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/handles.inline.hpp"
49 #include "runtime/mutexLocker.hpp"
50 #include "utilities/copy.hpp"
51 #include "utilities/macros.hpp"
52
53 #include "oops/flatArrayKlass.hpp"
54
55 // Allocation...
56
57 FlatArrayKlass::FlatArrayKlass(Klass* element_klass, Symbol* name, LayoutKind lk) : ArrayKlass(name, Kind, markWord::flat_array_prototype(lk)) {
58 assert(element_klass->is_inline_klass(), "Expected Inline");
59 assert(lk == LayoutKind::NON_ATOMIC_FLAT || lk == LayoutKind::ATOMIC_FLAT || lk == LayoutKind::NULLABLE_ATOMIC_FLAT, "Must be a flat layout");
60
61 set_element_klass(InlineKlass::cast(element_klass));
62 set_class_loader_data(element_klass->class_loader_data());
63 set_layout_kind(lk);
64
65 set_layout_helper(array_layout_helper(InlineKlass::cast(element_klass), lk));
66 assert(is_array_klass(), "sanity");
67 assert(is_flatArray_klass(), "sanity");
68
69 #ifdef ASSERT
70 assert(layout_helper_is_array(layout_helper()), "Must be");
71 assert(layout_helper_is_flatArray(layout_helper()), "Must be");
72 assert(layout_helper_element_type(layout_helper()) == T_FLAT_ELEMENT, "Must be");
73 assert(prototype_header().is_flat_array(), "Must be");
74 switch(lk) {
75 case LayoutKind::NON_ATOMIC_FLAT:
76 case LayoutKind::ATOMIC_FLAT:
77 assert(layout_helper_is_null_free(layout_helper()), "Must be");
78 assert(prototype_header().is_null_free_array(), "Must be");
79 break;
80 case LayoutKind::NULLABLE_ATOMIC_FLAT:
81 assert(!layout_helper_is_null_free(layout_helper()), "Must be");
82 assert(!prototype_header().is_null_free_array(), "Must be");
83 break;
84 default:
85 ShouldNotReachHere();
86 break;
87 }
88 #endif // ASSERT
89
90 #ifndef PRODUCT
91 if (PrintFlatArrayLayout) {
92 print();
93 }
94 #endif
95 }
96
97 FlatArrayKlass* FlatArrayKlass::allocate_klass(Klass* eklass, LayoutKind lk, TRAPS) {
98 guarantee((!Universe::is_bootstrapping() || vmClasses::Object_klass_loaded()), "Really ?!");
99 assert(UseArrayFlattening, "Flatten array required");
100 assert(MultiArray_lock->holds_lock(THREAD), "must hold lock after bootstrapping");
101
102 InlineKlass* element_klass = InlineKlass::cast(eklass);
103 assert(element_klass->must_be_atomic() || (!AlwaysAtomicAccesses), "Atomic by-default");
104
105 // Eagerly allocate the direct array supertype.
106 Klass* super_klass = nullptr;
107 Klass* element_super = element_klass->super();
108 if (element_super != nullptr) {
109 // The element type has a direct super. E.g., String[] has direct super of Object[].
110 super_klass = element_klass->array_klass(CHECK_NULL);
111 // Also, see if the element has secondary supertypes.
112 // We need an array type for each.
113 const Array<Klass*>* element_supers = element_klass->secondary_supers();
114 for( int i = element_supers->length()-1; i >= 0; i-- ) {
115 Klass* elem_super = element_supers->at(i);
116 elem_super->array_klass(CHECK_NULL);
117 }
118 // Fall through because inheritance is acyclic and we hold the global recursive lock to allocate all the arrays.
119 }
120
121 Symbol* name = ArrayKlass::create_element_klass_array_name(element_klass, CHECK_NULL);
122 ClassLoaderData* loader_data = element_klass->class_loader_data();
123 int size = ArrayKlass::static_size(FlatArrayKlass::header_size());
124 FlatArrayKlass* vak = new (loader_data, size, THREAD) FlatArrayKlass(element_klass, name, lk);
125
126 ModuleEntry* module = vak->module();
127 assert(module != nullptr, "No module entry for array");
128 complete_create_array_klass(vak, super_klass, module, CHECK_NULL);
129
130 loader_data->add_class(vak);
131
132 return vak;
133 }
134
135 void FlatArrayKlass::initialize(TRAPS) {
136 element_klass()->initialize(THREAD);
137 }
138
139 void FlatArrayKlass::metaspace_pointers_do(MetaspaceClosure* it) {
140 ArrayKlass::metaspace_pointers_do(it);
141 it->push(&_element_klass);
142 }
143
144 // Oops allocation...
145 flatArrayOop FlatArrayKlass::allocate(int length, LayoutKind lk, TRAPS) {
146 check_array_allocation_length(length, max_elements(), CHECK_NULL);
147 int size = flatArrayOopDesc::object_size(layout_helper(), length);
148 flatArrayOop array = (flatArrayOop) Universe::heap()->array_allocate(this, size, length, true, CHECK_NULL);
149 return array;
150 }
151
152 oop FlatArrayKlass::multi_allocate(int rank, jint* last_size, TRAPS) {
153 // FlatArrays only have one dimension
154 ShouldNotReachHere();
155 }
156
157 jint FlatArrayKlass::array_layout_helper(InlineKlass* vk, LayoutKind lk) {
158 BasicType etype = T_FLAT_ELEMENT;
159 int esize = log2i_exact(round_up_power_of_2(vk->layout_size_in_bytes(lk)));
160 int hsize = arrayOopDesc::base_offset_in_bytes(etype);
161 bool null_free = lk != LayoutKind::NULLABLE_ATOMIC_FLAT;
162 int lh = Klass::array_layout_helper(_lh_array_tag_vt_value, null_free, hsize, etype, esize);
163
164 assert(lh < (int)_lh_neutral_value, "must look like an array layout");
165 assert(layout_helper_is_array(lh), "correct kind");
166 assert(layout_helper_is_flatArray(lh), "correct kind");
167 assert(!layout_helper_is_typeArray(lh), "correct kind");
168 assert(!layout_helper_is_objArray(lh), "correct kind");
169 assert(layout_helper_is_null_free(lh) == null_free, "correct kind");
170 assert(layout_helper_header_size(lh) == hsize, "correct decode");
171 assert(layout_helper_element_type(lh) == etype, "correct decode");
172 assert(layout_helper_log2_element_size(lh) == esize, "correct decode");
173 assert((1 << esize) < BytesPerLong || is_aligned(hsize, HeapWordsPerLong), "unaligned base");
174
175 return lh;
176 }
177
178 size_t FlatArrayKlass::oop_size(oop obj) const {
179 assert(obj->klass()->is_flatArray_klass(),"must be an flat array");
180 flatArrayOop array = flatArrayOop(obj);
181 return array->object_size();
182 }
183
184 // For now return the maximum number of array elements that will not exceed:
185 // nof bytes = "max_jint * HeapWord" since the "oopDesc::oop_iterate_size"
186 // returns "int" HeapWords, need fix for JDK-4718400 and JDK-8233189
187 jint FlatArrayKlass::max_elements() const {
188 // Check the max number of heap words limit first (because of int32_t in oopDesc_oop_size() etc)
189 size_t max_size = max_jint;
190 max_size -= (arrayOopDesc::base_offset_in_bytes(T_FLAT_ELEMENT) >> LogHeapWordSize);
191 max_size = align_down(max_size, MinObjAlignment);
192 max_size <<= LogHeapWordSize; // convert to max payload size in bytes
193 max_size >>= layout_helper_log2_element_size(_layout_helper); // divide by element size (in bytes) = max elements
194 // Within int32_t heap words, still can't exceed Java array element limit
195 if (max_size > max_jint) {
196 max_size = max_jint;
197 }
198 assert((max_size >> LogHeapWordSize) <= max_jint, "Overflow");
199 return (jint) max_size;
200 }
201
202 oop FlatArrayKlass::protection_domain() const {
203 return element_klass()->protection_domain();
204 }
205
206 // Temp hack having this here: need to move towards Access API
207 static bool needs_backwards_copy(arrayOop s, int src_pos,
208 arrayOop d, int dst_pos, int length) {
209 return (s == d) && (dst_pos > src_pos) && (dst_pos - src_pos) < length;
210 }
211
212 void FlatArrayKlass::copy_array(arrayOop s, int src_pos,
213 arrayOop d, int dst_pos, int length, TRAPS) {
214
215 assert(s->is_objArray() || s->is_flatArray(), "must be obj or flat array");
216
217 // Check destination
218 if ((!d->is_flatArray()) && (!d->is_objArray())) {
219 THROW(vmSymbols::java_lang_ArrayStoreException());
220 }
221
222 // Check if all offsets and lengths are non negative
223 if (src_pos < 0 || dst_pos < 0 || length < 0) {
224 THROW(vmSymbols::java_lang_ArrayIndexOutOfBoundsException());
225 }
226 // Check if the ranges are valid
227 if ( (((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length())
228 || (((unsigned int) length + (unsigned int) dst_pos) > (unsigned int) d->length()) ) {
229 THROW(vmSymbols::java_lang_ArrayIndexOutOfBoundsException());
230 }
231 // Check zero copy
232 if (length == 0)
233 return;
234
235 ArrayKlass* sk = ArrayKlass::cast(s->klass());
236 ArrayKlass* dk = ArrayKlass::cast(d->klass());
237 Klass* d_elem_klass = dk->element_klass();
238 Klass* s_elem_klass = sk->element_klass();
239 /**** CMH: compare and contrast impl, re-factor once we find edge cases... ****/
240
241 if (sk->is_flatArray_klass()) {
242 assert(sk == this, "Unexpected call to copy_array");
243 FlatArrayKlass* fsk = FlatArrayKlass::cast(sk);
244 // Check subtype, all src homogeneous, so just once
245 if (!s_elem_klass->is_subtype_of(d_elem_klass)) {
246 THROW(vmSymbols::java_lang_ArrayStoreException());
247 }
248
249 flatArrayOop sa = flatArrayOop(s);
250 InlineKlass* s_elem_vklass = element_klass();
251
252 // flatArray-to-flatArray
253 if (dk->is_flatArray_klass()) {
254 // element types MUST be exact, subtype check would be dangerous
255 if (d_elem_klass != this->element_klass()) {
256 THROW(vmSymbols::java_lang_ArrayStoreException());
257 }
258
259 FlatArrayKlass* fdk = FlatArrayKlass::cast(dk);
260 InlineKlass* vk = InlineKlass::cast(s_elem_klass);
261 flatArrayOop da = flatArrayOop(d);
262 int src_incr = fsk->element_byte_size();
263 int dst_incr = fdk->element_byte_size();
264
265 if (fsk->layout_kind() == fdk->layout_kind()) {
266 assert(src_incr == dst_incr, "Must be");
267 if (needs_backwards_copy(sa, src_pos, da, dst_pos, length)) {
268 address dst = (address) da->value_at_addr(dst_pos + length - 1, fdk->layout_helper());
269 address src = (address) sa->value_at_addr(src_pos + length - 1, fsk->layout_helper());
270 for (int i = 0; i < length; i++) {
271 // because source and destination have the same layout, bypassing the InlineKlass copy methods
272 // and call AccessAPI directly
273 HeapAccess<>::value_copy(src, dst, vk, fsk->layout_kind());
274 dst -= dst_incr;
275 src -= src_incr;
276 }
277 } else {
278 // source and destination share same layout, direct copy from array to array is possible
279 address dst = (address) da->value_at_addr(dst_pos, fdk->layout_helper());
280 address src = (address) sa->value_at_addr(src_pos, fsk->layout_helper());
281 for (int i = 0; i < length; i++) {
282 // because source and destination have the same layout, bypassing the InlineKlass copy methods
283 // and call AccessAPI directly
284 HeapAccess<>::value_copy(src, dst, vk, fsk->layout_kind());
285 dst += dst_incr;
286 src += src_incr;
287 }
288 }
289 } else {
290 flatArrayHandle hd(THREAD, da);
291 flatArrayHandle hs(THREAD, sa);
292 // source and destination layouts mismatch, simpler solution is to copy through an intermediate buffer (heap instance)
293 bool need_null_check = fsk->layout_kind() == LayoutKind::NULLABLE_ATOMIC_FLAT && fdk->layout_kind() != LayoutKind::NULLABLE_ATOMIC_FLAT;
294 oop buffer = vk->allocate_instance(CHECK);
295 address dst = (address) hd->value_at_addr(dst_pos, fdk->layout_helper());
296 address src = (address) hs->value_at_addr(src_pos, fsk->layout_helper());
297 for (int i = 0; i < length; i++) {
298 if (need_null_check) {
299 if (vk->is_payload_marked_as_null(src)) {
300 THROW(vmSymbols::java_lang_NullPointerException());
301 }
302 }
303 vk->copy_payload_to_addr(src, vk->payload_addr(buffer), fsk->layout_kind(), true);
304 if (vk->has_nullable_atomic_layout()) {
305 // Setting null marker to not zero for non-nullable source layouts
306 vk->mark_payload_as_non_null(vk->payload_addr(buffer));
307 }
308 vk->copy_payload_to_addr(vk->payload_addr(buffer), dst, fdk->layout_kind(), true);
309 dst += dst_incr;
310 src += src_incr;
311 }
312 }
313 } else { // flatArray-to-objArray
314 assert(dk->is_objArray_klass(), "Expected objArray here");
315 // Need to allocate each new src elem payload -> dst oop
316 objArrayHandle dh(THREAD, (objArrayOop)d);
317 flatArrayHandle sh(THREAD, sa);
318 InlineKlass* vk = InlineKlass::cast(s_elem_klass);
319 for (int i = 0; i < length; i++) {
320 oop o = sh->read_value_from_flat_array(src_pos + i, CHECK);
321 dh->obj_at_put(dst_pos + i, o);
322 }
323 }
324 } else {
325 assert(s->is_objArray(), "Expected objArray");
326 objArrayOop sa = objArrayOop(s);
327 assert(d->is_flatArray(), "Expected flatArray"); // objArray-to-flatArray
328 InlineKlass* d_elem_vklass = InlineKlass::cast(d_elem_klass);
329 flatArrayOop da = flatArrayOop(d);
330 FlatArrayKlass* fdk = FlatArrayKlass::cast(da->klass());
331 InlineKlass* vk = InlineKlass::cast(d_elem_klass);
332
333 for (int i = 0; i < length; i++) {
334 da->write_value_to_flat_array(sa->obj_at(src_pos + i), dst_pos + i, CHECK);
335 }
336 }
337 }
338
339 ModuleEntry* FlatArrayKlass::module() const {
340 assert(element_klass() != nullptr, "FlatArrayKlass returned unexpected nullptr bottom_klass");
341 // The array is defined in the module of its bottom class
342 return element_klass()->module();
343 }
344
345 PackageEntry* FlatArrayKlass::package() const {
346 assert(element_klass() != nullptr, "FlatArrayKlass returned unexpected nullptr bottom_klass");
347 return element_klass()->package();
348 }
349
350 bool FlatArrayKlass::can_be_primary_super_slow() const {
351 return true;
352 }
353
354 GrowableArray<Klass*>* FlatArrayKlass::compute_secondary_supers(int num_extra_slots,
355 Array<InstanceKlass*>* transitive_interfaces) {
356 assert(transitive_interfaces == nullptr, "sanity");
357 // interfaces = { cloneable_klass, serializable_klass, elemSuper[], ... };
358 Array<Klass*>* elem_supers = element_klass()->secondary_supers();
359 int num_elem_supers = elem_supers == nullptr ? 0 : elem_supers->length();
360 int num_secondaries = num_extra_slots + 2 + num_elem_supers;
361 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(num_elem_supers+2);
362
363 secondaries->push(vmClasses::Cloneable_klass());
364 secondaries->push(vmClasses::Serializable_klass());
365 for (int i = 0; i < num_elem_supers; i++) {
366 Klass* elem_super = (Klass*) elem_supers->at(i);
367 Klass* array_super = elem_super->array_klass_or_null();
368 assert(array_super != nullptr, "must already have been created");
369 secondaries->push(array_super);
370 }
371 return secondaries;
372 }
373
374 u2 FlatArrayKlass::compute_modifier_flags() const {
375 // The modifier for an flatArray is the same as its element
376 // With the addition of ACC_IDENTITY
377 u2 element_flags = element_klass()->compute_modifier_flags();
378
379 u2 identity_flag = (Arguments::enable_preview()) ? JVM_ACC_IDENTITY : 0;
380
381 return (element_flags & (JVM_ACC_PUBLIC | JVM_ACC_PRIVATE | JVM_ACC_PROTECTED))
382 | (identity_flag | JVM_ACC_ABSTRACT | JVM_ACC_FINAL);
383 }
384
385 void FlatArrayKlass::print_on(outputStream* st) const {
386 #ifndef PRODUCT
387 assert(!is_objArray_klass(), "Unimplemented");
388
389 st->print("Flat Type Array: ");
390 Klass::print_on(st);
391
392 st->print(" - element klass: ");
393 element_klass()->print_value_on(st);
394 st->cr();
395
396 int elem_size = element_byte_size();
397 st->print(" - element size %i ", elem_size);
398 st->print("aligned layout size %i", 1 << layout_helper_log2_element_size(layout_helper()));
399 st->cr();
400 #endif //PRODUCT
401 }
402
403 void FlatArrayKlass::print_value_on(outputStream* st) const {
404 assert(is_klass(), "must be klass");
405
406 element_klass()->print_value_on(st);
407 st->print("[]");
408 }
409
410
411 #ifndef PRODUCT
412 void FlatArrayKlass::oop_print_on(oop obj, outputStream* st) {
413 ArrayKlass::oop_print_on(obj, st);
414 flatArrayOop va = flatArrayOop(obj);
415 InlineKlass* vk = element_klass();
416 int print_len = MIN2(va->length(), MaxElementPrintSize);
417 for(int index = 0; index < print_len; index++) {
418 int off = (address) va->value_at_addr(index, layout_helper()) - cast_from_oop<address>(obj);
419 st->print_cr(" - Index %3d offset %3d: ", index, off);
420 oop obj = cast_to_oop((address)va->value_at_addr(index, layout_helper()) - vk->payload_offset());
421 FieldPrinter print_field(st, obj);
422 vk->do_nonstatic_fields(&print_field);
423 st->cr();
424 }
425 int remaining = va->length() - print_len;
426 if (remaining > 0) {
427 st->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>", remaining);
428 }
429 }
430 #endif //PRODUCT
431
432 void FlatArrayKlass::oop_print_value_on(oop obj, outputStream* st) {
433 assert(obj->is_flatArray(), "must be flatArray");
434 st->print("a ");
435 element_klass()->print_value_on(st);
436 int len = flatArrayOop(obj)->length();
437 st->print("[%d] ", len);
438 obj->print_address_on(st);
439 if (PrintMiscellaneous && (WizardMode || Verbose)) {
440 int lh = layout_helper();
441 st->print("{");
442 for (int i = 0; i < len; i++) {
443 if (i > 4) {
444 st->print("..."); break;
445 }
446 st->print(" " INTPTR_FORMAT, (intptr_t)(void*)flatArrayOop(obj)->value_at_addr(i , lh));
447 }
448 st->print(" }");
449 }
450 }
451
452 // Verification
453 class VerifyElementClosure: public BasicOopIterateClosure {
454 public:
455 virtual void do_oop(oop* p) { VerifyOopClosure::verify_oop.do_oop(p); }
456 virtual void do_oop(narrowOop* p) { VerifyOopClosure::verify_oop.do_oop(p); }
457 };
458
459 void FlatArrayKlass::oop_verify_on(oop obj, outputStream* st) {
460 ArrayKlass::oop_verify_on(obj, st);
461 guarantee(obj->is_flatArray(), "must be flatArray");
462
463 if (contains_oops()) {
464 flatArrayOop va = flatArrayOop(obj);
465 VerifyElementClosure ec;
466 va->oop_iterate(&ec);
467 }
468 }
469
470 void FlatArrayKlass::verify_on(outputStream* st) {
471 ArrayKlass::verify_on(st);
472 guarantee(element_klass()->is_inline_klass(), "should be inline type klass");
473 }