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