mirror of
https://github.com/etcd-io/etcd.git
synced 2024-09-27 06:25:44 +00:00
29a6fd65ad
Since select{} won't prioritize, ctx.Done() can sometimes override
a pending message on recvc. Loop if recvc has messages instead.
Fixes #7340
139 lines
2.9 KiB
Go
139 lines
2.9 KiB
Go
// Copyright 2017 The etcd Authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package grpcproxy
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import (
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"golang.org/x/net/context"
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"google.golang.org/grpc"
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"google.golang.org/grpc/metadata"
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)
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// chanServerStream implements grpc.ServerStream with a chanStream
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type chanServerStream struct {
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headerc chan<- metadata.MD
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trailerc chan<- metadata.MD
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grpc.Stream
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headers []metadata.MD
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}
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func (ss *chanServerStream) SendHeader(md metadata.MD) error {
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if ss.headerc == nil {
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return errAlreadySentHeader
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}
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outmd := make(map[string][]string)
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for _, h := range append(ss.headers, md) {
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for k, v := range h {
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outmd[k] = v
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}
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}
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select {
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case ss.headerc <- outmd:
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ss.headerc = nil
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ss.headers = nil
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return nil
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case <-ss.Context().Done():
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}
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return ss.Context().Err()
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}
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func (ss *chanServerStream) SetHeader(md metadata.MD) error {
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if ss.headerc == nil {
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return errAlreadySentHeader
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}
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ss.headers = append(ss.headers, md)
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return nil
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}
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func (ss *chanServerStream) SetTrailer(md metadata.MD) {
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ss.trailerc <- md
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}
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// chanClientStream implements grpc.ClientStream with a chanStream
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type chanClientStream struct {
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headerc <-chan metadata.MD
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trailerc <-chan metadata.MD
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*chanStream
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}
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func (cs *chanClientStream) Header() (metadata.MD, error) {
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select {
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case md := <-cs.headerc:
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return md, nil
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case <-cs.Context().Done():
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}
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return nil, cs.Context().Err()
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}
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func (cs *chanClientStream) Trailer() metadata.MD {
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select {
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case md := <-cs.trailerc:
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return md
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case <-cs.Context().Done():
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return nil
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}
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}
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func (cs *chanClientStream) CloseSend() error {
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close(cs.chanStream.sendc)
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return nil
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}
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// chanStream implements grpc.Stream using channels
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type chanStream struct {
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recvc <-chan interface{}
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sendc chan<- interface{}
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ctx context.Context
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cancel context.CancelFunc
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}
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func (s *chanStream) Context() context.Context { return s.ctx }
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func (s *chanStream) SendMsg(m interface{}) error {
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select {
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case s.sendc <- m:
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if err, ok := m.(error); ok {
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return err
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}
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return nil
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case <-s.ctx.Done():
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}
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return s.ctx.Err()
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}
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func (s *chanStream) RecvMsg(m interface{}) error {
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v := m.(*interface{})
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for {
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select {
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case msg, ok := <-s.recvc:
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if !ok {
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return grpc.ErrClientConnClosing
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}
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if err, ok := msg.(error); ok {
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return err
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}
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*v = msg
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return nil
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case <-s.ctx.Done():
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}
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if len(s.recvc) == 0 {
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// prioritize any pending recv messages over canceled context
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break
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}
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}
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return s.ctx.Err()
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}
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