1 /*
2 * Copyright 1999-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
24
25 #include "incls/_precompiled.incl"
26 #include "incls/_ciInstanceKlass.cpp.incl"
27
28 // ciInstanceKlass
29 //
30 // This class represents a klassOop in the HotSpot virtual machine
31 // whose Klass part in an instanceKlass.
32
33 // ------------------------------------------------------------------
34 // ciInstanceKlass::ciInstanceKlass
35 //
36 // Loaded instance klass.
37 ciInstanceKlass::ciInstanceKlass(KlassHandle h_k) :
38 ciKlass(h_k), _non_static_fields(NULL)
39 {
40 assert(get_Klass()->oop_is_instance(), "wrong type");
41 instanceKlass* ik = get_instanceKlass();
42
43 AccessFlags access_flags = ik->access_flags();
44 _flags = ciFlags(access_flags);
45 _has_finalizer = access_flags.has_finalizer();
46 _has_subklass = ik->subklass() != NULL;
47 _is_initialized = ik->is_initialized();
48 // Next line must follow and use the result of the previous line:
49 _is_linked = _is_initialized || ik->is_linked();
50 _nonstatic_field_size = ik->nonstatic_field_size();
51 _has_nonstatic_fields = ik->has_nonstatic_fields();
52 _nonstatic_fields = NULL; // initialized lazily by compute_nonstatic_fields:
53
54 _nof_implementors = ik->nof_implementors();
55 for (int i = 0; i < implementors_limit; i++) {
56 _implementors[i] = NULL; // we will fill these lazily
57 }
58
59 Thread *thread = Thread::current();
60 if (ciObjectFactory::is_initialized()) {
61 _loader = JNIHandles::make_local(thread, ik->class_loader());
62 _protection_domain = JNIHandles::make_local(thread,
63 ik->protection_domain());
64 _is_shared = false;
65 } else {
66 Handle h_loader(thread, ik->class_loader());
67 Handle h_protection_domain(thread, ik->protection_domain());
68 _loader = JNIHandles::make_global(h_loader);
69 _protection_domain = JNIHandles::make_global(h_protection_domain);
70 _is_shared = true;
71 }
72
73 // Lazy fields get filled in only upon request.
74 _super = NULL;
75 _java_mirror = NULL;
76
77 if (is_shared()) {
78 if (h_k() != SystemDictionary::object_klass()) {
79 super();
80 }
81 java_mirror();
82 //compute_nonstatic_fields(); // done outside of constructor
83 }
84
85 _field_cache = NULL;
86 }
87
88 // Version for unloaded classes:
89 ciInstanceKlass::ciInstanceKlass(ciSymbol* name,
90 jobject loader, jobject protection_domain)
91 : ciKlass(name, ciInstanceKlassKlass::make())
92 {
93 assert(name->byte_at(0) != '[', "not an instance klass");
94 _is_initialized = false;
95 _is_linked = false;
96 _nonstatic_field_size = -1;
97 _has_nonstatic_fields = false;
98 _nonstatic_fields = NULL;
99 _nof_implementors = -1;
100 _loader = loader;
101 _protection_domain = protection_domain;
102 _is_shared = false;
103 _super = NULL;
104 _java_mirror = NULL;
105 _field_cache = NULL;
106 }
107
108
109
110 // ------------------------------------------------------------------
111 // ciInstanceKlass::compute_shared_is_initialized
112 bool ciInstanceKlass::compute_shared_is_initialized() {
113 GUARDED_VM_ENTRY(
114 instanceKlass* ik = get_instanceKlass();
115 _is_initialized = ik->is_initialized();
116 return _is_initialized;
117 )
118 }
119
120 // ------------------------------------------------------------------
121 // ciInstanceKlass::compute_shared_is_linked
122 bool ciInstanceKlass::compute_shared_is_linked() {
123 GUARDED_VM_ENTRY(
124 instanceKlass* ik = get_instanceKlass();
125 _is_linked = ik->is_linked();
126 return _is_linked;
127 )
128 }
129
130 // ------------------------------------------------------------------
131 // ciInstanceKlass::compute_shared_has_subklass
132 bool ciInstanceKlass::compute_shared_has_subklass() {
133 GUARDED_VM_ENTRY(
134 instanceKlass* ik = get_instanceKlass();
135 _has_subklass = ik->subklass() != NULL;
136 return _has_subklass;
137 )
138 }
139
140 // ------------------------------------------------------------------
141 // ciInstanceKlass::compute_shared_nof_implementors
142 int ciInstanceKlass::compute_shared_nof_implementors() {
143 // We requery this property, since it is a very old ciObject.
144 GUARDED_VM_ENTRY(
145 instanceKlass* ik = get_instanceKlass();
146 _nof_implementors = ik->nof_implementors();
147 return _nof_implementors;
148 )
149 }
150
151 // ------------------------------------------------------------------
152 // ciInstanceKlass::loader
153 oop ciInstanceKlass::loader() {
154 ASSERT_IN_VM;
155 return JNIHandles::resolve(_loader);
156 }
157
158 // ------------------------------------------------------------------
159 // ciInstanceKlass::loader_handle
160 jobject ciInstanceKlass::loader_handle() {
161 return _loader;
162 }
163
164 // ------------------------------------------------------------------
165 // ciInstanceKlass::protection_domain
166 oop ciInstanceKlass::protection_domain() {
167 ASSERT_IN_VM;
168 return JNIHandles::resolve(_protection_domain);
169 }
170
171 // ------------------------------------------------------------------
172 // ciInstanceKlass::protection_domain_handle
173 jobject ciInstanceKlass::protection_domain_handle() {
174 return _protection_domain;
175 }
176
177 // ------------------------------------------------------------------
178 // ciInstanceKlass::field_cache
179 //
180 // Get the field cache associated with this klass.
181 ciConstantPoolCache* ciInstanceKlass::field_cache() {
182 if (is_shared()) {
183 return NULL;
184 }
185 if (_field_cache == NULL) {
186 assert(!is_java_lang_Object(), "Object has no fields");
187 Arena* arena = CURRENT_ENV->arena();
188 _field_cache = new (arena) ciConstantPoolCache(arena, 5);
189 }
190 return _field_cache;
191 }
192
193 // ------------------------------------------------------------------
194 // ciInstanceKlass::get_canonical_holder
195 //
196 ciInstanceKlass* ciInstanceKlass::get_canonical_holder(int offset) {
197 #ifdef ASSERT
198 if (!(offset >= 0 && offset < layout_helper())) {
199 tty->print("*** get_canonical_holder(%d) on ", offset);
200 this->print();
201 tty->print_cr(" ***");
202 };
203 assert(offset >= 0 && offset < layout_helper(), "offset must be tame");
204 #endif
205
206 if (offset < instanceOopDesc::base_offset_in_bytes()) {
207 // All header offsets belong properly to java/lang/Object.
208 return CURRENT_ENV->Object_klass();
209 }
210
211 ciInstanceKlass* self = this;
212 for (;;) {
213 assert(self->is_loaded(), "must be loaded to have size");
214 ciInstanceKlass* super = self->super();
215 if (super == NULL || super->nof_nonstatic_fields() == 0 ||
216 !super->contains_field_offset(offset)) {
217 return self;
218 } else {
219 self = super; // return super->get_canonical_holder(offset)
220 }
221 }
222 }
223
224 // ------------------------------------------------------------------
225 // ciInstanceKlass::is_java_lang_Object
226 //
227 // Is this klass java.lang.Object?
228 bool ciInstanceKlass::is_java_lang_Object() {
229 return equals(CURRENT_ENV->Object_klass());
230 }
231
232 // ------------------------------------------------------------------
233 // ciInstanceKlass::uses_default_loader
234 bool ciInstanceKlass::uses_default_loader() {
235 VM_ENTRY_MARK;
236 return loader() == NULL;
237 }
238
239 // ------------------------------------------------------------------
240 // ciInstanceKlass::print_impl
241 //
242 // Implementation of the print method.
243 void ciInstanceKlass::print_impl(outputStream* st) {
244 ciKlass::print_impl(st);
245 GUARDED_VM_ENTRY(st->print(" loader=0x%x", (address)loader());)
246 if (is_loaded()) {
247 st->print(" loaded=true initialized=%s finalized=%s subklass=%s size=%d flags=",
248 bool_to_str(is_initialized()),
249 bool_to_str(has_finalizer()),
250 bool_to_str(has_subklass()),
251 layout_helper());
252
253 _flags.print_klass_flags();
254
255 if (_super) {
256 st->print(" super=");
257 _super->print_name();
258 }
259 if (_java_mirror) {
260 st->print(" mirror=PRESENT");
261 }
262 } else {
263 st->print(" loaded=false");
264 }
265 }
266
267 // ------------------------------------------------------------------
268 // ciInstanceKlass::super
269 //
270 // Get the superklass of this klass.
271 ciInstanceKlass* ciInstanceKlass::super() {
272 assert(is_loaded(), "must be loaded");
273 if (_super == NULL && !is_java_lang_Object()) {
274 GUARDED_VM_ENTRY(
275 klassOop super_klass = get_instanceKlass()->super();
276 _super = CURRENT_ENV->get_object(super_klass)->as_instance_klass();
277 )
278 }
279 return _super;
280 }
281
282 // ------------------------------------------------------------------
283 // ciInstanceKlass::java_mirror
284 //
285 // Get the instance of java.lang.Class corresponding to this klass.
286 ciInstance* ciInstanceKlass::java_mirror() {
287 assert(is_loaded(), "must be loaded");
288 if (_java_mirror == NULL) {
289 _java_mirror = ciKlass::java_mirror();
290 }
291 return _java_mirror;
292 }
293
294 // ------------------------------------------------------------------
295 // ciInstanceKlass::unique_concrete_subklass
296 ciInstanceKlass* ciInstanceKlass::unique_concrete_subklass() {
297 if (!is_loaded()) return NULL; // No change if class is not loaded
298 if (!is_abstract()) return NULL; // Only applies to abstract classes.
299 if (!has_subklass()) return NULL; // Must have at least one subklass.
300 VM_ENTRY_MARK;
301 instanceKlass* ik = get_instanceKlass();
302 Klass* up = ik->up_cast_abstract();
303 assert(up->oop_is_instance(), "must be instanceKlass");
304 if (ik == up) {
305 return NULL;
306 }
307 return CURRENT_THREAD_ENV->get_object(up->as_klassOop())->as_instance_klass();
308 }
309
310 // ------------------------------------------------------------------
311 // ciInstanceKlass::has_finalizable_subclass
312 bool ciInstanceKlass::has_finalizable_subclass() {
313 if (!is_loaded()) return true;
314 VM_ENTRY_MARK;
315 return Dependencies::find_finalizable_subclass(get_instanceKlass()) != NULL;
316 }
317
318 // ------------------------------------------------------------------
319 // ciInstanceKlass::get_field_by_offset
320 ciField* ciInstanceKlass::get_field_by_offset(int field_offset, bool is_static) {
321 if (!is_static) {
322 for (int i = 0, len = nof_nonstatic_fields(); i < len; i++) {
323 ciField* field = _nonstatic_fields->at(i);
324 int field_off = field->offset_in_bytes();
325 if (field_off == field_offset)
326 return field;
327 if (field_off > field_offset)
328 break;
329 // could do binary search or check bins, but probably not worth it
330 }
331 return NULL;
332 }
333 VM_ENTRY_MARK;
334 instanceKlass* k = get_instanceKlass();
335 fieldDescriptor fd;
336 if (!k->find_field_from_offset(field_offset, is_static, &fd)) {
337 return NULL;
338 }
339 ciField* field = new (CURRENT_THREAD_ENV->arena()) ciField(&fd);
340 return field;
341 }
342
343 // ------------------------------------------------------------------
344 // ciInstanceKlass::non_static_fields.
345
346 class NonStaticFieldFiller: public FieldClosure {
347 GrowableArray<ciField*>* _arr;
348 ciEnv* _curEnv;
349 public:
350 NonStaticFieldFiller(ciEnv* curEnv, GrowableArray<ciField*>* arr) :
351 _curEnv(curEnv), _arr(arr)
352 {}
353 void do_field(fieldDescriptor* fd) {
354 ciField* field = new (_curEnv->arena()) ciField(fd);
355 _arr->append(field);
356 }
357 };
358
359 GrowableArray<ciField*>* ciInstanceKlass::non_static_fields() {
360 if (_non_static_fields == NULL) {
361 VM_ENTRY_MARK;
362 ciEnv* curEnv = ciEnv::current();
363 instanceKlass* ik = get_instanceKlass();
364 int max_n_fields = ik->fields()->length()/instanceKlass::next_offset;
365
366 _non_static_fields =
367 new (curEnv->arena()) GrowableArray<ciField*>(max_n_fields);
368 NonStaticFieldFiller filler(curEnv, _non_static_fields);
369 ik->do_nonstatic_fields(&filler);
370 }
371 return _non_static_fields;
372 }
373
374 static int sort_field_by_offset(ciField** a, ciField** b) {
375 return (*a)->offset_in_bytes() - (*b)->offset_in_bytes();
376 // (no worries about 32-bit overflow...)
377 }
378
379 // ------------------------------------------------------------------
380 // ciInstanceKlass::compute_nonstatic_fields
381 int ciInstanceKlass::compute_nonstatic_fields() {
382 assert(is_loaded(), "must be loaded");
383
384 if (_nonstatic_fields != NULL)
385 return _nonstatic_fields->length();
386
387 if (!has_nonstatic_fields()) {
388 Arena* arena = CURRENT_ENV->arena();
389 _nonstatic_fields = new (arena) GrowableArray<ciField*>(arena, 0, 0, NULL);
390 return 0;
391 }
392 assert(!is_java_lang_Object(), "bootstrap OK");
393
394 // Size in bytes of my fields, including inherited fields.
395 int fsize = nonstatic_field_size() * heapOopSize;
396
397 ciInstanceKlass* super = this->super();
398 GrowableArray<ciField*>* super_fields = NULL;
399 if (super != NULL && super->has_nonstatic_fields()) {
400 int super_fsize = super->nonstatic_field_size() * heapOopSize;
401 int super_flen = super->nof_nonstatic_fields();
402 super_fields = super->_nonstatic_fields;
403 assert(super_flen == 0 || super_fields != NULL, "first get nof_fields");
404 // See if I am no larger than my super; if so, I can use his fields.
405 if (fsize == super_fsize) {
406 _nonstatic_fields = super_fields;
407 return super_fields->length();
408 }
409 }
410
411 GrowableArray<ciField*>* fields = NULL;
412 GUARDED_VM_ENTRY({
413 fields = compute_nonstatic_fields_impl(super_fields);
414 });
415
416 if (fields == NULL) {
417 // This can happen if this class (java.lang.Class) has invisible fields.
418 _nonstatic_fields = super_fields;
419 return super_fields->length();
420 }
421
422 int flen = fields->length();
423
424 // Now sort them by offset, ascending.
425 // (In principle, they could mix with superclass fields.)
426 fields->sort(sort_field_by_offset);
427 #ifdef ASSERT
428 int last_offset = instanceOopDesc::base_offset_in_bytes();
429 for (int i = 0; i < fields->length(); i++) {
430 ciField* field = fields->at(i);
431 int offset = field->offset_in_bytes();
432 int size = (field->_type == NULL) ? heapOopSize : field->size_in_bytes();
433 assert(last_offset <= offset, "no field overlap");
434 if (last_offset > (int)sizeof(oopDesc))
435 assert((offset - last_offset) < BytesPerLong, "no big holes");
436 // Note: Two consecutive T_BYTE fields will be separated by wordSize-1
437 // padding bytes if one of them is declared by a superclass.
438 // This is a minor inefficiency classFileParser.cpp.
439 last_offset = offset + size;
440 }
441 assert(last_offset <= (int)instanceOopDesc::base_offset_in_bytes() + fsize, "no overflow");
442 #endif
443
444 _nonstatic_fields = fields;
445 return flen;
446 }
447
448 GrowableArray<ciField*>*
449 ciInstanceKlass::compute_nonstatic_fields_impl(GrowableArray<ciField*>*
450 super_fields) {
451 ASSERT_IN_VM;
452 Arena* arena = CURRENT_ENV->arena();
453 int flen = 0;
454 GrowableArray<ciField*>* fields = NULL;
455 instanceKlass* k = get_instanceKlass();
456 typeArrayOop fields_array = k->fields();
457 for (int pass = 0; pass <= 1; pass++) {
458 for (int i = 0, alen = fields_array->length(); i < alen; i += instanceKlass::next_offset) {
459 fieldDescriptor fd;
460 fd.initialize(k->as_klassOop(), i);
461 if (fd.is_static()) continue;
462 if (pass == 0) {
463 flen += 1;
464 } else {
465 ciField* field = new (arena) ciField(&fd);
466 fields->append(field);
467 }
468 }
469
470 // Between passes, allocate the array:
471 if (pass == 0) {
472 if (flen == 0) {
473 return NULL; // return nothing if none are locally declared
474 }
475 if (super_fields != NULL) {
476 flen += super_fields->length();
477 }
478 fields = new (arena) GrowableArray<ciField*>(arena, flen, 0, NULL);
479 if (super_fields != NULL) {
480 fields->appendAll(super_fields);
481 }
482 }
483 }
484 assert(fields->length() == flen, "sanity");
485 return fields;
486 }
487
488 // ------------------------------------------------------------------
489 // ciInstanceKlass::find_method
490 //
491 // Find a method in this klass.
492 ciMethod* ciInstanceKlass::find_method(ciSymbol* name, ciSymbol* signature) {
493 VM_ENTRY_MARK;
494 instanceKlass* k = get_instanceKlass();
495 symbolOop name_sym = name->get_symbolOop();
496 symbolOop sig_sym= signature->get_symbolOop();
497
498 methodOop m = k->find_method(name_sym, sig_sym);
499 if (m == NULL) return NULL;
500
501 return CURRENT_THREAD_ENV->get_object(m)->as_method();
502 }
503
504 // ------------------------------------------------------------------
505 // ciInstanceKlass::is_leaf_type
506 bool ciInstanceKlass::is_leaf_type() {
507 assert(is_loaded(), "must be loaded");
508 if (is_shared()) {
509 return is_final(); // approximately correct
510 } else {
511 return !_has_subklass && (_nof_implementors == 0);
512 }
513 }
514
515 // ------------------------------------------------------------------
516 // ciInstanceKlass::implementor
517 //
518 // Report an implementor of this interface.
519 // Returns NULL if exact information is not available.
520 // Note that there are various races here, since my copy
521 // of _nof_implementors might be out of date with respect
522 // to results returned by instanceKlass::implementor.
523 // This is OK, since any dependencies we decide to assert
524 // will be checked later under the Compile_lock.
525 ciInstanceKlass* ciInstanceKlass::implementor(int n) {
526 if (n > implementors_limit) {
527 return NULL;
528 }
529 ciInstanceKlass* impl = _implementors[n];
530 if (impl == NULL) {
531 if (_nof_implementors > implementors_limit) {
532 return NULL;
533 }
534 // Go into the VM to fetch the implementor.
535 {
536 VM_ENTRY_MARK;
537 klassOop k = get_instanceKlass()->implementor(n);
538 if (k != NULL) {
539 impl = CURRENT_THREAD_ENV->get_object(k)->as_instance_klass();
540 }
541 }
542 // Memoize this result.
543 if (!is_shared()) {
544 _implementors[n] = (impl == NULL)? this: impl;
545 }
546 } else if (impl == this) {
547 impl = NULL; // memoized null result from a VM query
548 }
549 return impl;
550 }