view agent/src/share/classes/sun/jvm/hotspot/HelloWorld.java @ 6972:bd7a7ce2e264

6830717: replay of compilations would help with debugging Summary: When java process crashed in compiler thread, repeat the compilation process will help finding root cause. This is done with using SA dump application class data and replay data from core dump, then use debug version of jvm to recompile the problematic java method. Reviewed-by: kvn, twisti, sspitsyn Contributed-by: yumin.qi@oracle.com
author minqi
date Mon, 12 Nov 2012 14:03:53 -0800
parents 37be97a58393
children
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/*
 * Copyright (c) 2000, 2011, Oracle and/or its affiliates. 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.
 *
 */

package sun.jvm.hotspot;

import java.lang.reflect.*;

public class HelloWorld {
  private static String helloWorldString = "Hello, world!";
  private static volatile int helloWorldTrigger = 0;
  private static final boolean useMethodInvoke = false;
  private static Object lock = new Object();

  public static void main(String[] args) {
    int foo = a();

    System.out.println("HelloWorld exiting. a() = " + foo);
  }

  private static int a() {
    return 1 + b();
  }

  private static int b() {
    return 1 + c();
  }

  private static int c() {
    return 1 + d("Hi");
  }

  private static int d(String x) {
    System.out.println("HelloWorld.d() received \"" + x + "\" as argument");
    synchronized(lock) {
      if (useMethodInvoke) {
        try {
          Method method = HelloWorld.class.getMethod("e");
          Integer result = (Integer) method.invoke(null, new Object[0]);
          return result.intValue();
        }
        catch (Exception e) {
          throw new RuntimeException(e.toString());
        }
      } else {

        int i = fib(10); // 89
        long l = i;
        float f = i;
        double d = i;
        char c = (char) i;
        short s = (short) i;
        byte b = (byte) i;

        int ret = e();

        System.out.println("Tenth Fibonacci number in all formats: " +
                           i + ", " +
                           l + ", " +
                           f + ", " +
                           d + ", " +
                           c + ", " +
                           s + ", " +
                           b);

        return ret;
      }
    }
  }

  public static int e() {
    System.out.println("Going to sleep...");

    int i = 0;

    while (helloWorldTrigger == 0) {
      if (++i == 1000000) {
        System.gc();
      }
    }

    System.out.println(helloWorldString);

    while (helloWorldTrigger != 0) {
    }

    return i;
  }

  // Tree-recursive implementation for test
  public static int fib(int n) {
    if (n < 2) {
      return 1;
    }
    return fib(n - 1) + fib(n - 2);
  }
}