net/http: add onClose hook to fake net listener

Avoids a race condition: If we set an onClose hook on a conn
created by a listener, then setting the hook can race with
the connection closing.

Change-Id: Ibadead3abbe4335d41f1e2cf84f4696fe98166b3
Reviewed-on: https://go-review.googlesource.com/c/go/+/658655
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
Auto-Submit: Damien Neil <dneil@google.com>

diff --git a/src/net/http/netconn_test.go b/src/net/http/netconn_test.go
index ed02b98d43ee9ddfc8188eae5f2074ebc9f6f242..52b8069f8b33e175f89d7d35493d0e3ae2b77bfd 100644 (file)
--- a/src/net/http/netconn_test.go
+++ b/src/net/http/netconn_test.go
@@ -35,7 +35,8 @@ type fakeNetListener struct {
        addr         netip.AddrPort
        locPort      uint16
 
-       onDial func() // called when making a new connection
+       onDial  func()             // called when making a new connection
+       onClose func(*fakeNetConn) // called when closing a connection
 
        trackConns bool // set this to record all created conns
        conns      []*fakeNetConn
@@ -65,6 +66,8 @@ func (li *fakeNetListener) connect() *fakeNetConn {
        locAddr := netip.AddrPortFrom(netip.AddrFrom4([4]byte{127, 0, 0, 1}), li.locPort)
        li.locPort++
        c0, c1 := fakeNetPipe(li.addr, locAddr)
+       c0.onClose = li.onClose
+       c1.onClose = li.onClose
        li.queue = append(li.queue, c0)
        if li.trackConns {
                li.conns = append(li.conns, c0)
@@ -124,7 +127,7 @@ type fakeNetConn struct {
        // peer is the other endpoint.
        peer *fakeNetConn
 
-       onClose func() // called when closing
+       onClose func(*fakeNetConn) // called when closing
 }
 
 // Read reads data from the connection.
@@ -167,7 +170,7 @@ func (c *fakeNetConn) IsClosedByPeer() bool {
 // Close closes the connection.
 func (c *fakeNetConn) Close() error {
        if c.onClose != nil {
-               c.onClose()
+               c.onClose(c)
        }
        // Local half of the conn is now closed.
        c.loc.lock()

diff --git a/src/net/http/transport_test.go b/src/net/http/transport_test.go
index 7166c11279233426deb85b084c8cce741115f179..431dc4ee20ca4409af2b016f671f24b0698f4fd1 100644 (file)
--- a/src/net/http/transport_test.go
+++ b/src/net/http/transport_test.go
@@ -4250,6 +4250,10 @@ func testTransportIdleConnRacesRequest(t testing.TB, mode testMode) {
        cst.li.onDial = func() {
                <-dialc
        }
+       closec := make(chan struct{})
+       cst.li.onClose = func(*fakeNetConn) {
+               <-closec
+       }
        ctx, cancel := context.WithCancel(context.Background())
        req1c := make(chan error)
        go func() {
@@ -4279,10 +4283,6 @@ func testTransportIdleConnRacesRequest(t testing.TB, mode testMode) {
        //
        // First: Wait for IdleConnTimeout. The net.Conn.Close blocks.
        synctest.Wait()
-       closec := make(chan struct{})
-       cst.li.conns[0].peer.onClose = func() {
-               <-closec
-       }
        time.Sleep(timeout)
        synctest.Wait()
        // Make a request, which will use a new connection (since the existing one is closing).