1 /*
  2  * Copyright (c) 1997, 2021, 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 "gc/shared/collectedHeap.inline.hpp"
 29 #include "gc/shared/gc_globals.hpp"
 30 #include "memory/resourceArea.hpp"
 31 #include "memory/universe.hpp"
 32 #include "oops/access.inline.hpp"
 33 #include "oops/compressedOops.inline.hpp"
 34 #include "oops/oop.inline.hpp"
 35 #include "oops/verifyOopClosure.hpp"
 36 #include "runtime/handles.inline.hpp"
 37 #include "runtime/thread.inline.hpp"
 38 #include "utilities/copy.hpp"
 39 #include "utilities/macros.hpp"
 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(cast_to_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 = cast_to_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* current = Thread::current();
108   ResetNoHandleMark rnm; // Might be called from LEAF/QUICK ENTRY
109   HandleMark hm(current);
110   Handle object(current, 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-zero. If we're
121   // at a safepoint, it must not be zero.
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().value() != 0) {
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 VerifyOopClosure VerifyOopClosure::verify_oop;
139 
140 template <class T> void VerifyOopClosure::do_oop_work(T* p) {
141   oop obj = RawAccess<>::oop_load(p);
142   guarantee(oopDesc::is_oop_or_null(obj), "invalid oop: " INTPTR_FORMAT, p2i((oopDesc*) obj));
143 }
144 
145 void VerifyOopClosure::do_oop(oop* p)       { VerifyOopClosure::do_oop_work(p); }
146 void VerifyOopClosure::do_oop(narrowOop* p) { VerifyOopClosure::do_oop_work(p); }
147 
148 // type test operations that doesn't require inclusion of oop.inline.hpp.
149 bool oopDesc::is_instance_noinline()          const { return is_instance();            }
150 bool oopDesc::is_array_noinline()             const { return is_array();               }
151 bool oopDesc::is_objArray_noinline()          const { return is_objArray();            }
152 bool oopDesc::is_typeArray_noinline()         const { return is_typeArray();           }
153 bool oopDesc::is_stackChunk_noinline()        const { return is_stackChunk();          }
154 
155 bool oopDesc::has_klass_gap() {
156   // Only has a klass gap when compressed class pointers are used.
157   return UseCompressedClassPointers;
158 }
159 
160 #if INCLUDE_CDS_JAVA_HEAP
161 void oopDesc::set_narrow_klass(narrowKlass nk) {
162   assert(DumpSharedSpaces, "Used by CDS only. Do not abuse!");
163   assert(UseCompressedClassPointers, "must be");
164   _metadata._compressed_klass = nk;
165 }
166 #endif
167 
168 void* oopDesc::load_klass_raw(oop obj) {
169   if (UseCompressedClassPointers) {
170     narrowKlass narrow_klass = obj->_metadata._compressed_klass;
171     if (narrow_klass == 0) return NULL;
172     return (void*)CompressedKlassPointers::decode_raw(narrow_klass);
173   } else {
174     return obj->_metadata._klass;
175   }
176 }
177 
178 void* oopDesc::load_oop_raw(oop obj, int offset) {
179   uintptr_t addr = (uintptr_t)(void*)obj + (uint)offset;
180   if (UseCompressedOops) {
181     narrowOop narrow_oop = *(narrowOop*)addr;
182     if (CompressedOops::is_null(narrow_oop)) return NULL;
183     return (void*)CompressedOops::decode_raw(narrow_oop);
184   } else {
185     return *(void**)addr;
186   }
187 }
188 
189 oop oopDesc::obj_field_acquire(int offset) const                      { return HeapAccess<MO_ACQUIRE>::oop_load_at(as_oop(), offset); }
190 
191 void oopDesc::obj_field_put_raw(int offset, oop value)                { RawAccess<>::oop_store_at(as_oop(), offset, value); }
192 void oopDesc::release_obj_field_put(int offset, oop value)            { HeapAccess<MO_RELEASE>::oop_store_at(as_oop(), offset, value); }
193 void oopDesc::obj_field_put_volatile(int offset, oop value)           { HeapAccess<MO_SEQ_CST>::oop_store_at(as_oop(), offset, value); }
194 
195 address oopDesc::address_field(int offset) const                      { return *field_addr<address>(offset); }
196 address oopDesc::address_field_acquire(int offset) const              { return Atomic::load_acquire(field_addr<address>(offset)); }
197 
198 void oopDesc::address_field_put(int offset, address value)            { *field_addr<address>(offset) = value; }
199 void oopDesc::release_address_field_put(int offset, address value)    { Atomic::release_store(field_addr<address>(offset), value); }
200 
201 Metadata* oopDesc::metadata_field(int offset) const                   { return *field_addr<Metadata*>(offset); }
202 void oopDesc::metadata_field_put(int offset, Metadata* value)         { *field_addr<Metadata*>(offset) = value; }
203 
204 Metadata* oopDesc::metadata_field_acquire(int offset) const           { return Atomic::load_acquire(field_addr<Metadata*>(offset)); }
205 void oopDesc::release_metadata_field_put(int offset, Metadata* value) { Atomic::release_store(field_addr<Metadata*>(offset), value); }
206 
207 jbyte oopDesc::byte_field_acquire(int offset) const                   { return Atomic::load_acquire(field_addr<jbyte>(offset)); }
208 void oopDesc::release_byte_field_put(int offset, jbyte value)         { Atomic::release_store(field_addr<jbyte>(offset), value); }
209 
210 jchar oopDesc::char_field_acquire(int offset) const                   { return Atomic::load_acquire(field_addr<jchar>(offset)); }
211 void oopDesc::release_char_field_put(int offset, jchar value)         { Atomic::release_store(field_addr<jchar>(offset), value); }
212 
213 jboolean oopDesc::bool_field_acquire(int offset) const                { return Atomic::load_acquire(field_addr<jboolean>(offset)); }
214 void oopDesc::release_bool_field_put(int offset, jboolean value)      { Atomic::release_store(field_addr<jboolean>(offset), jboolean(value & 1)); }
215 
216 jint oopDesc::int_field_acquire(int offset) const                     { return Atomic::load_acquire(field_addr<jint>(offset)); }
217 void oopDesc::release_int_field_put(int offset, jint value)           { Atomic::release_store(field_addr<jint>(offset), value); }
218 
219 jshort oopDesc::short_field_acquire(int offset) const                 { return Atomic::load_acquire(field_addr<jshort>(offset)); }
220 void oopDesc::release_short_field_put(int offset, jshort value)       { Atomic::release_store(field_addr<jshort>(offset), value); }
221 
222 jlong oopDesc::long_field_acquire(int offset) const                   { return Atomic::load_acquire(field_addr<jlong>(offset)); }
223 void oopDesc::release_long_field_put(int offset, jlong value)         { Atomic::release_store(field_addr<jlong>(offset), value); }
224 
225 jfloat oopDesc::float_field_acquire(int offset) const                 { return Atomic::load_acquire(field_addr<jfloat>(offset)); }
226 void oopDesc::release_float_field_put(int offset, jfloat value)       { Atomic::release_store(field_addr<jfloat>(offset), value); }
227 
228 jdouble oopDesc::double_field_acquire(int offset) const               { return Atomic::load_acquire(field_addr<jdouble>(offset)); }
229 void oopDesc::release_double_field_put(int offset, jdouble value)     { Atomic::release_store(field_addr<jdouble>(offset), value); }
230 
231 #ifdef ASSERT
232 void oopDesc::verify_forwardee(oop forwardee) {
233 #if INCLUDE_CDS_JAVA_HEAP
234   assert(!Universe::heap()->is_archived_object(forwardee) && !Universe::heap()->is_archived_object(this),
235          "forwarding archive object");
236 #endif
237 }
238 
239 bool oopDesc::size_might_change() {
240   // UseParallelGC and UseG1GC can change the length field
241   // of an "old copy" of an object array in the young gen so it indicates
242   // the grey portion of an already copied array. This will cause the first
243   // disjunct below to fail if the two comparands are computed across such
244   // a concurrent change.
245   return Universe::heap()->is_gc_active() && is_objArray() && is_forwarded() && (UseParallelGC || UseG1GC);
246 }
247 #endif
--- EOF ---