1 /*
   2  * Copyright (c) 2017, 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 import java.lang.instrument.ClassFileTransformer;
  26 import java.lang.instrument.Instrumentation;
  27 import java.lang.instrument.IllegalClassFormatException;
  28 import java.security.ProtectionDomain;
  29 
  30 public class GCDuringDumpTransformer implements ClassFileTransformer {
  31     static int n = 0;
  32     public byte[] transform(ClassLoader loader, String name, Class<?> classBeingRedefined,
  33                             ProtectionDomain pd, byte[] buffer) throws IllegalClassFormatException {
  34         n++;
  35 
  36         System.out.println("dump time loading: " + name + " in loader: " + loader);
  37         System.out.println("making garbage: " + n);
  38         try {
  39             makeGarbage();
  40         } catch (Throwable t) {
  41             t.printStackTrace();
  42             try {
  43                 Thread.sleep(200); // let GC to have a chance to run
  44             } catch (Throwable t2) {}
  45         }
  46         System.out.println("making garbage: done");
  47 
  48         return null;
  49     }
  50 
  51     private static Instrumentation savedInstrumentation;
  52 
  53     public static void premain(String agentArguments, Instrumentation instrumentation) {
  54         System.out.println("ClassFileTransformer.premain() is called");
  55         instrumentation.addTransformer(new GCDuringDumpTransformer(), /*canRetransform=*/true);
  56         savedInstrumentation = instrumentation;
  57     }
  58 
  59     public static Instrumentation getInstrumentation() {
  60         return savedInstrumentation;
  61     }
  62 
  63     public static void agentmain(String args, Instrumentation inst) throws Exception {
  64         premain(args, inst);
  65     }
  66 

   1 /*
   2  * Copyright (c) 2017, 2018, 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 import java.lang.instrument.ClassFileTransformer;
  26 import java.lang.instrument.Instrumentation;
  27 import java.lang.instrument.IllegalClassFormatException;
  28 import java.security.ProtectionDomain;
  29 
  30 public class GCDuringDumpTransformer implements ClassFileTransformer {

  31     public byte[] transform(ClassLoader loader, String name, Class<?> classBeingRedefined,
  32                             ProtectionDomain pd, byte[] buffer) throws IllegalClassFormatException {




  33         try {
  34             makeGarbage();
  35         } catch (Throwable t) {
  36             t.printStackTrace();
  37             try {
  38                 Thread.sleep(200); // let GC to have a chance to run
  39             } catch (Throwable t2) {}
  40         }

  41 
  42         return null;
  43     }
  44 
  45     private static Instrumentation savedInstrumentation;
  46 
  47     public static void premain(String agentArguments, Instrumentation instrumentation) {
  48         System.out.println("ClassFileTransformer.premain() is called");
  49         instrumentation.addTransformer(new GCDuringDumpTransformer(), /*canRetransform=*/true);
  50         savedInstrumentation = instrumentation;
  51     }
  52 
  53     public static Instrumentation getInstrumentation() {
  54         return savedInstrumentation;
  55     }
  56 
  57     public static void agentmain(String args, Instrumentation inst) throws Exception {
  58         premain(args, inst);
  59     }
  60