1 /*
  2  * Copyright (c) 1999, 2022, 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 "ci/ciCallSite.hpp"
 27 #include "ci/ciInstance.hpp"
 28 #include "ci/ciInstanceKlass.hpp"
 29 #include "ci/ciMemberName.hpp"
 30 #include "ci/ciMethod.hpp"
 31 #include "ci/ciMethodData.hpp"
 32 #include "ci/ciMethodHandle.hpp"
 33 #include "ci/ciMethodType.hpp"
 34 #include "ci/ciNullObject.hpp"
 35 #include "ci/ciObjArray.hpp"
 36 #include "ci/ciObjArrayKlass.hpp"
 37 #include "ci/ciObject.hpp"
 38 #include "ci/ciObjectFactory.hpp"
 39 #include "ci/ciReplay.hpp"
 40 #include "ci/ciSymbol.hpp"
 41 #include "ci/ciSymbols.hpp"
 42 #include "ci/ciTypeArray.hpp"
 43 #include "ci/ciTypeArrayKlass.hpp"
 44 #include "ci/ciUtilities.inline.hpp"
 45 #include "classfile/javaClasses.inline.hpp"
 46 #include "classfile/vmClasses.hpp"
 47 #include "compiler/compiler_globals.hpp"
 48 #include "gc/shared/collectedHeap.inline.hpp"
 49 #include "memory/allocation.inline.hpp"
 50 #include "memory/universe.hpp"
 51 #include "oops/oop.inline.hpp"
 52 #include "runtime/handles.inline.hpp"
 53 #include "runtime/signature.hpp"
 54 #include "utilities/macros.hpp"
 55 
 56 // ciObjectFactory
 57 //
 58 // This class handles requests for the creation of new instances
 59 // of ciObject and its subclasses.  It contains a caching mechanism
 60 // which ensures that for each oop, at most one ciObject is created.
 61 // This invariant allows more efficient implementation of ciObject.
 62 //
 63 // Implementation note: the oop->ciObject mapping is represented as
 64 // a table stored in an array.  Even though objects are moved
 65 // by the garbage collector, the compactor preserves their relative
 66 // order; address comparison of oops (in perm space) is safe so long
 67 // as we prohibit GC during our comparisons.  We currently use binary
 68 // search to find the oop in the table, and inserting a new oop
 69 // into the table may be costly.  If this cost ends up being
 70 // problematic the underlying data structure can be switched to some
 71 // sort of balanced binary tree.
 72 
 73 GrowableArray<ciMetadata*>* ciObjectFactory::_shared_ci_metadata = NULL;
 74 ciSymbol*                 ciObjectFactory::_shared_ci_symbols[vmSymbols::number_of_symbols()];
 75 int                       ciObjectFactory::_shared_ident_limit = 0;
 76 volatile bool             ciObjectFactory::_initialized = false;
 77 
 78 
 79 // ------------------------------------------------------------------
 80 // ciObjectFactory::ciObjectFactory
 81 ciObjectFactory::ciObjectFactory(Arena* arena,
 82                                  int expected_size)
 83                                  : _arena(arena),
 84                                    _ci_metadata(arena, expected_size, 0, NULL),
 85                                    _unloaded_methods(arena, 4, 0, NULL),
 86                                    _unloaded_klasses(arena, 8, 0, NULL),
 87                                    _unloaded_instances(arena, 4, 0, NULL),
 88                                    _return_addresses(arena, 8, 0, NULL),
 89                                    _symbols(arena, 100, 0, NULL),
 90                                    _next_ident(_shared_ident_limit),
 91                                    _non_perm_count(0) {
 92   for (int i = 0; i < NON_PERM_BUCKETS; i++) {
 93     _non_perm_bucket[i] = NULL;
 94   }
 95 
 96   // If the shared ci objects exist append them to this factory's objects
 97   if (_shared_ci_metadata != NULL) {
 98     _ci_metadata.appendAll(_shared_ci_metadata);
 99   }
100 }
101 
102 // ------------------------------------------------------------------
103 // ciObjectFactory::ciObjectFactory
104 void ciObjectFactory::initialize() {
105   ASSERT_IN_VM;
106   JavaThread* thread = JavaThread::current();
107   HandleMark  handle_mark(thread);
108 
109   // This Arena is long lived and exists in the resource mark of the
110   // compiler thread that initializes the initial ciObjectFactory which
111   // creates the shared ciObjects that all later ciObjectFactories use.
112   Arena* arena = new (mtCompiler) Arena(mtCompiler);
113   ciEnv initial(arena);
114   ciEnv* env = ciEnv::current();
115   env->_factory->init_shared_objects();
116 
117   _initialized = true;
118 
119 }
120 
121 void ciObjectFactory::init_shared_objects() {
122 
123   _next_ident = 1;  // start numbering CI objects at 1
124 
125   {
126     // Create the shared symbols, but not in _shared_ci_metadata.
127     for (auto index : EnumRange<vmSymbolID>{}) {
128       Symbol* vmsym = vmSymbols::symbol_at(index);
129       assert(vmSymbols::find_sid(vmsym) == index, "1-1 mapping");
130       ciSymbol* sym = new (_arena) ciSymbol(vmsym, index);
131       init_ident_of(sym);
132       _shared_ci_symbols[vmSymbols::as_int(index)] = sym;
133     }
134 #ifdef ASSERT
135     for (auto index : EnumRange<vmSymbolID>{}) {
136       Symbol* vmsym = vmSymbols::symbol_at(index);
137       ciSymbol* sym = vm_symbol_at(index);
138       assert(sym->get_symbol() == vmsym, "oop must match");
139     }
140     assert(ciSymbols::void_class_signature()->get_symbol() == vmSymbols::void_class_signature(), "spot check");
141 #endif
142   }
143 
144   for (int i = T_BOOLEAN; i <= T_CONFLICT; i++) {
145     BasicType t = (BasicType)i;
146     if (type2name(t) != NULL && !is_reference_type(t) &&
147         t != T_NARROWOOP && t != T_NARROWKLASS) {
148       ciType::_basic_types[t] = new (_arena) ciType(t);
149       init_ident_of(ciType::_basic_types[t]);
150     }
151   }
152 
153   ciEnv::_null_object_instance = new (_arena) ciNullObject();
154   init_ident_of(ciEnv::_null_object_instance);
155 
156 #define VM_CLASS_DEFN(name, ignore_s)                              \
157   if (vmClasses::name##_is_loaded()) \
158     ciEnv::_##name = get_metadata(vmClasses::name())->as_instance_klass();
159 
160   VM_CLASSES_DO(VM_CLASS_DEFN)
161 #undef VM_CLASS_DEFN
162 
163   for (int len = -1; len != _ci_metadata.length(); ) {
164     len = _ci_metadata.length();
165     for (int i2 = 0; i2 < len; i2++) {
166       ciMetadata* obj = _ci_metadata.at(i2);
167       assert (obj->is_metadata(), "what else would it be?");
168       if (obj->is_loaded() && obj->is_instance_klass()) {
169         obj->as_instance_klass()->compute_nonstatic_fields();
170       }
171     }
172   }
173 
174   ciEnv::_unloaded_cisymbol = ciObjectFactory::get_symbol(vmSymbols::dummy_symbol());
175   // Create dummy InstanceKlass and ObjArrayKlass object and assign them idents
176   ciEnv::_unloaded_ciinstance_klass = new (_arena) ciInstanceKlass(ciEnv::_unloaded_cisymbol, NULL, NULL);
177   init_ident_of(ciEnv::_unloaded_ciinstance_klass);
178   ciEnv::_unloaded_ciobjarrayklass = new (_arena) ciObjArrayKlass(ciEnv::_unloaded_cisymbol, ciEnv::_unloaded_ciinstance_klass, 1);
179   init_ident_of(ciEnv::_unloaded_ciobjarrayklass);
180   assert(ciEnv::_unloaded_ciobjarrayklass->is_obj_array_klass(), "just checking");
181 
182   get_metadata(Universe::boolArrayKlassObj());
183   get_metadata(Universe::charArrayKlassObj());
184   get_metadata(Universe::floatArrayKlassObj());
185   get_metadata(Universe::doubleArrayKlassObj());
186   get_metadata(Universe::byteArrayKlassObj());
187   get_metadata(Universe::shortArrayKlassObj());
188   get_metadata(Universe::intArrayKlassObj());
189   get_metadata(Universe::longArrayKlassObj());
190 
191   assert(_non_perm_count == 0, "no shared non-perm objects");
192 
193   // The shared_ident_limit is the first ident number that will
194   // be used for non-shared objects.  That is, numbers less than
195   // this limit are permanently assigned to shared CI objects,
196   // while the higher numbers are recycled afresh by each new ciEnv.
197 
198   _shared_ident_limit = _next_ident;
199   _shared_ci_metadata = &_ci_metadata;
200 }
201 
202 
203 ciSymbol* ciObjectFactory::get_symbol(Symbol* key) {
204   vmSymbolID sid = vmSymbols::find_sid(key);
205   if (sid != vmSymbolID::NO_SID) {
206     // do not pollute the main cache with it
207     return vm_symbol_at(sid);
208   }
209 
210   assert(vmSymbols::find_sid(key) == vmSymbolID::NO_SID, "");
211   ciSymbol* s = new (arena()) ciSymbol(key, vmSymbolID::NO_SID);
212   _symbols.push(s);
213   return s;
214 }
215 
216 // Decrement the refcount when done on symbols referenced by this compilation.
217 void ciObjectFactory::remove_symbols() {
218   for (int i = 0; i < _symbols.length(); i++) {
219     ciSymbol* s = _symbols.at(i);
220     s->get_symbol()->decrement_refcount();
221   }
222   // Since _symbols is resource allocated we're not allowed to delete it
223   // but it'll go away just the same.
224 }
225 
226 // ------------------------------------------------------------------
227 // ciObjectFactory::get
228 //
229 // Get the ciObject corresponding to some oop.  If the ciObject has
230 // already been created, it is returned.  Otherwise, a new ciObject
231 // is created.
232 ciObject* ciObjectFactory::get(oop key) {
233   ASSERT_IN_VM;
234 
235   assert(Universe::heap()->is_in(key), "must be");
236 
237   NonPermObject* &bucket = find_non_perm(key);
238   if (bucket != NULL) {
239     return bucket->object();
240   }
241 
242   // The ciObject does not yet exist.  Create it and insert it
243   // into the cache.
244   Handle keyHandle(Thread::current(), key);
245   ciObject* new_object = create_new_object(keyHandle());
246   assert(keyHandle() == new_object->get_oop(), "must be properly recorded");
247   init_ident_of(new_object);
248   assert(Universe::heap()->is_in(new_object->get_oop()), "must be");
249 
250   // Not a perm-space object.
251   insert_non_perm(bucket, keyHandle(), new_object);
252   return new_object;
253 }
254 
255 int ciObjectFactory::metadata_compare(Metadata* const& key, ciMetadata* const& elt) {
256   Metadata* value = elt->constant_encoding();
257   if (key < value)      return -1;
258   else if (key > value) return 1;
259   else                  return 0;
260 }
261 
262 // ------------------------------------------------------------------
263 // ciObjectFactory::cached_metadata
264 //
265 // Get the ciMetadata corresponding to some Metadata. If the ciMetadata has
266 // already been created, it is returned. Otherwise, null is returned.
267 ciMetadata* ciObjectFactory::cached_metadata(Metadata* key) {
268   ASSERT_IN_VM;
269 
270   bool found = false;
271   int index = _ci_metadata.find_sorted<Metadata*, ciObjectFactory::metadata_compare>(key, found);
272 
273   if (!found) {
274     return NULL;
275   }
276   return _ci_metadata.at(index)->as_metadata();
277 }
278 
279 
280 // ------------------------------------------------------------------
281 // ciObjectFactory::get_metadata
282 //
283 // Get the ciMetadata corresponding to some Metadata. If the ciMetadata has
284 // already been created, it is returned. Otherwise, a new ciMetadata
285 // is created.
286 ciMetadata* ciObjectFactory::get_metadata(Metadata* key) {
287   ASSERT_IN_VM;
288 
289   if (ReplayCompiles && key->is_klass()) {
290     Klass* k = (Klass*)key;
291     if (k->is_instance_klass() && ciReplay::is_klass_unresolved((InstanceKlass*)k)) {
292       // Klass was unresolved at replay dump time. Simulate this case.
293       return ciEnv::_unloaded_ciinstance_klass;
294     }
295   }
296 
297 #ifdef ASSERT
298   if (CIObjectFactoryVerify) {
299     Metadata* last = NULL;
300     for (int j = 0; j < _ci_metadata.length(); j++) {
301       Metadata* o = _ci_metadata.at(j)->constant_encoding();
302       assert(last < o, "out of order");
303       last = o;
304     }
305   }
306 #endif // ASSERT
307   int len = _ci_metadata.length();
308   bool found = false;
309   int index = _ci_metadata.find_sorted<Metadata*, ciObjectFactory::metadata_compare>(key, found);
310 #ifdef ASSERT
311   if (CIObjectFactoryVerify) {
312     for (int i = 0; i < _ci_metadata.length(); i++) {
313       if (_ci_metadata.at(i)->constant_encoding() == key) {
314         assert(index == i, " bad lookup");
315       }
316     }
317   }
318 #endif
319 
320   if (!found) {
321     // The ciMetadata does not yet exist. Create it and insert it
322     // into the cache.
323     ciMetadata* new_object = create_new_metadata(key);
324     init_ident_of(new_object);
325     assert(new_object->is_metadata(), "must be");
326 
327     if (len != _ci_metadata.length()) {
328       // creating the new object has recursively entered new objects
329       // into the table.  We need to recompute our index.
330       index = _ci_metadata.find_sorted<Metadata*, ciObjectFactory::metadata_compare>(key, found);
331     }
332     assert(!found, "no double insert");
333     _ci_metadata.insert_before(index, new_object);
334     return new_object;
335   }
336   return _ci_metadata.at(index)->as_metadata();
337 }
338 
339 // ------------------------------------------------------------------
340 // ciObjectFactory::create_new_object
341 //
342 // Create a new ciObject from an oop.
343 //
344 // Implementation note: this functionality could be virtual behavior
345 // of the oop itself.  For now, we explicitly marshal the object.
346 ciObject* ciObjectFactory::create_new_object(oop o) {
347   EXCEPTION_CONTEXT;
348 
349   if (o->is_instance()) {
350     instanceHandle h_i(THREAD, (instanceOop)o);
351     if (java_lang_invoke_CallSite::is_instance(o))
352       return new (arena()) ciCallSite(h_i);
353     else if (java_lang_invoke_MemberName::is_instance(o))
354       return new (arena()) ciMemberName(h_i);
355     else if (java_lang_invoke_MethodHandle::is_instance(o))
356       return new (arena()) ciMethodHandle(h_i);
357     else if (java_lang_invoke_MethodType::is_instance(o))
358       return new (arena()) ciMethodType(h_i);
359     else
360       return new (arena()) ciInstance(h_i);
361   } else if (o->is_objArray()) {
362     objArrayHandle h_oa(THREAD, (objArrayOop)o);
363     return new (arena()) ciObjArray(h_oa);
364   } else if (o->is_typeArray()) {
365     typeArrayHandle h_ta(THREAD, (typeArrayOop)o);
366     return new (arena()) ciTypeArray(h_ta);
367   }
368 
369   // The oop is of some type not supported by the compiler interface.
370   ShouldNotReachHere();
371   return NULL;
372 }
373 
374 // ------------------------------------------------------------------
375 // ciObjectFactory::create_new_metadata
376 //
377 // Create a new ciMetadata from a Metadata*.
378 //
379 // Implementation note: in order to keep Metadata live, an auxiliary ciObject
380 // is used, which points to it's holder.
381 ciMetadata* ciObjectFactory::create_new_metadata(Metadata* o) {
382   EXCEPTION_CONTEXT;
383 
384   if (o->is_klass()) {
385     Klass* k = (Klass*)o;
386     if (k->is_instance_klass()) {
387       assert(!ReplayCompiles || ciReplay::no_replay_state() || !ciReplay::is_klass_unresolved((InstanceKlass*)k), "must be whitelisted for replay compilation");
388       return new (arena()) ciInstanceKlass(k);
389     } else if (k->is_objArray_klass()) {
390       return new (arena()) ciObjArrayKlass(k);
391     } else if (k->is_typeArray_klass()) {
392       return new (arena()) ciTypeArrayKlass(k);
393     }
394   } else if (o->is_method()) {
395     methodHandle h_m(THREAD, (Method*)o);
396     ciEnv *env = CURRENT_THREAD_ENV;
397     ciInstanceKlass* holder = env->get_instance_klass(h_m()->method_holder());
398     return new (arena()) ciMethod(h_m, holder);
399   } else if (o->is_methodData()) {
400     // Hold methodHandle alive - might not be necessary ???
401     methodHandle h_m(THREAD, ((MethodData*)o)->method());
402     return new (arena()) ciMethodData((MethodData*)o);
403   }
404 
405   // The Metadata* is of some type not supported by the compiler interface.
406   ShouldNotReachHere();
407   return NULL;
408 }
409 
410 //------------------------------------------------------------------
411 // ciObjectFactory::get_unloaded_method
412 //
413 // Get the ciMethod representing an unloaded/unfound method.
414 //
415 // Implementation note: unloaded methods are currently stored in
416 // an unordered array, requiring a linear-time lookup for each
417 // unloaded method.  This may need to change.
418 ciMethod* ciObjectFactory::get_unloaded_method(ciInstanceKlass* holder,
419                                                ciSymbol*        name,
420                                                ciSymbol*        signature,
421                                                ciInstanceKlass* accessor) {
422   assert(accessor != NULL, "need origin of access");
423   ciSignature* that = NULL;
424   for (int i = 0; i < _unloaded_methods.length(); i++) {
425     ciMethod* entry = _unloaded_methods.at(i);
426     if (entry->holder()->equals(holder) &&
427         entry->name()->equals(name) &&
428         entry->signature()->as_symbol()->equals(signature)) {
429       // Short-circuit slow resolve.
430       if (entry->signature()->accessing_klass() == accessor) {
431         // We've found a match.
432         return entry;
433       } else {
434         // Lazily create ciSignature
435         if (that == NULL)  that = new (arena()) ciSignature(accessor, constantPoolHandle(), signature);
436         if (entry->signature()->equals(that)) {
437           // We've found a match.
438           return entry;
439         }
440       }
441     }
442   }
443 
444   // This is a new unloaded method.  Create it and stick it in
445   // the cache.
446   ciMethod* new_method = new (arena()) ciMethod(holder, name, signature, accessor);
447 
448   init_ident_of(new_method);
449   _unloaded_methods.append(new_method);
450 
451   return new_method;
452 }
453 
454 //------------------------------------------------------------------
455 // ciObjectFactory::get_unloaded_klass
456 //
457 // Get a ciKlass representing an unloaded klass.
458 //
459 // Implementation note: unloaded klasses are currently stored in
460 // an unordered array, requiring a linear-time lookup for each
461 // unloaded klass.  This may need to change.
462 ciKlass* ciObjectFactory::get_unloaded_klass(ciKlass* accessing_klass,
463                                              ciSymbol* name,
464                                              bool create_if_not_found) {
465   EXCEPTION_CONTEXT;
466   oop loader = NULL;
467   oop domain = NULL;
468   if (accessing_klass != NULL) {
469     loader = accessing_klass->loader();
470     domain = accessing_klass->protection_domain();
471   }
472   for (int i = 0; i < _unloaded_klasses.length(); i++) {
473     ciKlass* entry = _unloaded_klasses.at(i);
474     if (entry->name()->equals(name) &&
475         entry->loader() == loader &&
476         entry->protection_domain() == domain) {
477       // We've found a match.
478       return entry;
479     }
480   }
481 
482   if (!create_if_not_found)
483     return NULL;
484 
485   // This is a new unloaded klass.  Create it and stick it in
486   // the cache.
487   ciKlass* new_klass = NULL;
488 
489   // Two cases: this is an unloaded ObjArrayKlass or an
490   // unloaded InstanceKlass.  Deal with both.
491   if (name->char_at(0) == JVM_SIGNATURE_ARRAY) {
492     // Decompose the name.'
493     SignatureStream ss(name->get_symbol(), false);
494     int dimension = ss.skip_array_prefix();  // skip all '['s
495     BasicType element_type = ss.type();
496     assert(element_type != T_ARRAY, "unsuccessful decomposition");
497     ciKlass* element_klass = NULL;
498     if (element_type == T_OBJECT) {
499       ciEnv *env = CURRENT_THREAD_ENV;
500       ciSymbol* ci_name = env->get_symbol(ss.as_symbol());
501       element_klass =
502         env->get_klass_by_name(accessing_klass, ci_name, false)->as_instance_klass();
503     } else {
504       assert(dimension > 1, "one dimensional type arrays are always loaded.");
505 
506       // The type array itself takes care of one of the dimensions.
507       dimension--;
508 
509       // The element klass is a TypeArrayKlass.
510       element_klass = ciTypeArrayKlass::make(element_type);
511     }
512     new_klass = new (arena()) ciObjArrayKlass(name, element_klass, dimension);
513   } else {
514     jobject loader_handle = NULL;
515     jobject domain_handle = NULL;
516     if (accessing_klass != NULL) {
517       loader_handle = accessing_klass->loader_handle();
518       domain_handle = accessing_klass->protection_domain_handle();
519     }
520     new_klass = new (arena()) ciInstanceKlass(name, loader_handle, domain_handle);
521   }
522   init_ident_of(new_klass);
523   _unloaded_klasses.append(new_klass);
524 
525   return new_klass;
526 }
527 
528 
529 //------------------------------------------------------------------
530 // ciObjectFactory::get_unloaded_instance
531 //
532 // Get a ciInstance representing an as-yet undetermined instance of a given class.
533 //
534 ciInstance* ciObjectFactory::get_unloaded_instance(ciInstanceKlass* instance_klass) {
535   for (int i = 0; i < _unloaded_instances.length(); i++) {
536     ciInstance* entry = _unloaded_instances.at(i);
537     if (entry->klass()->equals(instance_klass)) {
538       // We've found a match.
539       return entry;
540     }
541   }
542 
543   // This is a new unloaded instance.  Create it and stick it in
544   // the cache.
545   ciInstance* new_instance = new (arena()) ciInstance(instance_klass);
546 
547   init_ident_of(new_instance);
548   _unloaded_instances.append(new_instance);
549 
550   // make sure it looks the way we want:
551   assert(!new_instance->is_loaded(), "");
552   assert(new_instance->klass() == instance_klass, "");
553 
554   return new_instance;
555 }
556 
557 
558 //------------------------------------------------------------------
559 // ciObjectFactory::get_unloaded_klass_mirror
560 //
561 // Get a ciInstance representing an unresolved klass mirror.
562 //
563 // Currently, this ignores the parameters and returns a unique unloaded instance.
564 ciInstance* ciObjectFactory::get_unloaded_klass_mirror(ciKlass* type) {
565   assert(ciEnv::_Class_klass != NULL, "");
566   return get_unloaded_instance(ciEnv::_Class_klass->as_instance_klass());
567 }
568 
569 //------------------------------------------------------------------
570 // ciObjectFactory::get_unloaded_method_handle_constant
571 //
572 // Get a ciInstance representing an unresolved method handle constant.
573 //
574 // Currently, this ignores the parameters and returns a unique unloaded instance.
575 ciInstance* ciObjectFactory::get_unloaded_method_handle_constant(ciKlass*  holder,
576                                                                  ciSymbol* name,
577                                                                  ciSymbol* signature,
578                                                                  int       ref_kind) {
579   assert(ciEnv::_MethodHandle_klass != NULL, "");
580   return get_unloaded_instance(ciEnv::_MethodHandle_klass->as_instance_klass());
581 }
582 
583 //------------------------------------------------------------------
584 // ciObjectFactory::get_unloaded_method_type_constant
585 //
586 // Get a ciInstance representing an unresolved method type constant.
587 //
588 // Currently, this ignores the parameters and returns a unique unloaded instance.
589 ciInstance* ciObjectFactory::get_unloaded_method_type_constant(ciSymbol* signature) {
590   assert(ciEnv::_MethodType_klass != NULL, "");
591   return get_unloaded_instance(ciEnv::_MethodType_klass->as_instance_klass());
592 }
593 
594 ciInstance* ciObjectFactory::get_unloaded_object_constant() {
595   assert(ciEnv::_Object_klass != NULL, "");
596   return get_unloaded_instance(ciEnv::_Object_klass->as_instance_klass());
597 }
598 
599 //------------------------------------------------------------------
600 // ciObjectFactory::get_empty_methodData
601 //
602 // Get the ciMethodData representing the methodData for a method with
603 // none.
604 ciMethodData* ciObjectFactory::get_empty_methodData() {
605   ciMethodData* new_methodData = new (arena()) ciMethodData();
606   init_ident_of(new_methodData);
607   return new_methodData;
608 }
609 
610 //------------------------------------------------------------------
611 // ciObjectFactory::get_return_address
612 //
613 // Get a ciReturnAddress for a specified bci.
614 ciReturnAddress* ciObjectFactory::get_return_address(int bci) {
615   for (int i = 0; i < _return_addresses.length(); i++) {
616     ciReturnAddress* entry = _return_addresses.at(i);
617     if (entry->bci() == bci) {
618       // We've found a match.
619       return entry;
620     }
621   }
622 
623   ciReturnAddress* new_ret_addr = new (arena()) ciReturnAddress(bci);
624   init_ident_of(new_ret_addr);
625   _return_addresses.append(new_ret_addr);
626   return new_ret_addr;
627 }
628 
629 // ------------------------------------------------------------------
630 // ciObjectFactory::init_ident_of
631 void ciObjectFactory::init_ident_of(ciBaseObject* obj) {
632   obj->set_ident(_next_ident++);
633 }
634 
635 static ciObjectFactory::NonPermObject* emptyBucket = NULL;
636 
637 // ------------------------------------------------------------------
638 // ciObjectFactory::find_non_perm
639 //
640 // Use a small hash table, hashed on the klass of the key.
641 // If there is no entry in the cache corresponding to this oop, return
642 // the null tail of the bucket into which the oop should be inserted.
643 ciObjectFactory::NonPermObject* &ciObjectFactory::find_non_perm(oop key) {
644   assert(Universe::heap()->is_in(key), "must be");
645   ciMetadata* klass = get_metadata(key->klass());
646   NonPermObject* *bp = &_non_perm_bucket[(unsigned) klass->hash() % NON_PERM_BUCKETS];
647   for (NonPermObject* p; (p = (*bp)) != NULL; bp = &p->next()) {
648     if (is_equal(p, key))  break;
649   }
650   return (*bp);
651 }
652 
653 
654 
655 // ------------------------------------------------------------------
656 // Code for for NonPermObject
657 //
658 inline ciObjectFactory::NonPermObject::NonPermObject(ciObjectFactory::NonPermObject* &bucket, oop key, ciObject* object) {
659   assert(ciObjectFactory::is_initialized(), "");
660   _object = object;
661   _next = bucket;
662   bucket = this;
663 }
664 
665 
666 
667 // ------------------------------------------------------------------
668 // ciObjectFactory::insert_non_perm
669 //
670 // Insert a ciObject into the non-perm table.
671 void ciObjectFactory::insert_non_perm(ciObjectFactory::NonPermObject* &where, oop key, ciObject* obj) {
672   assert(Universe::heap()->is_in_or_null(key), "must be");
673   assert(&where != &emptyBucket, "must not try to fill empty bucket");
674   NonPermObject* p = new (arena()) NonPermObject(where, key, obj);
675   assert(where == p && is_equal(p, key) && p->object() == obj, "entry must match");
676   assert(find_non_perm(key) == p, "must find the same spot");
677   ++_non_perm_count;
678 }
679 
680 // ------------------------------------------------------------------
681 // ciObjectFactory::vm_symbol_at
682 // Get the ciSymbol corresponding to some index in vmSymbols.
683 ciSymbol* ciObjectFactory::vm_symbol_at(vmSymbolID sid) {
684   int index = vmSymbols::as_int(sid);
685   return _shared_ci_symbols[index];
686 }
687 
688 // ------------------------------------------------------------------
689 // ciObjectFactory::metadata_do
690 void ciObjectFactory::metadata_do(MetadataClosure* f) {
691   for (int j = 0; j < _ci_metadata.length(); j++) {
692     Metadata* o = _ci_metadata.at(j)->constant_encoding();
693     f->do_metadata(o);
694   }
695 }
696 
697 // ------------------------------------------------------------------
698 // ciObjectFactory::print_contents_impl
699 void ciObjectFactory::print_contents_impl() {
700   int len = _ci_metadata.length();
701   tty->print_cr("ciObjectFactory (%d) meta data contents:", len);
702   for (int i = 0; i < len; i++) {
703     _ci_metadata.at(i)->print();
704     tty->cr();
705   }
706 }
707 
708 // ------------------------------------------------------------------
709 // ciObjectFactory::print_contents
710 void ciObjectFactory::print_contents() {
711   print();
712   tty->cr();
713   GUARDED_VM_ENTRY(print_contents_impl();)
714 }
715 
716 // ------------------------------------------------------------------
717 // ciObjectFactory::print
718 //
719 // Print debugging information about the object factory
720 void ciObjectFactory::print() {
721   tty->print("<ciObjectFactory oops=%d metadata=%d unloaded_methods=%d unloaded_instances=%d unloaded_klasses=%d>",
722              _non_perm_count, _ci_metadata.length(), _unloaded_methods.length(),
723              _unloaded_instances.length(),
724              _unloaded_klasses.length());
725 }