1/* 2 * Copyright (c) 2012, 2017, 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 * @key intermittent 27 * @summary Test that Selector doesn't spin when changing interest ops 28 */ 29 30import java.net.*; 31import java.nio.ByteBuffer; 32import java.nio.channels.*; 33import static java.nio.channels.SelectionKey.*; 34import java.io.IOException; 35 36public class ChangingInterests { 37 38 static int OPS[] = { 0, OP_WRITE, OP_READ, (OP_WRITE|OP_READ) }; 39 40 static String toOpsString(int ops) { 41 String s = ""; 42 if ((ops & OP_READ) > 0) 43 s += "POLLIN"; 44 if ((ops & OP_WRITE) > 0) { 45 if (s.length() > 0) 46 s += "|"; 47 s += "POLLOUT"; 48 } 49 if (s.length() == 0) 50 s = "0"; 51 return "(" + s + ")"; 52 } 53 54 /** 55 * Writes two bytes to 'out' and reads one byte from 'in' so 56 * as to make 'in' readable. 57 */ 58 static void makeReadable(SocketChannel out, SocketChannel in) throws IOException { 59 out.write(ByteBuffer.wrap(new byte[2])); 60 ByteBuffer oneByte = ByteBuffer.wrap(new byte[1]); 61 do { 62 int n = in.read(oneByte); 63 if (n == 1) { 64 break; 65 } else if (n == 0) { 66 try { 67 Thread.sleep(50); 68 } catch (InterruptedException ignore) { } 69 } else { 70 throw new RuntimeException 71 ("Expected to read 0 or 1 byte; actual number was " + n); 72 } 73 } while (true); 74 } 75 76 static void drain(SocketChannel sc) throws IOException { 77 ByteBuffer buf = ByteBuffer.allocate(100); 78 int n; 79 while ((n = sc.read(buf)) > 0) { 80 buf.rewind(); 81 } 82 } 83 84 /** 85 * Changes the given key's interest set from one set to another and then 86 * checks the selected key set and the key's channel. 87 */ 88 static void testChange(SelectionKey key, int from, int to) throws IOException { 89 Selector sel = key.selector(); 90 assertTrue(sel.keys().size() == 1, "Only one channel should be registered"); 91 92 // ensure that channel is registered with the "from" interest set 93 key.interestOps(from); 94 sel.selectNow(); 95 sel.selectedKeys().clear(); 96 97 // change to the "to" interest set 98 key.interestOps(to); 99 System.out.println("select..."); 100 int selected = sel.selectNow(); 101 System.out.println("" + selected + " channel(s) selected"); 102 103 int expected = (to == 0) ? 0 : 1; 104 assertTrue(selected == expected, "Expected " + expected); 105 106 // check selected keys 107 for (SelectionKey k: sel.selectedKeys()) { 108 assertTrue(k == key, "Unexpected key selected"); 109 110 boolean readable = k.isReadable(); 111 boolean writable = k.isWritable(); 112 113 System.out.println("key readable: " + readable); 114 System.out.println("key writable: " + writable); 115 116 if ((to & OP_READ) == 0) { 117 assertTrue(!readable, "Not expected to be readable"); 118 } else { 119 assertTrue(readable, "Expected to be readable"); 120 } 121 122 if ((to & OP_WRITE) == 0) { 123 assertTrue(!writable, "Not expected to be writable"); 124 } else { 125 assertTrue(writable, "Expected to be writable"); 126 } 127 128 sel.selectedKeys().clear(); 129 } 130 } 131 132 /** 133 * Tests that given Selector's select method blocks. 134 */ 135 static void testForSpin(Selector sel) throws IOException { 136 System.out.println("Test for spin..."); 137 long start = System.currentTimeMillis(); 138 int count = 3; 139 while (count-- > 0) { 140 int selected = sel.select(1000); 141 System.out.println("" + selected + " channel(s) selected"); 142 assertTrue(selected == 0, "Channel should not be selected"); 143 } 144 long dur = System.currentTimeMillis() - start; 145 assertTrue(dur > 1000, "select was too short"); 146 } 147 148 public static void main(String[] args) throws IOException { 149 InetAddress lh = InetAddress.getLocalHost(); 150 151 // create loopback connection 152 ServerSocketChannel ssc = 153 ServerSocketChannel.open().bind(new InetSocketAddress(0)); 154 155 final SocketChannel sc = SocketChannel.open(); 156 sc.setOption(StandardSocketOptions.TCP_NODELAY, true); 157 sc.connect(new InetSocketAddress(lh, ssc.socket().getLocalPort())); 158 SocketChannel peer = ssc.accept(); 159 peer.setOption(StandardSocketOptions.TCP_NODELAY, true); 160 161 sc.configureBlocking(false); 162 163 // ensure that channel "sc" is readable 164 makeReadable(peer, sc); 165 166 try (Selector sel = Selector.open()) { 167 SelectionKey key = sc.register(sel, 0); 168 sel.selectNow(); 169 170 // test all transitions 171 for (int from: OPS) { 172 for (int to: OPS) { 173 174 System.out.println(toOpsString(from) + " -> " + toOpsString(to)); 175 176 testChange(key, from, to); 177 178 // if the interst ops is now 0 then Selector should not spin 179 if (to == 0) 180 testForSpin(sel); 181 182 // if interest ops is now OP_READ then make non-readable 183 // and test that Selector does not spin. 184 if (to == OP_READ) { 185 System.out.println("Drain channel..."); 186 drain(sc); 187 testForSpin(sel); 188 System.out.println("Make channel readable again"); 189 makeReadable(peer, sc); 190 } 191 192 System.out.println(); 193 } 194 } 195 196 } finally { 197 sc.close(); 198 peer.close(); 199 ssc.close(); 200 } 201 } 202 203 static void assertTrue(boolean v, String msg) { 204 if (!v) throw new RuntimeException(msg); 205 } 206 207} 208