1 /*
   2  * Copyright (c) 1997, 2019, 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 #include "precompiled.hpp"
  26 #include "classfile/altHashing.hpp"
  27 #include "classfile/javaClasses.inline.hpp"
  28 #include "memory/heapShared.inline.hpp"
  29 #include "memory/resourceArea.hpp"
  30 #include "memory/universe.hpp"
  31 #include "oops/access.inline.hpp"
  32 #include "oops/compressedOops.inline.hpp"
  33 #include "oops/oop.inline.hpp"
  34 #include "oops/verifyOopClosure.hpp"
  35 #include "runtime/handles.inline.hpp"
  36 #include "runtime/thread.inline.hpp"
  37 #include "utilities/copy.hpp"
  38 
  39 bool always_do_update_barrier = false;
  40 
  41 void oopDesc::print_on(outputStream* st) const {
  42   if (this == NULL) {
  43     st->print_cr("NULL");
  44   } else if (*((juint*)this) == badHeapWordVal) {
  45     st->print("BAD WORD");
  46   } else if (*((juint*)this) == badMetaWordVal) {
  47     st->print("BAD META WORD");
  48   } else {
  49     klass()->oop_print_on(oop(this), st);
  50   }
  51 }
  52 
  53 void oopDesc::print_address_on(outputStream* st) const {
  54   st->print("{" INTPTR_FORMAT "}", p2i(this));
  55 
  56 }
  57 
  58 void oopDesc::print()         { print_on(tty);         }
  59 
  60 void oopDesc::print_address() { print_address_on(tty); }
  61 
  62 char* oopDesc::print_string() {
  63   stringStream st;
  64   print_on(&st);
  65   return st.as_string();
  66 }
  67 
  68 void oopDesc::print_value() {
  69   print_value_on(tty);
  70 }
  71 
  72 char* oopDesc::print_value_string() {
  73   char buf[100];
  74   stringStream st(buf, sizeof(buf));
  75   print_value_on(&st);
  76   return st.as_string();
  77 }
  78 
  79 void oopDesc::print_value_on(outputStream* st) const {
  80   if (this == NULL) {
  81     st->print("NULL");
  82   } else {
  83     oop obj = oop(this);
  84     if (java_lang_String::is_instance(obj)) {
  85       java_lang_String::print(obj, st);
  86       print_address_on(st);
  87     } else {
  88       klass()->oop_print_value_on(obj, st);
  89     }
  90   }
  91 }
  92 
  93 
  94 void oopDesc::verify_on(outputStream* st, oopDesc* oop_desc) {
  95   if (oop_desc != NULL) {
  96     oop_desc->klass()->oop_verify_on(oop_desc, st);
  97   }
  98 }
  99 
 100 
 101 void oopDesc::verify(oopDesc* oop_desc) {
 102   verify_on(tty, oop_desc);
 103 }
 104 
 105 intptr_t oopDesc::slow_identity_hash() {
 106   // slow case; we have to acquire the micro lock in order to locate the header
 107   Thread* THREAD = Thread::current();
 108   ResetNoHandleMark rnm; // Might be called from LEAF/QUICK ENTRY
 109   HandleMark hm(THREAD);
 110   Handle object(THREAD, this);
 111   return ObjectSynchronizer::identity_hash_value_for(object);
 112 }
 113 
 114 // used only for asserts and guarantees
 115 bool oopDesc::is_oop(oop obj, bool ignore_mark_word) {
 116   if (!Universe::heap()->is_oop(obj)) {
 117     return false;
 118   }
 119 
 120   // Header verification: the mark is typically non-NULL. If we're
 121   // at a safepoint, it must not be null.
 122   // Outside of a safepoint, the header could be changing (for example,
 123   // another thread could be inflating a lock on this object).
 124   if (ignore_mark_word) {
 125     return true;
 126   }
 127   if (obj->mark_raw() != NULL) {
 128     return true;
 129   }
 130   return !SafepointSynchronize::is_at_safepoint();
 131 }
 132 
 133 // used only for asserts and guarantees
 134 bool oopDesc::is_oop_or_null(oop obj, bool ignore_mark_word) {
 135   return obj == NULL ? true : is_oop(obj, ignore_mark_word);
 136 }
 137 
 138 #ifndef PRODUCT
 139 #if INCLUDE_CDS_JAVA_HEAP
 140 bool oopDesc::is_archived_object(oop p) {
 141   return HeapShared::is_archived_object(p);
 142 }
 143 #endif
 144 #endif // PRODUCT
 145 
 146 VerifyOopClosure VerifyOopClosure::verify_oop;
 147 
 148 template <class T> void VerifyOopClosure::do_oop_work(T* p) {
 149   oop obj = RawAccess<>::oop_load(p);
 150   guarantee(oopDesc::is_oop_or_null(obj), "invalid oop: " INTPTR_FORMAT, p2i((oopDesc*) obj));
 151 }
 152 
 153 void VerifyOopClosure::do_oop(oop* p)       { VerifyOopClosure::do_oop_work(p); }
 154 void VerifyOopClosure::do_oop(narrowOop* p) { VerifyOopClosure::do_oop_work(p); }
 155 
 156 // type test operations that doesn't require inclusion of oop.inline.hpp.
 157 bool oopDesc::is_instance_noinline()          const { return is_instance();            }
 158 bool oopDesc::is_array_noinline()             const { return is_array();               }
 159 bool oopDesc::is_objArray_noinline()          const { return is_objArray();            }
 160 bool oopDesc::is_typeArray_noinline()         const { return is_typeArray();           }
 161 
 162 bool oopDesc::has_klass_gap() {
 163   // Only has a klass gap when compressed class pointers are used.
 164   return UseCompressedClassPointers;
 165 }
 166 
 167 void* oopDesc::load_klass_raw(oop obj) {
 168   if (UseCompressedClassPointers) {
 169     narrowKlass narrow_klass = *(obj->compressed_klass_addr());
 170     if (narrow_klass == 0) return NULL;
 171     return (void*)CompressedKlassPointers::decode_raw(narrow_klass);
 172   } else {
 173     return *(void**)(obj->klass_addr());
 174   }
 175 }
 176 
 177 void* oopDesc::load_oop_raw(oop obj, int offset) {
 178   uintptr_t addr = (uintptr_t)(void*)obj + (uint)offset;
 179   if (UseCompressedOops) {
 180     narrowOop narrow_oop = *(narrowOop*)addr;
 181     if (narrow_oop == 0) return NULL;
 182     return (void*)CompressedOops::decode_raw(narrow_oop);
 183   } else {
 184     return *(void**)addr;
 185   }
 186 }
 187 
 188 bool oopDesc::is_valid(oop obj) {
 189   if (!is_object_aligned(obj)) return false;
 190   if ((size_t)(oopDesc*)obj < os::min_page_size()) return false;
 191 
 192   // We need at least the mark and the klass word in the committed region.
 193   if (!os::is_readable_range(obj, (oopDesc*)obj + 1)) return false;
 194   if (!Universe::heap()->is_in(obj)) return false;
 195 
 196   Klass* k = (Klass*)load_klass_raw(obj);
 197   return Klass::is_valid(k);
 198 }
 199 
 200 oop oopDesc::oop_or_null(address addr) {
 201   if (is_valid(oop(addr))) {
 202     // We were just given an oop directly.
 203     return oop(addr);
 204   }
 205 
 206   // Try to find addr using block_start.
 207   HeapWord* p = Universe::heap()->block_start(addr);
 208   if (p != NULL && Universe::heap()->block_is_obj(p)) {
 209     if (!is_valid(oop(p))) return NULL;
 210     return oop(p);
 211   }
 212 
 213   // If we can't find it it just may mean that heap wasn't parsable.
 214   return NULL;
 215 }
 216 
 217 oop oopDesc::obj_field_acquire(int offset) const                      { return HeapAccess<MO_ACQUIRE>::oop_load_at(as_oop(), offset); }
 218 
 219 void oopDesc::obj_field_put_raw(int offset, oop value)                { RawAccess<>::oop_store_at(as_oop(), offset, value); }
 220 void oopDesc::release_obj_field_put(int offset, oop value)            { HeapAccess<MO_RELEASE>::oop_store_at(as_oop(), offset, value); }
 221 void oopDesc::obj_field_put_volatile(int offset, oop value)           { HeapAccess<MO_SEQ_CST>::oop_store_at(as_oop(), offset, value); }
 222 
 223 address oopDesc::address_field(int offset) const                      { return HeapAccess<>::load_at(as_oop(), offset); }
 224 address oopDesc::address_field_acquire(int offset) const              { return HeapAccess<MO_ACQUIRE>::load_at(as_oop(), offset); }
 225 
 226 void oopDesc::address_field_put(int offset, address value)            { HeapAccess<>::store_at(as_oop(), offset, value); }
 227 void oopDesc::release_address_field_put(int offset, address value)    { HeapAccess<MO_RELEASE>::store_at(as_oop(), offset, value); }
 228 
 229 Metadata* oopDesc::metadata_field(int offset) const                   { return HeapAccess<>::load_at(as_oop(), offset); }
 230 Metadata* oopDesc::metadata_field_raw(int offset) const               { return RawAccess<>::load_at(as_oop(), offset); }
 231 void oopDesc::metadata_field_put(int offset, Metadata* value)         { HeapAccess<>::store_at(as_oop(), offset, value); }
 232 
 233 Metadata* oopDesc::metadata_field_acquire(int offset) const           { return HeapAccess<MO_ACQUIRE>::load_at(as_oop(), offset); }
 234 void oopDesc::release_metadata_field_put(int offset, Metadata* value) { HeapAccess<MO_RELEASE>::store_at(as_oop(), offset, value); }
 235 
 236 jbyte oopDesc::byte_field_acquire(int offset) const                   { return HeapAccess<MO_ACQUIRE>::load_at(as_oop(), offset); }
 237 void oopDesc::release_byte_field_put(int offset, jbyte value)         { HeapAccess<MO_RELEASE>::store_at(as_oop(), offset, value); }
 238 
 239 jchar oopDesc::char_field_acquire(int offset) const                   { return HeapAccess<MO_ACQUIRE>::load_at(as_oop(), offset); }
 240 void oopDesc::release_char_field_put(int offset, jchar value)         { HeapAccess<MO_RELEASE>::store_at(as_oop(), offset, value); }
 241 
 242 jboolean oopDesc::bool_field_acquire(int offset) const                { return HeapAccess<MO_ACQUIRE>::load_at(as_oop(), offset); }
 243 void oopDesc::release_bool_field_put(int offset, jboolean value)      { HeapAccess<MO_RELEASE>::store_at(as_oop(), offset, jboolean(value & 1)); }
 244 
 245 jint oopDesc::int_field_acquire(int offset) const                     { return HeapAccess<MO_ACQUIRE>::load_at(as_oop(), offset); }
 246 void oopDesc::release_int_field_put(int offset, jint value)           { HeapAccess<MO_RELEASE>::store_at(as_oop(), offset, value); }
 247 
 248 jshort oopDesc::short_field_acquire(int offset) const                 { return HeapAccess<MO_ACQUIRE>::load_at(as_oop(), offset); }
 249 void oopDesc::release_short_field_put(int offset, jshort value)       { HeapAccess<MO_RELEASE>::store_at(as_oop(), offset, value); }
 250 
 251 jlong oopDesc::long_field_acquire(int offset) const                   { return HeapAccess<MO_ACQUIRE>::load_at(as_oop(), offset); }
 252 void oopDesc::release_long_field_put(int offset, jlong value)         { HeapAccess<MO_RELEASE>::store_at(as_oop(), offset, value); }
 253 
 254 jfloat oopDesc::float_field_acquire(int offset) const                 { return HeapAccess<MO_ACQUIRE>::load_at(as_oop(), offset); }
 255 void oopDesc::release_float_field_put(int offset, jfloat value)       { HeapAccess<MO_RELEASE>::store_at(as_oop(), offset, value); }
 256 
 257 jdouble oopDesc::double_field_acquire(int offset) const               { return HeapAccess<MO_ACQUIRE>::load_at(as_oop(), offset); }
 258 void oopDesc::release_double_field_put(int offset, jdouble value)     { HeapAccess<MO_RELEASE>::store_at(as_oop(), offset, value); }