11d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert/* 21d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Copyright (C) 2011 The Guava Authors 31d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 41d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Licensed under the Apache License, Version 2.0 (the "License"); 51d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * you may not use this file except in compliance with the License. 61d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * You may obtain a copy of the License at 71d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 81d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * http://www.apache.org/licenses/LICENSE-2.0 91d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 101d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Unless required by applicable law or agreed to in writing, software 111d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * distributed under the License is distributed on an "AS IS" BASIS, 121d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 131d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * See the License for the specific language governing permissions and 141d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * limitations under the License. 151d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 161d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 171d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertpackage com.google.common.base; 181d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 191d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.annotations.Beta; 201d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.annotations.GwtCompatible; 211d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 221d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert/** 231d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * A time source; returns a time value representing the number of nanoseconds 241d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * elapsed since some fixed but arbitrary point in time. 251d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 261d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @author Kevin Bourrillion 271d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @since 10.0 281d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * (<a href="http://code.google.com/p/guava-libraries/wiki/Compatibility" 291d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * >mostly source-compatible</a> since 9.0) 301d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 311d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert@Beta 321d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert@GwtCompatible 331d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertpublic abstract class Ticker { 341d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 351d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Constructor for use by subclasses. 361d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 371d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert protected Ticker() {} 381d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 391d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 401d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Returns the number of nanoseconds elapsed since this ticker's fixed 411d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * point of reference. 421d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 431d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public abstract long read(); 441d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 451d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 461d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * A ticker that reads the current time using {@link System#nanoTime}. 471d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 481d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @since 10.0 491d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 501d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public static Ticker systemTicker() { 511d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return SYSTEM_TICKER; 521d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 531d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 541d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private static final Ticker SYSTEM_TICKER = new Ticker() { 551d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override 561d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public long read() { 571d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return Platform.systemNanoTime(); 581d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 591d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert }; 601d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert} 61