| /* |
| * Copyright 2016 The gRPC Authors |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package io.grpc.internal; |
| |
| import io.grpc.Status; |
| import javax.annotation.CheckReturnValue; |
| import javax.annotation.Nullable; |
| import javax.annotation.concurrent.ThreadSafe; |
| |
| /** |
| * A {@link ClientTransport} that has life-cycle management. |
| * |
| * <p>{@link #start} must be the first method call to this interface and return before calling other |
| * methods. |
| * |
| * <p>Typically the transport owns the streams it creates through {@link #newStream}, while some |
| * implementations may transfer the streams to somewhere else. Either way they must conform to the |
| * contract defined by {@link #shutdown}, {@link Listener#transportShutdown} and |
| * {@link Listener#transportTerminated}. |
| */ |
| @ThreadSafe |
| public interface ManagedClientTransport extends ClientTransport { |
| |
| /** |
| * Starts transport. This method may only be called once. |
| * |
| * <p>Implementations must not call {@code listener} from within {@link #start}; implementations |
| * are expected to notify listener on a separate thread or when the returned {@link Runnable} is |
| * run. This method and the returned {@code Runnable} should not throw any exceptions. |
| * |
| * @param listener non-{@code null} listener of transport events |
| * @return a {@link Runnable} that is executed after-the-fact by the original caller, typically |
| * after locks are released |
| */ |
| @CheckReturnValue |
| @Nullable |
| Runnable start(Listener listener); |
| |
| /** |
| * Initiates an orderly shutdown of the transport. Existing streams continue, but the transport |
| * will not own any new streams. New streams will either fail (once |
| * {@link Listener#transportShutdown} callback called), or be transferred off this transport (in |
| * which case they may succeed). This method may only be called once. |
| */ |
| void shutdown(Status reason); |
| |
| /** |
| * Initiates a forceful shutdown in which preexisting and new calls are closed. Existing calls |
| * should be closed with the provided {@code reason}. |
| */ |
| void shutdownNow(Status reason); |
| |
| /** |
| * Receives notifications for the transport life-cycle events. Implementation does not need to be |
| * thread-safe, so notifications must be properly synchronized externally. |
| */ |
| interface Listener { |
| /** |
| * The transport is shutting down. This transport will stop owning new streams, but existing |
| * streams may continue, and the transport may still be able to process {@link #newStream} as |
| * long as it doesn't own the new streams. Shutdown could have been caused by an error or normal |
| * operation. It is possible that this method is called without {@link #shutdown} being called. |
| * |
| * <p>This is called exactly once, and must be called prior to {@link #transportTerminated}. |
| * |
| * @param s the reason for the shutdown. |
| */ |
| void transportShutdown(Status s); |
| |
| /** |
| * The transport completed shutting down. All resources have been released. All streams have |
| * either been closed or transferred off this transport. This transport may still be able to |
| * process {@link #newStream} as long as it doesn't own the new streams. |
| * |
| * <p>This is called exactly once, and must be called after {@link #transportShutdown} has been |
| * called. |
| */ |
| void transportTerminated(); |
| |
| /** |
| * The transport is ready to accept traffic, because the connection is established. This is |
| * called at most once. |
| */ |
| void transportReady(); |
| |
| /** |
| * Called whenever the transport's in-use state has changed. A transport is in-use when it has |
| * at least one stream. |
| */ |
| void transportInUse(boolean inUse); |
| } |
| } |