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 }