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 import com.sun.management.HotSpotDiagnosticMXBean;
  34 import sun.hotspot.WhiteBox;
  35 
  36 public class WBStackSize {
  37 
  38     static final long MIN_STACK_SIZE = 8 * 1024;
  39     static final long MAX_STACK_SIZE_ALLOCATED_IN_MAIN = 200 * 1024; // current value is about 130k on 64-bit platforms
  40 
  41     static final WhiteBox wb = WhiteBox.getWhiteBox();
  42 
  43     static long stackRemainingSize = -1;
  44 
  45     static int eatAllStack() {
  46         return eatAllStack() * 2;
  47     }
  48     
  49     static void testStackOverflow() {
  50 
  51         stackRemainingSize = wb.getThreadRemainingStackSize();
  52 
  53         if (stackRemainingSize > MIN_STACK_SIZE) {
  54 
  55             try {
  56                 testStackOverflow();
  57             } catch (StackOverflowError e) {
  58                 // We caught SOE too early. The error will be reported in main()
  59             }
  60 
  61         } else {
  62 
  63             try {
  64                 eatAllStack();
  65                 throw new RuntimeException("Haven't caught StackOverflowError at all. Is 2*2==4 on this machine?");
  66             } catch (StackOverflowError e) {
  67                 // OK: we caught the anticipated error
  68             }
  69         }
  70     }
  71 
  72     public static void main(String[] args) {
  73         HotSpotDiagnosticMXBean bean = sun.management.ManagementFactoryHelper.getDiagnosticMXBean();
  74         long tss = Long.valueOf(bean.getVMOption("ThreadStackSize").getValue()) * 1024;
  75 
  76         System.out.println("ThreadStackSize VM option = " + tss);
  77 
  78         long fss = wb.getThreadFullStackSize();
  79         System.out.println("Full stack size " + fss);
  80 
  81         if (fss < tss * 0.9 || fss > tss * 1.1) {
  82             throw new RuntimeException("getThreadFullStackSize value [" + fss 
  83                                      + "] should be within 90%..110% of the value returned by HotSpotDiagnosticMXBean");
  84         }
  85 
  86         long rss = wb.getThreadRemainingStackSize();
  87         System.out.println("Remaining stack size " + rss);
  88         
  89         // Up to 200k can be already allocated by VM
  90         if (rss > tss || (tss > MAX_STACK_SIZE_ALLOCATED_IN_MAIN && rss < tss - MAX_STACK_SIZE_ALLOCATED_IN_MAIN)) {
  91             throw new RuntimeException("getThreadRemainingStackSize value [" + rss 
  92                                      + "] should be at least ThreadStackSize value [" + tss + "] minus [" 
  93                                      + MAX_STACK_SIZE_ALLOCATED_IN_MAIN + "]");
  94         }
  95 
  96         testStackOverflow();
  97 
  98         if (stackRemainingSize > MIN_STACK_SIZE) {
  99             throw new RuntimeException("Caught StackOverflowError too early: when there were " 
 100                                      + stackRemainingSize + " bytes in stack");
 101         } else if (stackRemainingSize < 0) {
 102             throw new RuntimeException("Internal test error: stackRemainingSize < 0");
 103         } else {
 104             System.out.println("Caught StackOverflowError as expected");
 105         }
 106     }
 107 }