net/http: non-keepalive connections close successfully

Connections did not close if Request.Close or Response.Close was true. This meant that if the user wanted the connection to close, or if the server requested it via "Connection: close", the connection would not be closed.

Fixes #1967.

R=golang-dev, rsc, bradfitz
CC=golang-dev
https://golang.org/cl/6201044

src/pkg/net/http/transport.go

@@ -599,6 +599,10 @@ func (pc *persistConn) readLoop() {
 		// before we race and peek on the underlying bufio reader.
 		if waitForBodyRead != nil {
 			<-waitForBodyRead
+		} else if !alive {
+			// If waitForBodyRead is nil, and we're not alive, we
+			// must close the connection before we leave the loop.
+			pc.close()
 		}
 	}
 }

src/pkg/net/http/transport_test.go

@@ -13,13 +13,15 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
+	"net"
 	. "net/http"
 	"net/http/httptest"
 	"net/url"
 	"os"
 	"runtime"
 	"strconv"
 	"strings"
+	"sync"
 	"testing"
 	"time"
 )
@@ -35,6 +37,64 @@ var hostPortHandler = HandlerFunc(func(w ResponseWriter, r *Request) {
 	w.Write([]byte(r.RemoteAddr))
 })
 
+type testCloseConn struct {
+	net.Conn
+	set *testConnSet
+}
+
+func (conn *testCloseConn) Close() error {
+	conn.set.remove(conn)
+	return conn.Conn.Close()
+}
+
+type testConnSet struct {
+	set   map[net.Conn]bool
+	mutex sync.Mutex
+}
+
+func (tcs *testConnSet) insert(c net.Conn) {
+	tcs.mutex.Lock()
+	defer tcs.mutex.Unlock()
+	tcs.set[c] = true
+}
+
+func (tcs *testConnSet) remove(c net.Conn) {
+	tcs.mutex.Lock()
+	defer tcs.mutex.Unlock()
+	// just change to false, so we have a full set of opened connections
+	tcs.set[c] = false
+}
+
+// some tests use this to manage raw tcp connections for later inspection
+func makeTestDial() (*testConnSet, func(n, addr string) (net.Conn, error)) {
+	connSet := &testConnSet{
+		set: make(map[net.Conn]bool),
+	}
+	dial := func(n, addr string) (net.Conn, error) {
+		c, err := net.Dial(n, addr)
+		if err != nil {
+			return nil, err
+		}
+		tc := &testCloseConn{c, connSet}
+		connSet.insert(tc)
+		return tc, nil
+	}
+	return connSet, dial
+}
+
+func (tcs *testConnSet) countClosed() (closed, total int) {
+	tcs.mutex.Lock()
+	defer tcs.mutex.Unlock()
+
+	total = len(tcs.set)
+	for _, open := range tcs.set {
+		if !open {
+			closed += 1
+		}
+	}
+	return
+}
+
 // Two subsequent requests and verify their response is the same.
 // The response from the server is our own IP:port
 func TestTransportKeepAlives(t *testing.T) {
@@ -72,8 +132,12 @@ func TestTransportConnectionCloseOnResponse(t *testing.T) {
 	ts := httptest.NewServer(hostPortHandler)
 	defer ts.Close()
 
+	connSet, testDial := makeTestDial()
+
 	for _, connectionClose := range []bool{false, true} {
-		tr := &Transport{}
+		tr := &Transport{
+			Dial: testDial,
+		}
 		c := &Client{Transport: tr}
 
 		fetch := func(n int) string {
@@ -107,15 +171,26 @@ func TestTransportConnectionCloseOnResponse(t *testing.T) {
 			t.Errorf("error in connectionClose=%v. unexpected bodiesDiffer=%v; body1=%q; body2=%q",
 				connectionClose, bodiesDiffer, body1, body2)
 		}
+
+		tr.CloseIdleConnections()
+	}
+
+	closed, total := connSet.countClosed()
+	if closed < total {
+		t.Errorf("%d out of %d tcp connections were not closed", total-closed, total)
 	}
 }
 
 func TestTransportConnectionCloseOnRequest(t *testing.T) {
 	ts := httptest.NewServer(hostPortHandler)
 	defer ts.Close()
 
+	connSet, testDial := makeTestDial()
+
 	for _, connectionClose := range []bool{false, true} {
-		tr := &Transport{}
+		tr := &Transport{
+			Dial: testDial,
+		}
 		c := &Client{Transport: tr}
 
 		fetch := func(n int) string {
@@ -149,6 +224,13 @@ func TestTransportConnectionCloseOnRequest(t *testing.T) {
 			t.Errorf("error in connectionClose=%v. unexpected bodiesDiffer=%v; body1=%q; body2=%q",
 				connectionClose, bodiesDiffer, body1, body2)
 		}
+
+		tr.CloseIdleConnections()
+	}
+
+	closed, total := connSet.countClosed()
+	if closed < total {
+		t.Errorf("%d out of %d tcp connections were not closed", total-closed, total)
 	}
 }