1 /*
 2  * Copyright (c) 2017, 2020, Oracle and/or its affiliates. All rights reserved.
 3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 4  *
 5  * This code is free software; you can redistribute it and/or modify it
 6  * under the terms of the GNU General Public License version 2 only, as
 7  * published by the Free Software Foundation.  Oracle designates this
 8  * particular file as subject to the "Classpath" exception as provided
 9  * by Oracle in the LICENSE file that accompanied this code.
10  *
11  * This code is distributed in the hope that it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14  * version 2 for more details (a copy is included in the LICENSE file that
15  * accompanied this code).
16  *
17  * You should have received a copy of the GNU General Public License version
18  * 2 along with this work; if not, write to the Free Software Foundation,
19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20  *
21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22  * or visit www.oracle.com if you need additional information or have any
23  * questions.
24  */
25 package sun.nio.ch;
26 
27 import java.io.IOException;
28 import java.util.ServiceConfigurationError;
29 import sun.security.action.GetPropertyAction;
30 
31 abstract class PollerProvider {
32     PollerProvider() { }
33 
34     /**
35      * Creates a Poller for read ops.
36      */
37     abstract Poller readPoller() throws IOException;
38 
39     /**
40      * Creates a Poller for write ops.
41      */
42     abstract Poller writePoller() throws IOException;
43 
44     /**
45      * Creates the PollerProvider.
46      */
47     static PollerProvider provider() {
48         String cn = GetPropertyAction.privilegedGetProperty("jdk.PollerProvider");
49         if (cn != null) {
50             try {
51                 Class<?> clazz = Class.forName(cn, true, ClassLoader.getSystemClassLoader());
52                 return (PollerProvider) clazz.getConstructor().newInstance();
53             } catch (Exception e) {
54                 throw new ServiceConfigurationError(null, e);
55             }
56         } else {
57             return new DefaultPollerProvider();
58         }
59     }
60 }