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/javaThread.hpp"
39 #include "runtime/synchronizer.hpp"
40 #include "utilities/macros.hpp"
41
42 void oopDesc::print_on(outputStream* st) const {
43 if (*((juint*)this) == badHeapWordVal) {
44 st->print_cr("BAD WORD");
45 } else if (*((juint*)this) == badMetaWordVal) {
46 st->print_cr("BAD META WORD");
47 } else {
48 klass()->oop_print_on(cast_to_oop(this), st);
49 }
50 }
51
52 void oopDesc::print_address_on(outputStream* st) const {
53 st->print("{" PTR_FORMAT "}", p2i(this));
54
55 }
56
57 void oopDesc::print_name_on(outputStream* st) const {
58 if (*((juint*)this) == badHeapWordVal) {
59 st->print_cr("BAD WORD");
60 } else if (*((juint*)this) == badMetaWordVal) {
61 st->print_cr("BAD META WORD");
62 } else {
63 st->print_cr("%s", klass()->external_name());
64 }
65 }
66
67 void oopDesc::print() { print_on(tty); }
68
69 void oopDesc::print_address() { print_address_on(tty); }
70
71 char* oopDesc::print_string() {
72 stringStream st;
73 print_on(&st);
74 return st.as_string();
75 }
76
77 void oopDesc::print_value() {
78 print_value_on(tty);
79 }
80
81 char* oopDesc::print_value_string() {
82 char buf[100];
83 stringStream st(buf, sizeof(buf));
84 print_value_on(&st);
85 return st.as_string();
86 }
87
88 void oopDesc::print_value_on(outputStream* st) const {
89 oop obj = const_cast<oopDesc*>(this);
90 if (java_lang_String::is_instance(obj)) {
91 java_lang_String::print(obj, st);
92 print_address_on(st);
93 } else {
94 klass()->oop_print_value_on(obj, st);
95 }
96 }
97
98
99 void oopDesc::verify_on(outputStream* st, oopDesc* oop_desc) {
100 if (oop_desc != nullptr) {
101 oop_desc->klass()->oop_verify_on(oop_desc, st);
102 }
103 }
104
105
106 void oopDesc::verify(oopDesc* oop_desc) {
107 verify_on(tty, oop_desc);
108 }
109
110 intptr_t oopDesc::slow_identity_hash() {
111 // slow case; we have to acquire the micro lock in order to locate the header
112 Thread* current = Thread::current();
113 return ObjectSynchronizer::FastHashCode(current, this);
114 }
115
116 // used only for asserts and guarantees
117 bool oopDesc::is_oop(oop obj, bool ignore_mark_word) {
118 if (!Universe::heap()->is_oop(obj)) {
119 return false;
120 }
121
122 // Header verification: the mark is typically non-zero. If we're
123 // at a safepoint, it must not be zero, except when using the new lightweight locking.
124 // Outside of a safepoint, the header could be changing (for example,
125 // another thread could be inflating a lock on this object).
126 if (ignore_mark_word) {
127 return true;
128 }
129 if (obj->mark().value() != 0) {
130 return true;
131 }
132 return LockingMode == LM_LIGHTWEIGHT || !SafepointSynchronize::is_at_safepoint();
133 }
134
135 // used only for asserts and guarantees
136 bool oopDesc::is_oop_or_null(oop obj, bool ignore_mark_word) {
137 return obj == nullptr ? true : is_oop(obj, ignore_mark_word);
138 }
139
140 VerifyOopClosure VerifyOopClosure::verify_oop;
141
142 template <class T> void VerifyOopClosure::do_oop_work(T* p) {
143 oop obj = RawAccess<>::oop_load(p);
144 guarantee(oopDesc::is_oop_or_null(obj), "invalid oop: " PTR_FORMAT, p2i(obj));
145 }
146
147 void VerifyOopClosure::do_oop(oop* p) { VerifyOopClosure::do_oop_work(p); }
148 void VerifyOopClosure::do_oop(narrowOop* p) { VerifyOopClosure::do_oop_work(p); }
149
150 // type test operations that doesn't require inclusion of oop.inline.hpp.
151 bool oopDesc::is_instance_noinline() const { return is_instance(); }
152 bool oopDesc::is_instanceRef_noinline() const { return is_instanceRef(); }
153 bool oopDesc::is_stackChunk_noinline() const { return is_stackChunk(); }
154 bool oopDesc::is_array_noinline() const { return is_array(); }
155 bool oopDesc::is_objArray_noinline() const { return is_objArray(); }
156 bool oopDesc::is_typeArray_noinline() const { return is_typeArray(); }
157
158 bool oopDesc::has_klass_gap() {
159 // Only has a klass gap when compressed class pointers are used.
160 return UseCompressedClassPointers;
161 }
162
163 #if INCLUDE_CDS_JAVA_HEAP
164 void oopDesc::set_narrow_klass(narrowKlass nk) {
165 assert(DumpSharedSpaces, "Used by CDS only. Do not abuse!");
166 assert(UseCompressedClassPointers, "must be");
167 _metadata._compressed_klass = nk;
168 }
169 #endif
170
171 void* oopDesc::load_klass_raw(oop obj) {
172 if (UseCompressedClassPointers) {
173 narrowKlass narrow_klass = obj->_metadata._compressed_klass;
174 if (narrow_klass == 0) return nullptr;
175 return (void*)CompressedKlassPointers::decode_raw(narrow_klass);
176 } else {
177 return obj->_metadata._klass;
178 }
179 }
180
181 void* oopDesc::load_oop_raw(oop obj, int offset) {
182 uintptr_t addr = (uintptr_t)(void*)obj + (uint)offset;
183 if (UseCompressedOops) {
184 narrowOop narrow_oop = *(narrowOop*)addr;
185 if (CompressedOops::is_null(narrow_oop)) return nullptr;
186 return (void*)CompressedOops::decode_raw(narrow_oop);
187 } else {
188 return *(void**)addr;
189 }
190 }
191
192 oop oopDesc::obj_field_acquire(int offset) const { return HeapAccess<MO_ACQUIRE>::oop_load_at(as_oop(), offset); }
193
194 void oopDesc::obj_field_put_raw(int offset, oop value) { assert(!(UseZGC && ZGenerational), "Generational ZGC must use store barriers");
195 RawAccess<>::oop_store_at(as_oop(), offset, value); }
196 void oopDesc::release_obj_field_put(int offset, oop value) { HeapAccess<MO_RELEASE>::oop_store_at(as_oop(), offset, value); }
197 void oopDesc::obj_field_put_volatile(int offset, oop value) { HeapAccess<MO_SEQ_CST>::oop_store_at(as_oop(), offset, value); }
198
199 address oopDesc::address_field(int offset) const { return *field_addr<address>(offset); }
200 address oopDesc::address_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<address>(offset)); }
201
202 void oopDesc::address_field_put(int offset, address value) { *field_addr<address>(offset) = value; }
203 void oopDesc::release_address_field_put(int offset, address value) { Atomic::release_store(field_addr<address>(offset), value); }
204
205 Metadata* oopDesc::metadata_field(int offset) const { return *field_addr<Metadata*>(offset); }
206 void oopDesc::metadata_field_put(int offset, Metadata* value) { *field_addr<Metadata*>(offset) = value; }
207
208 Metadata* oopDesc::metadata_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<Metadata*>(offset)); }
209 void oopDesc::release_metadata_field_put(int offset, Metadata* value) { Atomic::release_store(field_addr<Metadata*>(offset), value); }
210
211 jbyte oopDesc::byte_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jbyte>(offset)); }
212 void oopDesc::release_byte_field_put(int offset, jbyte value) { Atomic::release_store(field_addr<jbyte>(offset), value); }
213
214 jchar oopDesc::char_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jchar>(offset)); }
215 void oopDesc::release_char_field_put(int offset, jchar value) { Atomic::release_store(field_addr<jchar>(offset), value); }
216
217 jboolean oopDesc::bool_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jboolean>(offset)); }
218 void oopDesc::release_bool_field_put(int offset, jboolean value) { Atomic::release_store(field_addr<jboolean>(offset), jboolean(value & 1)); }
219
220 jint oopDesc::int_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jint>(offset)); }
221 void oopDesc::release_int_field_put(int offset, jint value) { Atomic::release_store(field_addr<jint>(offset), value); }
222
223 jshort oopDesc::short_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jshort>(offset)); }
224 void oopDesc::release_short_field_put(int offset, jshort value) { Atomic::release_store(field_addr<jshort>(offset), value); }
225
226 jlong oopDesc::long_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jlong>(offset)); }
227 void oopDesc::release_long_field_put(int offset, jlong value) { Atomic::release_store(field_addr<jlong>(offset), value); }
228
229 jfloat oopDesc::float_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jfloat>(offset)); }
230 void oopDesc::release_float_field_put(int offset, jfloat value) { Atomic::release_store(field_addr<jfloat>(offset), value); }
231
232 jdouble oopDesc::double_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jdouble>(offset)); }
233 void oopDesc::release_double_field_put(int offset, jdouble value) { Atomic::release_store(field_addr<jdouble>(offset), value); }
234
235 #ifdef ASSERT
236 bool oopDesc::size_might_change() {
237 // UseParallelGC and UseG1GC can change the length field
238 // of an "old copy" of an object array in the young gen so it indicates
239 // the grey portion of an already copied array. This will cause the first
240 // disjunct below to fail if the two comparands are computed across such
241 // a concurrent change.
242 return Universe::heap()->is_gc_active() && is_objArray() && is_forwarded() && (UseParallelGC || UseG1GC);
243 }
244 #endif