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 <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::do_oop(closure, referent_addr);
  45   }
  46 }
  47 
  48 template <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::do_oop(closure, discovered_addr);
  53   }
  54 }
  55 
  56 static inline oop load_referent(oop obj, ReferenceType type) {
  57   if (type == REF_PHANTOM) {
  58     return HeapAccess<ON_PHANTOM_OOP_REF | AS_NO_KEEPALIVE>::oop_load(java_lang_ref_Reference::referent_addr_raw(obj));
  59   } else {
  60     return HeapAccess<ON_WEAK_OOP_REF | AS_NO_KEEPALIVE>::oop_load(java_lang_ref_Reference::referent_addr_raw(obj));
  61   }
  62 }
  63 
  64 template <typename T, class OopClosureType>
  65 bool InstanceRefKlass::try_discover(oop obj, ReferenceType type, OopClosureType* closure) {
  66   ReferenceDiscoverer* rd = closure->ref_discoverer();
  67   if (rd != NULL) {
  68     oop referent = load_referent(obj, type);
  69     if (referent != NULL) {
  70       if (!referent->is_gc_marked()) {
  71         // Only try to discover if not yet marked.
  72         return rd->discover_reference(obj, type);
  73       }
  74     }
  75   }
  76   return false;
  77 }
  78 
  79 template <typename T, class OopClosureType, class Contains>
  80 void InstanceRefKlass::oop_oop_iterate_discovery(oop obj, ReferenceType type, OopClosureType* closure, Contains& contains) {
  81   // Try to discover reference and return if it succeeds.
  82   if (try_discover<T>(obj, type, closure)) {
  83     return;
  84   }
  85 
  86   // Treat referent and discovered as normal oops.
  87   do_referent<T>(obj, closure, contains);
  88   do_discovered<T>(obj, closure, contains);
  89 }
  90 
  91 template <typename T, class OopClosureType, class Contains>
  92 void InstanceRefKlass::oop_oop_iterate_discovered_and_discovery(oop obj, ReferenceType type, OopClosureType* closure, Contains& contains) {
  93   // Explicitly apply closure to the discovered field.
  94   do_discovered<T>(obj, closure, contains);
  95   // Then do normal reference processing with discovery.
  96   oop_oop_iterate_discovery<T>(obj, type, closure, contains);
  97 }
  98 
  99 template <typename T, class OopClosureType, class Contains>
 100 void InstanceRefKlass::oop_oop_iterate_fields(oop obj, OopClosureType* closure, Contains& contains) {
 101   assert(closure->ref_discoverer() == NULL, "ReferenceDiscoverer should not be set");
 102   do_referent<T>(obj, closure, contains);
 103   do_discovered<T>(obj, closure, contains);
 104 }
 105 
 106 template <typename T, class OopClosureType, class Contains>
 107 void InstanceRefKlass::oop_oop_iterate_fields_except_referent(oop obj, OopClosureType* closure, Contains& contains) {
 108   assert(closure->ref_discoverer() == NULL, "ReferenceDiscoverer should not be set");
 109   do_discovered<T>(obj, closure, contains);
 110 }
 111 
 112 template <typename T, class OopClosureType, class Contains>
 113 void InstanceRefKlass::oop_oop_iterate_ref_processing(oop obj, OopClosureType* closure, Contains& contains) {
 114   switch (closure->reference_iteration_mode()) {
 115     case OopIterateClosure::DO_DISCOVERY:
 116       trace_reference_gc<T>("do_discovery", obj);
 117       oop_oop_iterate_discovery<T>(obj, reference_type(), closure, contains);
 118       break;
 119     case OopIterateClosure::DO_DISCOVERED_AND_DISCOVERY:
 120       trace_reference_gc<T>("do_discovered_and_discovery", obj);
 121       oop_oop_iterate_discovered_and_discovery<T>(obj, reference_type(), closure, contains);
 122       break;
 123     case OopIterateClosure::DO_FIELDS:
 124       trace_reference_gc<T>("do_fields", obj);
 125       oop_oop_iterate_fields<T>(obj, closure, contains);
 126       break;
 127     case OopIterateClosure::DO_FIELDS_EXCEPT_REFERENT:
 128       trace_reference_gc<T>("do_fields_except_referent", obj);
 129       oop_oop_iterate_fields_except_referent<T>(obj, closure, contains);
 130       break;
 131     default:
 132       ShouldNotReachHere();
 133   }
 134 }
 135 
 136 class AlwaysContains {
 137  public:
 138   template <typename T> bool operator()(T* p) const { return true; }
 139 };
 140 
 141 template <typename T, class OopClosureType>
 142 void InstanceRefKlass::oop_oop_iterate_ref_processing(oop obj, OopClosureType* closure) {
 143   AlwaysContains always_contains;
 144   oop_oop_iterate_ref_processing<T>(obj, closure, always_contains);
 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 <typename T, class OopClosureType>
 155 void InstanceRefKlass::oop_oop_iterate_ref_processing_bounded(oop obj, OopClosureType* closure, MemRegion mr) {
 156   const MrContains contains(mr);
 157   oop_oop_iterate_ref_processing<T>(obj, closure, contains);
 158 }
 159 
 160 template <typename T, class OopClosureType>
 161 void InstanceRefKlass::oop_oop_iterate(oop obj, OopClosureType* closure) {
 162   InstanceKlass::oop_oop_iterate<T>(obj, closure);
 163 
 164   oop_oop_iterate_ref_processing<T>(obj, closure);
 165 }
 166 
 167 template <typename T, class OopClosureType>
 168 void InstanceRefKlass::oop_oop_iterate_reverse(oop obj, OopClosureType* closure) {
 169   InstanceKlass::oop_oop_iterate_reverse<T>(obj, closure);
 170 
 171   oop_oop_iterate_ref_processing<T>(obj, closure);
 172 }
 173 
 174 template <typename T, class OopClosureType>
 175 void InstanceRefKlass::oop_oop_iterate_bounded(oop obj, OopClosureType* closure, MemRegion mr) {
 176   InstanceKlass::oop_oop_iterate_bounded<T>(obj, closure, mr);
 177 
 178   oop_oop_iterate_ref_processing_bounded<T>(obj, closure, mr);
 179 }
 180 
 181 #ifdef ASSERT
 182 template <typename T>
 183 void InstanceRefKlass::trace_reference_gc(const char *s, oop obj) {
 184   T* referent_addr   = (T*) java_lang_ref_Reference::referent_addr_raw(obj);
 185   T* discovered_addr = (T*) java_lang_ref_Reference::discovered_addr_raw(obj);
 186 
 187   log_develop_trace(gc, ref)("InstanceRefKlass %s for obj " PTR_FORMAT, s, p2i(obj));
 188   if (java_lang_ref_Reference::is_phantom(obj)) {
 189     log_develop_trace(gc, ref)("     referent_addr/* " PTR_FORMAT " / " PTR_FORMAT,
 190                                p2i(referent_addr), p2i((oop)HeapAccess<ON_PHANTOM_OOP_REF | AS_NO_KEEPALIVE>::oop_load(referent_addr)));
 191   } else {
 192     log_develop_trace(gc, ref)("     referent_addr/* " PTR_FORMAT " / " PTR_FORMAT,
 193                                p2i(referent_addr), p2i((oop)HeapAccess<ON_WEAK_OOP_REF | AS_NO_KEEPALIVE>::oop_load(referent_addr)));
 194   }
 195   log_develop_trace(gc, ref)("     discovered_addr/* " PTR_FORMAT " / " PTR_FORMAT,
 196       p2i(discovered_addr), p2i((oop)HeapAccess<AS_NO_KEEPALIVE>::oop_load(discovered_addr)));
 197 }
 198 #endif
 199 
 200 #endif // SHARE_VM_OOPS_INSTANCEREFKLASS_INLINE_HPP