TooSmallStackSize.java revision 11142:6d92296d52ca 
1/*
2 * Copyright (c) 2014, 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
26 * @bug 6762191
27 * @summary Setting stack size to 16K causes segmentation fault
28 * @compile TooSmallStackSize.java
29 * @run main TooSmallStackSize
30 */
31
32/*
33 * The primary purpose of this test is to make sure we can run with a 16k stack
34 * size without crashing. Also this test will determine the minimum allowed
35 * stack size for the platform (as provided by the JVM error message when a very
36 * small stack is used), and then verify that the JVM can be launched with that stack
37 * size without a crash or any error messages.
38 */
39
40public class TooSmallStackSize extends TestHelper {
41    /* for debugging. Normally false. */
42    static final boolean verbose = false;
43
44    static void printTestOutput(TestResult tr) {
45        System.out.println("*** exitValue = " + tr.exitValue);
46        for (String x : tr.testOutput) {
47            System.out.println(x);
48        }
49    }
50
51    /*
52     * Returns the minimum stack size this platform will allowed based on the
53     * contents of the error message the JVM outputs when too small of a
54     * -Xss size was used.
55     *
56     * The TestResult argument must contain the result of having already run
57     * the JVM with too small of a stack size.
58     */
59    static String getMinStackAllowed(TestResult tr) {
60        /*
61         * The JVM output will contain in one of the lines:
62         *   "The stack size specified is too small, Specify at least 100k"
63         * Although the actual size will vary. We need to extract this size
64         * string from the output and return it.
65         */
66        String matchStr = "Specify at least ";
67        for (String x : tr.testOutput) {
68            int match_idx = x.indexOf(matchStr);
69            if (match_idx >= 0) {
70                int size_start_idx = match_idx + matchStr.length();
71                int k_start_idx = x.indexOf("k", size_start_idx);
72                return x.substring(size_start_idx, k_start_idx + 1); // include the "k"
73            }
74        }
75
76        System.out.println("FAILED: Could not get the stack size from the output");
77        throw new RuntimeException("test fails");
78    }
79
80    /*
81     * Run the JVM with the specified stack size.
82     *
83     * Returns the minimum allowed stack size gleaned from the error message,
84     * if there is an error message. Otherwise returns the stack size passed in.
85     */
86    static String checkStack(String stackSize) {
87        String min_stack_allowed;
88        TestResult tr;
89
90        if (verbose)
91            System.out.println("*** Testing " + stackSize);
92        tr = doExec(javaCmd, "-Xss" + stackSize, "-version");
93        if (verbose)
94            printTestOutput(tr);
95
96        if (tr.isOK()) {
97            System.out.println("PASSED: got no error message with stack size of " + stackSize);
98            min_stack_allowed = stackSize;
99        } else {
100            if (tr.contains("The stack size specified is too small")) {
101                System.out.println("PASSED: got expected error message with stack size of " + stackSize);
102                min_stack_allowed = getMinStackAllowed(tr);
103            } else {
104                // Likely a crash
105                System.out.println("FAILED: Did not get expected error message with stack size of " + stackSize);
106                throw new RuntimeException("test fails");
107            }
108        }
109
110        return min_stack_allowed;
111    }
112
113    /*
114     * Run the JVM with the minimum allowed stack size. This should always succeed.
115     */
116    static void checkMinStackAllowed(String stackSize) {
117        TestResult tr = null;
118
119        if (verbose)
120            System.out.println("*** Testing " + stackSize);
121        tr = doExec(javaCmd, "-Xss" + stackSize, "-version");
122        if (verbose)
123            printTestOutput(tr);
124
125        if (tr.isOK()) {
126            System.out.println("PASSED: VM launched with minimum allowed stack size of " + stackSize);
127        } else {
128            // Likely a crash
129            System.out.println("FAILED: VM failed to launch with minimum allowed stack size of " + stackSize);
130            throw new RuntimeException("test fails");
131        }
132    }
133
134    public static void main(String... args) {
135        /*
136         * The result of a 16k stack size should be a quick exit with a complaint
137         * that the stack size is too small. However, for some win32 builds, the
138         * stack is always at least 64k, and this also sometimes is the minimum
139         * allowed size, so we won't see an error in this case.
140         *
141         * This test case will also produce a crash on some platforms if the fix
142         * for 6762191 is not yet in place.
143         */
144        checkStack("16k");
145
146        /*
147         * Try with a 32k stack size, which is the size that the launcher will
148         * set to if you try setting to anything smaller. This should produce the same
149         * result as setting to 16k if the fix for 6762191 is in place.
150         */
151        String min_stack_allowed = checkStack("32k");
152
153        /*
154         * Try again with a the minimum stack size that was given in the error message
155         */
156        checkMinStackAllowed(min_stack_allowed);
157    }
158}
159