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/compressedOops.inline.hpp"
34 #include "oops/oop.inline.hpp"
35 #include "oops/verifyOopClosure.hpp"
36 #include "runtime/handles.inline.hpp"
37 #include "runtime/javaThread.hpp"
38 #include "runtime/synchronizer.hpp"
39 #include "utilities/macros.hpp"
40
41 void oopDesc::print_on(outputStream* st) const {
42 if (*((juint*)this) == badHeapWordVal) {
43 st->print_cr("BAD WORD");
44 } else if (*((juint*)this) == badMetaWordVal) {
45 st->print_cr("BAD META WORD");
46 } else {
47 klass()->oop_print_on(cast_to_oop(this), st);
48 }
49 }
50
51 void oopDesc::print_address_on(outputStream* st) const {
52 st->print("{" PTR_FORMAT "}", p2i(this));
53
54 }
55
56 void oopDesc::print_name_on(outputStream* st) const {
57 if (*((juint*)this) == badHeapWordVal) {
58 st->print_cr("BAD WORD");
59 } else if (*((juint*)this) == badMetaWordVal) {
60 st->print_cr("BAD META WORD");
61 } else {
62 st->print_cr("%s", klass()->external_name());
63 }
64 }
65
66 void oopDesc::print() { print_on(tty); }
67
68 void oopDesc::print_address() { print_address_on(tty); }
69
70 char* oopDesc::print_string() {
71 stringStream st;
72 print_on(&st);
73 return st.as_string();
74 }
75
76 void oopDesc::print_value() {
77 print_value_on(tty);
78 }
79
80 char* oopDesc::print_value_string() {
81 char buf[100];
82 stringStream st(buf, sizeof(buf));
83 print_value_on(&st);
84 return st.as_string();
85 }
86
87 void oopDesc::print_value_on(outputStream* st) const {
88 oop obj = const_cast<oopDesc*>(this);
89 if (java_lang_String::is_instance(obj)) {
90 java_lang_String::print(obj, st);
91 print_address_on(st);
92 } else {
93 klass()->oop_print_value_on(obj, st);
94 }
95 }
96
97
98 void oopDesc::verify_on(outputStream* st, oopDesc* oop_desc) {
99 if (oop_desc != nullptr) {
100 oop_desc->klass()->oop_verify_on(oop_desc, st);
101 }
102 }
103
104
105 void oopDesc::verify(oopDesc* oop_desc) {
106 verify_on(tty, oop_desc);
107 }
108
109 intptr_t oopDesc::slow_identity_hash() {
110 // slow case; we have to acquire the micro lock in order to locate the header
111 Thread* current = Thread::current();
112 return ObjectSynchronizer::FastHashCode(current, this);
113 }
114
115 // used only for asserts and guarantees
116 bool oopDesc::is_oop(oop obj, bool ignore_mark_word) {
117 if (!Universe::heap()->is_oop(obj)) {
118 return false;
119 }
120
121 // Header verification: the mark is typically non-zero. If we're
122 // at a safepoint, it must not be zero, except when using the new lightweight locking.
123 // Outside of a safepoint, the header could be changing (for example,
124 // another thread could be inflating a lock on this object).
125 if (ignore_mark_word) {
126 return true;
127 }
128 if (obj->mark().value() != 0) {
129 return true;
130 }
131 return LockingMode == LM_LIGHTWEIGHT || !SafepointSynchronize::is_at_safepoint();
132 }
133
134 // used only for asserts and guarantees
135 bool oopDesc::is_oop_or_null(oop obj, bool ignore_mark_word) {
136 return obj == nullptr ? true : is_oop(obj, ignore_mark_word);
137 }
138
139 VerifyOopClosure VerifyOopClosure::verify_oop;
140
141 template <class T> void VerifyOopClosure::do_oop_work(T* p) {
142 oop obj = RawAccess<>::oop_load(p);
143 guarantee(oopDesc::is_oop_or_null(obj), "invalid oop: " PTR_FORMAT, p2i(obj));
144 }
145
146 void VerifyOopClosure::do_oop(oop* p) { VerifyOopClosure::do_oop_work(p); }
147 void VerifyOopClosure::do_oop(narrowOop* p) { VerifyOopClosure::do_oop_work(p); }
148
149 // type test operations that doesn't require inclusion of oop.inline.hpp.
150 bool oopDesc::is_instance_noinline() const { return is_instance(); }
151 bool oopDesc::is_instanceRef_noinline() const { return is_instanceRef(); }
152 bool oopDesc::is_stackChunk_noinline() const { return is_stackChunk(); }
153 bool oopDesc::is_array_noinline() const { return is_array(); }
154 bool oopDesc::is_objArray_noinline() const { return is_objArray(); }
155 bool oopDesc::is_typeArray_noinline() const { return is_typeArray(); }
156
157 bool oopDesc::has_klass_gap() {
158 // Only has a klass gap when compressed class pointers are used.
159 // Except when using compact headers.
160 return UseCompressedClassPointers && !UseCompactObjectHeaders;
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 (UseCompactObjectHeaders) {
173 return obj->klass();
174 } else if (UseCompressedClassPointers) {
175 narrowKlass narrow_klass = obj->_metadata._compressed_klass;
176 if (narrow_klass == 0) return nullptr;
177 return (void*)CompressedKlassPointers::decode_raw(narrow_klass);
178 } else {
179 return obj->_metadata._klass;
180 }
181 }
182
183 void* oopDesc::load_oop_raw(oop obj, int offset) {
184 uintptr_t addr = (uintptr_t)(void*)obj + (uint)offset;
185 if (UseCompressedOops) {
186 narrowOop narrow_oop = *(narrowOop*)addr;
187 if (CompressedOops::is_null(narrow_oop)) return nullptr;
188 return (void*)CompressedOops::decode_raw(narrow_oop);
189 } else {
190 return *(void**)addr;
191 }
192 }
193
194 oop oopDesc::obj_field_acquire(int offset) const { return HeapAccess<MO_ACQUIRE>::oop_load_at(as_oop(), offset); }
195
196 void oopDesc::obj_field_put_raw(int offset, oop value) { assert(!(UseZGC && ZGenerational), "Generational ZGC must use store barriers");
197 RawAccess<>::oop_store_at(as_oop(), offset, value); }
198 void oopDesc::release_obj_field_put(int offset, oop value) { HeapAccess<MO_RELEASE>::oop_store_at(as_oop(), offset, value); }
199 void oopDesc::obj_field_put_volatile(int offset, oop value) { HeapAccess<MO_SEQ_CST>::oop_store_at(as_oop(), offset, value); }
200
201 address oopDesc::address_field(int offset) const { return *field_addr<address>(offset); }
202 address oopDesc::address_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<address>(offset)); }
203
204 void oopDesc::address_field_put(int offset, address value) { *field_addr<address>(offset) = value; }
205 void oopDesc::release_address_field_put(int offset, address value) { Atomic::release_store(field_addr<address>(offset), value); }
206
207 Metadata* oopDesc::metadata_field(int offset) const { return *field_addr<Metadata*>(offset); }
208 void oopDesc::metadata_field_put(int offset, Metadata* value) { *field_addr<Metadata*>(offset) = value; }
209
210 Metadata* oopDesc::metadata_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<Metadata*>(offset)); }
211 void oopDesc::release_metadata_field_put(int offset, Metadata* value) { Atomic::release_store(field_addr<Metadata*>(offset), value); }
212
213 jbyte oopDesc::byte_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jbyte>(offset)); }
214 void oopDesc::release_byte_field_put(int offset, jbyte value) { Atomic::release_store(field_addr<jbyte>(offset), value); }
215
216 jchar oopDesc::char_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jchar>(offset)); }
217 void oopDesc::release_char_field_put(int offset, jchar value) { Atomic::release_store(field_addr<jchar>(offset), value); }
218
219 jboolean oopDesc::bool_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jboolean>(offset)); }
220 void oopDesc::release_bool_field_put(int offset, jboolean value) { Atomic::release_store(field_addr<jboolean>(offset), jboolean(value & 1)); }
221
222 jint oopDesc::int_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jint>(offset)); }
223 void oopDesc::release_int_field_put(int offset, jint value) { Atomic::release_store(field_addr<jint>(offset), value); }
224
225 jshort oopDesc::short_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jshort>(offset)); }
226 void oopDesc::release_short_field_put(int offset, jshort value) { Atomic::release_store(field_addr<jshort>(offset), value); }
227
228 jlong oopDesc::long_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jlong>(offset)); }
229 void oopDesc::release_long_field_put(int offset, jlong value) { Atomic::release_store(field_addr<jlong>(offset), value); }
230
231 jfloat oopDesc::float_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jfloat>(offset)); }
232 void oopDesc::release_float_field_put(int offset, jfloat value) { Atomic::release_store(field_addr<jfloat>(offset), value); }
233
234 jdouble oopDesc::double_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jdouble>(offset)); }
235 void oopDesc::release_double_field_put(int offset, jdouble value) { Atomic::release_store(field_addr<jdouble>(offset), value); }
236
237 #ifdef ASSERT
238 bool oopDesc::size_might_change() {
239 // UseParallelGC and UseG1GC can change the length field
240 // of an "old copy" of an object array in the young gen so it indicates
241 // the grey portion of an already copied array. This will cause the first
242 // disjunct below to fail if the two comparands are computed across such
243 // a concurrent change.
244 return Universe::heap()->is_stw_gc_active() && is_objArray() && is_forwarded() && (UseParallelGC || UseG1GC);
245 }
246 #endif