1 /*
   2  * Copyright (c) 1997, 2013, 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 #ifndef SHARE_VM_OOPS_INSTANCEREFKLASS_HPP
  26 #define SHARE_VM_OOPS_INSTANCEREFKLASS_HPP
  27 
  28 #include "memory/specialized_oop_closures.hpp"
  29 #include "oops/instanceKlass.hpp"
  30 #include "utilities/macros.hpp"
  31 
  32 // An InstanceRefKlass is a specialized InstanceKlass for Java
  33 // classes that are subclasses of java/lang/ref/Reference.
  34 //
  35 // These classes are used to implement soft/weak/final/phantom
  36 // references and finalization, and need special treatment by the
  37 // garbage collector.
  38 //
  39 // During GC discovered reference objects are added (chained) to one
  40 // of the four lists below, depending on the type of reference.
  41 // The linked occurs through the next field in class java/lang/ref/Reference.
  42 //
  43 // Afterwards, the discovered references are processed in decreasing
  44 // order of reachability. Reference objects eligible for notification
  45 // are linked to the static pending_list in class java/lang/ref/Reference,
  46 // and the pending list lock object in the same class is notified.
  47 
  48 

   1 /*
   2  * Copyright (c) 1997, 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 #ifndef SHARE_VM_OOPS_INSTANCEREFKLASS_HPP
  26 #define SHARE_VM_OOPS_INSTANCEREFKLASS_HPP
  27 
  28 #include "gc/shared/specialized_oop_closures.hpp"
  29 #include "oops/instanceKlass.hpp"
  30 #include "utilities/macros.hpp"
  31 
  32 // An InstanceRefKlass is a specialized InstanceKlass for Java
  33 // classes that are subclasses of java/lang/ref/Reference.
  34 //
  35 // These classes are used to implement soft/weak/final/phantom
  36 // references and finalization, and need special treatment by the
  37 // garbage collector.
  38 //
  39 // During GC discovered reference objects are added (chained) to one
  40 // of the four lists below, depending on the type of reference.
  41 // The linked occurs through the next field in class java/lang/ref/Reference.
  42 //
  43 // Afterwards, the discovered references are processed in decreasing
  44 // order of reachability. Reference objects eligible for notification
  45 // are linked to the static pending_list in class java/lang/ref/Reference,
  46 // and the pending list lock object in the same class is notified.
  47 
  48