1 /*
2 * Copyright (c) 2017, 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 "precompiled.hpp"
26 #include "classfile/moduleEntry.hpp"
27 #include "classfile/packageEntry.hpp"
28 #include "classfile/symbolTable.hpp"
29 #include "classfile/systemDictionary.hpp"
30 #include "classfile/vmSymbols.hpp"
31 #include "gc/shared/collectedHeap.inline.hpp"
32 #include "memory/iterator.inline.hpp"
33 #include "memory/metadataFactory.hpp"
34 #include "memory/metaspaceClosure.hpp"
35 #include "memory/oopFactory.hpp"
36 #include "memory/resourceArea.hpp"
37 #include "memory/universe.hpp"
38 #include "oops/arrayKlass.inline.hpp"
39 #include "oops/arrayOop.hpp"
40 #include "oops/flatArrayOop.hpp"
41 #include "oops/flatArrayOop.inline.hpp"
42 #include "oops/inlineKlass.hpp"
43 #include "oops/instanceKlass.hpp"
44 #include "oops/klass.inline.hpp"
45 #include "oops/objArrayKlass.hpp"
46 #include "oops/objArrayOop.inline.hpp"
47 #include "oops/oop.inline.hpp"
48 #include "oops/verifyOopClosure.hpp"
49 #include "runtime/handles.inline.hpp"
50 #include "runtime/mutexLocker.hpp"
51 #include "utilities/copy.hpp"
52 #include "utilities/macros.hpp"
53
54 #include "oops/flatArrayKlass.hpp"
55
56 // Allocation...
57
58 FlatArrayKlass::FlatArrayKlass(Klass* element_klass, Symbol* name, LayoutKind lk) : ArrayKlass(name, Kind) {
59 assert(element_klass->is_inline_klass(), "Expected Inline");
60 assert(lk == NON_ATOMIC_FLAT || lk == ATOMIC_FLAT || lk == NULLABLE_ATOMIC_FLAT, "Must be a flat layout");
61
62 set_element_klass(InlineKlass::cast(element_klass));
63 set_class_loader_data(element_klass->class_loader_data());
64 set_layout_kind(lk);
65
66 set_layout_helper(array_layout_helper(InlineKlass::cast(element_klass), lk));
67 assert(is_array_klass(), "sanity");
68 assert(is_flatArray_klass(), "sanity");
69 assert(is_null_free_array_klass(), "sanity");
70
71 #ifdef _LP64
72 set_prototype_header(markWord::flat_array_prototype(lk));
73 assert(prototype_header().is_flat_array(), "sanity");
74 #else
75 fatal("Not supported yet");
76 set_prototype_header(markWord::inline_type_prototype());
77 #endif
78
79 #ifdef ASSERT
80 switch(lk) {
81 case NON_ATOMIC_FLAT:
82 assert(layout_helper_is_null_free(layout_helper()), "Must be");
83 assert(layout_helper_is_array(layout_helper()), "Must be");
84 assert(layout_helper_is_flatArray(layout_helper()), "Must be");
85 assert(layout_helper_element_type(layout_helper()) == T_FLAT_ELEMENT, "Must be");
86 assert(prototype_header().is_null_free_array(), "Must be");
87 assert(prototype_header().is_flat_array(), "Must be");
88 break;
89 default:
90 break;
91 }
92 #endif // ASSERT
93
94 #ifndef PRODUCT
95 if (PrintFlatArrayLayout) {
96 print();
97 }
98 #endif
99 }
100
101 FlatArrayKlass* FlatArrayKlass::allocate_klass(Klass* eklass, LayoutKind lk, TRAPS) {
102 guarantee((!Universe::is_bootstrapping() || vmClasses::Object_klass_loaded()), "Really ?!");
103 assert(UseFlatArray, "Flatten array required");
104 assert(MultiArray_lock->holds_lock(THREAD), "must hold lock after bootstrapping");
105
106 InlineKlass* element_klass = InlineKlass::cast(eklass);
107 assert(element_klass->must_be_atomic() || (!InlineArrayAtomicAccess), "Atomic by-default");
108
109 // Eagerly allocate the direct array supertype.
110 Klass* super_klass = nullptr;
111 Klass* element_super = element_klass->super();
112 if (element_super != nullptr) {
113 // The element type has a direct super. E.g., String[] has direct super of Object[].
114 super_klass = element_klass->array_klass(CHECK_NULL);
115 // Also, see if the element has secondary supertypes.
116 // We need an array type for each.
117 const Array<Klass*>* element_supers = element_klass->secondary_supers();
118 for( int i = element_supers->length()-1; i >= 0; i-- ) {
119 Klass* elem_super = element_supers->at(i);
120 elem_super->array_klass(CHECK_NULL);
121 }
122 // Fall through because inheritance is acyclic and we hold the global recursive lock to allocate all the arrays.
123 }
124
125 Symbol* name = ArrayKlass::create_element_klass_array_name(element_klass, CHECK_NULL);
126 ClassLoaderData* loader_data = element_klass->class_loader_data();
127 int size = ArrayKlass::static_size(FlatArrayKlass::header_size());
128 FlatArrayKlass* vak = new (loader_data, size, THREAD) FlatArrayKlass(element_klass, name, lk);
129
130 ModuleEntry* module = vak->module();
131 assert(module != nullptr, "No module entry for array");
132 complete_create_array_klass(vak, super_klass, module, CHECK_NULL);
133
134 loader_data->add_class(vak);
135
136 return vak;
137 }
138
139 void FlatArrayKlass::initialize(TRAPS) {
140 element_klass()->initialize(THREAD);
141 }
142
143 void FlatArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) {
144 ArrayKlass::metaspace_pointers_do(it);
145 it->push(&_element_klass);
146 }
147
148 // Oops allocation...
149 flatArrayOop FlatArrayKlass::allocate(int length, LayoutKind lk, TRAPS) {
150 check_array_allocation_length(length, max_elements(), CHECK_NULL);
151 int size = flatArrayOopDesc::object_size(layout_helper(), length);
152 flatArrayOop array = (flatArrayOop) Universe::heap()->array_allocate(this, size, length, true, CHECK_NULL);
153 return array;
154 }
155
156 oop FlatArrayKlass::multi_allocate(int rank, jint* last_size, TRAPS) {
157 // FlatArrays only have one dimension
158 ShouldNotReachHere();
159 }
160
161 jint FlatArrayKlass::array_layout_helper(InlineKlass* vk, LayoutKind lk) {
162 BasicType etype = T_FLAT_ELEMENT;
163 int esize = log2i_exact(round_up_power_of_2(vk->layout_size_in_bytes(lk)));
164 int hsize = arrayOopDesc::base_offset_in_bytes(etype);
165
166 int lh = Klass::array_layout_helper(_lh_array_tag_vt_value, true, hsize, etype, esize);
167
168 assert(lh < (int)_lh_neutral_value, "must look like an array layout");
169 assert(layout_helper_is_array(lh), "correct kind");
170 assert(layout_helper_is_flatArray(lh), "correct kind");
171 assert(!layout_helper_is_typeArray(lh), "correct kind");
172 assert(!layout_helper_is_objArray(lh), "correct kind");
173 assert(layout_helper_is_null_free(lh), "correct kind");
174 assert(layout_helper_header_size(lh) == hsize, "correct decode");
175 assert(layout_helper_element_type(lh) == etype, "correct decode");
176 assert(layout_helper_log2_element_size(lh) == esize, "correct decode");
177 assert((1 << esize) < BytesPerLong || is_aligned(hsize, HeapWordsPerLong), "unaligned base");
178
179 return lh;
180 }
181
182 size_t FlatArrayKlass::oop_size(oop obj) const {
183 assert(obj->klass()->is_flatArray_klass(),"must be an flat array");
184 flatArrayOop array = flatArrayOop(obj);
185 return array->object_size();
186 }
187
188 // For now return the maximum number of array elements that will not exceed:
189 // nof bytes = "max_jint * HeapWord" since the "oopDesc::oop_iterate_size"
190 // returns "int" HeapWords, need fix for JDK-4718400 and JDK-8233189
191 jint FlatArrayKlass::max_elements() const {
192 // Check the max number of heap words limit first (because of int32_t in oopDesc_oop_size() etc)
193 size_t max_size = max_jint;
194 max_size -= (arrayOopDesc::base_offset_in_bytes(T_FLAT_ELEMENT) >> LogHeapWordSize);
195 max_size = align_down(max_size, MinObjAlignment);
196 max_size <<= LogHeapWordSize; // convert to max payload size in bytes
197 max_size >>= layout_helper_log2_element_size(_layout_helper); // divide by element size (in bytes) = max elements
198 // Within int32_t heap words, still can't exceed Java array element limit
199 if (max_size > max_jint) {
200 max_size = max_jint;
201 }
202 assert((max_size >> LogHeapWordSize) <= max_jint, "Overflow");
203 return (jint) max_size;
204 }
205
206 oop FlatArrayKlass::protection_domain() const {
207 return element_klass()->protection_domain();
208 }
209
210 // Temp hack having this here: need to move towards Access API
211 static bool needs_backwards_copy(arrayOop s, int src_pos,
212 arrayOop d, int dst_pos, int length) {
213 return (s == d) && (dst_pos > src_pos) && (dst_pos - src_pos) < length;
214 }
215
216 void FlatArrayKlass::copy_array(arrayOop s, int src_pos,
217 arrayOop d, int dst_pos, int length, TRAPS) {
218
219 assert(s->is_objArray() || s->is_flatArray(), "must be obj or flat array");
220
221 // Check destination
222 if ((!d->is_flatArray()) && (!d->is_objArray())) {
223 THROW(vmSymbols::java_lang_ArrayStoreException());
224 }
225
226 // Check if all offsets and lengths are non negative
227 if (src_pos < 0 || dst_pos < 0 || length < 0) {
228 THROW(vmSymbols::java_lang_ArrayIndexOutOfBoundsException());
229 }
230 // Check if the ranges are valid
231 if ( (((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length())
232 || (((unsigned int) length + (unsigned int) dst_pos) > (unsigned int) d->length()) ) {
233 THROW(vmSymbols::java_lang_ArrayIndexOutOfBoundsException());
234 }
235 // Check zero copy
236 if (length == 0)
237 return;
238
239 ArrayKlass* sk = ArrayKlass::cast(s->klass());
240 ArrayKlass* dk = ArrayKlass::cast(d->klass());
241 Klass* d_elem_klass = dk->element_klass();
242 Klass* s_elem_klass = sk->element_klass();
243 /**** CMH: compare and contrast impl, re-factor once we find edge cases... ****/
244
245 if (sk->is_flatArray_klass()) {
246 assert(sk == this, "Unexpected call to copy_array");
247 FlatArrayKlass* fsk = FlatArrayKlass::cast(sk);
248 // Check subtype, all src homogeneous, so just once
249 if (!s_elem_klass->is_subtype_of(d_elem_klass)) {
250 THROW(vmSymbols::java_lang_ArrayStoreException());
251 }
252
253 flatArrayOop sa = flatArrayOop(s);
254 InlineKlass* s_elem_vklass = element_klass();
255
256 // flatArray-to-flatArray
257 if (dk->is_flatArray_klass()) {
258 // element types MUST be exact, subtype check would be dangerous
259 if (d_elem_klass != this->element_klass()) {
260 THROW(vmSymbols::java_lang_ArrayStoreException());
261 }
262
263 FlatArrayKlass* fdk = FlatArrayKlass::cast(dk);
264 InlineKlass* vk = InlineKlass::cast(s_elem_klass);
265 flatArrayOop da = flatArrayOop(d);
266 int src_incr = fsk->element_byte_size();
267 int dst_incr = fdk->element_byte_size();
268
269 if (fsk->layout_kind() == fdk->layout_kind()) {
270 assert(src_incr == dst_incr, "Must be");
271 if (needs_backwards_copy(sa, src_pos, da, dst_pos, length)) {
272 address dst = (address) da->value_at_addr(dst_pos + length - 1, fdk->layout_helper());
273 address src = (address) sa->value_at_addr(src_pos + length - 1, fsk->layout_helper());
274 for (int i = 0; i < length; i++) {
275 // because source and destination have the same layout, bypassing the InlineKlass copy methods
276 // and call AccessAPI directly
277 HeapAccess<>::value_copy(src, dst, vk, fsk->layout_kind());
278 dst -= dst_incr;
279 src -= src_incr;
280 }
281 } else {
282 // source and destination share same layout, direct copy from array to array is possible
283 address dst = (address) da->value_at_addr(dst_pos, fdk->layout_helper());
284 address src = (address) sa->value_at_addr(src_pos, fsk->layout_helper());
285 for (int i = 0; i < length; i++) {
286 // because source and destination have the same layout, bypassing the InlineKlass copy methods
287 // and call AccessAPI directly
288 HeapAccess<>::value_copy(src, dst, vk, fsk->layout_kind());
289 dst += dst_incr;
290 src += src_incr;
291 }
292 }
293 } else {
294 flatArrayHandle hd(THREAD, da);
295 flatArrayHandle hs(THREAD, sa);
296 // source and destination layouts mismatch, simpler solution is to copy through an intermediate buffer (heap instance)
297 bool need_null_check = fsk->layout_kind() == NULLABLE_ATOMIC_FLAT && fdk->layout_kind() != NULLABLE_ATOMIC_FLAT;
298 oop buffer = vk->allocate_instance(CHECK);
299 address dst = (address) hd->value_at_addr(dst_pos, fdk->layout_helper());
300 address src = (address) hs->value_at_addr(src_pos, fsk->layout_helper());
301 for (int i = 0; i < length; i++) {
302 if (need_null_check) {
303 if (vk->is_payload_marked_as_null(src)) {
304 THROW(vmSymbols::java_lang_NullPointerException());
305 }
306 }
307 vk->copy_payload_to_addr(src, vk->data_for_oop(buffer), fsk->layout_kind(), true);
308 if (vk->has_nullable_atomic_layout()) {
309 // Setting null marker to not zero for non-nullable source layouts
310 vk->mark_payload_as_non_null(vk->data_for_oop(buffer));
311 }
312 vk->copy_payload_to_addr(vk->data_for_oop(buffer), dst, fdk->layout_kind(), true);
313 dst += dst_incr;
314 src += src_incr;
315 }
316 }
317 } else { // flatArray-to-objArray
318 assert(dk->is_objArray_klass(), "Expected objArray here");
319 // Need to allocate each new src elem payload -> dst oop
320 objArrayHandle dh(THREAD, (objArrayOop)d);
321 flatArrayHandle sh(THREAD, sa);
322 InlineKlass* vk = InlineKlass::cast(s_elem_klass);
323 for (int i = 0; i < length; i++) {
324 oop o = sh->read_value_from_flat_array(src_pos + i, CHECK);
325 dh->obj_at_put(dst_pos + i, o);
326 }
327 }
328 } else {
329 assert(s->is_objArray(), "Expected objArray");
330 objArrayOop sa = objArrayOop(s);
331 assert(d->is_flatArray(), "Expected flatArray"); // objArray-to-flatArray
332 InlineKlass* d_elem_vklass = InlineKlass::cast(d_elem_klass);
333 flatArrayOop da = flatArrayOop(d);
334 FlatArrayKlass* fdk = FlatArrayKlass::cast(da->klass());
335 InlineKlass* vk = InlineKlass::cast(d_elem_klass);
336
337 for (int i = 0; i < length; i++) {
338 da->write_value_to_flat_array(sa->obj_at(src_pos + i), dst_pos + i, CHECK);
339 }
340 }
341 }
342
343 ModuleEntry* FlatArrayKlass::module() const {
344 assert(element_klass() != nullptr, "FlatArrayKlass returned unexpected nullptr bottom_klass");
345 // The array is defined in the module of its bottom class
346 return element_klass()->module();
347 }
348
349 PackageEntry* FlatArrayKlass::package() const {
350 assert(element_klass() != nullptr, "FlatArrayKlass returned unexpected nullptr bottom_klass");
351 return element_klass()->package();
352 }
353
354 bool FlatArrayKlass::can_be_primary_super_slow() const {
355 return true;
356 }
357
358 GrowableArray<Klass*>* FlatArrayKlass::compute_secondary_supers(int num_extra_slots,
359 Array<InstanceKlass*>* transitive_interfaces) {
360 assert(transitive_interfaces == nullptr, "sanity");
361 // interfaces = { cloneable_klass, serializable_klass, elemSuper[], ... };
362 Array<Klass*>* elem_supers = element_klass()->secondary_supers();
363 int num_elem_supers = elem_supers == nullptr ? 0 : elem_supers->length();
364 int num_secondaries = num_extra_slots + 2 + num_elem_supers;
365 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(num_elem_supers+2);
366
367 secondaries->push(vmClasses::Cloneable_klass());
368 secondaries->push(vmClasses::Serializable_klass());
369 for (int i = 0; i < num_elem_supers; i++) {
370 Klass* elem_super = (Klass*) elem_supers->at(i);
371 Klass* array_super = elem_super->array_klass_or_null();
372 assert(array_super != nullptr, "must already have been created");
373 secondaries->push(array_super);
374 }
375 return secondaries;
376 }
377
378 jint FlatArrayKlass::compute_modifier_flags() const {
379 // The modifier for an flatArray is the same as its element
380 // With the addition of ACC_IDENTITY
381 jint element_flags = element_klass()->compute_modifier_flags();
382
383 int identity_flag = (Arguments::enable_preview()) ? JVM_ACC_IDENTITY : 0;
384
385 return (element_flags & (JVM_ACC_PUBLIC | JVM_ACC_PRIVATE | JVM_ACC_PROTECTED))
386 | (identity_flag | JVM_ACC_ABSTRACT | JVM_ACC_FINAL);
387 }
388
389 void FlatArrayKlass::print_on(outputStream* st) const {
390 #ifndef PRODUCT
391 assert(!is_objArray_klass(), "Unimplemented");
392
393 st->print("Flat Type Array: ");
394 Klass::print_on(st);
395
396 st->print(" - element klass: ");
397 element_klass()->print_value_on(st);
398 st->cr();
399
400 int elem_size = element_byte_size();
401 st->print(" - element size %i ", elem_size);
402 st->print("aligned layout size %i", 1 << layout_helper_log2_element_size(layout_helper()));
403 st->cr();
404 #endif //PRODUCT
405 }
406
407 void FlatArrayKlass::print_value_on(outputStream* st) const {
408 assert(is_klass(), "must be klass");
409
410 element_klass()->print_value_on(st);
411 st->print("[]");
412 }
413
414
415 #ifndef PRODUCT
416 void FlatArrayKlass::oop_print_on(oop obj, outputStream* st) {
417 ArrayKlass::oop_print_on(obj, st);
418 flatArrayOop va = flatArrayOop(obj);
419 InlineKlass* vk = element_klass();
420 int print_len = MIN2(va->length(), MaxElementPrintSize);
421 for(int index = 0; index < print_len; index++) {
422 int off = (address) va->value_at_addr(index, layout_helper()) - cast_from_oop<address>(obj);
423 st->print_cr(" - Index %3d offset %3d: ", index, off);
424 oop obj = cast_to_oop((address)va->value_at_addr(index, layout_helper()) - vk->first_field_offset());
425 FieldPrinter print_field(st, obj);
426 vk->do_nonstatic_fields(&print_field);
427 st->cr();
428 }
429 int remaining = va->length() - print_len;
430 if (remaining > 0) {
431 st->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>", remaining);
432 }
433 }
434 #endif //PRODUCT
435
436 void FlatArrayKlass::oop_print_value_on(oop obj, outputStream* st) {
437 assert(obj->is_flatArray(), "must be flatArray");
438 st->print("a ");
439 element_klass()->print_value_on(st);
440 int len = flatArrayOop(obj)->length();
441 st->print("[%d] ", len);
442 obj->print_address_on(st);
443 if (PrintMiscellaneous && (WizardMode || Verbose)) {
444 int lh = layout_helper();
445 st->print("{");
446 for (int i = 0; i < len; i++) {
447 if (i > 4) {
448 st->print("..."); break;
449 }
450 st->print(" " INTPTR_FORMAT, (intptr_t)(void*)flatArrayOop(obj)->value_at_addr(i , lh));
451 }
452 st->print(" }");
453 }
454 }
455
456 // Verification
457 class VerifyElementClosure: public BasicOopIterateClosure {
458 public:
459 virtual void do_oop(oop* p) { VerifyOopClosure::verify_oop.do_oop(p); }
460 virtual void do_oop(narrowOop* p) { VerifyOopClosure::verify_oop.do_oop(p); }
461 };
462
463 void FlatArrayKlass::oop_verify_on(oop obj, outputStream* st) {
464 ArrayKlass::oop_verify_on(obj, st);
465 guarantee(obj->is_flatArray(), "must be flatArray");
466
467 if (contains_oops()) {
468 flatArrayOop va = flatArrayOop(obj);
469 VerifyElementClosure ec;
470 va->oop_iterate(&ec);
471 }
472 }
473
474 void FlatArrayKlass::verify_on(outputStream* st) {
475 ArrayKlass::verify_on(st);
476 guarantee(element_klass()->is_inline_klass(), "should be inline type klass");
477 }