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.
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  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_raw(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_raw(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_raw(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_raw(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   // Try to discover reference and return if it succeeds.
  81   if (try_discover<T>(obj, type, closure)) {
  82     return;
  83   }
  84 
  85   // Treat referent as normal oop.
  86   do_referent<nv, T>(obj, closure, contains);
  87 
  88   // Treat discovered as normal oop, if ref is not "active" (next non-NULL).
  89   T next_oop  = oopDesc::load_heap_oop((T*)java_lang_ref_Reference::next_addr_raw(obj));
  90   if (!oopDesc::is_null(next_oop)) {
  91     do_discovered<nv, T>(obj, closure, contains);
  92   }
  93 
  94   // Treat next as normal oop.
  95   do_next<nv, T>(obj, closure, contains);
  96 }
  97 
  98 template <bool nv, typename T, class OopClosureType, class Contains>
  99 void InstanceRefKlass::oop_oop_iterate_fields(oop obj, OopClosureType* closure, Contains& contains) {
 100   do_referent<nv, T>(obj, closure, contains);
 101   do_discovered<nv, T>(obj, closure, contains);
 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_discovered_and_discovery(oop obj, ReferenceType type, OopClosureType* closure, Contains& contains) {
 107   // Explicitly apply closure to the discovered field.
 108   do_discovered<nv, T>(obj, closure, contains);
 109   // Then do normal reference processing with discovery.
 110   oop_oop_iterate_discovery<nv, T>(obj, type, closure, contains);
 111 }
 112 
 113 template <bool nv, typename T, class OopClosureType, class Contains>
 114 void InstanceRefKlass::oop_oop_iterate_ref_processing_specialized(oop obj, OopClosureType* closure, Contains& contains) {
 115   switch (closure->reference_iteration_mode()) {
 116     case ExtendedOopClosure::DO_DISCOVERY:
 117       trace_reference_gc<T>("do_discovery", obj);
 118       oop_oop_iterate_discovery<nv, T>(obj, reference_type(), closure, contains);
 119       break;
 120     case ExtendedOopClosure::DO_DISCOVERED_AND_DISCOVERY:
 121       trace_reference_gc<T>("do_discovered_and_discovery", obj);
 122       oop_oop_iterate_discovered_and_discovery<nv, T>(obj, reference_type(), closure, contains);
 123       break;
 124     case ExtendedOopClosure::DO_FIELDS:
 125       trace_reference_gc<T>("do_fields", obj);
 126       oop_oop_iterate_fields<nv, T>(obj, closure, contains);
 127       break;
 128     default:
 129       ShouldNotReachHere();
 130   }
 131 }
 132 
 133 class AlwaysContains {
 134  public:
 135   template <typename T> bool operator()(T* p) const { return true; }
 136 };
 137 
 138 template <bool nv, class OopClosureType>
 139 void InstanceRefKlass::oop_oop_iterate_ref_processing(oop obj, OopClosureType* closure) {
 140   AlwaysContains always_contains;
 141   if (UseCompressedOops) {
 142     oop_oop_iterate_ref_processing_specialized<nv, narrowOop>(obj, closure, always_contains);
 143   } else {
 144     oop_oop_iterate_ref_processing_specialized<nv, oop>(obj, closure, always_contains);
 145   }
 146 }
 147 
 148 class MrContains {
 149   const MemRegion _mr;
 150  public:
 151   MrContains(MemRegion mr) : _mr(mr) {}
 152   template <typename T> bool operator()(T* p) const { return _mr.contains(p); }
 153 };
 154 
 155 template <bool nv, class OopClosureType>
 156 void InstanceRefKlass::oop_oop_iterate_ref_processing_bounded(oop obj, OopClosureType* closure, MemRegion mr) {
 157   const MrContains contains(mr);
 158   if (UseCompressedOops) {
 159     oop_oop_iterate_ref_processing_specialized<nv, narrowOop>(obj, closure, contains);
 160   } else {
 161     oop_oop_iterate_ref_processing_specialized<nv, oop>(obj, closure, contains);
 162   }
 163 }
 164 
 165 template <bool nv, class OopClosureType>
 166 void InstanceRefKlass::oop_oop_iterate(oop obj, OopClosureType* closure) {
 167   InstanceKlass::oop_oop_iterate<nv>(obj, closure);
 168 
 169   oop_oop_iterate_ref_processing<nv>(obj, closure);
 170 }
 171 
 172 #if INCLUDE_ALL_GCS
 173 template <bool nv, class OopClosureType>
 174 void InstanceRefKlass::oop_oop_iterate_reverse(oop obj, OopClosureType* closure) {
 175   InstanceKlass::oop_oop_iterate_reverse<nv>(obj, closure);
 176 
 177   oop_oop_iterate_ref_processing<nv>(obj, closure);
 178 }
 179 #endif // INCLUDE_ALL_GCS
 180 
 181 
 182 template <bool nv, class OopClosureType>
 183 void InstanceRefKlass::oop_oop_iterate_bounded(oop obj, OopClosureType* closure, MemRegion mr) {
 184   InstanceKlass::oop_oop_iterate_bounded<nv>(obj, closure, mr);
 185 
 186   oop_oop_iterate_ref_processing_bounded<nv>(obj, closure, mr);
 187 }
 188 
 189 #ifdef ASSERT
 190 template <typename T>
 191 void InstanceRefKlass::trace_reference_gc(const char *s, oop obj) {
 192   T* referent_addr   = (T*) java_lang_ref_Reference::referent_addr_raw(obj);
 193   T* next_addr       = (T*) java_lang_ref_Reference::next_addr_raw(obj);
 194   T* discovered_addr = (T*) java_lang_ref_Reference::discovered_addr_raw(obj);
 195 
 196   log_develop_trace(gc, ref)("InstanceRefKlass %s for obj " PTR_FORMAT, s, p2i(obj));
 197   log_develop_trace(gc, ref)("     referent_addr/* " PTR_FORMAT " / " PTR_FORMAT,
 198       p2i(referent_addr), p2i(referent_addr ? (address)oopDesc::load_decode_heap_oop(referent_addr) : NULL));
 199   log_develop_trace(gc, ref)("     next_addr/* " PTR_FORMAT " / " PTR_FORMAT,
 200       p2i(next_addr), p2i(next_addr ? (address)oopDesc::load_decode_heap_oop(next_addr) : NULL));
 201   log_develop_trace(gc, ref)("     discovered_addr/* " PTR_FORMAT " / " PTR_FORMAT,
 202       p2i(discovered_addr), p2i(discovered_addr ? (address)oopDesc::load_decode_heap_oop(discovered_addr) : NULL));
 203 }
 204 #endif
 205 
 206 // Macro to define InstanceRefKlass::oop_oop_iterate for virtual/nonvirtual for
 207 // all closures.  Macros calling macros above for each oop size.
 208 #define ALL_INSTANCE_REF_KLASS_OOP_OOP_ITERATE_DEFN(OopClosureType, nv_suffix)  \
 209   OOP_OOP_ITERATE_DEFN(          InstanceRefKlass, OopClosureType, nv_suffix)   \
 210   OOP_OOP_ITERATE_DEFN_BOUNDED(  InstanceRefKlass, OopClosureType, nv_suffix)   \
 211   OOP_OOP_ITERATE_DEFN_BACKWARDS(InstanceRefKlass, OopClosureType, nv_suffix)
 212 
 213 #endif // SHARE_VM_OOPS_INSTANCEREFKLASS_INLINE_HPP