Thu, 13 Jan 2011 22:15:41 -0800
4926272: methodOopDesc::method_from_bcp is unsafe
Reviewed-by: coleenp, jrose, kvn, dcubed
1 /*
2 * Copyright (c) 1997, 2010, 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 */
25 #include "precompiled.hpp"
26 #include "classfile/systemDictionary.hpp"
27 #include "classfile/vmSymbols.hpp"
28 #include "gc_interface/collectedHeap.inline.hpp"
29 #include "memory/oopFactory.hpp"
30 #include "memory/resourceArea.hpp"
31 #include "oops/instanceKlass.hpp"
32 #include "oops/klass.inline.hpp"
33 #include "oops/klassOop.hpp"
34 #include "oops/oop.inline.hpp"
35 #include "oops/oop.inline2.hpp"
36 #include "runtime/atomic.hpp"
39 bool Klass::is_subclass_of(klassOop k) const {
40 // Run up the super chain and check
41 klassOop t = as_klassOop();
43 if (t == k) return true;
44 t = Klass::cast(t)->super();
46 while (t != NULL) {
47 if (t == k) return true;
48 t = Klass::cast(t)->super();
49 }
50 return false;
51 }
53 bool Klass::search_secondary_supers(klassOop k) const {
54 // Put some extra logic here out-of-line, before the search proper.
55 // This cuts down the size of the inline method.
57 // This is necessary, since I am never in my own secondary_super list.
58 if (this->as_klassOop() == k)
59 return true;
60 // Scan the array-of-objects for a match
61 int cnt = secondary_supers()->length();
62 for (int i = 0; i < cnt; i++) {
63 if (secondary_supers()->obj_at(i) == k) {
64 ((Klass*)this)->set_secondary_super_cache(k);
65 return true;
66 }
67 }
68 return false;
69 }
71 // Return self, except for abstract classes with exactly 1
72 // implementor. Then return the 1 concrete implementation.
73 Klass *Klass::up_cast_abstract() {
74 Klass *r = this;
75 while( r->is_abstract() ) { // Receiver is abstract?
76 Klass *s = r->subklass(); // Check for exactly 1 subklass
77 if( !s || s->next_sibling() ) // Oops; wrong count; give up
78 return this; // Return 'this' as a no-progress flag
79 r = s; // Loop till find concrete class
80 }
81 return r; // Return the 1 concrete class
82 }
84 // Find LCA in class hierarchy
85 Klass *Klass::LCA( Klass *k2 ) {
86 Klass *k1 = this;
87 while( 1 ) {
88 if( k1->is_subtype_of(k2->as_klassOop()) ) return k2;
89 if( k2->is_subtype_of(k1->as_klassOop()) ) return k1;
90 k1 = k1->super()->klass_part();
91 k2 = k2->super()->klass_part();
92 }
93 }
96 void Klass::check_valid_for_instantiation(bool throwError, TRAPS) {
97 ResourceMark rm(THREAD);
98 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
99 : vmSymbols::java_lang_InstantiationException(), external_name());
100 }
103 void Klass::copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS) {
104 THROW(vmSymbols::java_lang_ArrayStoreException());
105 }
108 void Klass::initialize(TRAPS) {
109 ShouldNotReachHere();
110 }
112 bool Klass::compute_is_subtype_of(klassOop k) {
113 assert(k->is_klass(), "argument must be a class");
114 return is_subclass_of(k);
115 }
118 methodOop Klass::uncached_lookup_method(symbolOop name, symbolOop signature) const {
119 #ifdef ASSERT
120 tty->print_cr("Error: uncached_lookup_method called on a klass oop."
121 " Likely error: reflection method does not correctly"
122 " wrap return value in a mirror object.");
123 #endif
124 ShouldNotReachHere();
125 return NULL;
126 }
128 klassOop Klass::base_create_klass_oop(KlassHandle& klass, int size,
129 const Klass_vtbl& vtbl, TRAPS) {
130 size = align_object_size(size);
131 // allocate and initialize vtable
132 Klass* kl = (Klass*) vtbl.allocate_permanent(klass, size, CHECK_NULL);
133 klassOop k = kl->as_klassOop();
135 { // Preinitialize supertype information.
136 // A later call to initialize_supers() may update these settings:
137 kl->set_super(NULL);
138 for (juint i = 0; i < Klass::primary_super_limit(); i++) {
139 kl->_primary_supers[i] = NULL;
140 }
141 kl->set_secondary_supers(NULL);
142 oop_store_without_check((oop*) &kl->_primary_supers[0], k);
143 kl->set_super_check_offset(primary_supers_offset_in_bytes() + sizeof(oopDesc));
144 }
146 kl->set_java_mirror(NULL);
147 kl->set_modifier_flags(0);
148 kl->set_layout_helper(Klass::_lh_neutral_value);
149 kl->set_name(NULL);
150 AccessFlags af;
151 af.set_flags(0);
152 kl->set_access_flags(af);
153 kl->set_subklass(NULL);
154 kl->set_next_sibling(NULL);
155 kl->set_alloc_count(0);
156 kl->set_alloc_size(0);
158 kl->set_prototype_header(markOopDesc::prototype());
159 kl->set_biased_lock_revocation_count(0);
160 kl->set_last_biased_lock_bulk_revocation_time(0);
162 return k;
163 }
165 KlassHandle Klass::base_create_klass(KlassHandle& klass, int size,
166 const Klass_vtbl& vtbl, TRAPS) {
167 klassOop ek = base_create_klass_oop(klass, size, vtbl, THREAD);
168 return KlassHandle(THREAD, ek);
169 }
171 void Klass_vtbl::post_new_init_klass(KlassHandle& klass,
172 klassOop new_klass,
173 int size) const {
174 assert(!new_klass->klass_part()->null_vtbl(), "Not a complete klass");
175 CollectedHeap::post_allocation_install_obj_klass(klass, new_klass, size);
176 }
178 void* Klass_vtbl::operator new(size_t ignored, KlassHandle& klass,
179 int size, TRAPS) {
180 // The vtable pointer is installed during the execution of
181 // constructors in the call to permanent_obj_allocate(). Delay
182 // the installation of the klass pointer into the new klass "k"
183 // until after the vtable pointer has been installed (i.e., until
184 // after the return of permanent_obj_allocate().
185 klassOop k =
186 (klassOop) CollectedHeap::permanent_obj_allocate_no_klass_install(klass,
187 size, CHECK_NULL);
188 return k->klass_part();
189 }
191 jint Klass::array_layout_helper(BasicType etype) {
192 assert(etype >= T_BOOLEAN && etype <= T_OBJECT, "valid etype");
193 // Note that T_ARRAY is not allowed here.
194 int hsize = arrayOopDesc::base_offset_in_bytes(etype);
195 int esize = type2aelembytes(etype);
196 bool isobj = (etype == T_OBJECT);
197 int tag = isobj ? _lh_array_tag_obj_value : _lh_array_tag_type_value;
198 int lh = array_layout_helper(tag, hsize, etype, exact_log2(esize));
200 assert(lh < (int)_lh_neutral_value, "must look like an array layout");
201 assert(layout_helper_is_javaArray(lh), "correct kind");
202 assert(layout_helper_is_objArray(lh) == isobj, "correct kind");
203 assert(layout_helper_is_typeArray(lh) == !isobj, "correct kind");
204 assert(layout_helper_header_size(lh) == hsize, "correct decode");
205 assert(layout_helper_element_type(lh) == etype, "correct decode");
206 assert(1 << layout_helper_log2_element_size(lh) == esize, "correct decode");
208 return lh;
209 }
211 bool Klass::can_be_primary_super_slow() const {
212 if (super() == NULL)
213 return true;
214 else if (super()->klass_part()->super_depth() >= primary_super_limit()-1)
215 return false;
216 else
217 return true;
218 }
220 void Klass::initialize_supers(klassOop k, TRAPS) {
221 if (FastSuperclassLimit == 0) {
222 // None of the other machinery matters.
223 set_super(k);
224 return;
225 }
226 if (k == NULL) {
227 set_super(NULL);
228 oop_store_without_check((oop*) &_primary_supers[0], (oop) this->as_klassOop());
229 assert(super_depth() == 0, "Object must already be initialized properly");
230 } else if (k != super() || k == SystemDictionary::Object_klass()) {
231 assert(super() == NULL || super() == SystemDictionary::Object_klass(),
232 "initialize this only once to a non-trivial value");
233 set_super(k);
234 Klass* sup = k->klass_part();
235 int sup_depth = sup->super_depth();
236 juint my_depth = MIN2(sup_depth + 1, (int)primary_super_limit());
237 if (!can_be_primary_super_slow())
238 my_depth = primary_super_limit();
239 for (juint i = 0; i < my_depth; i++) {
240 oop_store_without_check((oop*) &_primary_supers[i], (oop) sup->_primary_supers[i]);
241 }
242 klassOop *super_check_cell;
243 if (my_depth < primary_super_limit()) {
244 oop_store_without_check((oop*) &_primary_supers[my_depth], (oop) this->as_klassOop());
245 super_check_cell = &_primary_supers[my_depth];
246 } else {
247 // Overflow of the primary_supers array forces me to be secondary.
248 super_check_cell = &_secondary_super_cache;
249 }
250 set_super_check_offset((address)super_check_cell - (address) this->as_klassOop());
252 #ifdef ASSERT
253 {
254 juint j = super_depth();
255 assert(j == my_depth, "computed accessor gets right answer");
256 klassOop t = as_klassOop();
257 while (!Klass::cast(t)->can_be_primary_super()) {
258 t = Klass::cast(t)->super();
259 j = Klass::cast(t)->super_depth();
260 }
261 for (juint j1 = j+1; j1 < primary_super_limit(); j1++) {
262 assert(primary_super_of_depth(j1) == NULL, "super list padding");
263 }
264 while (t != NULL) {
265 assert(primary_super_of_depth(j) == t, "super list initialization");
266 t = Klass::cast(t)->super();
267 --j;
268 }
269 assert(j == (juint)-1, "correct depth count");
270 }
271 #endif
272 }
274 if (secondary_supers() == NULL) {
275 KlassHandle this_kh (THREAD, this);
277 // Now compute the list of secondary supertypes.
278 // Secondaries can occasionally be on the super chain,
279 // if the inline "_primary_supers" array overflows.
280 int extras = 0;
281 klassOop p;
282 for (p = super(); !(p == NULL || p->klass_part()->can_be_primary_super()); p = p->klass_part()->super()) {
283 ++extras;
284 }
286 // Compute the "real" non-extra secondaries.
287 objArrayOop secondary_oops = compute_secondary_supers(extras, CHECK);
288 objArrayHandle secondaries (THREAD, secondary_oops);
290 // Store the extra secondaries in the first array positions:
291 int fillp = extras;
292 for (p = this_kh->super(); !(p == NULL || p->klass_part()->can_be_primary_super()); p = p->klass_part()->super()) {
293 int i; // Scan for overflow primaries being duplicates of 2nd'arys
295 // This happens frequently for very deeply nested arrays: the
296 // primary superclass chain overflows into the secondary. The
297 // secondary list contains the element_klass's secondaries with
298 // an extra array dimension added. If the element_klass's
299 // secondary list already contains some primary overflows, they
300 // (with the extra level of array-ness) will collide with the
301 // normal primary superclass overflows.
302 for( i = extras; i < secondaries->length(); i++ )
303 if( secondaries->obj_at(i) == p )
304 break;
305 if( i < secondaries->length() )
306 continue; // It's a dup, don't put it in
307 secondaries->obj_at_put(--fillp, p);
308 }
309 // See if we had some dup's, so the array has holes in it.
310 if( fillp > 0 ) {
311 // Pack the array. Drop the old secondaries array on the floor
312 // and let GC reclaim it.
313 objArrayOop s2 = oopFactory::new_system_objArray(secondaries->length() - fillp, CHECK);
314 for( int i = 0; i < s2->length(); i++ )
315 s2->obj_at_put( i, secondaries->obj_at(i+fillp) );
316 secondaries = objArrayHandle(THREAD, s2);
317 }
319 #ifdef ASSERT
320 if (secondaries() != Universe::the_array_interfaces_array()) {
321 // We must not copy any NULL placeholders left over from bootstrap.
322 for (int j = 0; j < secondaries->length(); j++) {
323 assert(secondaries->obj_at(j) != NULL, "correct bootstrapping order");
324 }
325 }
326 #endif
328 this_kh->set_secondary_supers(secondaries());
329 }
330 }
332 objArrayOop Klass::compute_secondary_supers(int num_extra_slots, TRAPS) {
333 assert(num_extra_slots == 0, "override for complex klasses");
334 return Universe::the_empty_system_obj_array();
335 }
338 Klass* Klass::subklass() const {
339 return _subklass == NULL ? NULL : Klass::cast(_subklass);
340 }
342 instanceKlass* Klass::superklass() const {
343 assert(super() == NULL || super()->klass_part()->oop_is_instance(), "must be instance klass");
344 return _super == NULL ? NULL : instanceKlass::cast(_super);
345 }
347 Klass* Klass::next_sibling() const {
348 return _next_sibling == NULL ? NULL : Klass::cast(_next_sibling);
349 }
351 void Klass::set_subklass(klassOop s) {
352 assert(s != as_klassOop(), "sanity check");
353 oop_store_without_check((oop*)&_subklass, s);
354 }
356 void Klass::set_next_sibling(klassOop s) {
357 assert(s != as_klassOop(), "sanity check");
358 oop_store_without_check((oop*)&_next_sibling, s);
359 }
361 void Klass::append_to_sibling_list() {
362 debug_only(if (!SharedSkipVerify) as_klassOop()->verify();)
363 // add ourselves to superklass' subklass list
364 instanceKlass* super = superklass();
365 if (super == NULL) return; // special case: class Object
366 assert(SharedSkipVerify ||
367 (!super->is_interface() // interfaces cannot be supers
368 && (super->superklass() == NULL || !is_interface())),
369 "an interface can only be a subklass of Object");
370 klassOop prev_first_subklass = super->subklass_oop();
371 if (prev_first_subklass != NULL) {
372 // set our sibling to be the superklass' previous first subklass
373 set_next_sibling(prev_first_subklass);
374 }
375 // make ourselves the superklass' first subklass
376 super->set_subklass(as_klassOop());
377 debug_only(if (!SharedSkipVerify) as_klassOop()->verify();)
378 }
380 void Klass::remove_from_sibling_list() {
381 // remove receiver from sibling list
382 instanceKlass* super = superklass();
383 assert(super != NULL || as_klassOop() == SystemDictionary::Object_klass(), "should have super");
384 if (super == NULL) return; // special case: class Object
385 if (super->subklass() == this) {
386 // first subklass
387 super->set_subklass(_next_sibling);
388 } else {
389 Klass* sib = super->subklass();
390 while (sib->next_sibling() != this) {
391 sib = sib->next_sibling();
392 };
393 sib->set_next_sibling(_next_sibling);
394 }
395 }
397 void Klass::follow_weak_klass_links( BoolObjectClosure* is_alive, OopClosure* keep_alive) {
398 // This klass is alive but the subklass and siblings are not followed/updated.
399 // We update the subklass link and the subklass' sibling links here.
400 // Our own sibling link will be updated by our superclass (which must be alive
401 // since we are).
402 assert(is_alive->do_object_b(as_klassOop()), "just checking, this should be live");
403 if (ClassUnloading) {
404 klassOop sub = subklass_oop();
405 if (sub != NULL && !is_alive->do_object_b(sub)) {
406 // first subklass not alive, find first one alive
407 do {
408 #ifndef PRODUCT
409 if (TraceClassUnloading && WizardMode) {
410 ResourceMark rm;
411 tty->print_cr("[Unlinking class (subclass) %s]", sub->klass_part()->external_name());
412 }
413 #endif
414 sub = sub->klass_part()->next_sibling_oop();
415 } while (sub != NULL && !is_alive->do_object_b(sub));
416 set_subklass(sub);
417 }
418 // now update the subklass' sibling list
419 while (sub != NULL) {
420 klassOop next = sub->klass_part()->next_sibling_oop();
421 if (next != NULL && !is_alive->do_object_b(next)) {
422 // first sibling not alive, find first one alive
423 do {
424 #ifndef PRODUCT
425 if (TraceClassUnloading && WizardMode) {
426 ResourceMark rm;
427 tty->print_cr("[Unlinking class (sibling) %s]", next->klass_part()->external_name());
428 }
429 #endif
430 next = next->klass_part()->next_sibling_oop();
431 } while (next != NULL && !is_alive->do_object_b(next));
432 sub->klass_part()->set_next_sibling(next);
433 }
434 sub = next;
435 }
436 } else {
437 // Always follow subklass and sibling link. This will prevent any klasses from
438 // being unloaded (all classes are transitively linked from java.lang.Object).
439 keep_alive->do_oop(adr_subklass());
440 keep_alive->do_oop(adr_next_sibling());
441 }
442 }
445 void Klass::remove_unshareable_info() {
446 if (oop_is_instance()) {
447 instanceKlass* ik = (instanceKlass*)this;
448 if (ik->is_linked()) {
449 ik->unlink_class();
450 }
451 }
452 set_subklass(NULL);
453 set_next_sibling(NULL);
454 }
457 klassOop Klass::array_klass_or_null(int rank) {
458 EXCEPTION_MARK;
459 // No exception can be thrown by array_klass_impl when called with or_null == true.
460 // (In anycase, the execption mark will fail if it do so)
461 return array_klass_impl(true, rank, THREAD);
462 }
465 klassOop Klass::array_klass_or_null() {
466 EXCEPTION_MARK;
467 // No exception can be thrown by array_klass_impl when called with or_null == true.
468 // (In anycase, the execption mark will fail if it do so)
469 return array_klass_impl(true, THREAD);
470 }
473 klassOop Klass::array_klass_impl(bool or_null, int rank, TRAPS) {
474 fatal("array_klass should be dispatched to instanceKlass, objArrayKlass or typeArrayKlass");
475 return NULL;
476 }
479 klassOop Klass::array_klass_impl(bool or_null, TRAPS) {
480 fatal("array_klass should be dispatched to instanceKlass, objArrayKlass or typeArrayKlass");
481 return NULL;
482 }
485 void Klass::with_array_klasses_do(void f(klassOop k)) {
486 f(as_klassOop());
487 }
490 const char* Klass::external_name() const {
491 if (oop_is_instance()) {
492 instanceKlass* ik = (instanceKlass*) this;
493 if (ik->is_anonymous()) {
494 assert(AnonymousClasses, "");
495 intptr_t hash = ik->java_mirror()->identity_hash();
496 char hash_buf[40];
497 sprintf(hash_buf, "/" UINTX_FORMAT, (uintx)hash);
498 size_t hash_len = strlen(hash_buf);
500 size_t result_len = name()->utf8_length();
501 char* result = NEW_RESOURCE_ARRAY(char, result_len + hash_len + 1);
502 name()->as_klass_external_name(result, (int) result_len + 1);
503 assert(strlen(result) == result_len, "");
504 strcpy(result + result_len, hash_buf);
505 assert(strlen(result) == result_len + hash_len, "");
506 return result;
507 }
508 }
509 if (name() == NULL) return "<unknown>";
510 return name()->as_klass_external_name();
511 }
514 const char* Klass::signature_name() const {
515 if (name() == NULL) return "<unknown>";
516 return name()->as_C_string();
517 }
519 // Unless overridden, modifier_flags is 0.
520 jint Klass::compute_modifier_flags(TRAPS) const {
521 return 0;
522 }
524 int Klass::atomic_incr_biased_lock_revocation_count() {
525 return (int) Atomic::add(1, &_biased_lock_revocation_count);
526 }
528 // Unless overridden, jvmti_class_status has no flags set.
529 jint Klass::jvmti_class_status() const {
530 return 0;
531 }
533 // Printing
535 void Klass::oop_print_on(oop obj, outputStream* st) {
536 ResourceMark rm;
537 // print title
538 st->print_cr("%s ", internal_name());
539 obj->print_address_on(st);
541 if (WizardMode) {
542 // print header
543 obj->mark()->print_on(st);
544 }
546 // print class
547 st->print(" - klass: ");
548 obj->klass()->print_value_on(st);
549 st->cr();
550 }
552 void Klass::oop_print_value_on(oop obj, outputStream* st) {
553 // print title
554 ResourceMark rm; // Cannot print in debug mode without this
555 st->print("%s", internal_name());
556 obj->print_address_on(st);
557 }
559 // Verification
561 void Klass::oop_verify_on(oop obj, outputStream* st) {
562 guarantee(obj->is_oop(), "should be oop");
563 guarantee(obj->klass()->is_perm(), "should be in permspace");
564 guarantee(obj->klass()->is_klass(), "klass field is not a klass");
565 }
568 void Klass::oop_verify_old_oop(oop obj, oop* p, bool allow_dirty) {
569 /* $$$ I think this functionality should be handled by verification of
570 RememberedSet::verify_old_oop(obj, p, allow_dirty, false);
571 the card table. */
572 }
573 void Klass::oop_verify_old_oop(oop obj, narrowOop* p, bool allow_dirty) { }
575 #ifndef PRODUCT
577 void Klass::verify_vtable_index(int i) {
578 assert(oop_is_instance() || oop_is_array(), "only instanceKlass and arrayKlass have vtables");
579 if (oop_is_instance()) {
580 assert(i>=0 && i<((instanceKlass*)this)->vtable_length()/vtableEntry::size(), "index out of bounds");
581 } else {
582 assert(i>=0 && i<((arrayKlass*)this)->vtable_length()/vtableEntry::size(), "index out of bounds");
583 }
584 }
586 #endif