001    /*
002     * Copyright (C) 2011 The Guava Authors
003     *
004     * Licensed under the Apache License, Version 2.0 (the "License");
005     * you may not use this file except in compliance with the License.
006     * You may obtain a copy of the License at
007     *
008     * http://www.apache.org/licenses/LICENSE-2.0
009     *
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed under the License is distributed on an "AS IS" BASIS,
012     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013     * See the License for the specific language governing permissions and
014     * limitations under the License.
015     */
016    
017    package com.google.common.base;
018    
019    import com.google.common.annotations.Beta;
020    
021    /**
022     * A time source; returns a time value representing the number of nanoseconds
023     * elapsed since some fixed but arbitrary point in time.
024     *
025     * @author Kevin Bourrillion
026     * @since 9
027     */
028    @Beta
029    public interface Ticker {
030      /**
031       * Returns the number of nanoseconds elapsed since this ticker's fixed
032       * point of reference.
033       */
034      long read();
035    }