1 /*
2 * Copyright (c) 1997, 2023, 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/compressedKlass.inline.hpp"
34 #include "oops/compressedOops.inline.hpp"
35 #include "oops/oop.inline.hpp"
36 #include "oops/verifyOopClosure.hpp"
37 #include "runtime/handles.inline.hpp"
38 #include "runtime/interfaceSupport.inline.hpp"
39 #include "runtime/javaThread.hpp"
40 #include "runtime/synchronizer.hpp"
41 #include "utilities/macros.hpp"
42
43 void oopDesc::print_on(outputStream* st) const {
44 if (*((juint*)this) == badHeapWordVal) {
45 st->print_cr("BAD WORD");
46 } else if (*((juint*)this) == badMetaWordVal) {
47 st->print_cr("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("{" PTR_FORMAT "}", p2i(this));
55
56 }
57
58 void oopDesc::print_name_on(outputStream* st) const {
59 if (*((juint*)this) == badHeapWordVal) {
60 st->print_cr("BAD WORD");
61 } else if (*((juint*)this) == badMetaWordVal) {
62 st->print_cr("BAD META WORD");
63 } else {
64 st->print_cr("%s", klass()->external_name());
65 }
66 }
67
68 void oopDesc::print() { print_on(tty); }
69
70 void oopDesc::print_address() { print_address_on(tty); }
71
72 char* oopDesc::print_string() {
73 stringStream st;
74 print_on(&st);
75 return st.as_string();
76 }
77
78 void oopDesc::print_value() {
79 print_value_on(tty);
80 }
81
82 char* oopDesc::print_value_string() {
83 char buf[100];
84 stringStream st(buf, sizeof(buf));
85 print_value_on(&st);
86 return st.as_string();
87 }
88
89 void oopDesc::print_value_on(outputStream* st) const {
90 oop obj = const_cast<oopDesc*>(this);
91 if (java_lang_String::is_instance(obj)) {
92 java_lang_String::print(obj, st);
93 print_address_on(st);
94 } else {
95 klass()->oop_print_value_on(obj, st);
96 }
97 }
98
99
100 void oopDesc::verify_on(outputStream* st, oopDesc* oop_desc) {
101 if (oop_desc != nullptr) {
102 oop_desc->klass()->oop_verify_on(oop_desc, st);
103 }
104 }
105
106
107 void oopDesc::verify(oopDesc* oop_desc) {
108 verify_on(tty, oop_desc);
109 }
110
111 intptr_t oopDesc::slow_identity_hash() {
112 // slow case; we have to acquire the micro lock in order to locate the header
113 Thread* current = Thread::current();
114 return ObjectSynchronizer::FastHashCode(current, this);
115 }
116
117 // used only for asserts and guarantees
118 bool oopDesc::is_oop(oop obj, bool ignore_mark_word) {
119 if (!Universe::heap()->is_oop(obj)) {
120 return false;
121 }
122
123 // Header verification: the mark is typically non-zero. If we're
124 // at a safepoint, it must not be zero, except when using the new lightweight locking.
125 // Outside of a safepoint, the header could be changing (for example,
126 // another thread could be inflating a lock on this object).
127 if (ignore_mark_word) {
128 return true;
129 }
130 if (obj->mark().value() != 0) {
131 return true;
132 }
133 return LockingMode == LM_LIGHTWEIGHT || !SafepointSynchronize::is_at_safepoint();
134 }
135
136 // used only for asserts and guarantees
137 bool oopDesc::is_oop_or_null(oop obj, bool ignore_mark_word) {
138 return obj == nullptr ? true : is_oop(obj, ignore_mark_word);
139 }
140
141 VerifyOopClosure VerifyOopClosure::verify_oop;
142
143 template <class T> void VerifyOopClosure::do_oop_work(T* p) {
144 oop obj = RawAccess<>::oop_load(p);
145 guarantee(oopDesc::is_oop_or_null(obj), "invalid oop: " PTR_FORMAT, p2i(obj));
146 }
147
148 void VerifyOopClosure::do_oop(oop* p) { VerifyOopClosure::do_oop_work(p); }
149 void VerifyOopClosure::do_oop(narrowOop* p) { VerifyOopClosure::do_oop_work(p); }
150
151 // type test operations that doesn't require inclusion of oop.inline.hpp.
152 bool oopDesc::is_instance_noinline() const { return is_instance(); }
153 bool oopDesc::is_instanceRef_noinline() const { return is_instanceRef(); }
154 bool oopDesc::is_stackChunk_noinline() const { return is_stackChunk(); }
155 bool oopDesc::is_array_noinline() const { return is_array(); }
156 bool oopDesc::is_objArray_noinline() const { return is_objArray(); }
157 bool oopDesc::is_typeArray_noinline() const { return is_typeArray(); }
158
159 bool oopDesc::has_klass_gap() {
160 // Only has a klass gap when compressed class pointers are used, but
161 // only if not using compact headers..
162 return UseCompressedClassPointers && !UseCompactObjectHeaders;
163 }
164
165 #if INCLUDE_CDS_JAVA_HEAP
166 void oopDesc::set_narrow_klass(narrowKlass nk) {
167 assert(DumpSharedSpaces, "Used by CDS only. Do not abuse!");
168 assert(UseCompressedClassPointers, "must be");
169 if (UseCompactObjectHeaders) {
170 set_mark(mark().set_narrow_klass(nk));
171 } else {
172 _metadata._compressed_klass = nk;
173 }
174 }
175 #endif
176
177 void* oopDesc::load_klass_raw(oop obj) {
178 // TODO: Remove method altogether and replace with calls to obj->klass() ?
179 // OTOH, we may eventually get rid of locking in header, and then no
180 // longer have to deal with that anymore.
181 #ifdef _LP64
182 return obj->klass();
183 #else
184 return obj->_metadata._klass;
185 #endif
186 }
187
188 void* oopDesc::load_oop_raw(oop obj, int offset) {
189 uintptr_t addr = (uintptr_t)(void*)obj + (uint)offset;
190 if (UseCompressedOops) {
191 narrowOop narrow_oop = *(narrowOop*)addr;
192 if (CompressedOops::is_null(narrow_oop)) return nullptr;
193 return (void*)CompressedOops::decode_raw(narrow_oop);
194 } else {
195 return *(void**)addr;
196 }
197 }
198
199 oop oopDesc::obj_field_acquire(int offset) const { return HeapAccess<MO_ACQUIRE>::oop_load_at(as_oop(), offset); }
200
201 void oopDesc::obj_field_put_raw(int offset, oop value) { assert(!(UseZGC && ZGenerational), "Generational ZGC must use store barriers");
202 RawAccess<>::oop_store_at(as_oop(), offset, value); }
203 void oopDesc::release_obj_field_put(int offset, oop value) { HeapAccess<MO_RELEASE>::oop_store_at(as_oop(), offset, value); }
204 void oopDesc::obj_field_put_volatile(int offset, oop value) { HeapAccess<MO_SEQ_CST>::oop_store_at(as_oop(), offset, value); }
205
206 address oopDesc::address_field(int offset) const { return *field_addr<address>(offset); }
207 address oopDesc::address_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<address>(offset)); }
208
209 void oopDesc::address_field_put(int offset, address value) { *field_addr<address>(offset) = value; }
210 void oopDesc::release_address_field_put(int offset, address value) { Atomic::release_store(field_addr<address>(offset), value); }
211
212 Metadata* oopDesc::metadata_field(int offset) const { return *field_addr<Metadata*>(offset); }
213 void oopDesc::metadata_field_put(int offset, Metadata* value) { *field_addr<Metadata*>(offset) = value; }
214
215 Metadata* oopDesc::metadata_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<Metadata*>(offset)); }
216 void oopDesc::release_metadata_field_put(int offset, Metadata* value) { Atomic::release_store(field_addr<Metadata*>(offset), value); }
217
218 jbyte oopDesc::byte_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jbyte>(offset)); }
219 void oopDesc::release_byte_field_put(int offset, jbyte value) { Atomic::release_store(field_addr<jbyte>(offset), value); }
220
221 jchar oopDesc::char_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jchar>(offset)); }
222 void oopDesc::release_char_field_put(int offset, jchar value) { Atomic::release_store(field_addr<jchar>(offset), value); }
223
224 jboolean oopDesc::bool_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jboolean>(offset)); }
225 void oopDesc::release_bool_field_put(int offset, jboolean value) { Atomic::release_store(field_addr<jboolean>(offset), jboolean(value & 1)); }
226
227 jint oopDesc::int_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jint>(offset)); }
228 void oopDesc::release_int_field_put(int offset, jint value) { Atomic::release_store(field_addr<jint>(offset), value); }
229
230 jshort oopDesc::short_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jshort>(offset)); }
231 void oopDesc::release_short_field_put(int offset, jshort value) { Atomic::release_store(field_addr<jshort>(offset), value); }
232
233 jlong oopDesc::long_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jlong>(offset)); }
234 void oopDesc::release_long_field_put(int offset, jlong value) { Atomic::release_store(field_addr<jlong>(offset), value); }
235
236 jfloat oopDesc::float_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jfloat>(offset)); }
237 void oopDesc::release_float_field_put(int offset, jfloat value) { Atomic::release_store(field_addr<jfloat>(offset), value); }
238
239 jdouble oopDesc::double_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jdouble>(offset)); }
240 void oopDesc::release_double_field_put(int offset, jdouble value) { Atomic::release_store(field_addr<jdouble>(offset), value); }
241
242 #ifdef ASSERT
243 bool oopDesc::size_might_change() {
244 // UseParallelGC and UseG1GC can change the length field
245 // of an "old copy" of an object array in the young gen so it indicates
246 // the grey portion of an already copied array. This will cause the first
247 // disjunct below to fail if the two comparands are computed across such
248 // a concurrent change.
249 return Universe::heap()->is_gc_active() && is_objArray() && is_forwarded() && (UseParallelGC || UseG1GC);
250 }
251 #endif