Wed, 11 Jan 2012 17:34:02 -0500
7115199: Add event tracing hooks and Java Flight Recorder infrastructure
Summary: Added a nop tracing infrastructure, JFR makefile changes and other infrastructure used only by JFR.
Reviewed-by: acorn, sspitsyn
Contributed-by: markus.gronlund@oracle.com
1 /*
2 * Copyright (c) 1997, 2011, 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"
38 void Klass::set_name(Symbol* n) {
39 _name = n;
40 if (_name != NULL) _name->increment_refcount();
41 }
43 bool Klass::is_subclass_of(klassOop k) const {
44 // Run up the super chain and check
45 klassOop t = as_klassOop();
47 if (t == k) return true;
48 t = Klass::cast(t)->super();
50 while (t != NULL) {
51 if (t == k) return true;
52 t = Klass::cast(t)->super();
53 }
54 return false;
55 }
57 bool Klass::search_secondary_supers(klassOop k) const {
58 // Put some extra logic here out-of-line, before the search proper.
59 // This cuts down the size of the inline method.
61 // This is necessary, since I am never in my own secondary_super list.
62 if (this->as_klassOop() == k)
63 return true;
64 // Scan the array-of-objects for a match
65 int cnt = secondary_supers()->length();
66 for (int i = 0; i < cnt; i++) {
67 if (secondary_supers()->obj_at(i) == k) {
68 ((Klass*)this)->set_secondary_super_cache(k);
69 return true;
70 }
71 }
72 return false;
73 }
75 // Return self, except for abstract classes with exactly 1
76 // implementor. Then return the 1 concrete implementation.
77 Klass *Klass::up_cast_abstract() {
78 Klass *r = this;
79 while( r->is_abstract() ) { // Receiver is abstract?
80 Klass *s = r->subklass(); // Check for exactly 1 subklass
81 if( !s || s->next_sibling() ) // Oops; wrong count; give up
82 return this; // Return 'this' as a no-progress flag
83 r = s; // Loop till find concrete class
84 }
85 return r; // Return the 1 concrete class
86 }
88 // Find LCA in class hierarchy
89 Klass *Klass::LCA( Klass *k2 ) {
90 Klass *k1 = this;
91 while( 1 ) {
92 if( k1->is_subtype_of(k2->as_klassOop()) ) return k2;
93 if( k2->is_subtype_of(k1->as_klassOop()) ) return k1;
94 k1 = k1->super()->klass_part();
95 k2 = k2->super()->klass_part();
96 }
97 }
100 void Klass::check_valid_for_instantiation(bool throwError, TRAPS) {
101 ResourceMark rm(THREAD);
102 THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
103 : vmSymbols::java_lang_InstantiationException(), external_name());
104 }
107 void Klass::copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS) {
108 THROW(vmSymbols::java_lang_ArrayStoreException());
109 }
112 void Klass::initialize(TRAPS) {
113 ShouldNotReachHere();
114 }
116 bool Klass::compute_is_subtype_of(klassOop k) {
117 assert(k->is_klass(), "argument must be a class");
118 return is_subclass_of(k);
119 }
122 methodOop Klass::uncached_lookup_method(Symbol* name, Symbol* signature) const {
123 #ifdef ASSERT
124 tty->print_cr("Error: uncached_lookup_method called on a klass oop."
125 " Likely error: reflection method does not correctly"
126 " wrap return value in a mirror object.");
127 #endif
128 ShouldNotReachHere();
129 return NULL;
130 }
132 klassOop Klass::base_create_klass_oop(KlassHandle& klass, int size,
133 const Klass_vtbl& vtbl, TRAPS) {
134 size = align_object_size(size);
135 // allocate and initialize vtable
136 Klass* kl = (Klass*) vtbl.allocate_permanent(klass, size, CHECK_NULL);
137 klassOop k = kl->as_klassOop();
139 { // Preinitialize supertype information.
140 // A later call to initialize_supers() may update these settings:
141 kl->set_super(NULL);
142 for (juint i = 0; i < Klass::primary_super_limit(); i++) {
143 kl->_primary_supers[i] = NULL;
144 }
145 kl->set_secondary_supers(NULL);
146 oop_store_without_check((oop*) &kl->_primary_supers[0], k);
147 kl->set_super_check_offset(primary_supers_offset_in_bytes() + sizeof(oopDesc));
148 }
150 kl->set_java_mirror(NULL);
151 kl->set_modifier_flags(0);
152 kl->set_layout_helper(Klass::_lh_neutral_value);
153 kl->set_name(NULL);
154 AccessFlags af;
155 af.set_flags(0);
156 kl->set_access_flags(af);
157 kl->set_subklass(NULL);
158 kl->set_next_sibling(NULL);
159 kl->set_alloc_count(0);
160 kl->set_alloc_size(0);
161 #ifdef TRACE_SET_KLASS_TRACE_ID
162 TRACE_SET_KLASS_TRACE_ID(kl, 0);
163 #endif
165 kl->set_prototype_header(markOopDesc::prototype());
166 kl->set_biased_lock_revocation_count(0);
167 kl->set_last_biased_lock_bulk_revocation_time(0);
169 return k;
170 }
172 KlassHandle Klass::base_create_klass(KlassHandle& klass, int size,
173 const Klass_vtbl& vtbl, TRAPS) {
174 klassOop ek = base_create_klass_oop(klass, size, vtbl, THREAD);
175 return KlassHandle(THREAD, ek);
176 }
178 void Klass_vtbl::post_new_init_klass(KlassHandle& klass,
179 klassOop new_klass,
180 int size) const {
181 assert(!new_klass->klass_part()->null_vtbl(), "Not a complete klass");
182 CollectedHeap::post_allocation_install_obj_klass(klass, new_klass, size);
183 }
185 void* Klass_vtbl::operator new(size_t ignored, KlassHandle& klass,
186 int size, TRAPS) {
187 // The vtable pointer is installed during the execution of
188 // constructors in the call to permanent_obj_allocate(). Delay
189 // the installation of the klass pointer into the new klass "k"
190 // until after the vtable pointer has been installed (i.e., until
191 // after the return of permanent_obj_allocate().
192 klassOop k =
193 (klassOop) CollectedHeap::permanent_obj_allocate_no_klass_install(klass,
194 size, CHECK_NULL);
195 return k->klass_part();
196 }
198 jint Klass::array_layout_helper(BasicType etype) {
199 assert(etype >= T_BOOLEAN && etype <= T_OBJECT, "valid etype");
200 // Note that T_ARRAY is not allowed here.
201 int hsize = arrayOopDesc::base_offset_in_bytes(etype);
202 int esize = type2aelembytes(etype);
203 bool isobj = (etype == T_OBJECT);
204 int tag = isobj ? _lh_array_tag_obj_value : _lh_array_tag_type_value;
205 int lh = array_layout_helper(tag, hsize, etype, exact_log2(esize));
207 assert(lh < (int)_lh_neutral_value, "must look like an array layout");
208 assert(layout_helper_is_javaArray(lh), "correct kind");
209 assert(layout_helper_is_objArray(lh) == isobj, "correct kind");
210 assert(layout_helper_is_typeArray(lh) == !isobj, "correct kind");
211 assert(layout_helper_header_size(lh) == hsize, "correct decode");
212 assert(layout_helper_element_type(lh) == etype, "correct decode");
213 assert(1 << layout_helper_log2_element_size(lh) == esize, "correct decode");
215 return lh;
216 }
218 bool Klass::can_be_primary_super_slow() const {
219 if (super() == NULL)
220 return true;
221 else if (super()->klass_part()->super_depth() >= primary_super_limit()-1)
222 return false;
223 else
224 return true;
225 }
227 void Klass::initialize_supers(klassOop k, TRAPS) {
228 if (FastSuperclassLimit == 0) {
229 // None of the other machinery matters.
230 set_super(k);
231 return;
232 }
233 if (k == NULL) {
234 set_super(NULL);
235 oop_store_without_check((oop*) &_primary_supers[0], (oop) this->as_klassOop());
236 assert(super_depth() == 0, "Object must already be initialized properly");
237 } else if (k != super() || k == SystemDictionary::Object_klass()) {
238 assert(super() == NULL || super() == SystemDictionary::Object_klass(),
239 "initialize this only once to a non-trivial value");
240 set_super(k);
241 Klass* sup = k->klass_part();
242 int sup_depth = sup->super_depth();
243 juint my_depth = MIN2(sup_depth + 1, (int)primary_super_limit());
244 if (!can_be_primary_super_slow())
245 my_depth = primary_super_limit();
246 for (juint i = 0; i < my_depth; i++) {
247 oop_store_without_check((oop*) &_primary_supers[i], (oop) sup->_primary_supers[i]);
248 }
249 klassOop *super_check_cell;
250 if (my_depth < primary_super_limit()) {
251 oop_store_without_check((oop*) &_primary_supers[my_depth], (oop) this->as_klassOop());
252 super_check_cell = &_primary_supers[my_depth];
253 } else {
254 // Overflow of the primary_supers array forces me to be secondary.
255 super_check_cell = &_secondary_super_cache;
256 }
257 set_super_check_offset((address)super_check_cell - (address) this->as_klassOop());
259 #ifdef ASSERT
260 {
261 juint j = super_depth();
262 assert(j == my_depth, "computed accessor gets right answer");
263 klassOop t = as_klassOop();
264 while (!Klass::cast(t)->can_be_primary_super()) {
265 t = Klass::cast(t)->super();
266 j = Klass::cast(t)->super_depth();
267 }
268 for (juint j1 = j+1; j1 < primary_super_limit(); j1++) {
269 assert(primary_super_of_depth(j1) == NULL, "super list padding");
270 }
271 while (t != NULL) {
272 assert(primary_super_of_depth(j) == t, "super list initialization");
273 t = Klass::cast(t)->super();
274 --j;
275 }
276 assert(j == (juint)-1, "correct depth count");
277 }
278 #endif
279 }
281 if (secondary_supers() == NULL) {
282 KlassHandle this_kh (THREAD, this);
284 // Now compute the list of secondary supertypes.
285 // Secondaries can occasionally be on the super chain,
286 // if the inline "_primary_supers" array overflows.
287 int extras = 0;
288 klassOop p;
289 for (p = super(); !(p == NULL || p->klass_part()->can_be_primary_super()); p = p->klass_part()->super()) {
290 ++extras;
291 }
293 // Compute the "real" non-extra secondaries.
294 objArrayOop secondary_oops = compute_secondary_supers(extras, CHECK);
295 objArrayHandle secondaries (THREAD, secondary_oops);
297 // Store the extra secondaries in the first array positions:
298 int fillp = extras;
299 for (p = this_kh->super(); !(p == NULL || p->klass_part()->can_be_primary_super()); p = p->klass_part()->super()) {
300 int i; // Scan for overflow primaries being duplicates of 2nd'arys
302 // This happens frequently for very deeply nested arrays: the
303 // primary superclass chain overflows into the secondary. The
304 // secondary list contains the element_klass's secondaries with
305 // an extra array dimension added. If the element_klass's
306 // secondary list already contains some primary overflows, they
307 // (with the extra level of array-ness) will collide with the
308 // normal primary superclass overflows.
309 for( i = extras; i < secondaries->length(); i++ )
310 if( secondaries->obj_at(i) == p )
311 break;
312 if( i < secondaries->length() )
313 continue; // It's a dup, don't put it in
314 secondaries->obj_at_put(--fillp, p);
315 }
316 // See if we had some dup's, so the array has holes in it.
317 if( fillp > 0 ) {
318 // Pack the array. Drop the old secondaries array on the floor
319 // and let GC reclaim it.
320 objArrayOop s2 = oopFactory::new_system_objArray(secondaries->length() - fillp, CHECK);
321 for( int i = 0; i < s2->length(); i++ )
322 s2->obj_at_put( i, secondaries->obj_at(i+fillp) );
323 secondaries = objArrayHandle(THREAD, s2);
324 }
326 #ifdef ASSERT
327 if (secondaries() != Universe::the_array_interfaces_array()) {
328 // We must not copy any NULL placeholders left over from bootstrap.
329 for (int j = 0; j < secondaries->length(); j++) {
330 assert(secondaries->obj_at(j) != NULL, "correct bootstrapping order");
331 }
332 }
333 #endif
335 this_kh->set_secondary_supers(secondaries());
336 }
337 }
339 objArrayOop Klass::compute_secondary_supers(int num_extra_slots, TRAPS) {
340 assert(num_extra_slots == 0, "override for complex klasses");
341 return Universe::the_empty_system_obj_array();
342 }
345 Klass* Klass::subklass() const {
346 return _subklass == NULL ? NULL : Klass::cast(_subklass);
347 }
349 instanceKlass* Klass::superklass() const {
350 assert(super() == NULL || super()->klass_part()->oop_is_instance(), "must be instance klass");
351 return _super == NULL ? NULL : instanceKlass::cast(_super);
352 }
354 Klass* Klass::next_sibling() const {
355 return _next_sibling == NULL ? NULL : Klass::cast(_next_sibling);
356 }
358 void Klass::set_subklass(klassOop s) {
359 assert(s != as_klassOop(), "sanity check");
360 oop_store_without_check((oop*)&_subklass, s);
361 }
363 void Klass::set_next_sibling(klassOop s) {
364 assert(s != as_klassOop(), "sanity check");
365 oop_store_without_check((oop*)&_next_sibling, s);
366 }
368 void Klass::append_to_sibling_list() {
369 debug_only(if (!SharedSkipVerify) as_klassOop()->verify();)
370 // add ourselves to superklass' subklass list
371 instanceKlass* super = superklass();
372 if (super == NULL) return; // special case: class Object
373 assert(SharedSkipVerify ||
374 (!super->is_interface() // interfaces cannot be supers
375 && (super->superklass() == NULL || !is_interface())),
376 "an interface can only be a subklass of Object");
377 klassOop prev_first_subklass = super->subklass_oop();
378 if (prev_first_subklass != NULL) {
379 // set our sibling to be the superklass' previous first subklass
380 set_next_sibling(prev_first_subklass);
381 }
382 // make ourselves the superklass' first subklass
383 super->set_subklass(as_klassOop());
384 debug_only(if (!SharedSkipVerify) as_klassOop()->verify();)
385 }
387 void Klass::remove_from_sibling_list() {
388 // remove receiver from sibling list
389 instanceKlass* super = superklass();
390 assert(super != NULL || as_klassOop() == SystemDictionary::Object_klass(), "should have super");
391 if (super == NULL) return; // special case: class Object
392 if (super->subklass() == this) {
393 // first subklass
394 super->set_subklass(_next_sibling);
395 } else {
396 Klass* sib = super->subklass();
397 while (sib->next_sibling() != this) {
398 sib = sib->next_sibling();
399 };
400 sib->set_next_sibling(_next_sibling);
401 }
402 }
404 void Klass::follow_weak_klass_links( BoolObjectClosure* is_alive, OopClosure* keep_alive) {
405 // This klass is alive but the subklass and siblings are not followed/updated.
406 // We update the subklass link and the subklass' sibling links here.
407 // Our own sibling link will be updated by our superclass (which must be alive
408 // since we are).
409 assert(is_alive->do_object_b(as_klassOop()), "just checking, this should be live");
410 if (ClassUnloading) {
411 klassOop sub = subklass_oop();
412 if (sub != NULL && !is_alive->do_object_b(sub)) {
413 // first subklass not alive, find first one alive
414 do {
415 #ifndef PRODUCT
416 if (TraceClassUnloading && WizardMode) {
417 ResourceMark rm;
418 tty->print_cr("[Unlinking class (subclass) %s]", sub->klass_part()->external_name());
419 }
420 #endif
421 sub = sub->klass_part()->next_sibling_oop();
422 } while (sub != NULL && !is_alive->do_object_b(sub));
423 set_subklass(sub);
424 }
425 // now update the subklass' sibling list
426 while (sub != NULL) {
427 klassOop next = sub->klass_part()->next_sibling_oop();
428 if (next != NULL && !is_alive->do_object_b(next)) {
429 // first sibling not alive, find first one alive
430 do {
431 #ifndef PRODUCT
432 if (TraceClassUnloading && WizardMode) {
433 ResourceMark rm;
434 tty->print_cr("[Unlinking class (sibling) %s]", next->klass_part()->external_name());
435 }
436 #endif
437 next = next->klass_part()->next_sibling_oop();
438 } while (next != NULL && !is_alive->do_object_b(next));
439 sub->klass_part()->set_next_sibling(next);
440 }
441 sub = next;
442 }
443 } else {
444 // Always follow subklass and sibling link. This will prevent any klasses from
445 // being unloaded (all classes are transitively linked from java.lang.Object).
446 keep_alive->do_oop(adr_subklass());
447 keep_alive->do_oop(adr_next_sibling());
448 }
449 }
452 void Klass::remove_unshareable_info() {
453 if (oop_is_instance()) {
454 instanceKlass* ik = (instanceKlass*)this;
455 if (ik->is_linked()) {
456 ik->unlink_class();
457 }
458 }
459 // Clear the Java vtable if the oop has one.
460 // The vtable isn't shareable because it's in the wrong order wrt the methods
461 // once the method names get moved and resorted.
462 klassVtable* vt = vtable();
463 if (vt != NULL) {
464 assert(oop_is_instance() || oop_is_array(), "nothing else has vtable");
465 vt->clear_vtable();
466 }
467 set_subklass(NULL);
468 set_next_sibling(NULL);
469 }
472 void Klass::shared_symbols_iterate(SymbolClosure* closure) {
473 closure->do_symbol(&_name);
474 }
477 klassOop Klass::array_klass_or_null(int rank) {
478 EXCEPTION_MARK;
479 // No exception can be thrown by array_klass_impl when called with or_null == true.
480 // (In anycase, the execption mark will fail if it do so)
481 return array_klass_impl(true, rank, THREAD);
482 }
485 klassOop Klass::array_klass_or_null() {
486 EXCEPTION_MARK;
487 // No exception can be thrown by array_klass_impl when called with or_null == true.
488 // (In anycase, the execption mark will fail if it do so)
489 return array_klass_impl(true, THREAD);
490 }
493 klassOop Klass::array_klass_impl(bool or_null, int rank, TRAPS) {
494 fatal("array_klass should be dispatched to instanceKlass, objArrayKlass or typeArrayKlass");
495 return NULL;
496 }
499 klassOop Klass::array_klass_impl(bool or_null, TRAPS) {
500 fatal("array_klass should be dispatched to instanceKlass, objArrayKlass or typeArrayKlass");
501 return NULL;
502 }
505 void Klass::with_array_klasses_do(void f(klassOop k)) {
506 f(as_klassOop());
507 }
510 const char* Klass::external_name() const {
511 if (oop_is_instance()) {
512 instanceKlass* ik = (instanceKlass*) this;
513 if (ik->is_anonymous()) {
514 assert(EnableInvokeDynamic, "");
515 intptr_t hash = ik->java_mirror()->identity_hash();
516 char hash_buf[40];
517 sprintf(hash_buf, "/" UINTX_FORMAT, (uintx)hash);
518 size_t hash_len = strlen(hash_buf);
520 size_t result_len = name()->utf8_length();
521 char* result = NEW_RESOURCE_ARRAY(char, result_len + hash_len + 1);
522 name()->as_klass_external_name(result, (int) result_len + 1);
523 assert(strlen(result) == result_len, "");
524 strcpy(result + result_len, hash_buf);
525 assert(strlen(result) == result_len + hash_len, "");
526 return result;
527 }
528 }
529 if (name() == NULL) return "<unknown>";
530 return name()->as_klass_external_name();
531 }
534 const char* Klass::signature_name() const {
535 if (name() == NULL) return "<unknown>";
536 return name()->as_C_string();
537 }
539 // Unless overridden, modifier_flags is 0.
540 jint Klass::compute_modifier_flags(TRAPS) const {
541 return 0;
542 }
544 int Klass::atomic_incr_biased_lock_revocation_count() {
545 return (int) Atomic::add(1, &_biased_lock_revocation_count);
546 }
548 // Unless overridden, jvmti_class_status has no flags set.
549 jint Klass::jvmti_class_status() const {
550 return 0;
551 }
553 // Printing
555 void Klass::oop_print_on(oop obj, outputStream* st) {
556 ResourceMark rm;
557 // print title
558 st->print_cr("%s ", internal_name());
559 obj->print_address_on(st);
561 if (WizardMode) {
562 // print header
563 obj->mark()->print_on(st);
564 }
566 // print class
567 st->print(" - klass: ");
568 obj->klass()->print_value_on(st);
569 st->cr();
570 }
572 void Klass::oop_print_value_on(oop obj, outputStream* st) {
573 // print title
574 ResourceMark rm; // Cannot print in debug mode without this
575 st->print("%s", internal_name());
576 obj->print_address_on(st);
577 }
579 // Verification
581 void Klass::oop_verify_on(oop obj, outputStream* st) {
582 guarantee(obj->is_oop(), "should be oop");
583 guarantee(obj->klass()->is_perm(), "should be in permspace");
584 guarantee(obj->klass()->is_klass(), "klass field is not a klass");
585 }
588 void Klass::oop_verify_old_oop(oop obj, oop* p, bool allow_dirty) {
589 /* $$$ I think this functionality should be handled by verification of
590 RememberedSet::verify_old_oop(obj, p, allow_dirty, false);
591 the card table. */
592 }
593 void Klass::oop_verify_old_oop(oop obj, narrowOop* p, bool allow_dirty) { }
595 #ifndef PRODUCT
597 void Klass::verify_vtable_index(int i) {
598 assert(oop_is_instance() || oop_is_array(), "only instanceKlass and arrayKlass have vtables");
599 if (oop_is_instance()) {
600 assert(i>=0 && i<((instanceKlass*)this)->vtable_length()/vtableEntry::size(), "index out of bounds");
601 } else {
602 assert(i>=0 && i<((arrayKlass*)this)->vtable_length()/vtableEntry::size(), "index out of bounds");
603 }
604 }
606 #endif