Wakeup.java revision 418:9a01bb6b5cc8 
1/*
2 * Copyright 2001-2003 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 */
23
24/* @test
25 * @bug 6405995
26 * @summary Unit test for selector wakeup and interruption
27 * @library ..
28 */
29
30import java.io.*;
31import java.net.*;
32import java.nio.*;
33import java.nio.channels.*;
34import java.util.Random;
35
36public class Wakeup {
37
38    static void sleep(int millis) {
39        try {
40            Thread.sleep(millis);
41        } catch (InterruptedException x) {
42            x.printStackTrace();
43        }
44    }
45
46    static class Sleeper extends TestThread {
47        volatile boolean started = false;
48        volatile int entries = 0;
49        volatile int wakeups = 0;
50        volatile boolean wantInterrupt = false;
51        volatile boolean gotInterrupt = false;
52        volatile Exception exception = null;
53        volatile boolean closed = false;
54        Object gate = new Object();
55
56        Selector sel;
57
58        Sleeper(Selector sel) {
59            super("Sleeper", System.err);
60            this.sel = sel;
61        }
62
63        public void go() throws Exception {
64            started = true;
65            for (;;) {
66                synchronized (gate) { }
67                entries++;
68                try {
69                    sel.select();
70                } catch (ClosedSelectorException x) {
71                    closed = true;
72                }
73                boolean intr = Thread.currentThread().isInterrupted();
74                wakeups++;
75                System.err.println("Wakeup " + wakeups
76                                   + (closed ? " (closed)" : "")
77                                   + (intr ? " (intr)" : ""));
78                if (wakeups > 1000)
79                    throw new Exception("Too many wakeups");
80                if (closed)
81                    return;
82                if (wantInterrupt) {
83                    while (!Thread.interrupted())
84                        Thread.yield();
85                    gotInterrupt = true;
86                    wantInterrupt = false;
87                }
88            }
89        }
90
91    }
92
93    private static int checkedWakeups = 0;
94
95    private static void check(Sleeper sleeper, boolean intr)
96        throws Exception
97    {
98        checkedWakeups++;
99        if (sleeper.wakeups > checkedWakeups) {
100            sleeper.finish(100);
101            throw new Exception("Sleeper has run ahead");
102        }
103        int n = 0;
104        while (sleeper.wakeups < checkedWakeups) {
105            sleep(50);
106            if ((n += 50) > 1000) {
107                sleeper.finish(100);
108                throw new Exception("Sleeper appears to be dead ("
109                                    + checkedWakeups + ")");
110            }
111        }
112        if (sleeper.wakeups > checkedWakeups) {
113            sleeper.finish(100);
114            throw new Exception("Too many wakeups: Expected "
115                                + checkedWakeups
116                                + ", got " + sleeper.wakeups);
117        }
118        if (intr) {
119            n = 0;
120            // Interrupts can sometimes be delayed, so wait
121            while (!sleeper.gotInterrupt) {
122                sleep(50);
123                if ((n += 50) > 1000) {
124                    sleeper.finish(100);
125                    throw new Exception("Interrupt never delivered");
126                }
127            }
128            sleeper.gotInterrupt = false;
129        }
130        System.err.println("Check " + checkedWakeups
131                           + (intr ? " (intr " + n + ")" : ""));
132    }
133
134    public static void main(String[] args) throws Exception {
135
136        Selector sel = Selector.open();
137
138        // Wakeup before select
139        sel.wakeup();
140
141        Sleeper sleeper = new Sleeper(sel);
142
143        sleeper.start();
144        while (!sleeper.started)
145            sleep(50);
146
147        check(sleeper, false);          // 1
148
149        for (int i = 2; i < 5; i++) {
150            // Wakeup during select
151            sel.wakeup();
152            check(sleeper, false);      // 2 .. 4
153        }
154
155        // Double wakeup
156        synchronized (sleeper.gate) {
157            sel.wakeup();
158            check(sleeper, false);      // 5
159            sel.wakeup();
160            sel.wakeup();
161        }
162        check(sleeper, false);          // 6
163
164        // Interrupt
165        synchronized (sleeper.gate) {
166            sleeper.wantInterrupt = true;
167            sleeper.interrupt();
168            check(sleeper, true);       // 7
169        }
170
171        // Interrupt before select
172        while (sleeper.entries < 8)
173            Thread.yield();
174        synchronized (sleeper.gate) {
175            sel.wakeup();
176            check(sleeper, false);      // 8
177            sleeper.wantInterrupt = true;
178            sleeper.interrupt();
179            sleep(50);
180        }
181        check(sleeper, true);           // 9
182
183        // Close during select
184        while (sleeper.entries < 10)
185            Thread.yield();
186        synchronized (sleeper.gate) {
187            sel.close();
188            check(sleeper, false);      // 10
189        }
190
191        if (sleeper.finish(200) == 0)
192            throw new Exception("Test failed");
193        if (!sleeper.closed)
194            throw new Exception("Selector not closed");
195    }
196
197}
198