http: fix race in transport_test

R=rsc
CC=golang-dev
https://golang.org/cl/4414044

diff --git a/src/pkg/http/transport_test.go b/src/pkg/http/transport_test.go
index f83deedfc4adf1d0b7fe868c98c4d68926da4a48..de3a35153013f9b98dbc85480872a639eed7a35b 100644 (file)
--- a/src/pkg/http/transport_test.go
+++ b/src/pkg/http/transport_test.go
@@ -179,35 +179,47 @@ func TestTransportIdleCacheKeys(t *testing.T) {
 }
 
 func TestTransportMaxPerHostIdleConns(t *testing.T) {
-       ch := make(chan string)
+       resch := make(chan string)
+       gotReq := make(chan bool)
        ts := httptest.NewServer(HandlerFunc(func(w ResponseWriter, r *Request) {
-               w.Write([]byte(<-ch))
+               gotReq <- true
+               msg := <-resch
+               _, err := w.Write([]byte(msg))
+               if err != nil {
+                       t.Fatalf("Write: %v", err)
+               }
        }))
        defer ts.Close()
        maxIdleConns := 2
        tr := &Transport{DisableKeepAlives: false, MaxIdleConnsPerHost: maxIdleConns}
        c := &Client{Transport: tr}
 
-       // Start 3 outstanding requests (will hang until we write to
-       // ch)
+       // Start 3 outstanding requests and wait for the server to get them.
+       // Their responses will hang until we we write to resch, though.
        donech := make(chan bool)
        doReq := func() {
                resp, _, err := c.Get(ts.URL)
                if err != nil {
                        t.Error(err)
                }
-               ioutil.ReadAll(resp.Body)
+               _, err = ioutil.ReadAll(resp.Body)
+               if err != nil {
+                       t.Fatalf("ReadAll: %v", err)
+               }
                donech <- true
        }
        go doReq()
+       <-gotReq
        go doReq()
+       <-gotReq
        go doReq()
+       <-gotReq
 
        if e, g := 0, len(tr.IdleConnKeysForTesting()); e != g {
                t.Fatalf("Before writes, expected %d idle conn cache keys; got %d", e, g)
        }
 
-       ch <- "res1"
+       resch <- "res1"
        <-donech
        keys := tr.IdleConnKeysForTesting()
        if e, g := 1, len(keys); e != g {
@@ -221,13 +233,13 @@ func TestTransportMaxPerHostIdleConns(t *testing.T) {
                t.Errorf("after first response, expected %d idle conns; got %d", e, g)
        }
 
-       ch <- "res2"
+       resch <- "res2"
        <-donech
        if e, g := 2, tr.IdleConnCountForTesting(cacheKey); e != g {
                t.Errorf("after second response, expected %d idle conns; got %d", e, g)
        }
 
-       ch <- "res3"
+       resch <- "res3"
        <-donech
        if e, g := maxIdleConns, tr.IdleConnCountForTesting(cacheKey); e != g {
                t.Errorf("after third response, still expected %d idle conns; got %d", e, g)