1 /*
2 * Copyright (c) 1997, 2013, 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/classLoader.hpp"
27 #include "classfile/javaClasses.hpp"
28 #include "classfile/symbolTable.hpp"
29 #include "classfile/systemDictionary.hpp"
30 #include "classfile/vmSymbols.hpp"
31 #include "code/codeCache.hpp"
32 #include "code/dependencies.hpp"
33 #include "gc_interface/collectedHeap.inline.hpp"
34 #include "interpreter/interpreter.hpp"
35 #include "memory/cardTableModRefBS.hpp"
36 #include "memory/filemap.hpp"
37 #include "memory/gcLocker.inline.hpp"
38 #include "memory/genCollectedHeap.hpp"
39 #include "memory/genRemSet.hpp"
40 #include "memory/generation.hpp"
41 #include "memory/oopFactory.hpp"
42 #include "memory/permGen.hpp"
43 #include "memory/space.hpp"
44 #include "memory/universe.hpp"
45 #include "memory/universe.inline.hpp"
46 #include "oops/arrayKlassKlass.hpp"
47 #include "oops/compiledICHolderKlass.hpp"
48 #include "oops/constMethodKlass.hpp"
49 #include "oops/constantPoolKlass.hpp"
50 #include "oops/constantPoolOop.hpp"
51 #include "oops/cpCacheKlass.hpp"
52 #include "oops/cpCacheOop.hpp"
53 #include "oops/instanceKlass.hpp"
54 #include "oops/instanceMirrorKlass.hpp"
55 #include "oops/instanceKlassKlass.hpp"
56 #include "oops/instanceRefKlass.hpp"
57 #include "oops/klassKlass.hpp"
58 #include "oops/klassOop.hpp"
59 #include "oops/methodDataKlass.hpp"
60 #include "oops/methodKlass.hpp"
61 #include "oops/objArrayKlassKlass.hpp"
62 #include "oops/oop.inline.hpp"
63 #include "oops/typeArrayKlass.hpp"
64 #include "oops/typeArrayKlassKlass.hpp"
65 #include "prims/jvmtiRedefineClassesTrace.hpp"
66 #include "runtime/aprofiler.hpp"
67 #include "runtime/arguments.hpp"
68 #include "runtime/deoptimization.hpp"
69 #include "runtime/fprofiler.hpp"
70 #include "runtime/handles.inline.hpp"
71 #include "runtime/init.hpp"
72 #include "runtime/java.hpp"
73 #include "runtime/javaCalls.hpp"
74 #include "runtime/sharedRuntime.hpp"
75 #include "runtime/synchronizer.hpp"
76 #include "runtime/timer.hpp"
77 #include "runtime/vm_operations.hpp"
78 #include "services/memoryService.hpp"
79 #include "utilities/copy.hpp"
80 #include "utilities/events.hpp"
81 #include "utilities/hashtable.inline.hpp"
82 #include "utilities/preserveException.hpp"
83 #ifdef TARGET_OS_FAMILY_linux
84 # include "thread_linux.inline.hpp"
85 #endif
86 #ifdef TARGET_OS_FAMILY_solaris
87 # include "thread_solaris.inline.hpp"
88 #endif
89 #ifdef TARGET_OS_FAMILY_windows
90 # include "thread_windows.inline.hpp"
91 #endif
92 #ifdef TARGET_OS_FAMILY_bsd
93 # include "thread_bsd.inline.hpp"
94 #endif
95 #ifndef SERIALGC
96 #include "gc_implementation/concurrentMarkSweep/cmsAdaptiveSizePolicy.hpp"
97 #include "gc_implementation/concurrentMarkSweep/cmsCollectorPolicy.hpp"
98 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
99 #include "gc_implementation/g1/g1CollectorPolicy.hpp"
100 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp"
101 #endif
102
103 // Known objects
104 klassOop Universe::_boolArrayKlassObj = NULL;
105 klassOop Universe::_byteArrayKlassObj = NULL;
106 klassOop Universe::_charArrayKlassObj = NULL;
107 klassOop Universe::_intArrayKlassObj = NULL;
108 klassOop Universe::_shortArrayKlassObj = NULL;
109 klassOop Universe::_longArrayKlassObj = NULL;
110 klassOop Universe::_singleArrayKlassObj = NULL;
111 klassOop Universe::_doubleArrayKlassObj = NULL;
112 klassOop Universe::_typeArrayKlassObjs[T_VOID+1] = { NULL /*, NULL...*/ };
113 klassOop Universe::_objectArrayKlassObj = NULL;
114 klassOop Universe::_methodKlassObj = NULL;
115 klassOop Universe::_constMethodKlassObj = NULL;
116 klassOop Universe::_methodDataKlassObj = NULL;
117 klassOop Universe::_klassKlassObj = NULL;
118 klassOop Universe::_arrayKlassKlassObj = NULL;
119 klassOop Universe::_objArrayKlassKlassObj = NULL;
120 klassOop Universe::_typeArrayKlassKlassObj = NULL;
121 klassOop Universe::_instanceKlassKlassObj = NULL;
122 klassOop Universe::_constantPoolKlassObj = NULL;
123 klassOop Universe::_constantPoolCacheKlassObj = NULL;
124 klassOop Universe::_compiledICHolderKlassObj = NULL;
125 klassOop Universe::_systemObjArrayKlassObj = NULL;
126 oop Universe::_int_mirror = NULL;
127 oop Universe::_float_mirror = NULL;
128 oop Universe::_double_mirror = NULL;
129 oop Universe::_byte_mirror = NULL;
130 oop Universe::_bool_mirror = NULL;
131 oop Universe::_char_mirror = NULL;
132 oop Universe::_long_mirror = NULL;
133 oop Universe::_short_mirror = NULL;
134 oop Universe::_void_mirror = NULL;
135 oop Universe::_mirrors[T_VOID+1] = { NULL /*, NULL...*/ };
136 oop Universe::_main_thread_group = NULL;
137 oop Universe::_system_thread_group = NULL;
138 typeArrayOop Universe::_the_empty_byte_array = NULL;
139 typeArrayOop Universe::_the_empty_short_array = NULL;
140 typeArrayOop Universe::_the_empty_int_array = NULL;
141 objArrayOop Universe::_the_empty_system_obj_array = NULL;
142 objArrayOop Universe::_the_empty_class_klass_array = NULL;
143 objArrayOop Universe::_the_array_interfaces_array = NULL;
144 oop Universe::_the_null_string = NULL;
145 oop Universe::_the_min_jint_string = NULL;
146 LatestMethodOopCache* Universe::_finalizer_register_cache = NULL;
147 LatestMethodOopCache* Universe::_loader_addClass_cache = NULL;
148 LatestMethodOopCache* Universe::_pd_implies_cache = NULL;
149 ActiveMethodOopsCache* Universe::_reflect_invoke_cache = NULL;
150 oop Universe::_out_of_memory_error_java_heap = NULL;
151 oop Universe::_out_of_memory_error_perm_gen = NULL;
152 oop Universe::_out_of_memory_error_array_size = NULL;
153 oop Universe::_out_of_memory_error_gc_overhead_limit = NULL;
154 objArrayOop Universe::_preallocated_out_of_memory_error_array = NULL;
155 volatile jint Universe::_preallocated_out_of_memory_error_avail_count = 0;
156 bool Universe::_verify_in_progress = false;
157 oop Universe::_null_ptr_exception_instance = NULL;
158 oop Universe::_arithmetic_exception_instance = NULL;
159 oop Universe::_virtual_machine_error_instance = NULL;
160 oop Universe::_vm_exception = NULL;
161
162 // These variables are guarded by FullGCALot_lock.
163 debug_only(objArrayOop Universe::_fullgc_alot_dummy_array = NULL;)
164 debug_only(int Universe::_fullgc_alot_dummy_next = 0;)
165
166
167 // Heap
168 int Universe::_verify_count = 0;
169
170 int Universe::_base_vtable_size = 0;
171 bool Universe::_bootstrapping = false;
172 bool Universe::_fully_initialized = false;
173
174 size_t Universe::_heap_capacity_at_last_gc;
175 size_t Universe::_heap_used_at_last_gc = 0;
176
177 CollectedHeap* Universe::_collectedHeap = NULL;
178
179 NarrowOopStruct Universe::_narrow_oop = { NULL, 0, true };
180
181
182 void Universe::basic_type_classes_do(void f(klassOop)) {
183 f(boolArrayKlassObj());
184 f(byteArrayKlassObj());
185 f(charArrayKlassObj());
186 f(intArrayKlassObj());
187 f(shortArrayKlassObj());
188 f(longArrayKlassObj());
189 f(singleArrayKlassObj());
190 f(doubleArrayKlassObj());
191 }
192
193
194 void Universe::system_classes_do(void f(klassOop)) {
195 f(methodKlassObj());
196 f(constMethodKlassObj());
197 f(methodDataKlassObj());
198 f(klassKlassObj());
199 f(arrayKlassKlassObj());
200 f(objArrayKlassKlassObj());
201 f(typeArrayKlassKlassObj());
202 f(instanceKlassKlassObj());
203 f(constantPoolKlassObj());
204 f(systemObjArrayKlassObj());
205 }
206
207 void Universe::oops_do(OopClosure* f, bool do_all) {
208
209 f->do_oop((oop*) &_int_mirror);
210 f->do_oop((oop*) &_float_mirror);
211 f->do_oop((oop*) &_double_mirror);
212 f->do_oop((oop*) &_byte_mirror);
213 f->do_oop((oop*) &_bool_mirror);
214 f->do_oop((oop*) &_char_mirror);
215 f->do_oop((oop*) &_long_mirror);
216 f->do_oop((oop*) &_short_mirror);
217 f->do_oop((oop*) &_void_mirror);
218
219 // It's important to iterate over these guys even if they are null,
220 // since that's how shared heaps are restored.
221 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
222 f->do_oop((oop*) &_mirrors[i]);
223 }
224 assert(_mirrors[0] == NULL && _mirrors[T_BOOLEAN - 1] == NULL, "checking");
225
226 // %%% Consider moving those "shared oops" over here with the others.
227 f->do_oop((oop*)&_boolArrayKlassObj);
228 f->do_oop((oop*)&_byteArrayKlassObj);
229 f->do_oop((oop*)&_charArrayKlassObj);
230 f->do_oop((oop*)&_intArrayKlassObj);
231 f->do_oop((oop*)&_shortArrayKlassObj);
232 f->do_oop((oop*)&_longArrayKlassObj);
233 f->do_oop((oop*)&_singleArrayKlassObj);
234 f->do_oop((oop*)&_doubleArrayKlassObj);
235 f->do_oop((oop*)&_objectArrayKlassObj);
236 {
237 for (int i = 0; i < T_VOID+1; i++) {
238 if (_typeArrayKlassObjs[i] != NULL) {
239 assert(i >= T_BOOLEAN, "checking");
240 f->do_oop((oop*)&_typeArrayKlassObjs[i]);
241 } else if (do_all) {
242 f->do_oop((oop*)&_typeArrayKlassObjs[i]);
243 }
244 }
245 }
246 f->do_oop((oop*)&_methodKlassObj);
247 f->do_oop((oop*)&_constMethodKlassObj);
248 f->do_oop((oop*)&_methodDataKlassObj);
249 f->do_oop((oop*)&_klassKlassObj);
250 f->do_oop((oop*)&_arrayKlassKlassObj);
251 f->do_oop((oop*)&_objArrayKlassKlassObj);
252 f->do_oop((oop*)&_typeArrayKlassKlassObj);
253 f->do_oop((oop*)&_instanceKlassKlassObj);
254 f->do_oop((oop*)&_constantPoolKlassObj);
255 f->do_oop((oop*)&_constantPoolCacheKlassObj);
256 f->do_oop((oop*)&_compiledICHolderKlassObj);
257 f->do_oop((oop*)&_systemObjArrayKlassObj);
258 f->do_oop((oop*)&_the_empty_byte_array);
259 f->do_oop((oop*)&_the_empty_short_array);
260 f->do_oop((oop*)&_the_empty_int_array);
261 f->do_oop((oop*)&_the_empty_system_obj_array);
262 f->do_oop((oop*)&_the_empty_class_klass_array);
263 f->do_oop((oop*)&_the_array_interfaces_array);
264 f->do_oop((oop*)&_the_null_string);
265 f->do_oop((oop*)&_the_min_jint_string);
266 _finalizer_register_cache->oops_do(f);
267 _loader_addClass_cache->oops_do(f);
268 _pd_implies_cache->oops_do(f);
269 _reflect_invoke_cache->oops_do(f);
270 f->do_oop((oop*)&_out_of_memory_error_java_heap);
271 f->do_oop((oop*)&_out_of_memory_error_perm_gen);
272 f->do_oop((oop*)&_out_of_memory_error_array_size);
273 f->do_oop((oop*)&_out_of_memory_error_gc_overhead_limit);
274 if (_preallocated_out_of_memory_error_array != (oop)NULL) { // NULL when DumpSharedSpaces
275 f->do_oop((oop*)&_preallocated_out_of_memory_error_array);
276 }
277 f->do_oop((oop*)&_null_ptr_exception_instance);
278 f->do_oop((oop*)&_arithmetic_exception_instance);
279 f->do_oop((oop*)&_virtual_machine_error_instance);
280 f->do_oop((oop*)&_main_thread_group);
281 f->do_oop((oop*)&_system_thread_group);
282 f->do_oop((oop*)&_vm_exception);
283 debug_only(f->do_oop((oop*)&_fullgc_alot_dummy_array);)
284 }
285
286
287 void Universe::check_alignment(uintx size, uintx alignment, const char* name) {
288 if (size < alignment || size % alignment != 0) {
289 ResourceMark rm;
290 stringStream st;
291 st.print("Size of %s (%ld bytes) must be aligned to %ld bytes", name, size, alignment);
292 char* error = st.as_string();
293 vm_exit_during_initialization(error);
294 }
295 }
296
297
298 void Universe::genesis(TRAPS) {
299 ResourceMark rm;
300 { FlagSetting fs(_bootstrapping, true);
301
302 { MutexLocker mc(Compile_lock);
303
304 // determine base vtable size; without that we cannot create the array klasses
305 compute_base_vtable_size();
306
307 if (!UseSharedSpaces) {
308 _klassKlassObj = klassKlass::create_klass(CHECK);
309 _arrayKlassKlassObj = arrayKlassKlass::create_klass(CHECK);
310
311 _objArrayKlassKlassObj = objArrayKlassKlass::create_klass(CHECK);
312 _instanceKlassKlassObj = instanceKlassKlass::create_klass(CHECK);
313 _typeArrayKlassKlassObj = typeArrayKlassKlass::create_klass(CHECK);
314
315 _boolArrayKlassObj = typeArrayKlass::create_klass(T_BOOLEAN, sizeof(jboolean), CHECK);
316 _charArrayKlassObj = typeArrayKlass::create_klass(T_CHAR, sizeof(jchar), CHECK);
317 _singleArrayKlassObj = typeArrayKlass::create_klass(T_FLOAT, sizeof(jfloat), CHECK);
318 _doubleArrayKlassObj = typeArrayKlass::create_klass(T_DOUBLE, sizeof(jdouble), CHECK);
319 _byteArrayKlassObj = typeArrayKlass::create_klass(T_BYTE, sizeof(jbyte), CHECK);
320 _shortArrayKlassObj = typeArrayKlass::create_klass(T_SHORT, sizeof(jshort), CHECK);
321 _intArrayKlassObj = typeArrayKlass::create_klass(T_INT, sizeof(jint), CHECK);
322 _longArrayKlassObj = typeArrayKlass::create_klass(T_LONG, sizeof(jlong), CHECK);
323
324 _typeArrayKlassObjs[T_BOOLEAN] = _boolArrayKlassObj;
325 _typeArrayKlassObjs[T_CHAR] = _charArrayKlassObj;
326 _typeArrayKlassObjs[T_FLOAT] = _singleArrayKlassObj;
327 _typeArrayKlassObjs[T_DOUBLE] = _doubleArrayKlassObj;
328 _typeArrayKlassObjs[T_BYTE] = _byteArrayKlassObj;
329 _typeArrayKlassObjs[T_SHORT] = _shortArrayKlassObj;
330 _typeArrayKlassObjs[T_INT] = _intArrayKlassObj;
331 _typeArrayKlassObjs[T_LONG] = _longArrayKlassObj;
332
333 _methodKlassObj = methodKlass::create_klass(CHECK);
334 _constMethodKlassObj = constMethodKlass::create_klass(CHECK);
335 _methodDataKlassObj = methodDataKlass::create_klass(CHECK);
336 _constantPoolKlassObj = constantPoolKlass::create_klass(CHECK);
337 _constantPoolCacheKlassObj = constantPoolCacheKlass::create_klass(CHECK);
338
339 _compiledICHolderKlassObj = compiledICHolderKlass::create_klass(CHECK);
340 _systemObjArrayKlassObj = objArrayKlassKlass::cast(objArrayKlassKlassObj())->allocate_system_objArray_klass(CHECK);
341
342 _the_empty_byte_array = oopFactory::new_permanent_byteArray(0, CHECK);
343 _the_empty_short_array = oopFactory::new_permanent_shortArray(0, CHECK);
344 _the_empty_int_array = oopFactory::new_permanent_intArray(0, CHECK);
345 _the_empty_system_obj_array = oopFactory::new_system_objArray(0, CHECK);
346
347 _the_array_interfaces_array = oopFactory::new_system_objArray(2, CHECK);
348 }
349 }
350
351 vmSymbols::initialize(CHECK);
352
353 SystemDictionary::initialize(CHECK);
354
355 klassOop ok = SystemDictionary::Object_klass();
356
357 _the_null_string = StringTable::intern("null", CHECK);
358 _the_min_jint_string = StringTable::intern("-2147483648", CHECK);
359
360 if (UseSharedSpaces) {
361 // Verify shared interfaces array.
362 assert(_the_array_interfaces_array->obj_at(0) ==
363 SystemDictionary::Cloneable_klass(), "u3");
364 assert(_the_array_interfaces_array->obj_at(1) ==
365 SystemDictionary::Serializable_klass(), "u3");
366
367 // Verify element klass for system obj array klass
368 assert(objArrayKlass::cast(_systemObjArrayKlassObj)->element_klass() == ok, "u1");
369 assert(objArrayKlass::cast(_systemObjArrayKlassObj)->bottom_klass() == ok, "u2");
370
371 // Verify super class for the classes created above
372 assert(Klass::cast(boolArrayKlassObj() )->super() == ok, "u3");
373 assert(Klass::cast(charArrayKlassObj() )->super() == ok, "u3");
374 assert(Klass::cast(singleArrayKlassObj() )->super() == ok, "u3");
375 assert(Klass::cast(doubleArrayKlassObj() )->super() == ok, "u3");
376 assert(Klass::cast(byteArrayKlassObj() )->super() == ok, "u3");
377 assert(Klass::cast(shortArrayKlassObj() )->super() == ok, "u3");
378 assert(Klass::cast(intArrayKlassObj() )->super() == ok, "u3");
379 assert(Klass::cast(longArrayKlassObj() )->super() == ok, "u3");
380 assert(Klass::cast(constantPoolKlassObj() )->super() == ok, "u3");
381 assert(Klass::cast(systemObjArrayKlassObj())->super() == ok, "u3");
382 } else {
383 // Set up shared interfaces array. (Do this before supers are set up.)
384 _the_array_interfaces_array->obj_at_put(0, SystemDictionary::Cloneable_klass());
385 _the_array_interfaces_array->obj_at_put(1, SystemDictionary::Serializable_klass());
386
387 // Set element klass for system obj array klass
388 objArrayKlass::cast(_systemObjArrayKlassObj)->set_element_klass(ok);
389 objArrayKlass::cast(_systemObjArrayKlassObj)->set_bottom_klass(ok);
390
391 // Set super class for the classes created above
392 Klass::cast(boolArrayKlassObj() )->initialize_supers(ok, CHECK);
393 Klass::cast(charArrayKlassObj() )->initialize_supers(ok, CHECK);
394 Klass::cast(singleArrayKlassObj() )->initialize_supers(ok, CHECK);
395 Klass::cast(doubleArrayKlassObj() )->initialize_supers(ok, CHECK);
396 Klass::cast(byteArrayKlassObj() )->initialize_supers(ok, CHECK);
397 Klass::cast(shortArrayKlassObj() )->initialize_supers(ok, CHECK);
398 Klass::cast(intArrayKlassObj() )->initialize_supers(ok, CHECK);
399 Klass::cast(longArrayKlassObj() )->initialize_supers(ok, CHECK);
400 Klass::cast(constantPoolKlassObj() )->initialize_supers(ok, CHECK);
401 Klass::cast(systemObjArrayKlassObj())->initialize_supers(ok, CHECK);
402 Klass::cast(boolArrayKlassObj() )->set_super(ok);
403 Klass::cast(charArrayKlassObj() )->set_super(ok);
404 Klass::cast(singleArrayKlassObj() )->set_super(ok);
405 Klass::cast(doubleArrayKlassObj() )->set_super(ok);
406 Klass::cast(byteArrayKlassObj() )->set_super(ok);
407 Klass::cast(shortArrayKlassObj() )->set_super(ok);
408 Klass::cast(intArrayKlassObj() )->set_super(ok);
409 Klass::cast(longArrayKlassObj() )->set_super(ok);
410 Klass::cast(constantPoolKlassObj() )->set_super(ok);
411 Klass::cast(systemObjArrayKlassObj())->set_super(ok);
412 }
413
414 Klass::cast(boolArrayKlassObj() )->append_to_sibling_list();
415 Klass::cast(charArrayKlassObj() )->append_to_sibling_list();
416 Klass::cast(singleArrayKlassObj() )->append_to_sibling_list();
417 Klass::cast(doubleArrayKlassObj() )->append_to_sibling_list();
418 Klass::cast(byteArrayKlassObj() )->append_to_sibling_list();
419 Klass::cast(shortArrayKlassObj() )->append_to_sibling_list();
420 Klass::cast(intArrayKlassObj() )->append_to_sibling_list();
421 Klass::cast(longArrayKlassObj() )->append_to_sibling_list();
422 Klass::cast(constantPoolKlassObj() )->append_to_sibling_list();
423 Klass::cast(systemObjArrayKlassObj())->append_to_sibling_list();
424 } // end of core bootstrapping
425
426 // Initialize _objectArrayKlass after core bootstraping to make
427 // sure the super class is set up properly for _objectArrayKlass.
428 _objectArrayKlassObj = instanceKlass::
429 cast(SystemDictionary::Object_klass())->array_klass(1, CHECK);
430 // Add the class to the class hierarchy manually to make sure that
431 // its vtable is initialized after core bootstrapping is completed.
432 Klass::cast(_objectArrayKlassObj)->append_to_sibling_list();
433
434 // Compute is_jdk version flags.
435 // Only 1.3 or later has the java.lang.Shutdown class.
436 // Only 1.4 or later has the java.lang.CharSequence interface.
437 // Only 1.5 or later has the java.lang.management.MemoryUsage class.
438 if (JDK_Version::is_partially_initialized()) {
439 uint8_t jdk_version;
440 klassOop k = SystemDictionary::resolve_or_null(
441 vmSymbols::java_lang_management_MemoryUsage(), THREAD);
442 CLEAR_PENDING_EXCEPTION; // ignore exceptions
443 if (k == NULL) {
444 k = SystemDictionary::resolve_or_null(
445 vmSymbols::java_lang_CharSequence(), THREAD);
446 CLEAR_PENDING_EXCEPTION; // ignore exceptions
447 if (k == NULL) {
448 k = SystemDictionary::resolve_or_null(
449 vmSymbols::java_lang_Shutdown(), THREAD);
450 CLEAR_PENDING_EXCEPTION; // ignore exceptions
451 if (k == NULL) {
452 jdk_version = 2;
453 } else {
454 jdk_version = 3;
455 }
456 } else {
457 jdk_version = 4;
458 }
459 } else {
460 jdk_version = 5;
461 }
462 JDK_Version::fully_initialize(jdk_version);
463 }
464
465 #ifdef ASSERT
466 if (FullGCALot) {
467 // Allocate an array of dummy objects.
468 // We'd like these to be at the bottom of the old generation,
469 // so that when we free one and then collect,
470 // (almost) the whole heap moves
471 // and we find out if we actually update all the oops correctly.
472 // But we can't allocate directly in the old generation,
473 // so we allocate wherever, and hope that the first collection
474 // moves these objects to the bottom of the old generation.
475 // We can allocate directly in the permanent generation, so we do.
476 int size;
477 if (UseConcMarkSweepGC) {
478 warning("Using +FullGCALot with concurrent mark sweep gc "
479 "will not force all objects to relocate");
480 size = FullGCALotDummies;
481 } else {
482 size = FullGCALotDummies * 2;
483 }
484 objArrayOop naked_array = oopFactory::new_system_objArray(size, CHECK);
485 objArrayHandle dummy_array(THREAD, naked_array);
486 int i = 0;
487 while (i < size) {
488 if (!UseConcMarkSweepGC) {
489 // Allocate dummy in old generation
490 oop dummy = instanceKlass::cast(SystemDictionary::Object_klass())->allocate_instance(CHECK);
491 dummy_array->obj_at_put(i++, dummy);
492 }
493 // Allocate dummy in permanent generation
494 oop dummy = instanceKlass::cast(SystemDictionary::Object_klass())->allocate_permanent_instance(CHECK);
495 dummy_array->obj_at_put(i++, dummy);
496 }
497 {
498 // Only modify the global variable inside the mutex.
499 // If we had a race to here, the other dummy_array instances
500 // and their elements just get dropped on the floor, which is fine.
501 MutexLocker ml(FullGCALot_lock);
502 if (_fullgc_alot_dummy_array == NULL) {
503 _fullgc_alot_dummy_array = dummy_array();
504 }
505 }
506 assert(i == _fullgc_alot_dummy_array->length(), "just checking");
507 }
508 #endif
509 }
510
511
512 static inline void* dereference(void* addr) {
513 return *(void**)addr;
514 }
515
516 static inline void add_vtable(void** list, int* n, void* o, int count) {
517 guarantee((*n) < count, "vtable list too small");
518 void* vtable = dereference(o);
519 assert(dereference(vtable) != NULL, "invalid vtable");
520 list[(*n)++] = vtable;
521 }
522
523 void Universe::init_self_patching_vtbl_list(void** list, int count) {
524 int n = 0;
525 { klassKlass o; add_vtable(list, &n, &o, count); }
526 { arrayKlassKlass o; add_vtable(list, &n, &o, count); }
527 { objArrayKlassKlass o; add_vtable(list, &n, &o, count); }
528 { instanceKlassKlass o; add_vtable(list, &n, &o, count); }
529 { instanceKlass o; add_vtable(list, &n, &o, count); }
530 { instanceMirrorKlass o; add_vtable(list, &n, &o, count); }
531 { instanceRefKlass o; add_vtable(list, &n, &o, count); }
532 { typeArrayKlassKlass o; add_vtable(list, &n, &o, count); }
533 { typeArrayKlass o; add_vtable(list, &n, &o, count); }
534 { methodKlass o; add_vtable(list, &n, &o, count); }
535 { constMethodKlass o; add_vtable(list, &n, &o, count); }
536 { constantPoolKlass o; add_vtable(list, &n, &o, count); }
537 { constantPoolCacheKlass o; add_vtable(list, &n, &o, count); }
538 { objArrayKlass o; add_vtable(list, &n, &o, count); }
539 { methodDataKlass o; add_vtable(list, &n, &o, count); }
540 { compiledICHolderKlass o; add_vtable(list, &n, &o, count); }
541 #ifndef PRODUCT
542 // In non-product builds CHeapObj is derived from AllocatedObj,
543 // so symbols in CDS archive should have their vtable pointer patched.
544 { Symbol o; add_vtable(list, &n, &o, count); }
545 #endif
546 }
547
548
549 class FixupMirrorClosure: public ObjectClosure {
550 public:
551 virtual void do_object(oop obj) {
552 if (obj->is_klass()) {
553 EXCEPTION_MARK;
554 KlassHandle k(THREAD, klassOop(obj));
555 // We will never reach the CATCH below since Exceptions::_throw will cause
556 // the VM to exit if an exception is thrown during initialization
557 java_lang_Class::fixup_mirror(k, CATCH);
558 // This call unconditionally creates a new mirror for k,
559 // and links in k's component_mirror field if k is an array.
560 // If k is an objArray, k's element type must already have
561 // a mirror. In other words, this closure must process
562 // the component type of an objArray k before it processes k.
563 // This works because the permgen iterator presents arrays
564 // and their component types in order of creation.
565 }
566 }
567 };
568
569 void Universe::initialize_basic_type_mirrors(TRAPS) {
570 if (UseSharedSpaces) {
571 assert(_int_mirror != NULL, "already loaded");
572 assert(_void_mirror == _mirrors[T_VOID], "consistently loaded");
573 } else {
574
575 assert(_int_mirror==NULL, "basic type mirrors already initialized");
576 _int_mirror =
577 java_lang_Class::create_basic_type_mirror("int", T_INT, CHECK);
578 _float_mirror =
579 java_lang_Class::create_basic_type_mirror("float", T_FLOAT, CHECK);
580 _double_mirror =
581 java_lang_Class::create_basic_type_mirror("double", T_DOUBLE, CHECK);
582 _byte_mirror =
583 java_lang_Class::create_basic_type_mirror("byte", T_BYTE, CHECK);
584 _bool_mirror =
585 java_lang_Class::create_basic_type_mirror("boolean",T_BOOLEAN, CHECK);
586 _char_mirror =
587 java_lang_Class::create_basic_type_mirror("char", T_CHAR, CHECK);
588 _long_mirror =
589 java_lang_Class::create_basic_type_mirror("long", T_LONG, CHECK);
590 _short_mirror =
591 java_lang_Class::create_basic_type_mirror("short", T_SHORT, CHECK);
592 _void_mirror =
593 java_lang_Class::create_basic_type_mirror("void", T_VOID, CHECK);
594
595 _mirrors[T_INT] = _int_mirror;
596 _mirrors[T_FLOAT] = _float_mirror;
597 _mirrors[T_DOUBLE] = _double_mirror;
598 _mirrors[T_BYTE] = _byte_mirror;
599 _mirrors[T_BOOLEAN] = _bool_mirror;
600 _mirrors[T_CHAR] = _char_mirror;
601 _mirrors[T_LONG] = _long_mirror;
602 _mirrors[T_SHORT] = _short_mirror;
603 _mirrors[T_VOID] = _void_mirror;
604 //_mirrors[T_OBJECT] = instanceKlass::cast(_object_klass)->java_mirror();
605 //_mirrors[T_ARRAY] = instanceKlass::cast(_object_klass)->java_mirror();
606 }
607 }
608
609 void Universe::fixup_mirrors(TRAPS) {
610 // Bootstrap problem: all classes gets a mirror (java.lang.Class instance) assigned eagerly,
611 // but we cannot do that for classes created before java.lang.Class is loaded. Here we simply
612 // walk over permanent objects created so far (mostly classes) and fixup their mirrors. Note
613 // that the number of objects allocated at this point is very small.
614 assert(SystemDictionary::Class_klass_loaded(), "java.lang.Class should be loaded");
615
616 // Cache the start of the static fields
617 instanceMirrorKlass::init_offset_of_static_fields();
618
619 FixupMirrorClosure blk;
620 Universe::heap()->permanent_object_iterate(&blk);
621 }
622
623
624 static bool has_run_finalizers_on_exit = false;
625
626 void Universe::run_finalizers_on_exit() {
627 if (has_run_finalizers_on_exit) return;
628 has_run_finalizers_on_exit = true;
629
630 // Called on VM exit. This ought to be run in a separate thread.
631 if (TraceReferenceGC) tty->print_cr("Callback to run finalizers on exit");
632 {
633 PRESERVE_EXCEPTION_MARK;
634 KlassHandle finalizer_klass(THREAD, SystemDictionary::Finalizer_klass());
635 JavaValue result(T_VOID);
636 JavaCalls::call_static(
637 &result,
638 finalizer_klass,
639 vmSymbols::run_finalizers_on_exit_name(),
640 vmSymbols::void_method_signature(),
641 THREAD
642 );
643 // Ignore any pending exceptions
644 CLEAR_PENDING_EXCEPTION;
645 }
646 }
647
648
649 // initialize_vtable could cause gc if
650 // 1) we specified true to initialize_vtable and
651 // 2) this ran after gc was enabled
652 // In case those ever change we use handles for oops
653 void Universe::reinitialize_vtable_of(KlassHandle k_h, TRAPS) {
654 // init vtable of k and all subclasses
655 Klass* ko = k_h()->klass_part();
656 klassVtable* vt = ko->vtable();
657 if (vt) vt->initialize_vtable(false, CHECK);
658 if (ko->oop_is_instance()) {
659 instanceKlass* ik = (instanceKlass*)ko;
660 for (KlassHandle s_h(THREAD, ik->subklass()); s_h() != NULL; s_h = (THREAD, s_h()->klass_part()->next_sibling())) {
661 reinitialize_vtable_of(s_h, CHECK);
662 }
663 }
664 }
665
666
667 void initialize_itable_for_klass(klassOop k, TRAPS) {
668 instanceKlass::cast(k)->itable()->initialize_itable(false, CHECK);
669 }
670
671
672 void Universe::reinitialize_itables(TRAPS) {
673 SystemDictionary::classes_do(initialize_itable_for_klass, CHECK);
674
675 }
676
677
678 bool Universe::on_page_boundary(void* addr) {
679 return ((uintptr_t) addr) % os::vm_page_size() == 0;
680 }
681
682
683 bool Universe::should_fill_in_stack_trace(Handle throwable) {
684 // never attempt to fill in the stack trace of preallocated errors that do not have
685 // backtrace. These errors are kept alive forever and may be "re-used" when all
686 // preallocated errors with backtrace have been consumed. Also need to avoid
687 // a potential loop which could happen if an out of memory occurs when attempting
688 // to allocate the backtrace.
689 return ((throwable() != Universe::_out_of_memory_error_java_heap) &&
690 (throwable() != Universe::_out_of_memory_error_perm_gen) &&
691 (throwable() != Universe::_out_of_memory_error_array_size) &&
692 (throwable() != Universe::_out_of_memory_error_gc_overhead_limit));
693 }
694
695
696 oop Universe::gen_out_of_memory_error(oop default_err) {
697 // generate an out of memory error:
698 // - if there is a preallocated error with backtrace available then return it wth
699 // a filled in stack trace.
700 // - if there are no preallocated errors with backtrace available then return
701 // an error without backtrace.
702 int next;
703 if (_preallocated_out_of_memory_error_avail_count > 0) {
704 next = (int)Atomic::add(-1, &_preallocated_out_of_memory_error_avail_count);
705 assert(next < (int)PreallocatedOutOfMemoryErrorCount, "avail count is corrupt");
706 } else {
707 next = -1;
708 }
709 if (next < 0) {
710 // all preallocated errors have been used.
711 // return default
712 return default_err;
713 } else {
714 // get the error object at the slot and set set it to NULL so that the
715 // array isn't keeping it alive anymore.
716 oop exc = preallocated_out_of_memory_errors()->obj_at(next);
717 assert(exc != NULL, "slot has been used already");
718 preallocated_out_of_memory_errors()->obj_at_put(next, NULL);
719
720 // use the message from the default error
721 oop msg = java_lang_Throwable::message(default_err);
722 assert(msg != NULL, "no message");
723 java_lang_Throwable::set_message(exc, msg);
724
725 // populate the stack trace and return it.
726 java_lang_Throwable::fill_in_stack_trace_of_preallocated_backtrace(exc);
727 return exc;
728 }
729 }
730
731 static intptr_t non_oop_bits = 0;
732
733 void* Universe::non_oop_word() {
734 // Neither the high bits nor the low bits of this value is allowed
735 // to look like (respectively) the high or low bits of a real oop.
736 //
737 // High and low are CPU-specific notions, but low always includes
738 // the low-order bit. Since oops are always aligned at least mod 4,
739 // setting the low-order bit will ensure that the low half of the
740 // word will never look like that of a real oop.
741 //
742 // Using the OS-supplied non-memory-address word (usually 0 or -1)
743 // will take care of the high bits, however many there are.
744
745 if (non_oop_bits == 0) {
746 non_oop_bits = (intptr_t)os::non_memory_address_word() | 1;
747 }
748
749 return (void*)non_oop_bits;
750 }
751
752 jint universe_init() {
753 assert(!Universe::_fully_initialized, "called after initialize_vtables");
754 guarantee(1 << LogHeapWordSize == sizeof(HeapWord),
755 "LogHeapWordSize is incorrect.");
756 guarantee(sizeof(oop) >= sizeof(HeapWord), "HeapWord larger than oop?");
757 guarantee(sizeof(oop) % sizeof(HeapWord) == 0,
758 "oop size is not not a multiple of HeapWord size");
759 TraceTime timer("Genesis", TraceStartupTime);
760 GC_locker::lock(); // do not allow gc during bootstrapping
761 JavaClasses::compute_hard_coded_offsets();
762
763 // Get map info from shared archive file.
764 if (DumpSharedSpaces)
765 UseSharedSpaces = false;
766
767 FileMapInfo* mapinfo = NULL;
768 if (UseSharedSpaces) {
769 mapinfo = NEW_C_HEAP_OBJ(FileMapInfo, mtInternal);
770 memset(mapinfo, 0, sizeof(FileMapInfo));
771
772 // Open the shared archive file, read and validate the header. If
773 // initialization files, shared spaces [UseSharedSpaces] are
774 // disabled and the file is closed.
775
776 if (mapinfo->initialize()) {
777 FileMapInfo::set_current_info(mapinfo);
778 } else {
779 assert(!mapinfo->is_open() && !UseSharedSpaces,
780 "archive file not closed or shared spaces not disabled.");
781 }
782 }
783
784 jint status = Universe::initialize_heap();
785 if (status != JNI_OK) {
786 return status;
787 }
788
789 // We have a heap so create the methodOop caches before
790 // CompactingPermGenGen::initialize_oops() tries to populate them.
791 Universe::_finalizer_register_cache = new LatestMethodOopCache();
792 Universe::_loader_addClass_cache = new LatestMethodOopCache();
793 Universe::_pd_implies_cache = new LatestMethodOopCache();
794 Universe::_reflect_invoke_cache = new ActiveMethodOopsCache();
795
796 if (UseSharedSpaces) {
797
798 // Read the data structures supporting the shared spaces (shared
799 // system dictionary, symbol table, etc.). After that, access to
800 // the file (other than the mapped regions) is no longer needed, and
801 // the file is closed. Closing the file does not affect the
802 // currently mapped regions.
803
804 CompactingPermGenGen::initialize_oops();
805 mapinfo->close();
806
807 } else {
808 SymbolTable::create_table();
809 StringTable::create_table();
810 ClassLoader::create_package_info_table();
811 }
812
813 return JNI_OK;
814 }
815
816 // Choose the heap base address and oop encoding mode
817 // when compressed oops are used:
818 // Unscaled - Use 32-bits oops without encoding when
819 // NarrowOopHeapBaseMin + heap_size < 4Gb
820 // ZeroBased - Use zero based compressed oops with encoding when
821 // NarrowOopHeapBaseMin + heap_size < 32Gb
822 // HeapBased - Use compressed oops with heap base + encoding.
823
824 // 4Gb
825 static const uint64_t NarrowOopHeapMax = (uint64_t(max_juint) + 1);
826 // 32Gb
827 // OopEncodingHeapMax == NarrowOopHeapMax << LogMinObjAlignmentInBytes;
828
829 char* Universe::preferred_heap_base(size_t heap_size, NARROW_OOP_MODE mode) {
830 size_t base = 0;
831 #ifdef _LP64
832 if (UseCompressedOops) {
833 assert(mode == UnscaledNarrowOop ||
834 mode == ZeroBasedNarrowOop ||
835 mode == HeapBasedNarrowOop, "mode is invalid");
836 const size_t total_size = heap_size + HeapBaseMinAddress;
837 // Return specified base for the first request.
838 if (!FLAG_IS_DEFAULT(HeapBaseMinAddress) && (mode == UnscaledNarrowOop)) {
839 base = HeapBaseMinAddress;
840 } else if (total_size <= OopEncodingHeapMax && (mode != HeapBasedNarrowOop)) {
841 if (total_size <= NarrowOopHeapMax && (mode == UnscaledNarrowOop) &&
842 (Universe::narrow_oop_shift() == 0)) {
843 // Use 32-bits oops without encoding and
844 // place heap's top on the 4Gb boundary
845 base = (NarrowOopHeapMax - heap_size);
846 } else {
847 // Can't reserve with NarrowOopShift == 0
848 Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes);
849 if (mode == UnscaledNarrowOop ||
850 mode == ZeroBasedNarrowOop && total_size <= NarrowOopHeapMax) {
851 // Use zero based compressed oops with encoding and
852 // place heap's top on the 32Gb boundary in case
853 // total_size > 4Gb or failed to reserve below 4Gb.
854 base = (OopEncodingHeapMax - heap_size);
855 }
856 }
857 } else {
858 // Can't reserve below 32Gb.
859 Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes);
860 }
861 // Set narrow_oop_base and narrow_oop_use_implicit_null_checks
862 // used in ReservedHeapSpace() constructors.
863 // The final values will be set in initialize_heap() below.
864 if (base != 0 && (base + heap_size) <= OopEncodingHeapMax) {
865 // Use zero based compressed oops
866 Universe::set_narrow_oop_base(NULL);
867 // Don't need guard page for implicit checks in indexed
868 // addressing mode with zero based Compressed Oops.
869 Universe::set_narrow_oop_use_implicit_null_checks(true);
870 } else {
871 // Set to a non-NULL value so the ReservedSpace ctor computes
872 // the correct no-access prefix.
873 // The final value will be set in initialize_heap() below.
874 Universe::set_narrow_oop_base((address)NarrowOopHeapMax);
875 #ifdef _WIN64
876 if (UseLargePages) {
877 // Cannot allocate guard pages for implicit checks in indexed
878 // addressing mode when large pages are specified on windows.
879 Universe::set_narrow_oop_use_implicit_null_checks(false);
880 }
881 #endif // _WIN64
882 }
883 }
884 #endif
885 return (char*)base; // also return NULL (don't care) for 32-bit VM
886 }
887
888 jint Universe::initialize_heap() {
889
890 if (UseParallelGC) {
891 #ifndef SERIALGC
892 Universe::_collectedHeap = new ParallelScavengeHeap();
893 #else // SERIALGC
894 fatal("UseParallelGC not supported in java kernel vm.");
895 #endif // SERIALGC
896
897 } else if (UseG1GC) {
898 #ifndef SERIALGC
899 G1CollectorPolicy* g1p = new G1CollectorPolicy();
900 G1CollectedHeap* g1h = new G1CollectedHeap(g1p);
901 Universe::_collectedHeap = g1h;
902 #else // SERIALGC
903 fatal("UseG1GC not supported in java kernel vm.");
904 #endif // SERIALGC
905
906 } else {
907 GenCollectorPolicy *gc_policy;
908
909 if (UseSerialGC) {
910 gc_policy = new MarkSweepPolicy();
911 } else if (UseConcMarkSweepGC) {
912 #ifndef SERIALGC
913 if (UseAdaptiveSizePolicy) {
914 gc_policy = new ASConcurrentMarkSweepPolicy();
915 } else {
916 gc_policy = new ConcurrentMarkSweepPolicy();
917 }
918 #else // SERIALGC
919 fatal("UseConcMarkSweepGC not supported in java kernel vm.");
920 #endif // SERIALGC
921 } else { // default old generation
922 gc_policy = new MarkSweepPolicy();
923 }
924
925 Universe::_collectedHeap = new GenCollectedHeap(gc_policy);
926 }
927
928 jint status = Universe::heap()->initialize();
929 if (status != JNI_OK) {
930 return status;
931 }
932
933 #ifdef _LP64
934 if (UseCompressedOops) {
935 // Subtract a page because something can get allocated at heap base.
936 // This also makes implicit null checking work, because the
937 // memory+1 page below heap_base needs to cause a signal.
938 // See needs_explicit_null_check.
939 // Only set the heap base for compressed oops because it indicates
940 // compressed oops for pstack code.
941 bool verbose = PrintCompressedOopsMode || (PrintMiscellaneous && Verbose);
942 if (verbose) {
943 tty->cr();
944 tty->print("heap address: " PTR_FORMAT ", size: " SIZE_FORMAT " MB",
945 Universe::heap()->base(), Universe::heap()->reserved_region().byte_size()/M);
946 }
947 if ((uint64_t)Universe::heap()->reserved_region().end() > OopEncodingHeapMax) {
948 // Can't reserve heap below 32Gb.
949 Universe::set_narrow_oop_base(Universe::heap()->base() - os::vm_page_size());
950 Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes);
951 if (verbose) {
952 tty->print(", %s: "PTR_FORMAT,
953 narrow_oop_mode_to_string(HeapBasedNarrowOop),
954 Universe::narrow_oop_base());
955 }
956 } else {
957 Universe::set_narrow_oop_base(0);
958 if (verbose) {
959 tty->print(", %s", narrow_oop_mode_to_string(ZeroBasedNarrowOop));
960 }
961 #ifdef _WIN64
962 if (!Universe::narrow_oop_use_implicit_null_checks()) {
963 // Don't need guard page for implicit checks in indexed addressing
964 // mode with zero based Compressed Oops.
965 Universe::set_narrow_oop_use_implicit_null_checks(true);
966 }
967 #endif // _WIN64
968 if((uint64_t)Universe::heap()->reserved_region().end() > NarrowOopHeapMax) {
969 // Can't reserve heap below 4Gb.
970 Universe::set_narrow_oop_shift(LogMinObjAlignmentInBytes);
971 } else {
972 Universe::set_narrow_oop_shift(0);
973 if (verbose) {
974 tty->print(", %s", narrow_oop_mode_to_string(UnscaledNarrowOop));
975 }
976 }
977 }
978 if (verbose) {
979 tty->cr();
980 tty->cr();
981 }
982 }
983 assert(Universe::narrow_oop_base() == (Universe::heap()->base() - os::vm_page_size()) ||
984 Universe::narrow_oop_base() == NULL, "invalid value");
985 assert(Universe::narrow_oop_shift() == LogMinObjAlignmentInBytes ||
986 Universe::narrow_oop_shift() == 0, "invalid value");
987 #endif
988
989 // We will never reach the CATCH below since Exceptions::_throw will cause
990 // the VM to exit if an exception is thrown during initialization
991
992 if (UseTLAB) {
993 assert(Universe::heap()->supports_tlab_allocation(),
994 "Should support thread-local allocation buffers");
995 ThreadLocalAllocBuffer::startup_initialization();
996 }
997 return JNI_OK;
998 }
999
1000 // It's the caller's repsonsibility to ensure glitch-freedom
1001 // (if required).
1002 void Universe::update_heap_info_at_gc() {
1003 _heap_capacity_at_last_gc = heap()->capacity();
1004 _heap_used_at_last_gc = heap()->used();
1005 }
1006
1007
1008 const char* Universe::narrow_oop_mode_to_string(Universe::NARROW_OOP_MODE mode) {
1009 switch (mode) {
1010 case UnscaledNarrowOop:
1011 return "32-bits Oops";
1012 case ZeroBasedNarrowOop:
1013 return "zero based Compressed Oops";
1014 case HeapBasedNarrowOop:
1015 return "Compressed Oops with base";
1016 }
1017
1018 ShouldNotReachHere();
1019 return "";
1020 }
1021
1022
1023 Universe::NARROW_OOP_MODE Universe::narrow_oop_mode() {
1024 if (narrow_oop_base() != 0) {
1025 return HeapBasedNarrowOop;
1026 }
1027
1028 if (narrow_oop_shift() != 0) {
1029 return ZeroBasedNarrowOop;
1030 }
1031
1032 return UnscaledNarrowOop;
1033 }
1034
1035
1036 void universe2_init() {
1037 EXCEPTION_MARK;
1038 Universe::genesis(CATCH);
1039 }
1040
1041
1042 // This function is defined in JVM.cpp
1043 extern void initialize_converter_functions();
1044
1045 bool universe_post_init() {
1046 assert(!is_init_completed(), "Error: initialization not yet completed!");
1047 Universe::_fully_initialized = true;
1048 EXCEPTION_MARK;
1049 { ResourceMark rm;
1050 Interpreter::initialize(); // needed for interpreter entry points
1051 if (!UseSharedSpaces) {
1052 KlassHandle ok_h(THREAD, SystemDictionary::Object_klass());
1053 Universe::reinitialize_vtable_of(ok_h, CHECK_false);
1054 Universe::reinitialize_itables(CHECK_false);
1055 }
1056 }
1057
1058 klassOop k;
1059 instanceKlassHandle k_h;
1060 if (!UseSharedSpaces) {
1061 // Setup preallocated empty java.lang.Class array
1062 Universe::_the_empty_class_klass_array = oopFactory::new_objArray(SystemDictionary::Class_klass(), 0, CHECK_false);
1063 // Setup preallocated OutOfMemoryError errors
1064 k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_OutOfMemoryError(), true, CHECK_false);
1065 k_h = instanceKlassHandle(THREAD, k);
1066 Universe::_out_of_memory_error_java_heap = k_h->allocate_permanent_instance(CHECK_false);
1067 Universe::_out_of_memory_error_perm_gen = k_h->allocate_permanent_instance(CHECK_false);
1068 Universe::_out_of_memory_error_array_size = k_h->allocate_permanent_instance(CHECK_false);
1069 Universe::_out_of_memory_error_gc_overhead_limit =
1070 k_h->allocate_permanent_instance(CHECK_false);
1071
1072 // Setup preallocated NullPointerException
1073 // (this is currently used for a cheap & dirty solution in compiler exception handling)
1074 k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_NullPointerException(), true, CHECK_false);
1075 Universe::_null_ptr_exception_instance = instanceKlass::cast(k)->allocate_permanent_instance(CHECK_false);
1076 // Setup preallocated ArithmeticException
1077 // (this is currently used for a cheap & dirty solution in compiler exception handling)
1078 k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_ArithmeticException(), true, CHECK_false);
1079 Universe::_arithmetic_exception_instance = instanceKlass::cast(k)->allocate_permanent_instance(CHECK_false);
1080 // Virtual Machine Error for when we get into a situation we can't resolve
1081 k = SystemDictionary::resolve_or_fail(
1082 vmSymbols::java_lang_VirtualMachineError(), true, CHECK_false);
1083 bool linked = instanceKlass::cast(k)->link_class_or_fail(CHECK_false);
1084 if (!linked) {
1085 tty->print_cr("Unable to link/verify VirtualMachineError class");
1086 return false; // initialization failed
1087 }
1088 Universe::_virtual_machine_error_instance =
1089 instanceKlass::cast(k)->allocate_permanent_instance(CHECK_false);
1090
1091 Universe::_vm_exception = instanceKlass::cast(k)->allocate_permanent_instance(CHECK_false);
1092
1093 }
1094 if (!DumpSharedSpaces) {
1095 // These are the only Java fields that are currently set during shared space dumping.
1096 // We prefer to not handle this generally, so we always reinitialize these detail messages.
1097 Handle msg = java_lang_String::create_from_str("Java heap space", CHECK_false);
1098 java_lang_Throwable::set_message(Universe::_out_of_memory_error_java_heap, msg());
1099
1100 msg = java_lang_String::create_from_str("PermGen space", CHECK_false);
1101 java_lang_Throwable::set_message(Universe::_out_of_memory_error_perm_gen, msg());
1102
1103 msg = java_lang_String::create_from_str("Requested array size exceeds VM limit", CHECK_false);
1104 java_lang_Throwable::set_message(Universe::_out_of_memory_error_array_size, msg());
1105
1106 msg = java_lang_String::create_from_str("GC overhead limit exceeded", CHECK_false);
1107 java_lang_Throwable::set_message(Universe::_out_of_memory_error_gc_overhead_limit, msg());
1108
1109 msg = java_lang_String::create_from_str("/ by zero", CHECK_false);
1110 java_lang_Throwable::set_message(Universe::_arithmetic_exception_instance, msg());
1111
1112 // Setup the array of errors that have preallocated backtrace
1113 k = Universe::_out_of_memory_error_java_heap->klass();
1114 assert(k->klass_part()->name() == vmSymbols::java_lang_OutOfMemoryError(), "should be out of memory error");
1115 k_h = instanceKlassHandle(THREAD, k);
1116
1117 int len = (StackTraceInThrowable) ? (int)PreallocatedOutOfMemoryErrorCount : 0;
1118 Universe::_preallocated_out_of_memory_error_array = oopFactory::new_objArray(k_h(), len, CHECK_false);
1119 for (int i=0; i<len; i++) {
1120 oop err = k_h->allocate_permanent_instance(CHECK_false);
1121 Handle err_h = Handle(THREAD, err);
1122 java_lang_Throwable::allocate_backtrace(err_h, CHECK_false);
1123 Universe::preallocated_out_of_memory_errors()->obj_at_put(i, err_h());
1124 }
1125 Universe::_preallocated_out_of_memory_error_avail_count = (jint)len;
1126 }
1127
1128
1129 // Setup static method for registering finalizers
1130 // The finalizer klass must be linked before looking up the method, in
1131 // case it needs to get rewritten.
1132 instanceKlass::cast(SystemDictionary::Finalizer_klass())->link_class(CHECK_false);
1133 methodOop m = instanceKlass::cast(SystemDictionary::Finalizer_klass())->find_method(
1134 vmSymbols::register_method_name(),
1135 vmSymbols::register_method_signature());
1136 if (m == NULL || !m->is_static()) {
1137 THROW_MSG_(vmSymbols::java_lang_NoSuchMethodException(),
1138 "java.lang.ref.Finalizer.register", false);
1139 }
1140 Universe::_finalizer_register_cache->init(
1141 SystemDictionary::Finalizer_klass(), m, CHECK_false);
1142
1143 // Resolve on first use and initialize class.
1144 // Note: No race-condition here, since a resolve will always return the same result
1145
1146 // Setup method for security checks
1147 k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_reflect_Method(), true, CHECK_false);
1148 k_h = instanceKlassHandle(THREAD, k);
1149 k_h->link_class(CHECK_false);
1150 m = k_h->find_method(vmSymbols::invoke_name(), vmSymbols::object_object_array_object_signature());
1151 if (m == NULL || m->is_static()) {
1152 THROW_MSG_(vmSymbols::java_lang_NoSuchMethodException(),
1153 "java.lang.reflect.Method.invoke", false);
1154 }
1155 Universe::_reflect_invoke_cache->init(k_h(), m, CHECK_false);
1156
1157 // Setup method for registering loaded classes in class loader vector
1158 instanceKlass::cast(SystemDictionary::ClassLoader_klass())->link_class(CHECK_false);
1159 m = instanceKlass::cast(SystemDictionary::ClassLoader_klass())->find_method(vmSymbols::addClass_name(), vmSymbols::class_void_signature());
1160 if (m == NULL || m->is_static()) {
1161 THROW_MSG_(vmSymbols::java_lang_NoSuchMethodException(),
1162 "java.lang.ClassLoader.addClass", false);
1163 }
1164 Universe::_loader_addClass_cache->init(
1165 SystemDictionary::ClassLoader_klass(), m, CHECK_false);
1166
1167 // Setup method for checking protection domain
1168 instanceKlass::cast(SystemDictionary::ProtectionDomain_klass())->link_class(CHECK_false);
1169 m = instanceKlass::cast(SystemDictionary::ProtectionDomain_klass())->
1170 find_method(vmSymbols::impliesCreateAccessControlContext_name(),
1171 vmSymbols::void_boolean_signature());
1172 // Allow NULL which should only happen with bootstrapping.
1173 if (m != NULL) {
1174 if (m->is_static()) {
1175 // NoSuchMethodException doesn't actually work because it tries to run the
1176 // <init> function before java_lang_Class is linked. Print error and exit.
1177 tty->print_cr("ProtectionDomain.impliesCreateAccessControlContext() has the wrong linkage");
1178 return false; // initialization failed
1179 }
1180 Universe::_pd_implies_cache->init(
1181 SystemDictionary::ProtectionDomain_klass(), m, CHECK_false);;
1182 }
1183
1184 // The folowing is initializing converter functions for serialization in
1185 // JVM.cpp. If we clean up the StrictMath code above we may want to find
1186 // a better solution for this as well.
1187 initialize_converter_functions();
1188
1189 // This needs to be done before the first scavenge/gc, since
1190 // it's an input to soft ref clearing policy.
1191 {
1192 MutexLocker x(Heap_lock);
1193 Universe::update_heap_info_at_gc();
1194 }
1195
1196 // ("weak") refs processing infrastructure initialization
1197 Universe::heap()->post_initialize();
1198
1199 GC_locker::unlock(); // allow gc after bootstrapping
1200
1201 MemoryService::set_universe_heap(Universe::_collectedHeap);
1202 return true;
1203 }
1204
1205
1206 void Universe::compute_base_vtable_size() {
1207 _base_vtable_size = ClassLoader::compute_Object_vtable();
1208 }
1209
1210
1211 // %%% The Universe::flush_foo methods belong in CodeCache.
1212
1213 // Flushes compiled methods dependent on dependee.
1214 void Universe::flush_dependents_on(instanceKlassHandle dependee) {
1215 assert_lock_strong(Compile_lock);
1216
1217 if (CodeCache::number_of_nmethods_with_dependencies() == 0) return;
1218
1219 // CodeCache can only be updated by a thread_in_VM and they will all be
1220 // stopped dring the safepoint so CodeCache will be safe to update without
1221 // holding the CodeCache_lock.
1222
1223 KlassDepChange changes(dependee);
1224
1225 // Compute the dependent nmethods
1226 if (CodeCache::mark_for_deoptimization(changes) > 0) {
1227 // At least one nmethod has been marked for deoptimization
1228 VM_Deoptimize op;
1229 VMThread::execute(&op);
1230 }
1231 }
1232
1233 // Flushes compiled methods dependent on a particular CallSite
1234 // instance when its target is different than the given MethodHandle.
1235 void Universe::flush_dependents_on(Handle call_site, Handle method_handle) {
1236 assert_lock_strong(Compile_lock);
1237
1238 if (CodeCache::number_of_nmethods_with_dependencies() == 0) return;
1239
1240 // CodeCache can only be updated by a thread_in_VM and they will all be
1241 // stopped dring the safepoint so CodeCache will be safe to update without
1242 // holding the CodeCache_lock.
1243
1244 CallSiteDepChange changes(call_site(), method_handle());
1245
1246 // Compute the dependent nmethods that have a reference to a
1247 // CallSite object. We use instanceKlass::mark_dependent_nmethod
1248 // directly instead of CodeCache::mark_for_deoptimization because we
1249 // want dependents on the call site class only not all classes in
1250 // the ContextStream.
1251 int marked = 0;
1252 {
1253 MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1254 instanceKlass* call_site_klass = instanceKlass::cast(call_site->klass());
1255 marked = call_site_klass->mark_dependent_nmethods(changes);
1256 }
1257 if (marked > 0) {
1258 // At least one nmethod has been marked for deoptimization
1259 VM_Deoptimize op;
1260 VMThread::execute(&op);
1261 }
1262 }
1263
1264 #ifdef HOTSWAP
1265 // Flushes compiled methods dependent on dependee in the evolutionary sense
1266 void Universe::flush_evol_dependents_on(instanceKlassHandle ev_k_h) {
1267 // --- Compile_lock is not held. However we are at a safepoint.
1268 assert_locked_or_safepoint(Compile_lock);
1269 if (CodeCache::number_of_nmethods_with_dependencies() == 0) return;
1270
1271 // CodeCache can only be updated by a thread_in_VM and they will all be
1272 // stopped dring the safepoint so CodeCache will be safe to update without
1273 // holding the CodeCache_lock.
1274
1275 // Compute the dependent nmethods
1276 if (CodeCache::mark_for_evol_deoptimization(ev_k_h) > 0) {
1277 // At least one nmethod has been marked for deoptimization
1278
1279 // All this already happens inside a VM_Operation, so we'll do all the work here.
1280 // Stuff copied from VM_Deoptimize and modified slightly.
1281
1282 // We do not want any GCs to happen while we are in the middle of this VM operation
1283 ResourceMark rm;
1284 DeoptimizationMarker dm;
1285
1286 // Deoptimize all activations depending on marked nmethods
1287 Deoptimization::deoptimize_dependents();
1288
1289 // Make the dependent methods not entrant (in VM_Deoptimize they are made zombies)
1290 CodeCache::make_marked_nmethods_not_entrant();
1291 }
1292 }
1293 #endif // HOTSWAP
1294
1295
1296 // Flushes compiled methods dependent on dependee
1297 void Universe::flush_dependents_on_method(methodHandle m_h) {
1298 // --- Compile_lock is not held. However we are at a safepoint.
1299 assert_locked_or_safepoint(Compile_lock);
1300
1301 // CodeCache can only be updated by a thread_in_VM and they will all be
1302 // stopped dring the safepoint so CodeCache will be safe to update without
1303 // holding the CodeCache_lock.
1304
1305 // Compute the dependent nmethods
1306 if (CodeCache::mark_for_deoptimization(m_h()) > 0) {
1307 // At least one nmethod has been marked for deoptimization
1308
1309 // All this already happens inside a VM_Operation, so we'll do all the work here.
1310 // Stuff copied from VM_Deoptimize and modified slightly.
1311
1312 // We do not want any GCs to happen while we are in the middle of this VM operation
1313 ResourceMark rm;
1314 DeoptimizationMarker dm;
1315
1316 // Deoptimize all activations depending on marked nmethods
1317 Deoptimization::deoptimize_dependents();
1318
1319 // Make the dependent methods not entrant (in VM_Deoptimize they are made zombies)
1320 CodeCache::make_marked_nmethods_not_entrant();
1321 }
1322 }
1323
1324 void Universe::print() {
1325 print_on(gclog_or_tty);
1326 }
1327
1328 void Universe::print_on(outputStream* st, bool extended) {
1329 st->print_cr("Heap");
1330 if (!extended) {
1331 heap()->print_on(st);
1332 } else {
1333 heap()->print_extended_on(st);
1334 }
1335 }
1336
1337 void Universe::print_heap_at_SIGBREAK() {
1338 if (PrintHeapAtSIGBREAK) {
1339 MutexLocker hl(Heap_lock);
1340 print_on(tty);
1341 tty->cr();
1342 tty->flush();
1343 }
1344 }
1345
1346 void Universe::print_heap_before_gc(outputStream* st, bool ignore_extended) {
1347 st->print_cr("{Heap before GC invocations=%u (full %u):",
1348 heap()->total_collections(),
1349 heap()->total_full_collections());
1350 if (!PrintHeapAtGCExtended || ignore_extended) {
1351 heap()->print_on(st);
1352 } else {
1353 heap()->print_extended_on(st);
1354 }
1355 }
1356
1357 void Universe::print_heap_after_gc(outputStream* st, bool ignore_extended) {
1358 st->print_cr("Heap after GC invocations=%u (full %u):",
1359 heap()->total_collections(),
1360 heap()->total_full_collections());
1361 if (!PrintHeapAtGCExtended || ignore_extended) {
1362 heap()->print_on(st);
1363 } else {
1364 heap()->print_extended_on(st);
1365 }
1366 st->print_cr("}");
1367 }
1368
1369 void Universe::verify(bool silent, VerifyOption option) {
1370 if (SharedSkipVerify) {
1371 return;
1372 }
1373
1374 // The use of _verify_in_progress is a temporary work around for
1375 // 6320749. Don't bother with a creating a class to set and clear
1376 // it since it is only used in this method and the control flow is
1377 // straight forward.
1378 _verify_in_progress = true;
1379
1380 COMPILER2_PRESENT(
1381 assert(!DerivedPointerTable::is_active(),
1382 "DPT should not be active during verification "
1383 "(of thread stacks below)");
1384 )
1385
1386 ResourceMark rm;
1387 HandleMark hm; // Handles created during verification can be zapped
1388 _verify_count++;
1389
1390 if (!silent) gclog_or_tty->print("[Verifying ");
1391 if (!silent) gclog_or_tty->print("threads ");
1392 Threads::verify();
1393 heap()->verify(silent, option);
1394
1395 if (!silent) gclog_or_tty->print("syms ");
1396 SymbolTable::verify();
1397 if (!silent) gclog_or_tty->print("strs ");
1398 StringTable::verify();
1399 {
1400 MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1401 if (!silent) gclog_or_tty->print("zone ");
1402 CodeCache::verify();
1403 }
1404 if (!silent) gclog_or_tty->print("dict ");
1405 SystemDictionary::verify();
1406 if (!silent) gclog_or_tty->print("hand ");
1407 JNIHandles::verify();
1408 if (!silent) gclog_or_tty->print("C-heap ");
1409 os::check_heap();
1410 if (!silent) gclog_or_tty->print("code cache ");
1411 CodeCache::verify_oops();
1412 if (!silent) gclog_or_tty->print_cr("]");
1413
1414 _verify_in_progress = false;
1415 }
1416
1417 // Oop verification (see MacroAssembler::verify_oop)
1418
1419 static uintptr_t _verify_oop_data[2] = {0, (uintptr_t)-1};
1420 static uintptr_t _verify_klass_data[2] = {0, (uintptr_t)-1};
1421
1422
1423 static void calculate_verify_data(uintptr_t verify_data[2],
1424 HeapWord* low_boundary,
1425 HeapWord* high_boundary) {
1426 assert(low_boundary < high_boundary, "bad interval");
1427
1428 // decide which low-order bits we require to be clear:
1429 size_t alignSize = MinObjAlignmentInBytes;
1430 size_t min_object_size = CollectedHeap::min_fill_size();
1431
1432 // make an inclusive limit:
1433 uintptr_t max = (uintptr_t)high_boundary - min_object_size*wordSize;
1434 uintptr_t min = (uintptr_t)low_boundary;
1435 assert(min < max, "bad interval");
1436 uintptr_t diff = max ^ min;
1437
1438 // throw away enough low-order bits to make the diff vanish
1439 uintptr_t mask = (uintptr_t)(-1);
1440 while ((mask & diff) != 0)
1441 mask <<= 1;
1442 uintptr_t bits = (min & mask);
1443 assert(bits == (max & mask), "correct mask");
1444 // check an intermediate value between min and max, just to make sure:
1445 assert(bits == ((min + (max-min)/2) & mask), "correct mask");
1446
1447 // require address alignment, too:
1448 mask |= (alignSize - 1);
1449
1450 if (!(verify_data[0] == 0 && verify_data[1] == (uintptr_t)-1)) {
1451 assert(verify_data[0] == mask && verify_data[1] == bits, "mask stability");
1452 }
1453 verify_data[0] = mask;
1454 verify_data[1] = bits;
1455 }
1456
1457
1458 // Oop verification (see MacroAssembler::verify_oop)
1459 #ifndef PRODUCT
1460
1461 uintptr_t Universe::verify_oop_mask() {
1462 MemRegion m = heap()->reserved_region();
1463 calculate_verify_data(_verify_oop_data,
1464 m.start(),
1465 m.end());
1466 return _verify_oop_data[0];
1467 }
1468
1469
1470
1471 uintptr_t Universe::verify_oop_bits() {
1472 verify_oop_mask();
1473 return _verify_oop_data[1];
1474 }
1475
1476
1477 uintptr_t Universe::verify_klass_mask() {
1478 /* $$$
1479 // A klass can never live in the new space. Since the new and old
1480 // spaces can change size, we must settle for bounds-checking against
1481 // the bottom of the world, plus the smallest possible new and old
1482 // space sizes that may arise during execution.
1483 size_t min_new_size = Universe::new_size(); // in bytes
1484 size_t min_old_size = Universe::old_size(); // in bytes
1485 calculate_verify_data(_verify_klass_data,
1486 (HeapWord*)((uintptr_t)_new_gen->low_boundary + min_new_size + min_old_size),
1487 _perm_gen->high_boundary);
1488 */
1489 // Why doesn't the above just say that klass's always live in the perm
1490 // gen? I'll see if that seems to work...
1491 MemRegion permanent_reserved;
1492 switch (Universe::heap()->kind()) {
1493 default:
1494 // ???: What if a CollectedHeap doesn't have a permanent generation?
1495 ShouldNotReachHere();
1496 break;
1497 case CollectedHeap::GenCollectedHeap:
1498 case CollectedHeap::G1CollectedHeap: {
1499 SharedHeap* sh = (SharedHeap*) Universe::heap();
1500 permanent_reserved = sh->perm_gen()->reserved();
1501 break;
1502 }
1503 #ifndef SERIALGC
1504 case CollectedHeap::ParallelScavengeHeap: {
1505 ParallelScavengeHeap* psh = (ParallelScavengeHeap*) Universe::heap();
1506 permanent_reserved = psh->perm_gen()->reserved();
1507 break;
1508 }
1509 #endif // SERIALGC
1510 }
1511 calculate_verify_data(_verify_klass_data,
1512 permanent_reserved.start(),
1513 permanent_reserved.end());
1514
1515 return _verify_klass_data[0];
1516 }
1517
1518
1519
1520 uintptr_t Universe::verify_klass_bits() {
1521 verify_klass_mask();
1522 return _verify_klass_data[1];
1523 }
1524
1525
1526 uintptr_t Universe::verify_mark_mask() {
1527 return markOopDesc::lock_mask_in_place;
1528 }
1529
1530
1531
1532 uintptr_t Universe::verify_mark_bits() {
1533 intptr_t mask = verify_mark_mask();
1534 intptr_t bits = (intptr_t)markOopDesc::prototype();
1535 assert((bits & ~mask) == 0, "no stray header bits");
1536 return bits;
1537 }
1538 #endif // PRODUCT
1539
1540
1541 void Universe::compute_verify_oop_data() {
1542 verify_oop_mask();
1543 verify_oop_bits();
1544 verify_mark_mask();
1545 verify_mark_bits();
1546 verify_klass_mask();
1547 verify_klass_bits();
1548 }
1549
1550
1551 void CommonMethodOopCache::init(klassOop k, methodOop m, TRAPS) {
1552 if (!UseSharedSpaces) {
1553 _klass = k;
1554 }
1555 #ifndef PRODUCT
1556 else {
1557 // sharing initilization should have already set up _klass
1558 assert(_klass != NULL, "just checking");
1559 }
1560 #endif
1561
1562 _method_idnum = m->method_idnum();
1563 assert(_method_idnum >= 0, "sanity check");
1564 }
1565
1566
1567 ActiveMethodOopsCache::~ActiveMethodOopsCache() {
1568 if (_prev_methods != NULL) {
1569 for (int i = _prev_methods->length() - 1; i >= 0; i--) {
1570 jweak method_ref = _prev_methods->at(i);
1571 if (method_ref != NULL) {
1572 JNIHandles::destroy_weak_global(method_ref);
1573 }
1574 }
1575 delete _prev_methods;
1576 _prev_methods = NULL;
1577 }
1578 }
1579
1580
1581 void ActiveMethodOopsCache::add_previous_version(const methodOop method) {
1582 assert(Thread::current()->is_VM_thread(),
1583 "only VMThread can add previous versions");
1584
1585 if (_prev_methods == NULL) {
1586 // This is the first previous version so make some space.
1587 // Start with 2 elements under the assumption that the class
1588 // won't be redefined much.
1589 _prev_methods = new (ResourceObj::C_HEAP, mtClass) GrowableArray<jweak>(2, true);
1590 }
1591
1592 // RC_TRACE macro has an embedded ResourceMark
1593 RC_TRACE(0x00000100,
1594 ("add: %s(%s): adding prev version ref for cached method @%d",
1595 method->name()->as_C_string(), method->signature()->as_C_string(),
1596 _prev_methods->length()));
1597
1598 methodHandle method_h(method);
1599 jweak method_ref = JNIHandles::make_weak_global(method_h);
1600 _prev_methods->append(method_ref);
1601
1602 // Using weak references allows previous versions of the cached
1603 // method to be GC'ed when they are no longer needed. Since the
1604 // caller is the VMThread and we are at a safepoint, this is a good
1605 // time to clear out unused weak references.
1606
1607 for (int i = _prev_methods->length() - 1; i >= 0; i--) {
1608 jweak method_ref = _prev_methods->at(i);
1609 assert(method_ref != NULL, "weak method ref was unexpectedly cleared");
1610 if (method_ref == NULL) {
1611 _prev_methods->remove_at(i);
1612 // Since we are traversing the array backwards, we don't have to
1613 // do anything special with the index.
1614 continue; // robustness
1615 }
1616
1617 methodOop m = (methodOop)JNIHandles::resolve(method_ref);
1618 if (m == NULL) {
1619 // this method entry has been GC'ed so remove it
1620 JNIHandles::destroy_weak_global(method_ref);
1621 _prev_methods->remove_at(i);
1622 } else {
1623 // RC_TRACE macro has an embedded ResourceMark
1624 RC_TRACE(0x00000400, ("add: %s(%s): previous cached method @%d is alive",
1625 m->name()->as_C_string(), m->signature()->as_C_string(), i));
1626 }
1627 }
1628 } // end add_previous_version()
1629
1630
1631 bool ActiveMethodOopsCache::is_same_method(const methodOop method) const {
1632 instanceKlass* ik = instanceKlass::cast(klass());
1633 methodOop check_method = ik->method_with_idnum(method_idnum());
1634 assert(check_method != NULL, "sanity check");
1635 if (check_method == method) {
1636 // done with the easy case
1637 return true;
1638 }
1639
1640 if (_prev_methods != NULL) {
1641 // The cached method has been redefined at least once so search
1642 // the previous versions for a match.
1643 for (int i = 0; i < _prev_methods->length(); i++) {
1644 jweak method_ref = _prev_methods->at(i);
1645 assert(method_ref != NULL, "weak method ref was unexpectedly cleared");
1646 if (method_ref == NULL) {
1647 continue; // robustness
1648 }
1649
1650 check_method = (methodOop)JNIHandles::resolve(method_ref);
1651 if (check_method == method) {
1652 // a previous version matches
1653 return true;
1654 }
1655 }
1656 }
1657
1658 // either no previous versions or no previous version matched
1659 return false;
1660 }
1661
1662
1663 methodOop LatestMethodOopCache::get_methodOop() {
1664 if (klass() == NULL) return NULL;
1665 instanceKlass* ik = instanceKlass::cast(klass());
1666 methodOop m = ik->method_with_idnum(method_idnum());
1667 assert(m != NULL, "sanity check");
1668 return m;
1669 }
1670
1671
1672 #ifdef ASSERT
1673 // Release dummy object(s) at bottom of heap
1674 bool Universe::release_fullgc_alot_dummy() {
1675 MutexLocker ml(FullGCALot_lock);
1676 if (_fullgc_alot_dummy_array != NULL) {
1677 if (_fullgc_alot_dummy_next >= _fullgc_alot_dummy_array->length()) {
1678 // No more dummies to release, release entire array instead
1679 _fullgc_alot_dummy_array = NULL;
1680 return false;
1681 }
1682 if (!UseConcMarkSweepGC) {
1683 // Release dummy at bottom of old generation
1684 _fullgc_alot_dummy_array->obj_at_put(_fullgc_alot_dummy_next++, NULL);
1685 }
1686 // Release dummy at bottom of permanent generation
1687 _fullgc_alot_dummy_array->obj_at_put(_fullgc_alot_dummy_next++, NULL);
1688 }
1689 return true;
1690 }
1691
1692 #endif // ASSERT