1 /*
2 * Copyright (c) 2012, 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.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24 /* @test
25 * @bug 7200742
26 * @summary Test that Selector doesn't spin when changing interest ops
27 */
28
29 import java.net.*;
30 import java.nio.ByteBuffer;
31 import java.nio.channels.*;
32 import static java.nio.channels.SelectionKey.*;
33 import java.io.IOException;
34
35 public class ChangingInterests {
36
37 static int OPS[] = { 0, OP_WRITE, OP_READ, (OP_WRITE|OP_READ) };
38
39 static String toOpsString(int ops) {
40 String s = "";
41 if ((ops & OP_READ) > 0)
42 s += "POLLIN";
43 if ((ops & OP_WRITE) > 0) {
44 if (s.length() > 0)
45 s += "|";
46 s += "POLLOUT";
47 }
48 if (s.length() == 0)
49 s = "0";
50 return "(" + s + ")";
51 }
52
53 static void write1(SocketChannel peer) throws IOException {
54 peer.write(ByteBuffer.wrap(new byte[1]));
55 // give time for other end to be readable
56 try {
57 Thread.sleep(1000);
58 } catch (InterruptedException ignore) { }
59 }
60
61 static void drain(SocketChannel sc) throws IOException {
62 ByteBuffer buf = ByteBuffer.allocate(100);
63 int n;
64 while ((n = sc.read(buf)) > 0) {
65 buf.rewind();
66 }
67 }
68
69 /**
70 * Changes the given key's interest set from one set to another and then
71 * checks the selected key set and the key's channel.
72 */
73 static void testChange(SelectionKey key, int from, int to) throws IOException {
74 Selector sel = key.selector();
75 assertTrue(sel.keys().size() == 1, "Only one channel should be registered");
76
77 // ensure that channel is registered with the "from" interest set
78 key.interestOps(from);
79 sel.selectNow();
80 sel.selectedKeys().clear();
81
82 // change to the "to" interest set
83 key.interestOps(to);
84 System.out.println("select...");
85 int selected = sel.selectNow();
86 System.out.println("" + selected + " channel(s) selected");
87
88 int expected = (to == 0) ? 0 : 1;
89 assertTrue(selected == expected, "Expected " + expected);
90
91 // check selected keys
92 for (SelectionKey k: sel.selectedKeys()) {
93 assertTrue(k == key, "Unexpected key selected");
94
95 boolean readable = k.isReadable();
96 boolean writable = k.isWritable();
97
98 System.out.println("key readable: " + readable);
99 System.out.println("key writable: " + writable);
100
101 if ((to & OP_READ) == 0) {
102 assertTrue(!readable, "Not expected to be readable");
103 } else {
104 assertTrue(readable, "Expected to be readable");
105 }
106
107 if ((to & OP_WRITE) == 0) {
108 assertTrue(!writable, "Not expected to be writable");
109 } else {
110 assertTrue(writable, "Expected to be writable");
111 }
112
113 sel.selectedKeys().clear();
114 }
115 }
116
117 /**
118 * Tests that given Selector's select method blocks.
119 */
120 static void testForSpin(Selector sel) throws IOException {
121 System.out.println("Test for spin...");
122 long start = System.currentTimeMillis();
123 int count = 3;
124 while (count-- > 0) {
125 int selected = sel.select(1000);
126 System.out.println("" + selected + " channel(s) selected");
127 assertTrue(selected == 0, "Channel should not be selected");
128 }
129 long dur = System.currentTimeMillis() - start;
130 assertTrue(dur > 1000, "select was too short");
131 }
132
133 public static void main(String[] args) throws IOException {
134 InetAddress lh = InetAddress.getLocalHost();
135
136 // create loopback connection
137 ServerSocketChannel ssc =
138 ServerSocketChannel.open().bind(new InetSocketAddress(0));
139
140 final SocketChannel sc = SocketChannel.open();
141 sc.connect(new InetSocketAddress(lh, ssc.socket().getLocalPort()));
142 SocketChannel peer = ssc.accept();
143
144 sc.configureBlocking(false);
145
146 // ensure that channel "sc" is readable
147 write1(peer);
148
149 try (Selector sel = Selector.open()) {
150 SelectionKey key = sc.register(sel, 0);
151 sel.selectNow();
152
153 // test all transitions
154 for (int from: OPS) {
155 for (int to: OPS) {
156
157 System.out.println(toOpsString(from) + " -> " + toOpsString(to));
158
159 testChange(key, from, to);
160
161 // if the interst ops is now 0 then Selector should not spin
162 if (to == 0)
163 testForSpin(sel);
164
165 // if interest ops is now OP_READ then make non-readable
166 // and test that Selector does not spin.
167 if (to == OP_READ) {
168 System.out.println("Drain channel...");
169 drain(sc);
170 testForSpin(sel);
171 System.out.println("Make channel readable again");
172 write1(peer);
173 }
174
175 System.out.println();
176 }
177 }
178
179 } finally {
180 sc.close();
181 peer.close();
182 ssc.close();
183 }
184 }
185
186 static void assertTrue(boolean v, String msg) {
187 if (!v) throw new RuntimeException(msg);
188 }
189
190 }