPC server. -type ClientConn struct { - ctx context.Context - cancel context.CancelFunc - - target string - authority string - dopts dialOptions - - mu sync.RWMutex - conns map[Address]*addrConn -} - -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) - } - } -} - -// 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, - } - 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 !ac.dopts.insecure { - if ac.dopts.copts.TransportCredentials == nil { - return errNoTransportSecurity - } - } else { - if ac.dopts.copts.TransportCredentials != nil { - return errCredentialsConflict - } - for _, cd := range ac.dopts.copts.PerRPCCredentials { - if cd.RequireTransportSecurity() { - return errTransportCredentialsMissing - } - } - } - // 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 - } - stale := cc.conns[ac.addr] - cc.conns[ac.addr] = ac - 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) - } - } - // skipWait may overwrite the decision in ac.dopts.block. - if ac.dopts.block && !skipWait { - if err := ac.resetTransport(false); err != nil { - if err != errConnClosing { - // Tear down ac and delete it from cc.conns. - cc.mu.Lock() - delete(cc.conns, ac.addr) - cc.mu.Unlock() - ac.tearDown(err) - } - if e, ok := err.(transport.ConnectionError); ok && !e.Temporary() { - return e.Origin() - } - return err - } - // 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() - }() - } - return nil -} - -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 - 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() - } - if !ok { - if put != nil { - put() - } - return nil, nil, errConnClosing - } - t, err := ac.wait(ctx, cc.dopts.balancer != nil, !opts.BlockingWait) - if err != nil { - if put != nil { - put() - } - return nil, nil, err - } - return t, put, nil -} - -// Close tears down the ClientConn and all underlying connections. -func (cc *ClientConn) Close() error { - cc.cancel() - - cc.mu.Lock() - if cc.conns == nil { - cc.mu.Unlock() - return ErrClientConnClosing - } - conns := cc.conns - cc.conns = nil - cc.mu.Unlock() - if cc.dopts.balancer != nil { - cc.dopts.balancer.Close() - } - for _, ac := range conns { - ac.tearDown(ErrClientConnClosing) - } - return nil -} - -// addrConn is a network connection to a given address. -type addrConn struct { - ctx context.Context - cancel context.CancelFunc - - cc *ClientConn - addr Address - dopts dialOptions - events trace.EventLog - - mu sync.Mutex - state ConnectivityState - stateCV *sync.Cond - down func(error) // the handler called when a connection is down. - // 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 -} - -// 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...) - } -} - -// 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) { - ac.mu.Lock() - defer ac.mu.Unlock() - if sourceState != ac.state { - return ac.state, nil - } - 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 - } - } - return ac.state, nil -} - -func (ac *addrConn) resetTransport(closeTransport bool) error { - for retries := 0; ; retries++ { - ac.mu.Lock() - ac.printf("connecting") - if ac.state == Shutdown { - // ac.tearDown(...) has been invoked. - ac.mu.Unlock() - return errConnClosing - } - if ac.down != nil { - ac.down(downErrorf(false, true, "%v", errNetworkIO)) - ac.down = nil - } - ac.state = Connecting - ac.stateCV.Broadcast() - t := ac.transport - ac.mu.Unlock() - if closeTransport && t != nil { - t.Close() - } - sleepTime := ac.dopts.bs.backoff(retries) - timeout := minConnectTimeout - if timeout < sleepTime { - timeout = sleepTime - } - ctx, cancel := context.WithTimeout(ac.ctx, timeout) - connectTime := time.Now() - sinfo := transport.TargetInfo{ - Addr: ac.addr.Addr, - Metadata: ac.addr.Metadata, - } - newTransport, err := transport.NewClientTransport(ctx, sinfo, ac.dopts.copts) - if err != nil { - cancel() - - if e, ok := err.(transport.ConnectionError); ok && !e.Temporary() { - return 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 { - // 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 - } - ac.mu.Unlock() - closeTransport = false - select { - case <-time.After(sleepTime - time.Since(connectTime)): - case <-ac.ctx.Done(): - return ac.ctx.Err() - } - continue - } - ac.mu.Lock() - ac.printf("ready") - if ac.state == Shutdown { - // ac.tearDown(...) has been invoked. - ac.mu.Unlock() - newTransport.Close() - return errConnClosing - } - ac.state = Ready - ac.stateCV.Broadcast() - ac.transport = newTransport - 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) - } - ac.mu.Unlock() - return 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 { - ac.mu.Lock() - t := ac.transport - ac.mu.Unlock() - 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: - } - ac.mu.Lock() - if ac.state == Shutdown { - // ac has been shutdown. - ac.mu.Unlock() - return - } - 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 - } - } - } -} - -// 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. -func (ac *addrConn) wait(ctx context.Context, hasBalancer, failfast bool) (transport.ClientTransport, error) { - for { - ac.mu.Lock() - switch { - case ac.state == 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 == Ready: - ct := ac.transport - ac.mu.Unlock() - return ct, nil - case ac.state == 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: - } - } -} - -// 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.down != nil { - ac.down(downErrorf(false, false, "%v", err)) - ac.down = nil - } - 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() - } - if ac.state == Shutdown { - return - } - ac.state = Shutdown - ac.tearDownErr = err - ac.stateCV.Broadcast() - if ac.events != nil { - ac.events.Finish() - ac.events = nil - } - if ac.ready != nil { - close(ac.ready) - ac.ready = nil - } - if ac.transport != nil && err != errConnDrain { - ac.transport.Close() - } - return -} |