1 /*
   2  * Copyright (c) 1997, 2014, 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_INLINE_HPP
  26 #define SHARE_VM_OOPS_INSTANCEREFKLASS_INLINE_HPP
  27 
  28 #include "utilities/templateIdioms.hpp"
  29 #include "memory/specialized_oop_closures.inline.hpp"
  30 #include "oops/instanceRefKlass.hpp"
  31 #include "oops/instanceKlass.inline.hpp"
  32 
  33 template<class OopClosureType>
  34 inline int InstanceRefKlass::oop_iterate_and_dispatch(oop obj, OopClosureType *cl) {
  35   SpecializationStats::record_iterate_call_nv(SpecializationStats::irk);
  36   int size = InstanceKlass::oop_iterate_and_dispatch<OopClosureType>(obj, cl);
  37 
  38   if (UseCompressedOops) {
  39     do_metadata_if_applicable<OopClosureType, narrowOop, is_kind_of<OopClosureType, ExtendedOopClosure>::value>(obj, cl);
  40   } else {
  41     do_metadata_if_applicable<OopClosureType, oop, is_kind_of<OopClosureType, ExtendedOopClosure>::value>(obj, cl);
  42   }
  43 
  44   return size;
  45 }
  46 
  47 
  48 template<class OopClosureType, class OopType, bool is_extended>
  49 inline void InstanceRefKlass::do_metadata_if_applicable(oop obj, OopClosureType *cl) {
  50   OopType *disc_addr = (OopType*)java_lang_ref_Reference::discovered_addr(obj);
  51   if (is_extended && reinterpret_cast<ExtendedOopClosure*>(cl)->apply_to_weak_ref_discovered_field()) {
  52     OopClosureDispatcher::do_oop<OopClosureType, OopType>(cl, disc_addr);
  53   }
  54   OopType *referent_addr = (OopType*)java_lang_ref_Reference::discovered_addr(obj);
  55   OopType heap_oop = oopDesc::load_heap_oop(referent_addr);
  56   ReferenceProcessor *rp = is_extended ? reinterpret_cast<ExtendedOopClosure*>(cl)->_ref_processor : NULL;
  57   if (!oopDesc::is_null(heap_oop)) {
  58     oop referent = oopDesc::decode_heap_oop_not_null(heap_oop);
  59     if (!referent->is_gc_marked() && rp != NULL && rp->discover_reference(obj, reference_type())) {
  60       return;
  61     } else {
  62       /* treat referent as normal oop */
  63       SpecializationStats::record_do_oop_call_nv(SpecializationStats::irk);
  64       OopClosureDispatcher::do_oop<OopClosureType, OopType>(cl, referent_addr);
  65     }
  66   }
  67 
  68   OopType *next_addr = (OopType*)java_lang_ref_Reference::next_addr(obj);
  69   if (ReferenceProcessor::pending_list_uses_discovered_field()) {
  70     OopType next_oop = oopDesc::load_heap_oop(next_addr);
  71     /* Treat discovered as normal oop, if ref is not "active" (next non-NULL) */
  72     if (!oopDesc::is_null(next_oop)) {
  73       /* i.e. ref is not "active" */
  74       debug_only(
  75         if (TraceReferenceGC && PrintGCDetails) {
  76           gclog_or_tty->print_cr("   Process discovered as normal ", INTPTR_FORMAT, disc_addr);
  77         }
  78       )
  79     }
  80   } else {
  81     /* In the case of older JDKs which do not use the discovered field for  */
  82     /* the pending list, an inactive ref (next != NULL) must always have a  */
  83     /* NULL discovered field. */
  84     debug_only(
  85       OopType next_oop = oopDesc::load_heap_oop(next_addr);
  86       OopType disc_oop = oopDesc::load_heap_oop(disc_addr);
  87       assert(oopDesc::is_null(next_oop) || oopDesc::is_null(disc_oop),
  88             err_msg("Found an inactive reference " PTR_FORMAT " with a non-NULL discovered field", (oopDesc*)obj));
  89     )
  90   }
  91 
  92   /* treat next as normal oop */
  93   SpecializationStats::record_do_oop_call_nv(SpecializationStats::irk);
  94   OopClosureDispatcher::do_oop<OopClosureType, OopType>(cl, next_addr);
  95 }
  96 
  97 #endif // SHARE_VM_OOPS_INSTANCEREFKLASS_INLINE_HPP
  98