etcdserver, clientv3: let progressReportIntervalMilliseconds be private

progressReportIntervalMilliseconds (old
ProgressReportIntervalMilliseconds) is accessed by multiple goroutines
and it is reported as race.

For avoiding this report, this commit wraps the variable with
functions. They access the variable with atomic operations so the race
won't be reported.

clientv3/integration/watch_test.go

@@ -18,7 +18,6 @@ import (
 	"fmt"
 	"reflect"
 	"sort"
-	"sync/atomic"
 	"testing"
 	"time"
 
@@ -381,11 +380,11 @@ func testWatchWithProgressNotify(t *testing.T, watchOnPut bool) {
 	defer testutil.AfterTest(t)
 
 	// accelerate report interval so test terminates quickly
-	oldpi := v3rpc.ProgressReportIntervalMilliseconds
+	oldpi := v3rpc.GetProgressReportInterval()
 	// using atomics to avoid race warnings
-	atomic.StoreInt32(&v3rpc.ProgressReportIntervalMilliseconds, 3*1000)
+	v3rpc.SetProgressReportInterval(3 * time.Second)
 	pi := 3 * time.Second
-	defer func() { v3rpc.ProgressReportIntervalMilliseconds = oldpi }()
+	defer func() { v3rpc.SetProgressReportInterval(oldpi) }()
 
 	clus := integration.NewClusterV3(t, &integration.ClusterConfig{Size: 3})
 	defer clus.Terminate(t)

etcdserver/api/v3rpc/watch.go

@@ -42,12 +42,25 @@ func NewWatchServer(s *etcdserver.EtcdServer) pb.WatchServer {
 }
 
 var (
-	// expose for testing purpose. External test can change this to a
+	// External test can read this with GetProgressReportInterval()
-	// small value to finish fast. The type is int32 instead of time.Duration
+	// and change this to a small value to finish fast with
-	// in order to placate the race detector by setting the value with atomic stores.
+	// SetProgressReportInterval().
-	ProgressReportIntervalMilliseconds = int32(10 * 60 * 1000) // 10 minutes
+	progressReportInterval   = 10 * time.Minute
+	progressReportIntervalMu sync.RWMutex
 )
 
+func GetProgressReportInterval() time.Duration {
+	progressReportIntervalMu.RLock()
+	defer progressReportIntervalMu.RUnlock()
+	return progressReportInterval
+}
+
+func SetProgressReportInterval(newTimeout time.Duration) {
+	progressReportIntervalMu.Lock()
+	defer progressReportIntervalMu.Unlock()
+	progressReportInterval = newTimeout
+}
+
 const (
 	// We send ctrl response inside the read loop. We do not want
 	// send to block read, but we still want ctrl response we sent to
@@ -166,7 +179,7 @@ func (sws *serverWatchStream) sendLoop() {
 	// watch responses pending on a watch id creation message
 	pending := make(map[storage.WatchID][]*pb.WatchResponse)
 
-	interval := time.Duration(ProgressReportIntervalMilliseconds) * time.Millisecond
+	interval := GetProgressReportInterval()
 	progressTicker := time.NewTicker(interval)
 	defer progressTicker.Stop()
 

integration/v3_watch_test.go

@@ -20,7 +20,6 @@ import (
 	"reflect"
 	"sort"
 	"sync"
-	"sync/atomic"
 	"testing"
 	"time"
 
@@ -924,11 +923,11 @@ func waitResponse(wc pb.Watch_WatchClient, timeout time.Duration) (bool, *pb.Wat
 
 func TestWatchWithProgressNotify(t *testing.T) {
 	// accelerate report interval so test terminates quickly
-	oldpi := v3rpc.ProgressReportIntervalMilliseconds
+	oldpi := v3rpc.GetProgressReportInterval()
 	// using atomics to avoid race warnings
-	atomic.StoreInt32(&v3rpc.ProgressReportIntervalMilliseconds, 3*1000)
+	v3rpc.SetProgressReportInterval(3 * time.Second)
 	testInterval := 3 * time.Second
-	defer func() { v3rpc.ProgressReportIntervalMilliseconds = oldpi }()
+	defer func() { v3rpc.SetProgressReportInterval(oldpi) }()
 
 	defer testutil.AfterTest(t)
 	clus := NewClusterV3(t, &ClusterConfig{Size: 3})