1 /*
   2  * Copyright (c) 2014, 2015, 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  * @summary Test corner case that overflows malloc site hashtable bucket
  27  * @requires sun.arch.data.model == "32"
  28  * @key nmt jcmd stress
  29  * @modules java.base/jdk.internal.misc
  30  * @library /test/lib
  31  * @build sun.hotspot.WhiteBox
  32  * @run main ClassFileInstaller sun.hotspot.WhiteBox
  33  * @run main/othervm -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -XX:NativeMemoryTracking=detail MallocSiteHashOverflow
  34  */
  35 
  36 import jdk.test.lib.JDKToolFinder;
  37 import jdk.test.lib.process.ProcessTools;
  38 import jdk.test.lib.process.OutputAnalyzer;
  39 import sun.hotspot.WhiteBox;
  40 
  41 public class MallocSiteHashOverflow {
  42 
  43     public static void main(String args[]) throws Exception {
  44 
  45         // Size of entries based on malloc tracking header defined in mallocTracker.hpp
  46         // For 32-bit systems, create 257 malloc sites with the same hash bucket to overflow a hash bucket
  47         long entries = 257;
  48 
  49         OutputAnalyzer output;
  50         WhiteBox wb = WhiteBox.getWhiteBox();
  51         int MAX_HASH_SIZE = wb.NMTGetHashSize();
  52 
  53         // Grab my own PID
  54         String pid = Long.toString(ProcessTools.getProcessId());
  55         ProcessBuilder pb = new ProcessBuilder();
  56 
  57         // Verify that current tracking level is "detail"
  58         pb.command(new String[] { JDKToolFinder.getJDKTool("jcmd"), pid, "VM.native_memory", "statistics"});
  59         output = new OutputAnalyzer(pb.start());
  60         output.shouldContain("Native Memory Tracking Statistics");
  61 
  62         // Attempt to cause NMT to downgrade tracking level by allocating small amounts
  63         // of memory with random pseudo call stack
  64         int pc = 1;
  65         for (int i = 0; i < entries; i++) {
  66             long addr = wb.NMTMallocWithPseudoStack(1, pc);
  67             if (addr == 0) {
  68                 throw new RuntimeException("NMTMallocWithPseudoStack: out of memory");
  69             }
  70             // We free memory here since it doesn't affect pseudo malloc alloc site hash table entries
  71             wb.NMTFree(addr);
  72             pc += MAX_HASH_SIZE;
  73             if (i == entries) {
  74                 // Verify that tracking has been downgraded
  75                 pb.command(new String[] { JDKToolFinder.getJDKTool("jcmd"), pid, "VM.native_memory", "statistics"});
  76                 output = new OutputAnalyzer(pb.start());
  77                 output.shouldContain("Tracking level has been downgraded due to lack of resources");
  78             }
  79         }
  80     }
  81 }