1 /* 2 * Copyright (c) 1997, 2022, 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("BAD WORD"); 44 } else if (*((juint*)this) == badMetaWordVal) { 45 st->print("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() { print_on(tty); } 57 58 void oopDesc::print_address() { print_address_on(tty); } 59 60 char* oopDesc::print_string() { 61 stringStream st; 62 print_on(&st); 63 return st.as_string(); 64 } 65 66 void oopDesc::print_value() { 67 print_value_on(tty); 68 } 69 70 char* oopDesc::print_value_string() { 71 char buf[100]; 72 stringStream st(buf, sizeof(buf)); 73 print_value_on(&st); 74 return st.as_string(); 75 } 76 77 void oopDesc::print_value_on(outputStream* st) const { 78 oop obj = const_cast<oopDesc*>(this); 79 if (java_lang_String::is_instance(obj)) { 80 java_lang_String::print(obj, st); 81 print_address_on(st); 82 } else { 83 klass()->oop_print_value_on(obj, st); 84 } 85 } 86 87 88 void oopDesc::verify_on(outputStream* st, oopDesc* oop_desc) { 89 if (oop_desc != NULL) { 90 oop_desc->klass()->oop_verify_on(oop_desc, st); 91 } 92 } 93 94 95 void oopDesc::verify(oopDesc* oop_desc) { 96 verify_on(tty, oop_desc); 97 } 98 99 intptr_t oopDesc::slow_identity_hash() { 100 // slow case; we have to acquire the micro lock in order to locate the header 101 Thread* current = Thread::current(); 102 return ObjectSynchronizer::FastHashCode(current, this); 103 } 104 105 // used only for asserts and guarantees 106 bool oopDesc::is_oop(oop obj, bool ignore_mark_word) { 107 if (!Universe::heap()->is_oop(obj)) { 108 return false; 109 } 110 111 // Header verification: the mark is typically non-zero. If we're 112 // at a safepoint, it must not be zero. 113 // Outside of a safepoint, the header could be changing (for example, 114 // another thread could be inflating a lock on this object). 115 if (ignore_mark_word) { 116 return true; 117 } 118 if (obj->mark().value() != 0) { 119 return true; 120 } 121 return !SafepointSynchronize::is_at_safepoint() ; 122 } 123 124 // used only for asserts and guarantees 125 bool oopDesc::is_oop_or_null(oop obj, bool ignore_mark_word) { 126 return obj == NULL ? true : is_oop(obj, ignore_mark_word); 127 } 128 129 VerifyOopClosure VerifyOopClosure::verify_oop; 130 131 template <class T> void VerifyOopClosure::do_oop_work(T* p) { 132 oop obj = RawAccess<>::oop_load(p); 133 guarantee(oopDesc::is_oop_or_null(obj), "invalid oop: " PTR_FORMAT, p2i(obj)); 134 } 135 136 void VerifyOopClosure::do_oop(oop* p) { VerifyOopClosure::do_oop_work(p); } 137 void VerifyOopClosure::do_oop(narrowOop* p) { VerifyOopClosure::do_oop_work(p); } 138 139 // type test operations that doesn't require inclusion of oop.inline.hpp. 140 bool oopDesc::is_instance_noinline() const { return is_instance(); } 141 bool oopDesc::is_instanceRef_noinline() const { return is_instanceRef(); } 142 bool oopDesc::is_stackChunk_noinline() const { return is_stackChunk(); } 143 bool oopDesc::is_array_noinline() const { return is_array(); } 144 bool oopDesc::is_objArray_noinline() const { return is_objArray(); } 145 bool oopDesc::is_typeArray_noinline() const { return is_typeArray(); } 146 bool oopDesc::is_flatArray_noinline() const { return is_flatArray(); } 147 bool oopDesc::is_null_free_array_noinline() const { return is_null_free_array(); } 148 149 bool oopDesc::has_klass_gap() { 150 // Only has a klass gap when compressed class pointers are used. 151 return UseCompressedClassPointers; 152 } 153 154 #if INCLUDE_CDS_JAVA_HEAP 155 void oopDesc::set_narrow_klass(narrowKlass nk) { 156 assert(DumpSharedSpaces, "Used by CDS only. Do not abuse!"); 157 assert(UseCompressedClassPointers, "must be"); 158 _metadata._compressed_klass = nk; 159 } 160 #endif 161 162 void* oopDesc::load_klass_raw(oop obj) { 163 if (UseCompressedClassPointers) { 164 narrowKlass narrow_klass = obj->_metadata._compressed_klass; 165 if (narrow_klass == 0) return NULL; 166 return (void*)CompressedKlassPointers::decode_raw(narrow_klass); 167 } else { 168 return obj->_metadata._klass; 169 } 170 } 171 172 void* oopDesc::load_oop_raw(oop obj, int offset) { 173 uintptr_t addr = (uintptr_t)(void*)obj + (uint)offset; 174 if (UseCompressedOops) { 175 narrowOop narrow_oop = *(narrowOop*)addr; 176 if (CompressedOops::is_null(narrow_oop)) return NULL; 177 return (void*)CompressedOops::decode_raw(narrow_oop); 178 } else { 179 return *(void**)addr; 180 } 181 } 182 183 oop oopDesc::obj_field_acquire(int offset) const { return HeapAccess<MO_ACQUIRE>::oop_load_at(as_oop(), offset); } 184 185 void oopDesc::obj_field_put_raw(int offset, oop value) { RawAccess<>::oop_store_at(as_oop(), offset, value); } 186 void oopDesc::release_obj_field_put(int offset, oop value) { HeapAccess<MO_RELEASE>::oop_store_at(as_oop(), offset, value); } 187 void oopDesc::obj_field_put_volatile(int offset, oop value) { HeapAccess<MO_SEQ_CST>::oop_store_at(as_oop(), offset, value); } 188 189 address oopDesc::address_field(int offset) const { return *field_addr<address>(offset); } 190 address oopDesc::address_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<address>(offset)); } 191 192 void oopDesc::address_field_put(int offset, address value) { *field_addr<address>(offset) = value; } 193 void oopDesc::release_address_field_put(int offset, address value) { Atomic::release_store(field_addr<address>(offset), value); } 194 195 Metadata* oopDesc::metadata_field(int offset) const { return *field_addr<Metadata*>(offset); } 196 void oopDesc::metadata_field_put(int offset, Metadata* value) { *field_addr<Metadata*>(offset) = value; } 197 198 Metadata* oopDesc::metadata_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<Metadata*>(offset)); } 199 void oopDesc::release_metadata_field_put(int offset, Metadata* value) { Atomic::release_store(field_addr<Metadata*>(offset), value); } 200 201 jbyte oopDesc::byte_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jbyte>(offset)); } 202 void oopDesc::release_byte_field_put(int offset, jbyte value) { Atomic::release_store(field_addr<jbyte>(offset), value); } 203 204 jchar oopDesc::char_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jchar>(offset)); } 205 void oopDesc::release_char_field_put(int offset, jchar value) { Atomic::release_store(field_addr<jchar>(offset), value); } 206 207 jboolean oopDesc::bool_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jboolean>(offset)); } 208 void oopDesc::release_bool_field_put(int offset, jboolean value) { Atomic::release_store(field_addr<jboolean>(offset), jboolean(value & 1)); } 209 210 jint oopDesc::int_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jint>(offset)); } 211 void oopDesc::release_int_field_put(int offset, jint value) { Atomic::release_store(field_addr<jint>(offset), value); } 212 213 jshort oopDesc::short_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jshort>(offset)); } 214 void oopDesc::release_short_field_put(int offset, jshort value) { Atomic::release_store(field_addr<jshort>(offset), value); } 215 216 jlong oopDesc::long_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jlong>(offset)); } 217 void oopDesc::release_long_field_put(int offset, jlong value) { Atomic::release_store(field_addr<jlong>(offset), value); } 218 219 jfloat oopDesc::float_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jfloat>(offset)); } 220 void oopDesc::release_float_field_put(int offset, jfloat value) { Atomic::release_store(field_addr<jfloat>(offset), value); } 221 222 jdouble oopDesc::double_field_acquire(int offset) const { return Atomic::load_acquire(field_addr<jdouble>(offset)); } 223 void oopDesc::release_double_field_put(int offset, jdouble value) { Atomic::release_store(field_addr<jdouble>(offset), value); } 224 225 #ifdef ASSERT 226 void oopDesc::verify_forwardee(oop forwardee) { 227 #if INCLUDE_CDS_JAVA_HEAP 228 assert(!Universe::heap()->is_archived_object(forwardee) && !Universe::heap()->is_archived_object(this), 229 "forwarding archive object"); 230 #endif 231 } 232 233 bool oopDesc::size_might_change() { 234 // UseParallelGC and UseG1GC can change the length field 235 // of an "old copy" of an object array in the young gen so it indicates 236 // the grey portion of an already copied array. This will cause the first 237 // disjunct below to fail if the two comparands are computed across such 238 // a concurrent change. 239 return Universe::heap()->is_gc_active() && is_objArray() && is_forwarded() && (UseParallelGC || UseG1GC); 240 } 241 #endif