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 "classfile/moduleEntry.hpp"
26 #include "classfile/packageEntry.hpp"
27 #include "classfile/symbolTable.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "gc/shared/collectedHeap.inline.hpp"
31 #include "memory/iterator.inline.hpp"
32 #include "memory/metadataFactory.hpp"
33 #include "memory/metaspaceClosure.hpp"
34 #include "memory/oopFactory.hpp"
35 #include "memory/resourceArea.hpp"
36 #include "memory/universe.hpp"
37 #include "oops/arrayKlass.inline.hpp"
38 #include "oops/arrayOop.hpp"
39 #include "oops/flatArrayOop.hpp"
40 #include "oops/flatArrayOop.inline.hpp"
41 #include "oops/inlineKlass.hpp"
42 #include "oops/instanceKlass.hpp"
43 #include "oops/klass.inline.hpp"
44 #include "oops/objArrayKlass.hpp"
45 #include "oops/objArrayOop.inline.hpp"
46 #include "oops/oop.inline.hpp"
47 #include "oops/verifyOopClosure.hpp"
48 #include "runtime/arguments.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, ArrayProperties props, LayoutKind lk) :
59 ObjArrayKlass(1, element_klass, name, Kind, props, markWord::flat_array_prototype(lk)) {
60 assert(element_klass->is_inline_klass(), "Expected Inline");
61 assert(lk == LayoutKind::NON_ATOMIC_FLAT || lk == LayoutKind::ATOMIC_FLAT || lk == LayoutKind::NULLABLE_ATOMIC_FLAT, "Must be a flat layout");
62
63 set_element_klass(InlineKlass::cast(element_klass));
64 set_class_loader_data(element_klass->class_loader_data());
65 set_layout_kind(lk);
66
67 set_layout_helper(array_layout_helper(InlineKlass::cast(element_klass), lk));
68 assert(is_array_klass(), "sanity");
69 assert(is_flatArray_klass(), "sanity");
70
71 #ifdef ASSERT
72 assert(layout_helper_is_array(layout_helper()), "Must be");
73 assert(layout_helper_is_flatArray(layout_helper()), "Must be");
74 assert(layout_helper_element_type(layout_helper()) == T_FLAT_ELEMENT, "Must be");
75 assert(prototype_header().is_flat_array(), "Must be");
76 switch(lk) {
77 case LayoutKind::NON_ATOMIC_FLAT:
78 case LayoutKind::ATOMIC_FLAT:
79 assert(layout_helper_is_null_free(layout_helper()), "Must be");
80 assert(prototype_header().is_null_free_array(), "Must be");
81 break;
82 case LayoutKind::NULLABLE_ATOMIC_FLAT:
83 assert(!layout_helper_is_null_free(layout_helper()), "Must be");
84 assert(!prototype_header().is_null_free_array(), "Must be");
85 break;
86 default:
87 ShouldNotReachHere();
88 break;
89 }
90 #endif // ASSERT
91
92 #ifndef PRODUCT
93 if (PrintFlatArrayLayout) {
94 print();
95 }
96 #endif
97 }
98
99 FlatArrayKlass* FlatArrayKlass::allocate_klass(Klass* eklass, ArrayProperties props, LayoutKind lk, TRAPS) {
100 guarantee((!Universe::is_bootstrapping() || vmClasses::Object_klass_loaded()), "Really ?!");
101 assert(UseArrayFlattening, "Flatten array required");
102 assert(MultiArray_lock->holds_lock(THREAD), "must hold lock after bootstrapping");
103
104 InlineKlass* element_klass = InlineKlass::cast(eklass);
105 assert(element_klass->must_be_atomic() || (!AlwaysAtomicAccesses), "Atomic by-default");
106
107 // Eagerly allocate the direct array supertype.
108 Klass* super_klass = nullptr;
109 Klass* element_super = element_klass->super();
110 if (element_super != nullptr) {
111 // The element type has a direct super. E.g., String[] has direct super of Object[].
112 super_klass = element_klass->array_klass(CHECK_NULL);
113 }
114
115 Symbol* name = ArrayKlass::create_element_klass_array_name(element_klass, CHECK_NULL);
116 ClassLoaderData* loader_data = element_klass->class_loader_data();
117 int size = ArrayKlass::static_size(FlatArrayKlass::header_size());
118 FlatArrayKlass* vak = new (loader_data, size, THREAD) FlatArrayKlass(element_klass, name, props, lk);
119
120 ModuleEntry* module = vak->module();
121 assert(module != nullptr, "No module entry for array");
122 complete_create_array_klass(vak, super_klass, module, CHECK_NULL);
123
124 loader_data->add_class(vak);
125
126 return vak;
127 }
128
129 void FlatArrayKlass::initialize(TRAPS) {
130 element_klass()->initialize(THREAD);
131 }
132
133 void FlatArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) {
134 ObjArrayKlass::metaspace_pointers_do(it);
135 }
136
137 // Oops allocation...
138 objArrayOop FlatArrayKlass::allocate_instance(int length, ArrayProperties props, TRAPS) {
139 assert(UseArrayFlattening, "Must be enabled");
140 check_array_allocation_length(length, max_elements(), CHECK_NULL);
141 int size = flatArrayOopDesc::object_size(layout_helper(), length);
142 flatArrayOop array = (flatArrayOop) Universe::heap()->array_allocate(this, size, length, true, CHECK_NULL);
143 return array;
144 }
145
146 oop FlatArrayKlass::multi_allocate(int rank, jint* last_size, TRAPS) {
147 // FlatArrays only have one dimension
148 ShouldNotReachHere();
149 }
150
151 jint FlatArrayKlass::array_layout_helper(InlineKlass* vk, LayoutKind lk) {
152 BasicType etype = T_FLAT_ELEMENT;
153 int esize = log2i_exact(round_up_power_of_2(vk->layout_size_in_bytes(lk)));
154 int hsize = arrayOopDesc::base_offset_in_bytes(etype);
155 bool null_free = lk != LayoutKind::NULLABLE_ATOMIC_FLAT;
156 int lh = Klass::array_layout_helper(_lh_array_tag_flat_value, null_free, hsize, etype, esize);
157
158 assert(lh < (int)_lh_neutral_value, "must look like an array layout");
159 assert(layout_helper_is_array(lh), "correct kind");
160 assert(layout_helper_is_flatArray(lh), "correct kind");
161 assert(!layout_helper_is_typeArray(lh), "correct kind");
162 assert(layout_helper_is_null_free(lh) == null_free, "correct kind");
163 assert(layout_helper_header_size(lh) == hsize, "correct decode");
164 assert(layout_helper_element_type(lh) == etype, "correct decode");
165 assert(layout_helper_log2_element_size(lh) == esize, "correct decode");
166 assert((1 << esize) < BytesPerLong || is_aligned(hsize, HeapWordsPerLong), "unaligned base");
167
168 return lh;
169 }
170
171 size_t FlatArrayKlass::oop_size(oop obj) const {
172 // In this assert, we cannot safely access the Klass* with compact headers,
173 // because size_given_klass() calls oop_size() on objects that might be
174 // concurrently forwarded, which would overwrite the Klass*.
175 // Also, why we need to pass this layout_helper() to flatArrayOop::object_size.
176 assert(UseCompactObjectHeaders || obj->is_flatArray(),"must be an flat array");
177 flatArrayOop array = flatArrayOop(obj);
178 return array->object_size(layout_helper());
179 }
180
181 // For now return the maximum number of array elements that will not exceed:
182 // nof bytes = "max_jint * HeapWord" since the "oopDesc::oop_iterate_size"
183 // returns "int" HeapWords, need fix for JDK-4718400 and JDK-8233189
184 jint FlatArrayKlass::max_elements() const {
185 // Check the max number of heap words limit first (because of int32_t in oopDesc_oop_size() etc)
186 size_t max_size = max_jint;
187 max_size -= (arrayOopDesc::base_offset_in_bytes(T_FLAT_ELEMENT) >> LogHeapWordSize);
188 max_size = align_down(max_size, MinObjAlignment);
189 max_size <<= LogHeapWordSize; // convert to max payload size in bytes
190 max_size >>= layout_helper_log2_element_size(_layout_helper); // divide by element size (in bytes) = max elements
191 // Within int32_t heap words, still can't exceed Java array element limit
192 if (max_size > max_jint) {
193 max_size = max_jint;
194 }
195 assert((max_size >> LogHeapWordSize) <= max_jint, "Overflow");
196 return (jint) max_size;
197 }
198
199 oop FlatArrayKlass::protection_domain() const {
200 return element_klass()->protection_domain();
201 }
202
203 // Temp hack having this here: need to move towards Access API
204 static bool needs_backwards_copy(arrayOop s, int src_pos,
205 arrayOop d, int dst_pos, int length) {
206 return (s == d) && (dst_pos > src_pos) && (dst_pos - src_pos) < length;
207 }
208
209 void FlatArrayKlass::copy_array(arrayOop s, int src_pos,
210 arrayOop d, int dst_pos, int length, TRAPS) {
211
212 assert(s->is_objArray() || s->is_flatArray(), "must be obj or flat array");
213
214 // Check destination
215 if ((!d->is_flatArray()) && (!d->is_objArray())) {
216 THROW(vmSymbols::java_lang_ArrayStoreException());
217 }
218
219 // Check if all offsets and lengths are non negative
220 if (src_pos < 0 || dst_pos < 0 || length < 0) {
221 THROW(vmSymbols::java_lang_ArrayIndexOutOfBoundsException());
222 }
223 // Check if the ranges are valid
224 if ( (((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length())
225 || (((unsigned int) length + (unsigned int) dst_pos) > (unsigned int) d->length()) ) {
226 THROW(vmSymbols::java_lang_ArrayIndexOutOfBoundsException());
227 }
228 // Check zero copy
229 if (length == 0)
230 return;
231
232 ObjArrayKlass* sk = ObjArrayKlass::cast(s->klass());
233 ObjArrayKlass* dk = ObjArrayKlass::cast(d->klass());
234 Klass* d_elem_klass = dk->element_klass();
235 Klass* s_elem_klass = sk->element_klass();
236 /**** CMH: compare and contrast impl, re-factor once we find edge cases... ****/
237
238 if (sk->is_flatArray_klass()) {
239 assert(sk == this, "Unexpected call to copy_array");
240 FlatArrayKlass* fsk = FlatArrayKlass::cast(sk);
241 // Check subtype, all src homogeneous, so just once
242 if (!s_elem_klass->is_subtype_of(d_elem_klass)) {
243 THROW(vmSymbols::java_lang_ArrayStoreException());
244 }
245
246 flatArrayOop sa = flatArrayOop(s);
247 InlineKlass* s_elem_vklass = element_klass();
248
249 // flatArray-to-flatArray
250 if (dk->is_flatArray_klass()) {
251 // element types MUST be exact, subtype check would be dangerous
252 if (d_elem_klass != this->element_klass()) {
253 THROW(vmSymbols::java_lang_ArrayStoreException());
254 }
255
256 FlatArrayKlass* fdk = FlatArrayKlass::cast(dk);
257 InlineKlass* vk = InlineKlass::cast(s_elem_klass);
258 flatArrayOop da = flatArrayOop(d);
259 int src_incr = fsk->element_byte_size();
260 int dst_incr = fdk->element_byte_size();
261
262 if (fsk->layout_kind() == fdk->layout_kind()) {
263 assert(src_incr == dst_incr, "Must be");
264 if (needs_backwards_copy(sa, src_pos, da, dst_pos, length)) {
265 address dst = (address) da->value_at_addr(dst_pos + length - 1, fdk->layout_helper());
266 address src = (address) sa->value_at_addr(src_pos + length - 1, fsk->layout_helper());
267 for (int i = 0; i < length; i++) {
268 // because source and destination have the same layout, bypassing the InlineKlass copy methods
269 // and call AccessAPI directly
270 HeapAccess<>::value_copy(src, dst, vk, fsk->layout_kind());
271 dst -= dst_incr;
272 src -= src_incr;
273 }
274 } else {
275 // source and destination share same layout, direct copy from array to array is possible
276 address dst = (address) da->value_at_addr(dst_pos, fdk->layout_helper());
277 address src = (address) sa->value_at_addr(src_pos, fsk->layout_helper());
278 for (int i = 0; i < length; i++) {
279 // because source and destination have the same layout, bypassing the InlineKlass copy methods
280 // and call AccessAPI directly
281 HeapAccess<>::value_copy(src, dst, vk, fsk->layout_kind());
282 dst += dst_incr;
283 src += src_incr;
284 }
285 }
286 } else {
287 flatArrayHandle hd(THREAD, da);
288 flatArrayHandle hs(THREAD, sa);
289 // source and destination layouts mismatch, simpler solution is to copy through an intermediate buffer (heap instance)
290 bool need_null_check = fsk->layout_kind() == LayoutKind::NULLABLE_ATOMIC_FLAT && fdk->layout_kind() != LayoutKind::NULLABLE_ATOMIC_FLAT;
291 oop buffer = vk->allocate_instance(CHECK);
292 address dst = (address) hd->value_at_addr(dst_pos, fdk->layout_helper());
293 address src = (address) hs->value_at_addr(src_pos, fsk->layout_helper());
294 for (int i = 0; i < length; i++) {
295 if (need_null_check) {
296 if (vk->is_payload_marked_as_null(src)) {
297 THROW(vmSymbols::java_lang_NullPointerException());
298 }
299 }
300 vk->copy_payload_to_addr(src, vk->payload_addr(buffer), fsk->layout_kind(), true);
301 if (vk->has_nullable_atomic_layout()) {
302 // Setting null marker to not zero for non-nullable source layouts
303 vk->mark_payload_as_non_null(vk->payload_addr(buffer));
304 }
305 vk->copy_payload_to_addr(vk->payload_addr(buffer), dst, fdk->layout_kind(), true);
306 dst += dst_incr;
307 src += src_incr;
308 }
309 }
310 } else { // flatArray-to-objArray
311 assert(dk->is_refArray_klass(), "Expected objArray here");
312 // Need to allocate each new src elem payload -> dst oop
313 objArrayHandle dh(THREAD, (objArrayOop)d);
314 flatArrayHandle sh(THREAD, sa);
315 InlineKlass* vk = InlineKlass::cast(s_elem_klass);
316 for (int i = 0; i < length; i++) {
317 oop o = sh->obj_at(src_pos + i, CHECK);
318 dh->obj_at_put(dst_pos + i, o);
319 }
320 }
321 } else {
322 assert(s->is_objArray(), "Expected objArray");
323 objArrayOop sa = objArrayOop(s);
324 assert(d->is_flatArray(), "Expected flatArray"); // objArray-to-flatArray
325 InlineKlass* d_elem_vklass = InlineKlass::cast(d_elem_klass);
326 flatArrayOop da = flatArrayOop(d);
327 FlatArrayKlass* fdk = FlatArrayKlass::cast(da->klass());
328 InlineKlass* vk = InlineKlass::cast(d_elem_klass);
329
330 for (int i = 0; i < length; i++) {
331 da->obj_at_put( dst_pos + i, sa->obj_at(src_pos + i), CHECK);
332 }
333 }
334 }
335
336 ModuleEntry* FlatArrayKlass::module() const {
337 assert(element_klass() != nullptr, "FlatArrayKlass returned unexpected nullptr bottom_klass");
338 // The array is defined in the module of its bottom class
339 return element_klass()->module();
340 }
341
342 PackageEntry* FlatArrayKlass::package() const {
343 assert(element_klass() != nullptr, "FlatArrayKlass returned unexpected nullptr bottom_klass");
344 return element_klass()->package();
345 }
346
347 bool FlatArrayKlass::can_be_primary_super_slow() const {
348 return true;
349 }
350
351 GrowableArray<Klass*>* FlatArrayKlass::compute_secondary_supers(int num_extra_slots,
352 Array<InstanceKlass*>* transitive_interfaces) {
353 assert(transitive_interfaces == nullptr, "sanity");
354 // interfaces = { cloneable_klass, serializable_klass, elemSuper[], ... };
355 Array<Klass*>* elem_supers = element_klass()->secondary_supers();
356 int num_elem_supers = elem_supers == nullptr ? 0 : elem_supers->length();
357 int num_secondaries = num_extra_slots + 2 + num_elem_supers;
358 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(num_elem_supers+2);
359
360 secondaries->push(vmClasses::Cloneable_klass());
361 secondaries->push(vmClasses::Serializable_klass());
362 for (int i = 0; i < num_elem_supers; i++) {
363 Klass* elem_super = (Klass*) elem_supers->at(i);
364 Klass* array_super = elem_super->array_klass_or_null();
365 assert(array_super != nullptr, "must already have been created");
366 secondaries->push(array_super);
367 }
368 return secondaries;
369 }
370
371 u2 FlatArrayKlass::compute_modifier_flags() const {
372 // The modifier for an flatArray is the same as its element
373 // With the addition of ACC_IDENTITY
374 u2 element_flags = element_klass()->compute_modifier_flags();
375
376 u2 identity_flag = (Arguments::enable_preview()) ? JVM_ACC_IDENTITY : 0;
377
378 return (element_flags & (JVM_ACC_PUBLIC | JVM_ACC_PRIVATE | JVM_ACC_PROTECTED))
379 | (identity_flag | JVM_ACC_ABSTRACT | JVM_ACC_FINAL);
380 }
381
382 void FlatArrayKlass::print_on(outputStream* st) const {
383 #ifndef PRODUCT
384 assert(!is_refArray_klass(), "Unimplemented");
385
386 st->print("Flat Type Array: ");
387 Klass::print_on(st);
388
389 st->print(" - element klass: ");
390 element_klass()->print_value_on(st);
391 st->cr();
392
393 int elem_size = element_byte_size();
394 st->print(" - element size %i ", elem_size);
395 st->print("aligned layout size %i", 1 << layout_helper_log2_element_size(layout_helper()));
396 st->cr();
397 #endif //PRODUCT
398 }
399
400 void FlatArrayKlass::print_value_on(outputStream* st) const {
401 assert(is_klass(), "must be klass");
402
403 element_klass()->print_value_on(st);
404 st->print("[]");
405 }
406
407
408 #ifndef PRODUCT
409 void FlatArrayKlass::oop_print_on(oop obj, outputStream* st) {
410 ArrayKlass::oop_print_on(obj, st);
411 flatArrayOop va = flatArrayOop(obj);
412 InlineKlass* vk = element_klass();
413 int print_len = MIN2(va->length(), MaxElementPrintSize);
414 for(int index = 0; index < print_len; index++) {
415 int off = (address) va->value_at_addr(index, layout_helper()) - cast_from_oop<address>(obj);
416 st->print_cr(" - Index %3d offset %3d: ", index, off);
417 oop obj = cast_to_oop((address)va->value_at_addr(index, layout_helper()) - vk->payload_offset());
418 FieldPrinter print_field(st, obj);
419 vk->do_nonstatic_fields(&print_field);
420 st->cr();
421 }
422 int remaining = va->length() - print_len;
423 if (remaining > 0) {
424 st->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>", remaining);
425 }
426 }
427 #endif //PRODUCT
428
429 void FlatArrayKlass::oop_print_value_on(oop obj, outputStream* st) {
430 assert(obj->is_flatArray(), "must be flatArray");
431 st->print("a ");
432 element_klass()->print_value_on(st);
433 int len = flatArrayOop(obj)->length();
434 st->print("[%d] ", len);
435 obj->print_address_on(st);
436 if (PrintMiscellaneous && (WizardMode || Verbose)) {
437 int lh = layout_helper();
438 st->print("{");
439 for (int i = 0; i < len; i++) {
440 if (i > 4) {
441 st->print("..."); break;
442 }
443 st->print(" " INTPTR_FORMAT, (intptr_t)(void*)flatArrayOop(obj)->value_at_addr(i , lh));
444 }
445 st->print(" }");
446 }
447 }
448
449 // Verification
450 class VerifyElementClosure: public BasicOopIterateClosure {
451 public:
452 virtual void do_oop(oop* p) { VerifyOopClosure::verify_oop.do_oop(p); }
453 virtual void do_oop(narrowOop* p) { VerifyOopClosure::verify_oop.do_oop(p); }
454 };
455
456 void FlatArrayKlass::oop_verify_on(oop obj, outputStream* st) {
457 ArrayKlass::oop_verify_on(obj, st);
458 guarantee(obj->is_flatArray(), "must be flatArray");
459
460 if (contains_oops()) {
461 flatArrayOop va = flatArrayOop(obj);
462 VerifyElementClosure ec;
463 va->oop_iterate(&ec);
464 }
465 }
466
467 void FlatArrayKlass::verify_on(outputStream* st) {
468 ArrayKlass::verify_on(st);
469 guarantee(element_klass()->is_inline_klass(), "should be inline type klass");
470 }