rafthttp: always cancel in-flight request when pipeline.send

This fits the way for go1.5 to cancel request.

rafthttp/fake_roundtripper_go14_test.go

@@ -0,0 +1,35 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// 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.
+
+// +build !go1.5
+
+package rafthttp
+
+import (
+	"errors"
+	"net/http"
+)
+
+func (t *roundTripperBlocker) RoundTrip(req *http.Request) (*http.Response, error) {
+	c := make(chan struct{}, 1)
+	t.mu.Lock()
+	t.cancel[req] = c
+	t.mu.Unlock()
+	select {
+	case <-t.unblockc:
+		return &http.Response{StatusCode: http.StatusNoContent, Body: &nopReadCloser{}}, nil
+	case <-c:
+		return nil, errors.New("request canceled")
+	}
+}

rafthttp/fake_roundtripper_test.go

@@ -0,0 +1,37 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// 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.
+
+// +build go1.5
+
+package rafthttp
+
+import (
+	"errors"
+	"net/http"
+)
+
+func (t *roundTripperBlocker) RoundTrip(req *http.Request) (*http.Response, error) {
+	c := make(chan struct{}, 1)
+	t.mu.Lock()
+	t.cancel[req] = c
+	t.mu.Unlock()
+	select {
+	case <-t.unblockc:
+		return &http.Response{StatusCode: http.StatusNoContent, Body: &nopReadCloser{}}, nil
+	case <-req.Cancel:
+		return nil, errors.New("request canceled")
+	case <-c:
+		return nil, errors.New("request canceled")
+	}
+}

rafthttp/pipeline.go

@@ -25,6 +25,7 @@ import (
 	"time"
 
 	"github.com/coreos/etcd/etcdserver/stats"
+	"github.com/coreos/etcd/pkg/httputil"
 	"github.com/coreos/etcd/pkg/pbutil"
 	"github.com/coreos/etcd/pkg/types"
 	"github.com/coreos/etcd/raft"
@@ -43,10 +44,6 @@ const (
 
 var errStopped = errors.New("stopped")
 
-type canceler interface {
-	CancelRequest(*http.Request)
-}
-
 type pipeline struct {
 	from, to types.ID
 	cid      types.ID
@@ -149,15 +146,14 @@ func (p *pipeline) post(data []byte) (err error) {
 		}
 	}()
 	done := make(chan struct{}, 1)
+	cancel := httputil.RequestCanceler(p.tr, req)
 	go func() {
 		select {
 		case <-done:
 		case <-p.stopc:
 			waitSchedule()
 			stopped = true
-			if cancel, ok := p.tr.(canceler); ok {
-				cancel.CancelRequest(req)
-			}
+			cancel()
 		}
 	}()
 

rafthttp/pipeline_test.go

@@ -223,18 +223,6 @@ func newRoundTripperBlocker() *roundTripperBlocker {
 		cancel:   make(map[*http.Request]chan struct{}),
 	}
 }
-func (t *roundTripperBlocker) RoundTrip(req *http.Request) (*http.Response, error) {
-	c := make(chan struct{}, 1)
-	t.mu.Lock()
-	t.cancel[req] = c
-	t.mu.Unlock()
-	select {
-	case <-t.unblockc:
-		return &http.Response{StatusCode: http.StatusNoContent, Body: &nopReadCloser{}}, nil
-	case <-c:
-		return nil, errors.New("request canceled")
-	}
-}
 func (t *roundTripperBlocker) unblock() {
 	close(t.unblockc)
 }