Merge pull request #627 from yaoshengzhe/fix_querylogz_race_condition

fix querylogz test race conditions

go/vt/tabletserver/querylogz.go

@@ -14,7 +14,6 @@ import (
 
 	log "github.com/golang/glog"
 	"github.com/youtube/vitess/go/acl"
-	"github.com/youtube/vitess/go/streamlog"
 )
 
 var (
@@ -73,20 +72,20 @@ var (
 
 func init() {
 	http.HandleFunc("/querylogz", func(w http.ResponseWriter, r *http.Request) {
-		querylogzHandler(SqlQueryLogger, w, r)
+		ch := SqlQueryLogger.Subscribe("querylogz")
+		defer SqlQueryLogger.Unsubscribe(ch)
+		querylogzHandler(ch, w, r)
 	})
 }
 
 // querylogzHandler serves a human readable snapshot of the
 // current query log.
-func querylogzHandler(streamLogger *streamlog.StreamLogger, w http.ResponseWriter, r *http.Request) {
+func querylogzHandler(ch chan interface{}, w http.ResponseWriter, r *http.Request) {
 	if err := acl.CheckAccessHTTP(r, acl.DEBUGGING); err != nil {
 		acl.SendError(w, err)
 		return
 	}
 	timeout, limit := parseTimeoutLimitParams(r)
-	ch := streamLogger.Subscribe("querylogz")
-	defer streamLogger.Unsubscribe(ch)
 	startHTMLTable(w)
 	defer endHTMLTable(w)
 	w.Write(querylogzHeader)

go/vt/tabletserver/querylogz_test.go

@@ -13,7 +13,6 @@ import (
 	"testing"
 	"time"
 
-	"github.com/youtube/vitess/go/streamlog"
 	"github.com/youtube/vitess/go/vt/tabletserver/planbuilder"
 	"golang.org/x/net/context"
 )
@@ -21,9 +20,10 @@ import (
 func TestQuerylogzHandlerInvalidSqlQueryStats(t *testing.T) {
 	req, _ := http.NewRequest("GET", "/querylogz?timeout=0&limit=10", nil)
 	response := httptest.NewRecorder()
-	testLogger := streamlog.New("TestLogger", 100)
-	testLogger.Send("test msg")
-	querylogzHandler(testLogger, response, req)
+	ch := make(chan interface{}, 1)
+	ch <- "test msg"
+	querylogzHandler(ch, response, req)
+	close(ch)
 	if !strings.Contains(response.Body.String(), "error") {
 		t.Fatalf("should show an error page for an non SqlQueryStats")
 	}
@@ -45,8 +45,6 @@ func TestQuerylogzHandler(t *testing.T) {
 	logStats.CacheInvalidations = 3
 	logStats.TransactionID = 131
 
-	testLogger := streamlog.New("TestLogger", 100)
-
 	// fast query
 	fastQueryPattern := []string{
 		`<td>Execute</td>`,
@@ -70,9 +68,11 @@ func TestQuerylogzHandler(t *testing.T) {
 		`<td></td>`,
 	}
 	logStats.EndTime = logStats.StartTime.Add(1 * time.Millisecond)
-	testLogger.Send(logStats)
 	response := httptest.NewRecorder()
-	querylogzHandler(testLogger, response, req)
+	ch := make(chan interface{}, 1)
+	ch <- logStats
+	querylogzHandler(ch, response, req)
+	close(ch)
 	body, _ := ioutil.ReadAll(response.Body)
 	checkQuerylogzHasStats(t, fastQueryPattern, logStats, body)
 
@@ -99,9 +99,11 @@ func TestQuerylogzHandler(t *testing.T) {
 		`<td></td>`,
 	}
 	logStats.EndTime = logStats.StartTime.Add(20 * time.Millisecond)
-	testLogger.Send(logStats)
 	response = httptest.NewRecorder()
-	querylogzHandler(testLogger, response, req)
+	ch = make(chan interface{}, 1)
+	ch <- logStats
+	querylogzHandler(ch, response, req)
+	close(ch)
 	body, _ = ioutil.ReadAll(response.Body)
 	checkQuerylogzHasStats(t, mediumQueryPattern, logStats, body)
 
@@ -128,8 +130,10 @@ func TestQuerylogzHandler(t *testing.T) {
 		`<td></td>`,
 	}
 	logStats.EndTime = logStats.StartTime.Add(500 * time.Millisecond)
-	testLogger.Send(logStats)
-	querylogzHandler(testLogger, response, req)
+	ch = make(chan interface{}, 1)
+	ch <- logStats
+	querylogzHandler(ch, response, req)
+	close(ch)
 	body, _ = ioutil.ReadAll(response.Body)
 	checkQuerylogzHasStats(t, slowQueryPattern, logStats, body)
 }