1 /*
2 * Copyright (c) 1997, 2015, 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/symbolTable.hpp"
27 #include "classfile/systemDictionary.hpp"
28 #include "classfile/vmSymbols.hpp"
29 #include "gc_interface/collectedHeap.inline.hpp"
30 #include "memory/iterator.inline.hpp"
31 #include "memory/metadataFactory.hpp"
32 #include "memory/resourceArea.hpp"
33 #include "memory/specialized_oop_closures.hpp"
34 #include "memory/universe.inline.hpp"
35 #include "oops/instanceKlass.hpp"
36 #include "oops/klass.inline.hpp"
37 #include "oops/objArrayKlass.inline.hpp"
38 #include "oops/objArrayOop.inline.hpp"
39 #include "oops/oop.inline.hpp"
40 #include "oops/symbol.hpp"
41 #include "runtime/handles.inline.hpp"
42 #include "runtime/mutexLocker.hpp"
43 #include "runtime/orderAccess.inline.hpp"
44 #include "utilities/copy.hpp"
45 #include "utilities/macros.hpp"
46
47 ObjArrayKlass* ObjArrayKlass::allocate(ClassLoaderData* loader_data, int n, KlassHandle klass_handle, Symbol* name, TRAPS) {
48 assert(ObjArrayKlass::header_size() <= InstanceKlass::header_size(),
49 "array klasses must be same size as InstanceKlass");
50
51 int size = ArrayKlass::static_size(ObjArrayKlass::header_size());
52
53 return new (loader_data, size, THREAD) ObjArrayKlass(n, klass_handle, name);
54 }
55
56 Klass* ObjArrayKlass::allocate_objArray_klass(ClassLoaderData* loader_data,
57 int n, KlassHandle element_klass, TRAPS) {
58
59 // Eagerly allocate the direct array supertype.
60 KlassHandle super_klass = KlassHandle();
61 if (!Universe::is_bootstrapping() || SystemDictionary::Object_klass_loaded()) {
62 KlassHandle element_super (THREAD, element_klass->super());
63 if (element_super.not_null()) {
64 // The element type has a direct super. E.g., String[] has direct super of Object[].
65 super_klass = KlassHandle(THREAD, element_super->array_klass_or_null());
66 bool supers_exist = super_klass.not_null();
67 // Also, see if the element has secondary supertypes.
68 // We need an array type for each.
69 Array<Klass*>* element_supers = element_klass->secondary_supers();
70 for( int i = element_supers->length()-1; i >= 0; i-- ) {
71 Klass* elem_super = element_supers->at(i);
72 if (elem_super->array_klass_or_null() == NULL) {
73 supers_exist = false;
74 break;
75 }
76 }
77 if (!supers_exist) {
78 // Oops. Not allocated yet. Back out, allocate it, and retry.
79 KlassHandle ek;
80 {
81 MutexUnlocker mu(MultiArray_lock);
82 MutexUnlocker mc(Compile_lock); // for vtables
83 Klass* sk = element_super->array_klass(CHECK_0);
84 super_klass = KlassHandle(THREAD, sk);
85 for( int i = element_supers->length()-1; i >= 0; i-- ) {
86 KlassHandle elem_super (THREAD, element_supers->at(i));
87 elem_super->array_klass(CHECK_0);
88 }
89 // Now retry from the beginning
90 Klass* klass_oop = element_klass->array_klass(n, CHECK_0);
91 // Create a handle because the enclosing brace, when locking
92 // can cause a gc. Better to have this function return a Handle.
93 ek = KlassHandle(THREAD, klass_oop);
94 } // re-lock
95 return ek();
96 }
97 } else {
98 // The element type is already Object. Object[] has direct super of Object.
99 super_klass = KlassHandle(THREAD, SystemDictionary::Object_klass());
100 }
101 }
102
103 // Create type name for klass.
104 Symbol* name = NULL;
105 if (!element_klass->oop_is_instance() ||
106 (name = InstanceKlass::cast(element_klass())->array_name()) == NULL) {
107
108 ResourceMark rm(THREAD);
109 char *name_str = element_klass->name()->as_C_string();
110 int len = element_klass->name()->utf8_length();
111 char *new_str = NEW_RESOURCE_ARRAY(char, len + 4);
112 int idx = 0;
113 new_str[idx++] = '[';
114 if (element_klass->oop_is_instance()) { // it could be an array or simple type
115 new_str[idx++] = 'L';
116 }
117 memcpy(&new_str[idx], name_str, len * sizeof(char));
118 idx += len;
119 if (element_klass->oop_is_instance()) {
120 new_str[idx++] = ';';
121 }
122 new_str[idx++] = '\0';
123 name = SymbolTable::new_permanent_symbol(new_str, CHECK_0);
124 if (element_klass->oop_is_instance()) {
125 InstanceKlass* ik = InstanceKlass::cast(element_klass());
126 ik->set_array_name(name);
127 }
128 }
129
130 // Initialize instance variables
131 ObjArrayKlass* oak = ObjArrayKlass::allocate(loader_data, n, element_klass, name, CHECK_0);
132
133 // Add all classes to our internal class loader list here,
134 // including classes in the bootstrap (NULL) class loader.
135 // GC walks these as strong roots.
136 loader_data->add_class(oak);
137
138 // Call complete_create_array_klass after all instance variables has been initialized.
139 ArrayKlass::complete_create_array_klass(oak, super_klass, CHECK_0);
140
141 return oak;
142 }
143
144 ObjArrayKlass::ObjArrayKlass(int n, KlassHandle element_klass, Symbol* name) : ArrayKlass(name) {
145 this->set_dimension(n);
146 this->set_element_klass(element_klass());
147 // decrement refcount because object arrays are not explicitly freed. The
148 // InstanceKlass array_name() keeps the name counted while the klass is
149 // loaded.
150 name->decrement_refcount();
151
152 Klass* bk;
153 if (element_klass->oop_is_objArray()) {
154 bk = ObjArrayKlass::cast(element_klass())->bottom_klass();
155 } else {
156 bk = element_klass();
157 }
158 assert(bk != NULL && (bk->oop_is_instance() || bk->oop_is_typeArray()), "invalid bottom klass");
159 this->set_bottom_klass(bk);
160 this->set_class_loader_data(bk->class_loader_data());
161
162 this->set_layout_helper(array_layout_helper(T_OBJECT));
163 assert(this->oop_is_array(), "sanity");
164 assert(this->oop_is_objArray(), "sanity");
165 }
166
167 int ObjArrayKlass::oop_size(oop obj) const {
168 assert(obj->is_objArray(), "must be object array");
169 return objArrayOop(obj)->object_size();
170 }
171
172 objArrayOop ObjArrayKlass::allocate(int length, TRAPS) {
173 if (length >= 0) {
174 if (length <= arrayOopDesc::max_array_length(T_OBJECT)) {
175 int size = objArrayOopDesc::object_size(length);
176 KlassHandle h_k(THREAD, this);
177 return (objArrayOop)CollectedHeap::array_allocate(h_k, size, length, THREAD);
178 } else {
179 report_java_out_of_memory("Requested array size exceeds VM limit");
180 JvmtiExport::post_array_size_exhausted();
181 THROW_OOP_0(Universe::out_of_memory_error_array_size());
182 }
183 } else {
184 THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
185 }
186 }
187
188 static int multi_alloc_counter = 0;
189
190 oop ObjArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) {
191 int length = *sizes;
192 // Call to lower_dimension uses this pointer, so most be called before a
193 // possible GC
194 KlassHandle h_lower_dimension(THREAD, lower_dimension());
195 // If length < 0 allocate will throw an exception.
196 objArrayOop array = allocate(length, CHECK_NULL);
197 objArrayHandle h_array (THREAD, array);
198 if (rank > 1) {
199 if (length != 0) {
200 for (int index = 0; index < length; index++) {
201 ArrayKlass* ak = ArrayKlass::cast(h_lower_dimension());
202 oop sub_array = ak->multi_allocate(rank-1, &sizes[1], CHECK_NULL);
203 h_array->obj_at_put(index, sub_array);
204 }
205 } else {
206 // Since this array dimension has zero length, nothing will be
207 // allocated, however the lower dimension values must be checked
208 // for illegal values.
209 for (int i = 0; i < rank - 1; ++i) {
210 sizes += 1;
211 if (*sizes < 0) {
212 THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
213 }
214 }
215 }
216 }
217 return h_array();
218 }
219
220 // Either oop or narrowOop depending on UseCompressedOops.
221 template <class T> void ObjArrayKlass::do_copy(arrayOop s, T* src,
222 arrayOop d, T* dst, int length, TRAPS) {
223
224 BarrierSet* bs = Universe::heap()->barrier_set();
225 // For performance reasons, we assume we are that the write barrier we
226 // are using has optimized modes for arrays of references. At least one
227 // of the asserts below will fail if this is not the case.
228 assert(bs->has_write_ref_array_opt(), "Barrier set must have ref array opt");
229 assert(bs->has_write_ref_array_pre_opt(), "For pre-barrier as well.");
230
231 if (s == d) {
232 // since source and destination are equal we do not need conversion checks.
233 assert(length > 0, "sanity check");
234 bs->write_ref_array_pre(dst, length);
235 Copy::conjoint_oops_atomic(src, dst, length);
236 } else {
237 // We have to make sure all elements conform to the destination array
238 Klass* bound = ObjArrayKlass::cast(d->klass())->element_klass();
239 Klass* stype = ObjArrayKlass::cast(s->klass())->element_klass();
240 if (stype == bound || stype->is_subtype_of(bound)) {
241 // elements are guaranteed to be subtypes, so no check necessary
242 bs->write_ref_array_pre(dst, length);
243 Copy::conjoint_oops_atomic(src, dst, length);
244 } else {
245 // slow case: need individual subtype checks
246 // note: don't use obj_at_put below because it includes a redundant store check
247 T* from = src;
248 T* end = from + length;
249 for (T* p = dst; from < end; from++, p++) {
250 // XXX this is going to be slow.
251 T element = *from;
252 // even slower now
253 bool element_is_null = oopDesc::is_null(element);
254 oop new_val = element_is_null ? oop(NULL)
255 : oopDesc::decode_heap_oop_not_null(element);
256 if (element_is_null ||
257 (new_val->klass())->is_subtype_of(bound)) {
258 bs->write_ref_field_pre(p, new_val);
259 *p = element;
260 } else {
261 // We must do a barrier to cover the partial copy.
262 const size_t pd = pointer_delta(p, dst, (size_t)heapOopSize);
263 // pointer delta is scaled to number of elements (length field in
264 // objArrayOop) which we assume is 32 bit.
265 assert(pd == (size_t)(int)pd, "length field overflow");
266 bs->write_ref_array((HeapWord*)dst, pd);
267 THROW(vmSymbols::java_lang_ArrayStoreException());
268 return;
269 }
270 }
271 }
272 }
273 bs->write_ref_array((HeapWord*)dst, length);
274 }
275
276 void ObjArrayKlass::copy_array(arrayOop s, int src_pos, arrayOop d,
277 int dst_pos, int length, TRAPS) {
278 assert(s->is_objArray(), "must be obj array");
279
280 if (!d->is_objArray()) {
281 THROW(vmSymbols::java_lang_ArrayStoreException());
282 }
283
284 // Check is all offsets and lengths are non negative
285 if (src_pos < 0 || dst_pos < 0 || length < 0) {
286 THROW(vmSymbols::java_lang_ArrayIndexOutOfBoundsException());
287 }
288 // Check if the ranges are valid
289 if ( (((unsigned int) length + (unsigned int) src_pos) > (unsigned int) s->length())
290 || (((unsigned int) length + (unsigned int) dst_pos) > (unsigned int) d->length()) ) {
291 THROW(vmSymbols::java_lang_ArrayIndexOutOfBoundsException());
292 }
293
294 // Special case. Boundary cases must be checked first
295 // This allows the following call: copy_array(s, s.length(), d.length(), 0).
296 // This is correct, since the position is supposed to be an 'in between point', i.e., s.length(),
297 // points to the right of the last element.
298 if (length==0) {
299 return;
300 }
301 if (UseCompressedOops) {
302 narrowOop* const src = objArrayOop(s)->obj_at_addr<narrowOop>(src_pos);
303 narrowOop* const dst = objArrayOop(d)->obj_at_addr<narrowOop>(dst_pos);
304 do_copy<narrowOop>(s, src, d, dst, length, CHECK);
305 } else {
306 oop* const src = objArrayOop(s)->obj_at_addr<oop>(src_pos);
307 oop* const dst = objArrayOop(d)->obj_at_addr<oop>(dst_pos);
308 do_copy<oop> (s, src, d, dst, length, CHECK);
309 }
310 }
311
312
313 Klass* ObjArrayKlass::array_klass_impl(bool or_null, int n, TRAPS) {
314
315 assert(dimension() <= n, "check order of chain");
316 int dim = dimension();
317 if (dim == n) return this;
318
319 if (higher_dimension() == NULL) {
320 if (or_null) return NULL;
321
322 ResourceMark rm;
323 JavaThread *jt = (JavaThread *)THREAD;
324 {
325 MutexLocker mc(Compile_lock, THREAD); // for vtables
326 // Ensure atomic creation of higher dimensions
327 MutexLocker mu(MultiArray_lock, THREAD);
328
329 // Check if another thread beat us
330 if (higher_dimension() == NULL) {
331
332 // Create multi-dim klass object and link them together
333 Klass* k =
334 ObjArrayKlass::allocate_objArray_klass(class_loader_data(), dim + 1, this, CHECK_NULL);
335 ObjArrayKlass* ak = ObjArrayKlass::cast(k);
336 ak->set_lower_dimension(this);
337 OrderAccess::storestore();
338 set_higher_dimension(ak);
339 assert(ak->oop_is_objArray(), "incorrect initialization of ObjArrayKlass");
340 }
341 }
342 } else {
343 CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
344 }
345
346 ObjArrayKlass *ak = ObjArrayKlass::cast(higher_dimension());
347 if (or_null) {
348 return ak->array_klass_or_null(n);
349 }
350 return ak->array_klass(n, THREAD);
351 }
352
353 Klass* ObjArrayKlass::array_klass_impl(bool or_null, TRAPS) {
354 return array_klass_impl(or_null, dimension() + 1, THREAD);
355 }
356
357 bool ObjArrayKlass::can_be_primary_super_slow() const {
358 if (!bottom_klass()->can_be_primary_super())
359 // array of interfaces
360 return false;
361 else
362 return Klass::can_be_primary_super_slow();
363 }
364
365 GrowableArray<Klass*>* ObjArrayKlass::compute_secondary_supers(int num_extra_slots) {
366 // interfaces = { cloneable_klass, serializable_klass, elemSuper[], ... };
367 Array<Klass*>* elem_supers = element_klass()->secondary_supers();
368 int num_elem_supers = elem_supers == NULL ? 0 : elem_supers->length();
369 int num_secondaries = num_extra_slots + 2 + num_elem_supers;
370 if (num_secondaries == 2) {
371 // Must share this for correct bootstrapping!
372 set_secondary_supers(Universe::the_array_interfaces_array());
373 return NULL;
374 } else {
375 GrowableArray<Klass*>* secondaries = new GrowableArray<Klass*>(num_elem_supers+2);
376 secondaries->push(SystemDictionary::Cloneable_klass());
377 secondaries->push(SystemDictionary::Serializable_klass());
378 for (int i = 0; i < num_elem_supers; i++) {
379 Klass* elem_super = (Klass*) elem_supers->at(i);
380 Klass* array_super = elem_super->array_klass_or_null();
381 assert(array_super != NULL, "must already have been created");
382 secondaries->push(array_super);
383 }
384 return secondaries;
385 }
386 }
387
388 bool ObjArrayKlass::compute_is_subtype_of(Klass* k) {
389 if (!k->oop_is_objArray())
390 return ArrayKlass::compute_is_subtype_of(k);
391
392 ObjArrayKlass* oak = ObjArrayKlass::cast(k);
393 return element_klass()->is_subtype_of(oak->element_klass());
394 }
395
396 void ObjArrayKlass::initialize(TRAPS) {
397 bottom_klass()->initialize(THREAD); // dispatches to either InstanceKlass or TypeArrayKlass
398 }
399
400 // JVM support
401
402 jint ObjArrayKlass::compute_modifier_flags(TRAPS) const {
403 // The modifier for an objectArray is the same as its element
404 if (element_klass() == NULL) {
405 assert(Universe::is_bootstrapping(), "partial objArray only at startup");
406 return JVM_ACC_ABSTRACT | JVM_ACC_FINAL | JVM_ACC_PUBLIC;
407 }
408 // Return the flags of the bottom element type.
409 jint element_flags = bottom_klass()->compute_modifier_flags(CHECK_0);
410
411 return (element_flags & (JVM_ACC_PUBLIC | JVM_ACC_PRIVATE | JVM_ACC_PROTECTED))
412 | (JVM_ACC_ABSTRACT | JVM_ACC_FINAL);
413 }
414
415
416 // Printing
417
418 void ObjArrayKlass::print_on(outputStream* st) const {
419 #ifndef PRODUCT
420 Klass::print_on(st);
421 st->print(" - instance klass: ");
422 element_klass()->print_value_on(st);
423 st->cr();
424 #endif //PRODUCT
425 }
426
427 void ObjArrayKlass::print_value_on(outputStream* st) const {
428 assert(is_klass(), "must be klass");
429
430 element_klass()->print_value_on(st);
431 st->print("[]");
432 }
433
434 #ifndef PRODUCT
435
436 void ObjArrayKlass::oop_print_on(oop obj, outputStream* st) {
437 ArrayKlass::oop_print_on(obj, st);
438 assert(obj->is_objArray(), "must be objArray");
439 objArrayOop oa = objArrayOop(obj);
440 int print_len = MIN2((intx) oa->length(), MaxElementPrintSize);
441 for(int index = 0; index < print_len; index++) {
442 st->print(" - %3d : ", index);
443 oa->obj_at(index)->print_value_on(st);
444 st->cr();
445 }
446 int remaining = oa->length() - print_len;
447 if (remaining > 0) {
448 st->print_cr(" - <%d more elements, increase MaxElementPrintSize to print>", remaining);
449 }
450 }
451
452 #endif //PRODUCT
453
454 static int max_objArray_print_length = 4;
455
456 void ObjArrayKlass::oop_print_value_on(oop obj, outputStream* st) {
457 assert(obj->is_objArray(), "must be objArray");
458 st->print("a ");
459 element_klass()->print_value_on(st);
460 int len = objArrayOop(obj)->length();
461 st->print("[%d] ", len);
462 obj->print_address_on(st);
463 if (NOT_PRODUCT(PrintOopAddress ||) PrintMiscellaneous && (WizardMode || Verbose)) {
464 st->print("{");
465 for (int i = 0; i < len; i++) {
466 if (i > max_objArray_print_length) {
467 st->print("..."); break;
468 }
469 st->print(" "INTPTR_FORMAT, (intptr_t)(void*)objArrayOop(obj)->obj_at(i));
470 }
471 st->print(" }");
472 }
473 }
474
475 const char* ObjArrayKlass::internal_name() const {
476 return external_name();
477 }
478
479
480 // Verification
481
482 void ObjArrayKlass::verify_on(outputStream* st) {
483 ArrayKlass::verify_on(st);
484 guarantee(element_klass()->is_klass(), "should be klass");
485 guarantee(bottom_klass()->is_klass(), "should be klass");
486 Klass* bk = bottom_klass();
487 guarantee(bk->oop_is_instance() || bk->oop_is_typeArray(), "invalid bottom klass");
488 }
489
490 void ObjArrayKlass::oop_verify_on(oop obj, outputStream* st) {
491 ArrayKlass::oop_verify_on(obj, st);
492 guarantee(obj->is_objArray(), "must be objArray");
493 objArrayOop oa = objArrayOop(obj);
494 for(int index = 0; index < oa->length(); index++) {
495 guarantee(oa->obj_at(index)->is_oop_or_null(), "should be oop");
496 }
497 }