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 }
56
57 static void drain(SocketChannel sc) throws IOException {
58 ByteBuffer buf = ByteBuffer.allocate(100);
59 int n;
60 while ((n = sc.read(buf)) > 0) {
61 buf.rewind();
62 }
63 }
64
65 /**
66 * Changes the given key's interest set from one set to another and then
67 * checks the selected key set and the key's channel.
68 */
69 static void testChange(SelectionKey key, int from, int to) throws IOException {
70 Selector sel = key.selector();
71 assertTrue(sel.keys().size() == 1, "Only one channel should be registered");
72
73 // ensure that channel is registered with the "from" interest set
74 key.interestOps(from);
75 sel.selectNow();
76 sel.selectedKeys().clear();
77
78 // change to the "to" interest set
79 key.interestOps(to);
80
81 int readCounter = ((to & OP_READ) == 0) ? 0 : 1;
82 int writeCounter = ((to & OP_WRITE) == 0) ? 0 : 1;
83 System.out.printf("Expected number of readable events %d, writable events %d\n",
84 readCounter, writeCounter);
85
86 long start = System.currentTimeMillis();
87
88 while ((readCounter > 0 || writeCounter > 0)
89 && System.currentTimeMillis() - start < 10000) {
90 System.out.println("\ttry selection");
91 try {
92 Thread.sleep(1000);
93 } catch (InterruptedException ignore) {}
94
95 sel.selectNow();
96
97 // check selected keys
98 for (SelectionKey k : sel.selectedKeys()) {
99 assertTrue(k == key, "Unexpected key selected");
100
101 if (k.isReadable()) {
102 readCounter--;
103 }
104 if (k.isWritable()) {
105 writeCounter--;
106 }
107 }
108 }
109
110 verifyEvents(to, readCounter, writeCounter);
111 sel.selectedKeys().clear();
112 }
113
114 /**
115 * Verify actual arrived events with current interest configuration
116 */
117 static void verifyEvents(int op, int readCounter, int writeCounter) {
118 System.out.printf("Verify : %s <-> readCounter %d writeCounter %d\n",
119 toOpsString(op), readCounter, writeCounter);
120 switch (op) {
121 case 0 :
122 assertTrue(readCounter == 0 && writeCounter == 0,
123 "Expecting no event");
124 break;
125 case OP_READ :
126 assertTrue(readCounter == 0, "Expecting only read event");
127 break;
128 case OP_WRITE :
129 assertTrue(writeCounter == 0, "Expecting only write event");
130 break;
131 case OP_READ | OP_WRITE :
132 assertTrue(readCounter == 0 && writeCounter <= 0,
133 "Expecting read and write events");
134 break;
135 default:
136 assertTrue(false, "Wrong interest setting");
137 break;
138 }
139 }
140
141 /**
142 * Tests that given Selector's select method blocks.
143 */
144 static void testForSpin(Selector sel) throws IOException {
145 System.out.println("Test for spin...");
146 long start = System.currentTimeMillis();
147 int count = 3;
148 while (count-- > 0) {
149 int selected = sel.select(1000);
150 System.out.println("" + selected + " channel(s) selected");
151 assertTrue(selected == 0, "Channel should not be selected");
152 }
153 long dur = System.currentTimeMillis() - start;
154 assertTrue(dur > 1000, "select was too short");
155 }
156
157 public static void main(String[] args) throws IOException {
158 InetAddress lh = InetAddress.getLocalHost();
159
160 // create loopback connection
161 ServerSocketChannel ssc =
162 ServerSocketChannel.open().bind(new InetSocketAddress(0));
163
164 final SocketChannel sc = SocketChannel.open();
165 sc.connect(new InetSocketAddress(lh, ssc.socket().getLocalPort()));
166 SocketChannel peer = ssc.accept();
167
168 sc.configureBlocking(false);
169
170 // ensure that channel "sc" is readable
171 write1(peer);
172
173 try (Selector sel = Selector.open()) {
174 SelectionKey key = sc.register(sel, 0);
175 sel.selectNow();
176
177 // test all transitions
178 for (int from: OPS) {
179 for (int to: OPS) {
180
181 System.out.println(toOpsString(from) + " -> " + toOpsString(to));
182
183 testChange(key, from, to);
184
185 // if the interst ops is now 0 then Selector should not spin
186 if (to == 0)
187 testForSpin(sel);
188
189 // if interest ops is now OP_READ then make non-readable
190 // and test that Selector does not spin.
191 if (to == OP_READ) {
192 System.out.println("Drain channel...");
193 drain(sc);
194 testForSpin(sel);
195 System.out.println("Make channel readable again");
196 write1(peer);
197 }
198
199 System.out.println();
200 }
201 }
202
203 } finally {
204 sc.close();
205 peer.close();
206 ssc.close();
207 }
208 }
209
210 static void assertTrue(boolean v, String msg) {
211 if (!v) throw new RuntimeException(msg);
212 }
213
214 }