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mirror of https://github.com/golang/go synced 2024-11-26 23:21:22 -07:00

net/http: fix Server blocking after a Handler's Write fails

If a Handle's Write to a ResponseWriter fails (e.g. via a
net.Conn WriteDeadline via WriteTimeout on the Server), the
Server was blocking forever waiting for reads on that
net.Conn, even after a Write failed.

Instead, once we see a Write fail, close the connection,
since it's then dead to us anyway.

Fixes #4741

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/7301043
This commit is contained in:
Brad Fitzpatrick 2013-02-04 20:26:25 -08:00
parent a60ffed9e7
commit d1e16d06b4
2 changed files with 64 additions and 0 deletions

View File

@ -326,6 +326,66 @@ func TestServerTimeouts(t *testing.T) {
}
}
// golang.org/issue/4741 -- setting only a write timeout that triggers
// shouldn't cause a handler to block forever on reads (next HTTP
// request) that will never happen.
func TestOnlyWriteTimeout(t *testing.T) {
var conn net.Conn
var afterTimeoutErrc = make(chan error, 1)
ts := httptest.NewUnstartedServer(HandlerFunc(func(w ResponseWriter, req *Request) {
buf := make([]byte, 512<<10)
_, err := w.Write(buf)
if err != nil {
t.Errorf("handler Write error: %v", err)
return
}
conn.SetWriteDeadline(time.Now().Add(-30 * time.Second))
_, err = w.Write(buf)
afterTimeoutErrc <- err
}))
ts.Listener = trackLastConnListener{ts.Listener, &conn}
ts.Start()
defer ts.Close()
tr := &Transport{DisableKeepAlives: false}
defer tr.CloseIdleConnections()
c := &Client{Transport: tr}
errc := make(chan error)
go func() {
res, err := c.Get(ts.URL)
if err != nil {
errc <- err
return
}
_, err = io.Copy(ioutil.Discard, res.Body)
errc <- err
}()
select {
case err := <-errc:
if err == nil {
t.Errorf("expected an error from Get request")
}
case <-time.After(5 * time.Second):
t.Fatal("timeout waiting for Get error")
}
if err := <-afterTimeoutErrc; err == nil {
t.Error("expected write error after timeout")
}
}
// trackLastConnListener tracks the last net.Conn that was accepted.
type trackLastConnListener struct {
net.Listener
last *net.Conn // destination
}
func (l trackLastConnListener) Accept() (c net.Conn, err error) {
c, err = l.Listener.Accept()
*l.last = c
return
}
// TestIdentityResponse verifies that a handler can unset
func TestIdentityResponse(t *testing.T) {
handler := HandlerFunc(func(rw ResponseWriter, req *Request) {

View File

@ -223,6 +223,7 @@ func (cw *chunkWriter) Write(p []byte) (n int, err error) {
if cw.chunking {
_, err = fmt.Fprintf(cw.res.conn.buf, "%x\r\n", len(p))
if err != nil {
cw.res.conn.rwc.Close()
return
}
}
@ -230,6 +231,9 @@ func (cw *chunkWriter) Write(p []byte) (n int, err error) {
if cw.chunking && err == nil {
_, err = cw.res.conn.buf.Write(crlf)
}
if err != nil {
cw.res.conn.rwc.Close()
}
return
}