Mercurial > hg > truffle
view test/compiler/6912517/Test.java @ 10246:194f52aa2f23
7176479: G1: JVM crashes on T5-8 system with 1.5 TB heap
Summary: Refactor G1's hot card cache and card counts table into their own files. Simplify the card counts table, including removing the encoding of the card index in each entry. The card counts table now has a 1:1 correspondence with the cards spanned by heap. Space for the card counts table is reserved from virtual memory (rather than C heap) during JVM startup and is committed/expanded when the heap is expanded. Changes were also reviewed-by Vitaly Davidovich.
Reviewed-by: tschatzl, jmasa
author | johnc |
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date | Thu, 09 May 2013 11:16:39 -0700 |
parents | c18cbe5936b8 |
children |
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/* * Copyright 2009 D.E. Shaw. All Rights Reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ /** * @test * @bug 6912517 * @summary JIT bug compiles out (and stops running) code that needs to be run. Causes NPE. * * @run main/othervm -Xbatch -XX:CompileThreshold=100 -XX:+IgnoreUnrecognizedVMOptions -XX:-UseCompressedOops Test */ /** * Highlights a bug with the JIT compiler. * @author Matt Bruce m b r u c e __\at/__ g m a i l DOT c o m */ public class Test implements Runnable { private final Thread myThread; private Thread myInitialThread; private boolean myShouldCheckThreads; /** * Sets up the running thread, and starts it. */ public Test(int id) { myThread = new Thread(this); myThread.setName("Runner: " + id); myThread.start(); myShouldCheckThreads = false; } /** * @param shouldCheckThreads the shouldCheckThreads to set */ public void setShouldCheckThreads(boolean shouldCheckThreads) { myShouldCheckThreads = shouldCheckThreads; } /** * Starts up the two threads with enough delay between them for JIT to * kick in. * @param args * @throws InterruptedException */ public static void main(String[] args) throws InterruptedException { // let this run for a bit, so the "run" below is JITTed. for (int id = 0; id < 20; id++) { System.out.println("Starting thread: " + id); Test bug = new Test(id); bug.setShouldCheckThreads(true); Thread.sleep(2500); } } /** * @see java.lang.Runnable#run() */ public void run() { long runNumber = 0; while (true) { // run hot for a little while, give JIT time to kick in to this loop. // then run less hot. if (runNumber > 15000) { try { Thread.sleep(5); } catch (InterruptedException e) { e.printStackTrace(); } } runNumber++; ensureProperCallingThread(); } } private void ensureProperCallingThread() { // this should never be null. but with the JIT bug, it will be. // JIT BUG IS HERE ==>>>>> if (myShouldCheckThreads) { if (myInitialThread == null) { myInitialThread = Thread.currentThread(); } else if (myInitialThread != Thread.currentThread()) { System.out.println("Not working: " + myInitialThread.getName()); } } } }