in-progress changes.

Author: kannanjgithub

rls/src/main/java/io/grpc/rls/CachingRlsLbClient.java

@@ -132,6 +132,7 @@ final class CachingRlsLbClient {
   @GuardedBy("lock")
   private final RefCountedChildPolicyWrapperFactory refCountedChildPolicyWrapperFactory;
   private final ChannelLogger logger;
+  private final ChildPolicyWrapper fallbackChildPolicyWrapper;
 
   static {
     MetricInstrumentRegistry metricInstrumentRegistry
@@ -226,6 +227,10 @@ private CachingRlsLbClient(Builder builder) {
             lbPolicyConfig.getLoadBalancingPolicy(), childLbResolvedAddressFactory,
             childLbHelperProvider,
             new BackoffRefreshListener());
+    // TODO(creamsoup) wait until lb is ready
+    String defaultTarget = lbPolicyConfig.getRouteLookupConfig().defaultTarget();
+    logger.log(ChannelLogLevel.DEBUG, "starting fallback to {0}", defaultTarget);
+    fallbackChildPolicyWrapper = refCountedChildPolicyWrapperFactory.createOrGet(defaultTarget);
 
     gaugeRegistration = helper.getMetricRecorder()
         .registerBatchCallback(new BatchCallback() {
@@ -1015,12 +1020,8 @@ public PickResult pickSubchannel(PickSubchannelArgs args) {
       }
     }
 
-    private ChildPolicyWrapper fallbackChildPolicyWrapper;
-
     /** Uses Subchannel connected to default target. */
     private PickResult useFallback(PickSubchannelArgs args) {
-      // TODO(creamsoup) wait until lb is ready
-      startFallbackChildPolicy();
       SubchannelPicker picker = fallbackChildPolicyWrapper.getPicker();
       if (picker == null) {
         return PickResult.withNoResult();
@@ -1045,17 +1046,6 @@ private String determineMetricsPickResult(PickResult pickResult) {
       }
     }
 
-    private void startFallbackChildPolicy() {
-      String defaultTarget = lbPolicyConfig.getRouteLookupConfig().defaultTarget();
-      synchronized (lock) {
-        if (fallbackChildPolicyWrapper != null) {
-          return;
-        }
-        logger.log(ChannelLogLevel.DEBUG, "starting fallback to {0}", defaultTarget);
-        fallbackChildPolicyWrapper = refCountedChildPolicyWrapperFactory.createOrGet(defaultTarget);
-      }
-    }
-
     // GuardedBy CachingRlsLbClient.lock
     void close() {
       synchronized (lock) { // Lock is already held, but ErrorProne can't tell

rls/src/test/java/io/grpc/rls/CachingRlsLbClientTest.java

@@ -372,12 +372,14 @@ public void get_updatesLbState() throws Exception {
     ArgumentCaptor<SubchannelPicker> pickerCaptor = ArgumentCaptor.forClass(SubchannelPicker.class);
     ArgumentCaptor<ConnectivityState> stateCaptor =
         ArgumentCaptor.forClass(ConnectivityState.class);
-    inOrder.verify(helper, times(2))
+    inOrder.verify(helper, times(3))
         .updateBalancingState(stateCaptor.capture(), pickerCaptor.capture());
 
     assertThat(new HashSet<>(pickerCaptor.getAllValues())).hasSize(1);
+    // TRANSIENT_FAILURE is because the test setup pretends fallback is not available.
     assertThat(stateCaptor.getAllValues())
-        .containsExactly(ConnectivityState.CONNECTING, ConnectivityState.READY);
+        .containsExactly(ConnectivityState.TRANSIENT_FAILURE, ConnectivityState.CONNECTING,
+            ConnectivityState.READY);
     Metadata headers = new Metadata();
     PickResult pickResult = getPickResultForCreate(pickerCaptor, headers);
     assertThat(pickResult.getStatus().isOk()).isTrue();
@@ -439,7 +441,7 @@ public void timeout_not_changing_picked_subchannel() throws Exception {
     ArgumentCaptor<SubchannelPicker> pickerCaptor = ArgumentCaptor.forClass(SubchannelPicker.class);
     ArgumentCaptor<ConnectivityState> stateCaptor =
         ArgumentCaptor.forClass(ConnectivityState.class);
-    verify(helper, times(4)).updateBalancingState(stateCaptor.capture(), pickerCaptor.capture());
+    verify(helper, times(5)).updateBalancingState(stateCaptor.capture(), pickerCaptor.capture());
 
     Metadata headers = new Metadata();
     PickResult pickResult = getPickResultForCreate(pickerCaptor, headers);
@@ -509,7 +511,7 @@ public void get_withAdaptiveThrottler() throws Exception {
     ArgumentCaptor<SubchannelPicker> pickerCaptor = ArgumentCaptor.forClass(SubchannelPicker.class);
     ArgumentCaptor<ConnectivityState> stateCaptor =
         ArgumentCaptor.forClass(ConnectivityState.class);
-    inOrder.verify(helper, times(2))
+    inOrder.verify(helper, times(3))
         .updateBalancingState(stateCaptor.capture(), pickerCaptor.capture());
 
     Metadata headers = new Metadata();