1 /*
   2  * Copyright (c) 2015, 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 #ifndef SHARE_VM_OOPS_INSTANCEREFKLASS_INLINE_HPP
  26 #define SHARE_VM_OOPS_INSTANCEREFKLASS_INLINE_HPP
  27 
  28 #include "classfile/javaClasses.inline.hpp"
  29 #include "gc/shared/referenceProcessor.hpp"
  30 #include "logging/log.hpp"
  31 #include "oops/access.inline.hpp"
  32 #include "oops/compressedOops.inline.hpp"
  33 #include "oops/instanceKlass.inline.hpp"
  34 #include "oops/instanceRefKlass.hpp"
  35 #include "oops/oop.inline.hpp"
  36 #include "utilities/debug.hpp"
  37 #include "utilities/globalDefinitions.hpp"
  38 #include "utilities/macros.hpp"
  39 
  40 template <bool nv, typename T, class OopClosureType, class Contains>
  41 void InstanceRefKlass::do_referent(oop obj, OopClosureType* closure, Contains& contains) {
  42   T* referent_addr = (T*)java_lang_ref_Reference::referent_addr_raw(obj);
  43   if (contains(referent_addr)) {
  44     Devirtualizer<nv>::do_oop(closure, referent_addr);
  45   }
  46 }
  47 
  48 template <bool nv, typename T, class OopClosureType, class Contains>
  49 void InstanceRefKlass::do_discovered(oop obj, OopClosureType* closure, Contains& contains) {
  50   T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr_raw(obj);
  51   if (contains(discovered_addr)) {
  52     Devirtualizer<nv>::do_oop(closure, discovered_addr);
  53   }
  54 }
  55 
  56 template <typename T, class OopClosureType>
  57 bool InstanceRefKlass::try_discover(oop obj, ReferenceType type, OopClosureType* closure) {
  58   ReferenceDiscoverer* rd = closure->ref_discoverer();
  59   if (rd != NULL) {
  60     oop referent;
  61     if (type == REF_PHANTOM) {
  62       referent = HeapAccess<ON_PHANTOM_OOP_REF | AS_NO_KEEPALIVE>::oop_load(java_lang_ref_Reference::referent_addr_raw(obj));
  63     } else {
  64       referent = HeapAccess<ON_WEAK_OOP_REF | AS_NO_KEEPALIVE>::oop_load(java_lang_ref_Reference::referent_addr_raw(obj));
  65     }
  66     if (referent != NULL) {
  67       if (!referent->is_gc_marked()) {
  68         // Only try to discover if not yet marked.
  69         return rd->discover_reference(obj, type);
  70       }
  71     }
  72   }
  73   return false;
  74 }
  75 
  76 template <bool nv, typename T, class OopClosureType, class Contains>
  77 void InstanceRefKlass::oop_oop_iterate_discovery(oop obj, ReferenceType type, OopClosureType* closure, Contains& contains) {
  78   // Try to discover reference and return if it succeeds.
  79   if (try_discover<T>(obj, type, closure)) {
  80     return;
  81   }
  82 
  83   // Treat referent and discovered as normal oops.
  84   do_referent<nv, T>(obj, closure, contains);
  85   do_discovered<nv, T>(obj, closure, contains);
  86 }
  87 
  88 template <bool nv, typename T, class OopClosureType, class Contains>
  89 void InstanceRefKlass::oop_oop_iterate_fields(oop obj, OopClosureType* closure, Contains& contains) {
  90   do_referent<nv, T>(obj, closure, contains);
  91   do_discovered<nv, T>(obj, closure, contains);
  92 }
  93 
  94 template <bool nv, typename T, class OopClosureType, class Contains>
  95 void InstanceRefKlass::oop_oop_iterate_discovered_and_discovery(oop obj, ReferenceType type, OopClosureType* closure, Contains& contains) {
  96   // Explicitly apply closure to the discovered field.
  97   do_discovered<nv, T>(obj, closure, contains);
  98   // Then do normal reference processing with discovery.
  99   oop_oop_iterate_discovery<nv, T>(obj, type, closure, contains);
 100 }
 101 
 102 template <bool nv, typename T, class OopClosureType, class Contains>
 103 void InstanceRefKlass::oop_oop_iterate_ref_processing_specialized(oop obj, OopClosureType* closure, Contains& contains) {
 104   switch (closure->reference_iteration_mode()) {
 105     case ExtendedOopClosure::DO_DISCOVERY:
 106       trace_reference_gc<T>("do_discovery", obj);
 107       oop_oop_iterate_discovery<nv, T>(obj, reference_type(), closure, contains);
 108       break;
 109     case ExtendedOopClosure::DO_DISCOVERED_AND_DISCOVERY:
 110       trace_reference_gc<T>("do_discovered_and_discovery", obj);
 111       oop_oop_iterate_discovered_and_discovery<nv, T>(obj, reference_type(), closure, contains);
 112       break;
 113     case ExtendedOopClosure::DO_FIELDS:
 114       trace_reference_gc<T>("do_fields", obj);
 115       oop_oop_iterate_fields<nv, T>(obj, closure, contains);
 116       break;
 117     default:
 118       ShouldNotReachHere();
 119   }
 120 }
 121 
 122 class AlwaysContains {
 123  public:
 124   template <typename T> bool operator()(T* p) const { return true; }
 125 };
 126 
 127 template <bool nv, class OopClosureType>
 128 void InstanceRefKlass::oop_oop_iterate_ref_processing(oop obj, OopClosureType* closure) {
 129   AlwaysContains always_contains;
 130   if (UseCompressedOops) {
 131     oop_oop_iterate_ref_processing_specialized<nv, narrowOop>(obj, closure, always_contains);
 132   } else {
 133     oop_oop_iterate_ref_processing_specialized<nv, oop>(obj, closure, always_contains);
 134   }
 135 }
 136 
 137 class MrContains {
 138   const MemRegion _mr;
 139  public:
 140   MrContains(MemRegion mr) : _mr(mr) {}
 141   template <typename T> bool operator()(T* p) const { return _mr.contains(p); }
 142 };
 143 
 144 template <bool nv, class OopClosureType>
 145 void InstanceRefKlass::oop_oop_iterate_ref_processing_bounded(oop obj, OopClosureType* closure, MemRegion mr) {
 146   const MrContains contains(mr);
 147   if (UseCompressedOops) {
 148     oop_oop_iterate_ref_processing_specialized<nv, narrowOop>(obj, closure, contains);
 149   } else {
 150     oop_oop_iterate_ref_processing_specialized<nv, oop>(obj, closure, contains);
 151   }
 152 }
 153 
 154 template <bool nv, class OopClosureType>
 155 void InstanceRefKlass::oop_oop_iterate(oop obj, OopClosureType* closure) {
 156   InstanceKlass::oop_oop_iterate<nv>(obj, closure);
 157 
 158   oop_oop_iterate_ref_processing<nv>(obj, closure);
 159 }
 160 
 161 #if INCLUDE_OOP_OOP_ITERATE_BACKWARDS
 162 template <bool nv, class OopClosureType>
 163 void InstanceRefKlass::oop_oop_iterate_reverse(oop obj, OopClosureType* closure) {
 164   InstanceKlass::oop_oop_iterate_reverse<nv>(obj, closure);
 165 
 166   oop_oop_iterate_ref_processing<nv>(obj, closure);
 167 }
 168 #endif // INCLUDE_OOP_OOP_ITERATE_BACKWARDS
 169 
 170 
 171 template <bool nv, class OopClosureType>
 172 void InstanceRefKlass::oop_oop_iterate_bounded(oop obj, OopClosureType* closure, MemRegion mr) {
 173   InstanceKlass::oop_oop_iterate_bounded<nv>(obj, closure, mr);
 174 
 175   oop_oop_iterate_ref_processing_bounded<nv>(obj, closure, mr);
 176 }
 177 
 178 #ifdef ASSERT
 179 template <typename T>
 180 void InstanceRefKlass::trace_reference_gc(const char *s, oop obj) {
 181   T* referent_addr   = (T*) java_lang_ref_Reference::referent_addr_raw(obj);
 182   T* discovered_addr = (T*) java_lang_ref_Reference::discovered_addr_raw(obj);
 183 
 184   log_develop_trace(gc, ref)("InstanceRefKlass %s for obj " PTR_FORMAT, s, p2i(obj));
 185   log_develop_trace(gc, ref)("     referent_addr/* " PTR_FORMAT " / " PTR_FORMAT,
 186       p2i(referent_addr), p2i((oop)HeapAccess<ON_UNKNOWN_OOP_REF | AS_NO_KEEPALIVE>::oop_load_at(obj, java_lang_ref_Reference::referent_offset)));
 187   log_develop_trace(gc, ref)("     discovered_addr/* " PTR_FORMAT " / " PTR_FORMAT,
 188       p2i(discovered_addr), p2i((oop)HeapAccess<AS_NO_KEEPALIVE>::oop_load(discovered_addr)));
 189 }
 190 #endif
 191 
 192 // Macro to define InstanceRefKlass::oop_oop_iterate for virtual/nonvirtual for
 193 // all closures.  Macros calling macros above for each oop size.
 194 #define ALL_INSTANCE_REF_KLASS_OOP_OOP_ITERATE_DEFN(OopClosureType, nv_suffix)  \
 195   OOP_OOP_ITERATE_DEFN(          InstanceRefKlass, OopClosureType, nv_suffix)   \
 196   OOP_OOP_ITERATE_DEFN_BOUNDED(  InstanceRefKlass, OopClosureType, nv_suffix)   \
 197   OOP_OOP_ITERATE_DEFN_BACKWARDS(InstanceRefKlass, OopClosureType, nv_suffix)
 198 
 199 #endif // SHARE_VM_OOPS_INSTANCEREFKLASS_INLINE_HPP