core: ConnectivityStateManager is always enabled

There have been no callers of disable() since commit 1c7421be7.

core/src/main/java/io/grpc/internal/ConnectivityStateManager.java

@@ -17,14 +17,12 @@
 package io.grpc.internal;
 
 import static com.google.common.base.Preconditions.checkNotNull;
-import static com.google.common.base.Preconditions.checkState;
 
 import io.grpc.ConnectivityState;
 import io.grpc.ManagedChannel;
 import java.util.ArrayList;
 import java.util.concurrent.Executor;
 import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
 import javax.annotation.concurrent.NotThreadSafe;
 
 /**
@@ -63,11 +61,6 @@ final class ConnectivityStateManager {
    */
   void gotoState(@Nonnull ConnectivityState newState) {
     checkNotNull(newState, "newState");
-    checkState(!isDisabled(), "ConnectivityStateManager is already disabled");
-    gotoNullableState(newState);
-  }
-
-  private void gotoNullableState(@Nullable ConnectivityState newState) {
     if (state != newState && state != ConnectivityState.SHUTDOWN) {
       state = newState;
       if (listeners.isEmpty()) {
@@ -94,21 +87,6 @@ final class ConnectivityStateManager {
     return stateCopy;
   }
 
-  /**
-   * Call this method when the channel learns from the load balancer that channel state API is not
-   * supported.
-   */
-  void disable() {
-    gotoNullableState(null);
-  }
-
-  /**
-   * This method is threadsafe.
-   */
-  boolean isDisabled() {
-    return state == null;
-  }
-
   private static final class Listener {
     final Runnable callback;
     final Executor executor;

core/src/main/java/io/grpc/internal/ManagedChannelImpl.java

@@ -369,10 +369,8 @@ public final class ManagedChannelImpl extends ManagedChannel implements Instrume
     lbHelper.lb.shutdown();
     lbHelper = null;
     subchannelPicker = null;
-    if (!channelStateManager.isDisabled()) {
     channelStateManager.gotoState(IDLE);
   }
-  }
 
   // Must be run from channelExecutor
   private void cancelIdleTimer() {
@@ -596,10 +594,8 @@ public final class ManagedChannelImpl extends ManagedChannel implements Instrume
     channelExecutor.executeLater(new Runnable() {
       @Override
       public void run() {
-        if (!channelStateManager.isDisabled()) {
         channelStateManager.gotoState(SHUTDOWN);
       }
-      }
     });
 
     uncommittedRetriableStreamsRegistry.onShutdown(SHUTDOWN_STATUS);

core/src/test/java/io/grpc/internal/ConnectivityStateManagerTest.java

@@ -22,7 +22,6 @@ import static io.grpc.ConnectivityState.READY;
 import static io.grpc.ConnectivityState.SHUTDOWN;
 import static io.grpc.ConnectivityState.TRANSIENT_FAILURE;
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
 
 import com.google.common.util.concurrent.MoreExecutors;
 import io.grpc.ConnectivityState;
@@ -234,36 +233,6 @@ public class ConnectivityStateManagerTest {
     assertEquals(READY, sink.poll());
   }
 
-  @Test
-  public void disable() {
-    state.disable();
-    assertTrue(state.isDisabled());
-
-    thrown.expect(UnsupportedOperationException.class);
-    thrown.expectMessage("Channel state API is not implemented");
-    state.getState();
-  }
-
-  @Test
-  public void disableThenDisable() {
-    state.disable();
-    state.disable();
-    assertTrue(state.isDisabled());
-
-    thrown.expect(UnsupportedOperationException.class);
-    thrown.expectMessage("Channel state API is not implemented");
-    state.getState();
-  }
-
-  @Test
-  public void disableThenGotoReady() {
-    state.disable();
-
-    thrown.expect(IllegalStateException.class);
-    thrown.expectMessage("ConnectivityStateManager is already disabled");
-    state.gotoState(READY);
-  }
-
   @Test
   public void shutdownThenReady() {
     state.gotoState(SHUTDOWN);