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