1 /*
   2  * Copyright (c) 2015, 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 #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/instanceKlass.inline.hpp"
  32 #include "oops/instanceRefKlass.hpp"
  33 #include "oops/oop.inline.hpp"
  34 #include "utilities/debug.hpp"
  35 #include "utilities/globalDefinitions.hpp"
  36 #include "utilities/macros.hpp"
  37 
  38 template <bool nv, typename T, class OopClosureType, class Contains>
  39 void InstanceRefKlass::do_referent(oop obj, OopClosureType* closure, Contains& contains) {
  40   T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj);
  41   if (contains(referent_addr)) {
  42     Devirtualizer<nv>::do_oop(closure, referent_addr);
  43   }
  44 }
  45 
  46 template <bool nv, typename T, class OopClosureType, class Contains>
  47 void InstanceRefKlass::do_next(oop obj, OopClosureType* closure, Contains& contains) {
  48   T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj);
  49   if (contains(next_addr)) {
  50     Devirtualizer<nv>::do_oop(closure, next_addr);
  51   }
  52 }
  53 
  54 template <bool nv, typename T, class OopClosureType, class Contains>
  55 void InstanceRefKlass::do_discovered(oop obj, OopClosureType* closure, Contains& contains) {
  56   T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr(obj);
  57   if (contains(discovered_addr)) {
  58     Devirtualizer<nv>::do_oop(closure, discovered_addr);
  59   }
  60 }
  61 
  62 template <typename T, class OopClosureType>
  63 bool InstanceRefKlass::try_discover(oop obj, ReferenceType type, OopClosureType* closure) {
  64   ReferenceProcessor* rp = closure->ref_processor();
  65   if (rp != NULL) {
  66     T referent_oop = oopDesc::load_heap_oop((T*)java_lang_ref_Reference::referent_addr(obj));
  67     if (!oopDesc::is_null(referent_oop)) {
  68       oop referent = oopDesc::decode_heap_oop_not_null(referent_oop);
  69       if (!referent->is_gc_marked()) {
  70         // Only try to discover if not yet marked.
  71         return rp->discover_reference(obj, type);
  72       }
  73     }
  74   }
  75   return false;
  76 }
  77 
  78 template <bool nv, typename T, class OopClosureType, class Contains>
  79 void InstanceRefKlass::oop_oop_iterate_discovery(oop obj, ReferenceType type, OopClosureType* closure, Contains& contains) {
  80   log_develop_trace(gc, ref)("Process reference with discovery " PTR_FORMAT, p2i(obj));
  81 
  82   // Special case for some closures.
  83   if (closure->apply_to_weak_ref_discovered_field()) {
  84     do_discovered<nv, T>(obj, closure, contains);
  85   }
  86 
  87   // Try to discover reference and return if it succeeds.
  88   if (try_discover<T>(obj, type, closure)) {
  89     return;
  90   }
  91 
  92   // Treat referent as normal oop.
  93   do_referent<nv, T>(obj, closure, contains);
  94 
  95   // Treat discovered as normal oop, if ref is not "active" (next non-NULL).
  96   T next_oop  = oopDesc::load_heap_oop((T*)java_lang_ref_Reference::next_addr(obj));
  97   if (!oopDesc::is_null(next_oop)) {
  98     do_discovered<nv, T>(obj, closure, contains);
  99   }
 100 
 101   // Treat next as normal oop.
 102   do_next<nv, T>(obj, closure, contains);
 103 }
 104 
 105 template <bool nv, typename T, class OopClosureType, class Contains>
 106 void InstanceRefKlass::oop_oop_iterate_fields(oop obj, OopClosureType* closure, Contains& contains) {
 107   do_referent<nv, T>(obj, closure, contains);
 108   do_discovered<nv, T>(obj, closure, contains);
 109   do_next<nv, T>(obj, closure, contains);
 110 
 111   trace_reference_gc("InstanceRefKlass::oop_oop_iterate_fields()",
 112                      obj,
 113                      (T*)java_lang_ref_Reference::referent_addr(obj),
 114                      (T*)java_lang_ref_Reference::next_addr(obj),
 115                      (T*)java_lang_ref_Reference::discovered_addr(obj));
 116 }
 117 
 118 template <bool nv, typename T, class OopClosureType, class Contains>
 119 void InstanceRefKlass::oop_oop_iterate_ref_processing_specialized(oop obj, OopClosureType* closure, Contains& contains) {
 120   switch (closure->reference_iteration_mode()) {
 121     case ExtendedOopClosure::DO_DISCOVERY:
 122       oop_oop_iterate_discovery<nv, T>(obj, reference_type(), closure, contains);
 123       break;
 124     case ExtendedOopClosure::DO_FIELDS:
 125       oop_oop_iterate_fields<nv, T>(obj, closure, contains);
 126       break;
 127     default:
 128       ShouldNotReachHere();
 129   }
 130 }
 131 
 132 class AlwaysContains {
 133  public:
 134   template <typename T> bool operator()(T* p) const { return true; }
 135 };
 136 
 137 template <bool nv, class OopClosureType>
 138 void InstanceRefKlass::oop_oop_iterate_ref_processing(oop obj, OopClosureType* closure) {
 139   AlwaysContains always_contains;
 140   if (UseCompressedOops) {
 141     oop_oop_iterate_ref_processing_specialized<nv, narrowOop>(obj, closure, always_contains);
 142   } else {
 143     oop_oop_iterate_ref_processing_specialized<nv, oop>(obj, closure, always_contains);
 144   }
 145 }
 146 
 147 class MrContains {
 148   const MemRegion _mr;
 149  public:
 150   MrContains(MemRegion mr) : _mr(mr) {}
 151   template <typename T> bool operator()(T* p) const { return _mr.contains(p); }
 152 };
 153 
 154 template <bool nv, class OopClosureType>
 155 void InstanceRefKlass::oop_oop_iterate_ref_processing_bounded(oop obj, OopClosureType* closure, MemRegion mr) {
 156   const MrContains contains(mr);
 157   if (UseCompressedOops) {
 158     oop_oop_iterate_ref_processing_specialized<nv, narrowOop>(obj, closure, contains);
 159   } else {
 160     oop_oop_iterate_ref_processing_specialized<nv, oop>(obj, closure, contains);
 161   }
 162 }
 163 
 164 template <bool nv, class OopClosureType>
 165 void InstanceRefKlass::oop_oop_iterate(oop obj, OopClosureType* closure) {
 166   InstanceKlass::oop_oop_iterate<nv>(obj, closure);
 167 
 168   oop_oop_iterate_ref_processing<nv>(obj, closure);
 169 }
 170 
 171 #if INCLUDE_ALL_GCS
 172 template <bool nv, class OopClosureType>
 173 void InstanceRefKlass::oop_oop_iterate_reverse(oop obj, OopClosureType* closure) {
 174   InstanceKlass::oop_oop_iterate_reverse<nv>(obj, closure);
 175 
 176   oop_oop_iterate_ref_processing<nv>(obj, closure);
 177 }
 178 #endif // INCLUDE_ALL_GCS
 179 
 180 
 181 template <bool nv, class OopClosureType>
 182 void InstanceRefKlass::oop_oop_iterate_bounded(oop obj, OopClosureType* closure, MemRegion mr) {
 183   InstanceKlass::oop_oop_iterate_bounded<nv>(obj, closure, mr);
 184 
 185   oop_oop_iterate_ref_processing_bounded<nv>(obj, closure, mr);
 186 }
 187 
 188 #ifdef ASSERT
 189 template <typename T>
 190 void InstanceRefKlass::trace_reference_gc(const char *s, oop obj, T* referent_addr, T* next_addr, T* discovered_addr) {
 191   log_develop_trace(gc, ref)("%s obj " PTR_FORMAT, s, p2i(obj));
 192   log_develop_trace(gc, ref)("     referent_addr/* " PTR_FORMAT " / " PTR_FORMAT,
 193       p2i(referent_addr), p2i(referent_addr ? (address)oopDesc::load_decode_heap_oop(referent_addr) : NULL));
 194   log_develop_trace(gc, ref)("     next_addr/* " PTR_FORMAT " / " PTR_FORMAT,
 195       p2i(next_addr), p2i(next_addr ? (address)oopDesc::load_decode_heap_oop(next_addr) : NULL));
 196   log_develop_trace(gc, ref)("     discovered_addr/* " PTR_FORMAT " / " PTR_FORMAT,
 197       p2i(discovered_addr), p2i(discovered_addr ? (address)oopDesc::load_decode_heap_oop(discovered_addr) : NULL));
 198 }
 199 #endif
 200 
 201 // Macro to define InstanceRefKlass::oop_oop_iterate for virtual/nonvirtual for
 202 // all closures.  Macros calling macros above for each oop size.
 203 #define ALL_INSTANCE_REF_KLASS_OOP_OOP_ITERATE_DEFN(OopClosureType, nv_suffix)  \
 204   OOP_OOP_ITERATE_DEFN(          InstanceRefKlass, OopClosureType, nv_suffix)   \
 205   OOP_OOP_ITERATE_DEFN_BOUNDED(  InstanceRefKlass, OopClosureType, nv_suffix)   \
 206   OOP_OOP_ITERATE_DEFN_BACKWARDS(InstanceRefKlass, OopClosureType, nv_suffix)
 207 
 208 #endif // SHARE_VM_OOPS_INSTANCEREFKLASS_INLINE_HPP