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 WBStackSize
  26  * @summary verify that whitebox functions getThreadFullStackSize() and getThreadRemainingStackSize are working
  27  * @library /testlibrary /testlibrary/whitebox
  28  * @build WBStackSize
  29  * @run main ClassFileInstaller sun.hotspot.WhiteBox
  30  * @run main/othervm -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xss512k WBStackSize 
  31  */
  32 
  33 /* 
  34  * The test may product a false failure if too big StackYellowPages/StackRedPages/ShackShadowPages 
  35  * VM options are specified. The proper test would retrieve the page size from VM and account for these options
  36  * instead of check below:
  37  *     Math.abs(actualStackSize - configStackSize) > configStackSize * 0.1
  38  * 
  39  * Please file a test bug, if this is a problem.
  40  */
  41 
  42 import com.sun.management.HotSpotDiagnosticMXBean;
  43 import sun.hotspot.WhiteBox;
  44 
  45 public class WBStackSize {
  46 
  47     static final long K = 1024;
  48 
  49     static final long MIN_STACK_SIZE = 8 * K;
  50     static final long MAX_STACK_SIZE_ALLOCATED_IN_MAIN = 200 * K; // current value is about 130k on 64-bit platforms
  51 
  52     static final WhiteBox wb = WhiteBox.getWhiteBox();
  53 
  54     static long stackSizeOnOverflow = -1;
  55 
  56     static int eatAllStack() {
  57         return eatAllStack() * 2;
  58     }
  59     
  60     static void testStackOverflow() {
  61 
  62         stackSizeOnOverflow = wb.getThreadRemainingStackSize();
  63 
  64         if (stackSizeOnOverflow > MIN_STACK_SIZE) {
  65 
  66             try {
  67                 testStackOverflow();
  68             } catch (StackOverflowError e) {
  69                 // We caught SOE too early. The error will be reported in main()
  70             }
  71 
  72         } else {
  73 
  74             try {
  75                 eatAllStack();
  76                 throw new RuntimeException("Haven't caught StackOverflowError at all");
  77             } catch (StackOverflowError e) {
  78                 // OK: we caught the anticipated error
  79             }
  80         }
  81     }
  82 
  83     public static void main(String[] args) {
  84         HotSpotDiagnosticMXBean bean = sun.management.ManagementFactoryHelper.getDiagnosticMXBean();
  85         long configStackSize = Long.valueOf(bean.getVMOption("ThreadStackSize").getValue()) * K;
  86 
  87         System.out.println("ThreadStackSize VM option: " + configStackSize);
  88 
  89         long actualStackSize = wb.getThreadStackSize();
  90         System.out.println("Full stack size: " + actualStackSize);
  91 
  92         if (Math.abs(actualStackSize - configStackSize) > configStackSize * 0.1) {
  93             throw new RuntimeException("getThreadFullStackSize value [" + actualStackSize 
  94                                      + "] should be within 90%..110% of the value returned by HotSpotDiagnosticMXBean");
  95         }
  96 
  97         long remainingStackSize = wb.getThreadRemainingStackSize();
  98         System.out.println("Remaining stack size in main(): " + remainingStackSize);
  99         
 100         // Up to 200k can be already allocated by VM
 101         if (remainingStackSize > configStackSize 
 102                 || (configStackSize > MAX_STACK_SIZE_ALLOCATED_IN_MAIN 
 103                 && remainingStackSize < configStackSize - MAX_STACK_SIZE_ALLOCATED_IN_MAIN)) {
 104 
 105             throw new RuntimeException("getThreadRemainingStackSize value [" + remainingStackSize 
 106                                      + "] should be at least ThreadStackSize value [" + configStackSize + "] minus [" 
 107                                      + MAX_STACK_SIZE_ALLOCATED_IN_MAIN + "]");
 108         }
 109 
 110         testStackOverflow();
 111 
 112         if (stackSizeOnOverflow > MIN_STACK_SIZE) {
 113             throw new RuntimeException("Caught StackOverflowError too early: when there were " 
 114                                      + stackSizeOnOverflow + " bytes in stack");
 115         } else if (stackSizeOnOverflow < 0) {
 116             throw new RuntimeException("Internal test error: stackRemainingSize < 0");
 117         } else {
 118             System.out.println("Caught StackOverflowError as expected");
 119         }
 120     }
 121 }