1/*
2 * Copyright (c) 2014, 2016, 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/*
25 * @test WBStackSize
26 * @summary verify that whitebox functions getThreadFullStackSize() and getThreadRemainingStackSize are working
27 * @modules java.base/jdk.internal.misc
28 * @library /test/lib
29 * @build sun.hotspot.WhiteBox
30 * @run main ClassFileInstaller sun.hotspot.WhiteBox
31 *                              sun.hotspot.WhiteBox$WhiteBoxPermission
32 * @run main/othervm -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xss512k WBStackSize
33 */
34
35/*
36 * The test may product a false failure if too big StackYellowPages/StackRedPages/ShackShadowPages
37 * VM options are specified. The proper test would retrieve the page size from VM and account for these options
38 * instead of check below:
39 *     Math.abs(actualStackSize - configStackSize) > configStackSize * 0.1
40 *
41 * Please file a test bug, if this is a problem.
42 */
43
44import sun.hotspot.WhiteBox;
45
46public class WBStackSize {
47
48    static final long K = 1024;
49
50    static final long MIN_STACK_SIZE = 8 * K;
51    static final long MAX_STACK_SIZE_ALLOCATED_IN_MAIN = 150 * K; // current value is about 130k on 64-bit platforms
52
53    static final WhiteBox wb = WhiteBox.getWhiteBox();
54
55    static long stackSizeOnOverflow = -1;
56
57    static int eatAllStack() {
58        return eatAllStack() * 2;
59    }
60
61    static void testStackOverflow() {
62
63        stackSizeOnOverflow = wb.getThreadRemainingStackSize();
64
65        if (stackSizeOnOverflow > MIN_STACK_SIZE) {
66
67            try {
68                testStackOverflow();
69            } catch (StackOverflowError e) {
70                // We caught SOE too early. The error will be reported in main()
71            }
72
73        } else {
74
75            try {
76                eatAllStack();
77                throw new RuntimeException("Haven't caught StackOverflowError at all");
78            } catch (StackOverflowError e) {
79                // OK: we caught the anticipated error
80            }
81        }
82    }
83
84    public static void main(String[] args) {
85        long configStackSize = wb.getIntxVMFlag("ThreadStackSize") * K;
86        System.out.println("ThreadStackSize VM option: " + configStackSize);
87
88        long stackProtectionSize = wb.getIntxVMFlag("StackShadowPages") * wb.getVMPageSize();
89        System.out.println("Size of protected shadow pages: " + stackProtectionSize);
90
91        long actualStackSize = wb.getThreadStackSize();
92        System.out.println("Full stack size: " + actualStackSize);
93
94        if (Math.abs(actualStackSize - configStackSize) > configStackSize * 0.1) {
95            throw new RuntimeException("getThreadFullStackSize value [" + actualStackSize
96                                     + "] should be within 90%..110% of the value returned by HotSpotDiagnosticMXBean");
97        }
98
99        long remainingStackSize = wb.getThreadRemainingStackSize();
100        System.out.println("Remaining stack size in main(): " + remainingStackSize);
101
102        // Up to 150k can be already allocated by VM and some space is used for stack protection.
103        long spaceAlreadyOccupied = MAX_STACK_SIZE_ALLOCATED_IN_MAIN + stackProtectionSize;
104
105        if (remainingStackSize > configStackSize
106            || (configStackSize > spaceAlreadyOccupied
107                && remainingStackSize < configStackSize - spaceAlreadyOccupied)) {
108
109            throw new RuntimeException("getThreadRemainingStackSize value [" + remainingStackSize
110                                     + "] should be at least ThreadStackSize value [" + configStackSize + "] minus ["
111                                     + spaceAlreadyOccupied + "]");
112        }
113
114        testStackOverflow();
115
116        if (stackSizeOnOverflow > MIN_STACK_SIZE) {
117            throw new RuntimeException("Caught StackOverflowError too early: when there were "
118                                     + stackSizeOnOverflow + " bytes in stack");
119        } else if (stackSizeOnOverflow < 0) {
120            throw new RuntimeException("Internal test error: stackRemainingSize < 0");
121        } else {
122            System.out.println("Caught StackOverflowError as expected");
123        }
124    }
125}
126