1 /* 2 * Copyright 2019 The gRPC Authors 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package io.grpc.internal; 18 19 import javax.annotation.Nullable; 20 import javax.annotation.concurrent.ThreadSafe; 21 22 /** 23 * Provides transports for sending RPCs. 24 */ 25 @ThreadSafe 26 interface TransportProvider { 27 /** 28 * Returns a READY transport that will be used to create new streams. 29 * 30 * <p>Returns {@code null} if the state is not READY. Will try to connect if state is IDLE. 31 */ 32 @Nullable obtainActiveTransport()33 ClientTransport obtainActiveTransport(); 34 } 35