/* * Copyright (c) 2016, 2017, 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. * @library /test/lib * @modules java.base/jdk.internal.misc * java.management * @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: The '-Xss' and '-XX:ThreadStackSize=' options * both control Java thread stack size. This repo's version of the test * exercises the '-XX:ThreadStackSize' VM option. The jdk repo's version * of the test exercises the '-Xss' option. */ import jdk.test.lib.process.ProcessTools; import jdk.test.lib.process.OutputAnalyzer; public class TooSmallStackSize { /* 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"; /* * 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 testOutput argument must contain the result of having already run * the JVM with too small of a stack size. */ static String getMinStackAllowed(String testOutput) { /* * 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 "; int match_idx = testOutput.indexOf(matchStr); if (match_idx >= 0) { int size_start_idx = match_idx + matchStr.length(); int k_start_idx = testOutput.indexOf("k", size_start_idx); // don't include the 'k'; the caller will have to // add it back as needed. return testOutput.substring(size_start_idx, k_start_idx); } System.out.println("Expect='" + matchStr + "'"); System.out.println("Actual: " + testOutput); 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) throws Exception { String min_stack_allowed; System.out.println("*** Testing " + stackOption + stackSize); ProcessBuilder pb = ProcessTools.createJavaProcessBuilder( stackOption + stackSize, // Uncomment the following to get log output // that shows actual thread creation sizes. // "-Xlog:os+thread", "-version"); OutputAnalyzer output = new OutputAnalyzer(pb.start()); if (verbose) { System.out.println("stdout: " + output.getStdout()); } if (output.getExitValue() == 0) { // 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 exit_code == 0 with " + stackOption + stackSize); min_stack_allowed = stackSize; } else { String expect = "The " + optionMesg + " specified is too small"; if (verbose) { System.out.println("Expect='" + expect + "'"); } output.shouldContain(expect); min_stack_allowed = getMinStackAllowed(output.getStdout()); System.out.println("PASSED: got expected error message with " + stackOption + stackSize); } 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) throws Exception { System.out.println("*** Testing " + stackOption + stackSize); ProcessBuilder pb = ProcessTools.createJavaProcessBuilder( stackOption + stackSize, // Uncomment the following to get log output // that shows actual thread creation sizes. // "-Xlog:os+thread", "-version"); OutputAnalyzer output = new OutputAnalyzer(pb.start()); output.shouldHaveExitValue(0); System.out.println("PASSED: VM launched with " + stackOption + stackSize); } public static void main(String... args) throws Exception { /* * 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 64k 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, "64"); /* * Try again with a the minimum stack size that was given in the error message */ checkMinStackAllowed("-XX:ThreadStackSize=", ThreadStackSizeString, min_stack_allowed); /* * Now try with a stack size that is not page aligned. */ checkMinStackAllowed("-XX:ThreadStackSize=", ThreadStackSizeString, "513"); /* * Now redo the same tests with the compiler thread stack size: */ checkStack("-XX:CompilerThreadStackSize=", CompilerThreadStackSizeString, "16"); min_stack_allowed = checkStack("-XX:CompilerThreadStackSize=", CompilerThreadStackSizeString, "64"); checkMinStackAllowed("-XX:CompilerThreadStackSize=", CompilerThreadStackSizeString, min_stack_allowed); checkMinStackAllowed("-XX:CompilerThreadStackSize=", CompilerThreadStackSizeString, "513"); /* * Now redo the same tests with the VM thread stack size: */ checkStack("-XX:VMThreadStackSize=", VMThreadStackSizeString, "16"); min_stack_allowed = checkStack("-XX:VMThreadStackSize=", VMThreadStackSizeString, "64"); checkMinStackAllowed("-XX:VMThreadStackSize=", VMThreadStackSizeString, min_stack_allowed); checkMinStackAllowed("-XX:VMThreadStackSize=", VMThreadStackSizeString, "513"); } }