--- /dev/null Fri Sep 2 10:54:03 2016 +++ new/hotspot/test/runtime/Thread/TooSmallStackSize.java Fri Sep 2 10:54:02 2016 @@ -0,0 +1,201 @@ +/* + * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + */ + +/* + * @test + * @bug 8140520 + * @summary Setting small CompilerThreadStackSize, ThreadStackSize, and + * VMThreadStackSize values should result in an error message that shows + * the minimum stack size value for each thread type. + * @compile TooSmallStackSize.java + * @run main TooSmallStackSize + */ + +/* + * The primary purpose of this test is to make sure we can run with a + * stack smaller than the minimum without crashing. Also this test will + * determine the minimum allowed stack size for the platform (as + * provided by the JVM error message when a very small stack is used), + * and then verify that the JVM can be launched with that stack size + * without a crash or any error messages. + * + * Note: This repo's version of the test uses the '-XX:ThreadStackSize=n' + * VM option for Java thread stack size testing. The jdk repo's version + * of the test uses the '-Xss' option. + */ + +public class TooSmallStackSize extends TestHelper { + /* for debugging. Normally false. */ + static final boolean verbose = false; + static final String CompilerThreadStackSizeString = "CompilerThreadStackSize"; + static final String ThreadStackSizeString = "Java thread stack size"; + static final String VMThreadStackSizeString = "VMThreadStackSize"; + + static void printTestOutput(TestResult tr) { + System.out.println("*** exitValue = " + tr.exitValue); + for (String x : tr.testOutput) { + System.out.println(x); + } + } + + /* + * Returns the minimum stack size this platform will allowed based on the + * contents of the error message the JVM outputs when too small of a + * stack size was used. + * + * The TestResult argument must contain the result of having already run + * the JVM with too small of a stack size. + */ + static String getMinStackAllowed(TestResult tr) { + /* + * The JVM output will contain in one of the lines: + * "The CompilerThreadStackSize specified is too small. Specify at least 100k" + * "The Java thread stack size specified is too small. Specify at least 100k" + * "The VMThreadStackSize specified is too small. Specify at least 100k" + * Although the actual size will vary. We need to extract this size + * string from the output and return it. + */ + String matchStr = "Specify at least "; + for (String x : tr.testOutput) { + int match_idx = x.indexOf(matchStr); + if (match_idx >= 0) { + int size_start_idx = match_idx + matchStr.length(); + int k_start_idx = x.indexOf("k", size_start_idx); + // don't include the 'k'; the caller will have to + // add it back as needed. + return x.substring(size_start_idx, k_start_idx); + } + } + + System.out.println("FAILED: Could not get the stack size from the output"); + throw new RuntimeException("test fails"); + } + + /* + * Run the JVM with the specified stack size. + * + * Returns the minimum allowed stack size gleaned from the error message, + * if there is an error message. Otherwise returns the stack size passed in. + */ + static String checkStack(String stackOption, String optionMesg, String stackSize) { + String min_stack_allowed; + + if (verbose) + System.out.println("*** Testing " + stackOption + stackSize); + TestResult tr = doExec(javaCmd, stackOption + stackSize, + // Uncomment the following to get log output + // that shows actual thread creation sizes. + // "-Xlog:os+thread", + "-version"); + if (verbose) + printTestOutput(tr); + + if (tr.isOK()) { + // checkMinStackAllowed() is called with stackSize values + // that should be the minimum that works. This method, + // checkStack(), is called with stackSize values that + // should be too small and result in error messages. + // However, some platforms fix up a stackSize value that is + // too small into something that works so we have to allow + // for checkStack() calls that work. + System.out.println("PASSED: got no error message with " + stackOption + stackSize); + min_stack_allowed = stackSize; + } else { + String expect = "The " + optionMesg + " specified is too small"; + if (verbose) + System.out.println("Expect='" + expect + "'"); + if (tr.contains(expect)) { + System.out.println("PASSED: got expected error message with " + stackOption + stackSize); + min_stack_allowed = getMinStackAllowed(tr); + } else { + // Likely a crash + System.out.println("FAILED: Did not get expected error message with " + stackOption + stackSize); + throw new RuntimeException("test fails"); + } + } + + return min_stack_allowed; + } + + /* + * Run the JVM with the minimum allowed stack size. This should always succeed. + */ + static void checkMinStackAllowed(String stackOption, String optionMesg, String stackSize) { + if (verbose) + System.out.println("*** Testing " + stackOption + stackSize); + TestResult tr = doExec(javaCmd, stackOption + stackSize, + // Uncomment the following to get log output + // that shows actual thread creation sizes. + // "-Xlog:os+thread", + "-version"); + if (verbose) + printTestOutput(tr); + + if (tr.isOK()) { + System.out.println("PASSED: VM launched with " + stackOption + stackSize); + } else { + // Likely a crash + System.out.println("FAILED: VM failed to launch with " + stackOption + stackSize); + throw new RuntimeException("test fails"); + } + } + + public static void main(String... args) { + /* + * The result of a 16k stack size should be a quick exit with a complaint + * that the stack size is too small. However, for some win32 builds, the + * stack is always at least 64k, and this also sometimes is the minimum + * allowed size, so we won't see an error in this case. + * + * This test case will also produce a crash on some platforms if the fix + * for 6762191 is not yet in place. + */ + checkStack("-XX:ThreadStackSize=", ThreadStackSizeString, "16"); + + /* + * Try with a 32k stack size, which is the size that the launcher will + * set to if you try setting to anything smaller. This should produce the same + * result as setting to 16k if the fix for 6762191 is in place. + */ + String min_stack_allowed = checkStack("-XX:ThreadStackSize=", ThreadStackSizeString, "32"); + + /* + * Try again with a the minimum stack size that was given in the error message + */ + checkMinStackAllowed("-XX:ThreadStackSize=", ThreadStackSizeString, min_stack_allowed); + + /* + * Now redo the same tests with the compiler thread stack size: + */ + checkStack("-XX:CompilerThreadStackSize=", CompilerThreadStackSizeString, "16"); + min_stack_allowed = checkStack("-XX:CompilerThreadStackSize=", CompilerThreadStackSizeString, "32"); + checkMinStackAllowed("-XX:CompilerThreadStackSize=", CompilerThreadStackSizeString, min_stack_allowed); + + /* + * Now redo the same tests with the VM thread stack size: + */ + checkStack("-XX:VMThreadStackSize=", VMThreadStackSizeString, "16"); + min_stack_allowed = checkStack("-XX:VMThreadStackSize=", VMThreadStackSizeString, "32"); + checkMinStackAllowed("-XX:VMThreadStackSize=", VMThreadStackSizeString, min_stack_allowed); + } +}