1 /*
2 * Copyright (c) 2001-2017, Zoltan Farkas All Rights Reserved.
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17 *
18 * Additionally licensed with:
19 *
20 * Licensed under the Apache License, Version 2.0 (the "License");
21 * you may not use this file except in compliance with the License.
22 * You may obtain a copy of the License at
23 *
24 * http://www.apache.org/licenses/LICENSE-2.0
25 *
26 * Unless required by applicable law or agreed to in writing, software
27 * distributed under the License is distributed on an "AS IS" BASIS,
28 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
29 * See the License for the specific language governing permissions and
30 * limitations under the License.
31 */
32 package org.spf4j.concurrent;
33
34 import javax.annotation.ParametersAreNonnullByDefault;
35 import javax.annotation.concurrent.ThreadSafe;
36
37 /**
38 * A interface that abstracts a semaphore.
39 * @author zoly
40 */
41 @ParametersAreNonnullByDefault
42 @ThreadSafe
43 public interface Semaphore extends PermitSupplier {
44
45 /**
46 * release 1 permit.
47 */
48 default void release() {
49 release(1);
50 }
51
52 /**
53 * release a number of permits.
54 * @param nrPermits the number of permits to release.
55 */
56 void release(int nrPermits);
57
58 @Override
59 default Semaphore toSemaphore() {
60 return this;
61 }
62
63 }