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