1 /* 2 * Copyright 2017 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 java.util.concurrent.TimeUnit; 20 21 /** 22 * Time source representing the current system time in nanos. Used to inject a fake clock 23 * into unit tests. 24 */ 25 public interface TimeProvider { 26 /** Returns the current nano time. */ currentTimeNanos()27 long currentTimeNanos(); 28 29 TimeProvider SYSTEM_TIME_PROVIDER = new TimeProvider() { 30 final long offsetNanos = 31 TimeUnit.MILLISECONDS.toNanos(System.currentTimeMillis()) - System.nanoTime(); 32 33 @Override 34 public long currentTimeNanos() { 35 return System.nanoTime() + offsetNanos; 36 } 37 }; 38 } 39