1 /* 2 * Copyright 2017 Google LLC 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions are 6 * met: 7 * 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above 11 * copyright notice, this list of conditions and the following disclaimer 12 * in the documentation and/or other materials provided with the 13 * distribution. 14 * * Neither the name of Google LLC nor the names of its 15 * contributors may be used to endorse or promote products derived from 16 * this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 package com.google.api.gax.batching; 31 32 /** 33 * Semaphore64 is similar to {@link java.util.concurrent.Semaphore} but allows up to {@code 2^63-1} 34 * permits. It also allows adding / reducing permits to the original limit and acquire partial 35 * permits. 36 * 37 * <p>Users who do not need such large number of permits and the extra functionalities are strongly 38 * encouraged to use Java's {@code Semaphore} instead. It is almost certainly faster and less error 39 * prone. 40 */ 41 interface Semaphore64 { acquire(long permits)42 boolean acquire(long permits); 43 release(long permits)44 void release(long permits); 45 46 /** 47 * When try to acquire more permits than what's allowed, acquiring the limit instead of what's 48 * asked. 49 */ acquirePartial(long permits)50 boolean acquirePartial(long permits); 51 increasePermitLimit(long permits)52 void increasePermitLimit(long permits); 53 reducePermitLimit(long reduction)54 void reducePermitLimit(long reduction); 55 getPermitLimit()56 long getPermitLimit(); 57 } 58