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