1 /*
2 * Copyright (c) 1997, 2025, 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 "cds/cdsConfig.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 {
46 klass()->oop_print_on(cast_to_oop(this), st);
47 }
48 }
49
50 void oopDesc::print_address_on(outputStream* st) const {
51 st->print("{" PTR_FORMAT "}", p2i(this));
52
53 }
54
55 void oopDesc::print_name_on(outputStream* st) const {
56 if (*((juint*)this) == badHeapWordVal) {
57 st->print_cr("BAD WORD");
58 } else {
59 st->print_cr("%s", klass()->external_name());
60 }
61 }
62
63 void oopDesc::print() { print_on(tty); }
64
65 void oopDesc::print_address() { print_address_on(tty); }
66
67 char* oopDesc::print_string() {
68 stringStream st;
69 print_on(&st);
70 return st.as_string();
71 }
72
73 void oopDesc::print_value() {
74 print_value_on(tty);
75 }
76
77 char* oopDesc::print_value_string() {
78 char buf[100];
79 stringStream st(buf, sizeof(buf));
80 print_value_on(&st);
81 return st.as_string();
82 }
83
84 void oopDesc::print_value_on(outputStream* st) const {
85 oop obj = const_cast<oopDesc*>(this);
86 // We can't use java_lang_String::is_instance since that has klass assertions enabled.
87 // If the klass is garbage we want to just fail the check and continue printing, as
88 // opposed to aborting the VM entirely.
89 if (obj != nullptr && obj->klass_without_asserts() == vmClasses::String_klass()) {
90 java_lang_String::print(obj, st);
91 print_address_on(st);
92 } else {
93 Klass* k = klass_without_asserts();
94 if (k == nullptr) {
95 st->print("null klass");
96 } else if (!Metaspace::contains(k)) {
97 st->print("klass not in Metaspace");
98 } else if (!k->is_klass()) {
99 st->print("klass not a Klass");
100 } else {
101 k->oop_print_value_on(obj, st);
102 }
103 }
104 }
105
106
107 void oopDesc::verify_on(outputStream* st, oopDesc* oop_desc) {
108 if (oop_desc != nullptr) {
109 oop_desc->klass()->oop_verify_on(oop_desc, st);
110 }
111 }
112
113
114 void oopDesc::verify(oopDesc* oop_desc) {
115 verify_on(tty, oop_desc);
116 }
117
118 intptr_t oopDesc::slow_identity_hash() {
119 // slow case; we have to acquire the micro lock in order to locate the header
120 Thread* current = Thread::current();
121 return ObjectSynchronizer::FastHashCode(current, this);
122 }
123
124 // used only for asserts and guarantees
125 bool oopDesc::is_oop(oop obj) {
126 return Universe::heap()->is_oop(obj);
127 }
128
129 markWord oopDesc::initialize_hash_if_necessary(oop obj, Klass* k, markWord m) {
130 assert(UseCompactObjectHeaders, "only with compact object headers");
131 assert(!m.has_displaced_mark_helper(), "must not be displaced header");
132 assert(m.is_hashed_not_expanded(), "must be hashed but not moved");
133 assert(!m.is_hashed_expanded(), "must not be moved: " INTPTR_FORMAT, m.value());
134 uint32_t hash = static_cast<uint32_t>(ObjectSynchronizer::get_next_hash(nullptr, obj));
135 int offset = k->hash_offset_in_bytes(cast_to_oop(this), m);
136 assert(offset >= 4, "hash offset must not be in header");
137 log_develop_trace(gc)("Initializing hash for " PTR_FORMAT ", old: " PTR_FORMAT ", hash: %d, offset: %d, is_mirror: %s", p2i(this), p2i(obj), hash, offset, BOOL_TO_STR(k->is_mirror_instance_klass()));
138 int_field_put(offset, (jint) hash);
139 m = m.set_hashed_expanded();
140 assert(static_cast<uint32_t>(ObjectSynchronizer::get_hash(m, cast_to_oop(this), k)) == hash,
141 "hash must remain the same");
142 assert(m.narrow_klass() != 0, "must not be null");
143 return m;
144 }
145
146 // used only for asserts and guarantees
147 bool oopDesc::is_oop_or_null(oop obj) {
148 return obj == nullptr ? true : is_oop(obj);
149 }
150
151 VerifyOopClosure VerifyOopClosure::verify_oop;
152
153 template <class T> void VerifyOopClosure::do_oop_work(T* p) {
154 oop obj = RawAccess<>::oop_load(p);
155 guarantee(oopDesc::is_oop_or_null(obj), "invalid oop: " PTR_FORMAT, p2i(obj));
156 }
157
158 void VerifyOopClosure::do_oop(oop* p) { VerifyOopClosure::do_oop_work(p); }
159 void VerifyOopClosure::do_oop(narrowOop* p) { VerifyOopClosure::do_oop_work(p); }
160
161 // type test operations that doesn't require inclusion of oop.inline.hpp.
162 bool oopDesc::is_instance_noinline() const { return is_instance(); }
163 bool oopDesc::is_instanceRef_noinline() const { return is_instanceRef(); }
164 bool oopDesc::is_stackChunk_noinline() const { return is_stackChunk(); }
165 bool oopDesc::is_array_noinline() const { return is_array(); }
166 bool oopDesc::is_objArray_noinline() const { return is_objArray(); }
167 bool oopDesc::is_typeArray_noinline() const { return is_typeArray(); }
168
169 #if INCLUDE_CDS_JAVA_HEAP
170 void oopDesc::set_narrow_klass(narrowKlass nk) {
171 assert(CDSConfig::is_dumping_heap(), "Used by CDS only. Do not abuse!");
172 assert(UseCompressedClassPointers, "must be");
173 _metadata._compressed_klass = nk;
174 }
175 #endif
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 (CompressedOops::is_null(narrow_oop)) return nullptr;
182 return (void*)CompressedOops::decode_raw(narrow_oop);
183 } else {
184 return *(void**)addr;
185 }
186 }
187
188 oop oopDesc::obj_field_acquire(int offset) const { return HeapAccess<MO_ACQUIRE>::oop_load_at(as_oop(), offset); }
189
190 void oopDesc::obj_field_put_raw(int offset, oop value) { assert(!UseZGC, "ZGC must use store barriers");
191 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 AtomicAccess::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) { AtomicAccess::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 AtomicAccess::load_acquire(field_addr<Metadata*>(offset)); }
205 void oopDesc::release_metadata_field_put(int offset, Metadata* value) { AtomicAccess::release_store(field_addr<Metadata*>(offset), value); }
206
207 jbyte oopDesc::byte_field_acquire(int offset) const { return AtomicAccess::load_acquire(field_addr<jbyte>(offset)); }
208 void oopDesc::release_byte_field_put(int offset, jbyte value) { AtomicAccess::release_store(field_addr<jbyte>(offset), value); }
209
210 jchar oopDesc::char_field_acquire(int offset) const { return AtomicAccess::load_acquire(field_addr<jchar>(offset)); }
211 void oopDesc::release_char_field_put(int offset, jchar value) { AtomicAccess::release_store(field_addr<jchar>(offset), value); }
212
213 jboolean oopDesc::bool_field_acquire(int offset) const { return AtomicAccess::load_acquire(field_addr<jboolean>(offset)); }
214 void oopDesc::release_bool_field_put(int offset, jboolean value) { AtomicAccess::release_store(field_addr<jboolean>(offset), jboolean(value & 1)); }
215
216 jint oopDesc::int_field_acquire(int offset) const { return AtomicAccess::load_acquire(field_addr<jint>(offset)); }
217 void oopDesc::release_int_field_put(int offset, jint value) { AtomicAccess::release_store(field_addr<jint>(offset), value); }
218
219 jshort oopDesc::short_field_acquire(int offset) const { return AtomicAccess::load_acquire(field_addr<jshort>(offset)); }
220 void oopDesc::release_short_field_put(int offset, jshort value) { AtomicAccess::release_store(field_addr<jshort>(offset), value); }
221
222 jlong oopDesc::long_field_acquire(int offset) const { return AtomicAccess::load_acquire(field_addr<jlong>(offset)); }
223 void oopDesc::release_long_field_put(int offset, jlong value) { AtomicAccess::release_store(field_addr<jlong>(offset), value); }
224
225 jfloat oopDesc::float_field_acquire(int offset) const { return AtomicAccess::load_acquire(field_addr<jfloat>(offset)); }
226 void oopDesc::release_float_field_put(int offset, jfloat value) { AtomicAccess::release_store(field_addr<jfloat>(offset), value); }
227
228 jdouble oopDesc::double_field_acquire(int offset) const { return AtomicAccess::load_acquire(field_addr<jdouble>(offset)); }
229 void oopDesc::release_double_field_put(int offset, jdouble value) { AtomicAccess::release_store(field_addr<jdouble>(offset), value); }