Mon, 26 Jan 2009 12:47:21 -0800
6786503: Overflow list performance can be improved
Summary: Avoid overflow list walk in CMS & ParNew when it is unnecessary. Fix a couple of correctness issues, including a C-heap leak, in ParNew at the intersection of promotion failure, work queue overflow and object array chunking. Add stress testing option and related assertion checking.
Reviewed-by: jmasa
1 /*
2 * Copyright 1997-2008 Sun Microsystems, Inc. All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
25 # include "incls/_precompiled.incl"
26 # include "incls/_universe.cpp.incl"
28 // Known objects
29 klassOop Universe::_boolArrayKlassObj = NULL;
30 klassOop Universe::_byteArrayKlassObj = NULL;
31 klassOop Universe::_charArrayKlassObj = NULL;
32 klassOop Universe::_intArrayKlassObj = NULL;
33 klassOop Universe::_shortArrayKlassObj = NULL;
34 klassOop Universe::_longArrayKlassObj = NULL;
35 klassOop Universe::_singleArrayKlassObj = NULL;
36 klassOop Universe::_doubleArrayKlassObj = NULL;
37 klassOop Universe::_typeArrayKlassObjs[T_VOID+1] = { NULL /*, NULL...*/ };
38 klassOop Universe::_objectArrayKlassObj = NULL;
39 klassOop Universe::_symbolKlassObj = NULL;
40 klassOop Universe::_methodKlassObj = NULL;
41 klassOop Universe::_constMethodKlassObj = NULL;
42 klassOop Universe::_methodDataKlassObj = NULL;
43 klassOop Universe::_klassKlassObj = NULL;
44 klassOop Universe::_arrayKlassKlassObj = NULL;
45 klassOop Universe::_objArrayKlassKlassObj = NULL;
46 klassOop Universe::_typeArrayKlassKlassObj = NULL;
47 klassOop Universe::_instanceKlassKlassObj = NULL;
48 klassOop Universe::_constantPoolKlassObj = NULL;
49 klassOop Universe::_constantPoolCacheKlassObj = NULL;
50 klassOop Universe::_compiledICHolderKlassObj = NULL;
51 klassOop Universe::_systemObjArrayKlassObj = NULL;
52 oop Universe::_int_mirror = NULL;
53 oop Universe::_float_mirror = NULL;
54 oop Universe::_double_mirror = NULL;
55 oop Universe::_byte_mirror = NULL;
56 oop Universe::_bool_mirror = NULL;
57 oop Universe::_char_mirror = NULL;
58 oop Universe::_long_mirror = NULL;
59 oop Universe::_short_mirror = NULL;
60 oop Universe::_void_mirror = NULL;
61 oop Universe::_mirrors[T_VOID+1] = { NULL /*, NULL...*/ };
62 oop Universe::_main_thread_group = NULL;
63 oop Universe::_system_thread_group = NULL;
64 typeArrayOop Universe::_the_empty_byte_array = NULL;
65 typeArrayOop Universe::_the_empty_short_array = NULL;
66 typeArrayOop Universe::_the_empty_int_array = NULL;
67 objArrayOop Universe::_the_empty_system_obj_array = NULL;
68 objArrayOop Universe::_the_empty_class_klass_array = NULL;
69 objArrayOop Universe::_the_array_interfaces_array = NULL;
70 LatestMethodOopCache* Universe::_finalizer_register_cache = NULL;
71 LatestMethodOopCache* Universe::_loader_addClass_cache = NULL;
72 ActiveMethodOopsCache* Universe::_reflect_invoke_cache = NULL;
73 oop Universe::_out_of_memory_error_java_heap = NULL;
74 oop Universe::_out_of_memory_error_perm_gen = NULL;
75 oop Universe::_out_of_memory_error_array_size = NULL;
76 oop Universe::_out_of_memory_error_gc_overhead_limit = NULL;
77 objArrayOop Universe::_preallocated_out_of_memory_error_array = NULL;
78 volatile jint Universe::_preallocated_out_of_memory_error_avail_count = 0;
79 bool Universe::_verify_in_progress = false;
80 oop Universe::_null_ptr_exception_instance = NULL;
81 oop Universe::_arithmetic_exception_instance = NULL;
82 oop Universe::_virtual_machine_error_instance = NULL;
83 oop Universe::_vm_exception = NULL;
84 oop Universe::_emptySymbol = NULL;
86 // These variables are guarded by FullGCALot_lock.
87 debug_only(objArrayOop Universe::_fullgc_alot_dummy_array = NULL;)
88 debug_only(int Universe::_fullgc_alot_dummy_next = 0;)
91 // Heap
92 int Universe::_verify_count = 0;
94 int Universe::_base_vtable_size = 0;
95 bool Universe::_bootstrapping = false;
96 bool Universe::_fully_initialized = false;
98 size_t Universe::_heap_capacity_at_last_gc;
99 size_t Universe::_heap_used_at_last_gc = 0;
101 CollectedHeap* Universe::_collectedHeap = NULL;
102 address Universe::_heap_base = NULL;
105 void Universe::basic_type_classes_do(void f(klassOop)) {
106 f(boolArrayKlassObj());
107 f(byteArrayKlassObj());
108 f(charArrayKlassObj());
109 f(intArrayKlassObj());
110 f(shortArrayKlassObj());
111 f(longArrayKlassObj());
112 f(singleArrayKlassObj());
113 f(doubleArrayKlassObj());
114 }
117 void Universe::system_classes_do(void f(klassOop)) {
118 f(symbolKlassObj());
119 f(methodKlassObj());
120 f(constMethodKlassObj());
121 f(methodDataKlassObj());
122 f(klassKlassObj());
123 f(arrayKlassKlassObj());
124 f(objArrayKlassKlassObj());
125 f(typeArrayKlassKlassObj());
126 f(instanceKlassKlassObj());
127 f(constantPoolKlassObj());
128 f(systemObjArrayKlassObj());
129 }
131 void Universe::oops_do(OopClosure* f, bool do_all) {
133 f->do_oop((oop*) &_int_mirror);
134 f->do_oop((oop*) &_float_mirror);
135 f->do_oop((oop*) &_double_mirror);
136 f->do_oop((oop*) &_byte_mirror);
137 f->do_oop((oop*) &_bool_mirror);
138 f->do_oop((oop*) &_char_mirror);
139 f->do_oop((oop*) &_long_mirror);
140 f->do_oop((oop*) &_short_mirror);
141 f->do_oop((oop*) &_void_mirror);
143 // It's important to iterate over these guys even if they are null,
144 // since that's how shared heaps are restored.
145 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
146 f->do_oop((oop*) &_mirrors[i]);
147 }
148 assert(_mirrors[0] == NULL && _mirrors[T_BOOLEAN - 1] == NULL, "checking");
150 // %%% Consider moving those "shared oops" over here with the others.
151 f->do_oop((oop*)&_boolArrayKlassObj);
152 f->do_oop((oop*)&_byteArrayKlassObj);
153 f->do_oop((oop*)&_charArrayKlassObj);
154 f->do_oop((oop*)&_intArrayKlassObj);
155 f->do_oop((oop*)&_shortArrayKlassObj);
156 f->do_oop((oop*)&_longArrayKlassObj);
157 f->do_oop((oop*)&_singleArrayKlassObj);
158 f->do_oop((oop*)&_doubleArrayKlassObj);
159 f->do_oop((oop*)&_objectArrayKlassObj);
160 {
161 for (int i = 0; i < T_VOID+1; i++) {
162 if (_typeArrayKlassObjs[i] != NULL) {
163 assert(i >= T_BOOLEAN, "checking");
164 f->do_oop((oop*)&_typeArrayKlassObjs[i]);
165 } else if (do_all) {
166 f->do_oop((oop*)&_typeArrayKlassObjs[i]);
167 }
168 }
169 }
170 f->do_oop((oop*)&_symbolKlassObj);
171 f->do_oop((oop*)&_methodKlassObj);
172 f->do_oop((oop*)&_constMethodKlassObj);
173 f->do_oop((oop*)&_methodDataKlassObj);
174 f->do_oop((oop*)&_klassKlassObj);
175 f->do_oop((oop*)&_arrayKlassKlassObj);
176 f->do_oop((oop*)&_objArrayKlassKlassObj);
177 f->do_oop((oop*)&_typeArrayKlassKlassObj);
178 f->do_oop((oop*)&_instanceKlassKlassObj);
179 f->do_oop((oop*)&_constantPoolKlassObj);
180 f->do_oop((oop*)&_constantPoolCacheKlassObj);
181 f->do_oop((oop*)&_compiledICHolderKlassObj);
182 f->do_oop((oop*)&_systemObjArrayKlassObj);
183 f->do_oop((oop*)&_the_empty_byte_array);
184 f->do_oop((oop*)&_the_empty_short_array);
185 f->do_oop((oop*)&_the_empty_int_array);
186 f->do_oop((oop*)&_the_empty_system_obj_array);
187 f->do_oop((oop*)&_the_empty_class_klass_array);
188 f->do_oop((oop*)&_the_array_interfaces_array);
189 _finalizer_register_cache->oops_do(f);
190 _loader_addClass_cache->oops_do(f);
191 _reflect_invoke_cache->oops_do(f);
192 f->do_oop((oop*)&_out_of_memory_error_java_heap);
193 f->do_oop((oop*)&_out_of_memory_error_perm_gen);
194 f->do_oop((oop*)&_out_of_memory_error_array_size);
195 f->do_oop((oop*)&_out_of_memory_error_gc_overhead_limit);
196 if (_preallocated_out_of_memory_error_array != (oop)NULL) { // NULL when DumpSharedSpaces
197 f->do_oop((oop*)&_preallocated_out_of_memory_error_array);
198 }
199 f->do_oop((oop*)&_null_ptr_exception_instance);
200 f->do_oop((oop*)&_arithmetic_exception_instance);
201 f->do_oop((oop*)&_virtual_machine_error_instance);
202 f->do_oop((oop*)&_main_thread_group);
203 f->do_oop((oop*)&_system_thread_group);
204 f->do_oop((oop*)&_vm_exception);
205 f->do_oop((oop*)&_emptySymbol);
206 debug_only(f->do_oop((oop*)&_fullgc_alot_dummy_array);)
207 }
210 void Universe::check_alignment(uintx size, uintx alignment, const char* name) {
211 if (size < alignment || size % alignment != 0) {
212 ResourceMark rm;
213 stringStream st;
214 st.print("Size of %s (%ld bytes) must be aligned to %ld bytes", name, size, alignment);
215 char* error = st.as_string();
216 vm_exit_during_initialization(error);
217 }
218 }
221 void Universe::genesis(TRAPS) {
222 ResourceMark rm;
223 { FlagSetting fs(_bootstrapping, true);
225 { MutexLocker mc(Compile_lock);
227 // determine base vtable size; without that we cannot create the array klasses
228 compute_base_vtable_size();
230 if (!UseSharedSpaces) {
231 _klassKlassObj = klassKlass::create_klass(CHECK);
232 _arrayKlassKlassObj = arrayKlassKlass::create_klass(CHECK);
234 _objArrayKlassKlassObj = objArrayKlassKlass::create_klass(CHECK);
235 _instanceKlassKlassObj = instanceKlassKlass::create_klass(CHECK);
236 _typeArrayKlassKlassObj = typeArrayKlassKlass::create_klass(CHECK);
238 _symbolKlassObj = symbolKlass::create_klass(CHECK);
240 _emptySymbol = oopFactory::new_symbol("", CHECK);
242 _boolArrayKlassObj = typeArrayKlass::create_klass(T_BOOLEAN, sizeof(jboolean), CHECK);
243 _charArrayKlassObj = typeArrayKlass::create_klass(T_CHAR, sizeof(jchar), CHECK);
244 _singleArrayKlassObj = typeArrayKlass::create_klass(T_FLOAT, sizeof(jfloat), CHECK);
245 _doubleArrayKlassObj = typeArrayKlass::create_klass(T_DOUBLE, sizeof(jdouble), CHECK);
246 _byteArrayKlassObj = typeArrayKlass::create_klass(T_BYTE, sizeof(jbyte), CHECK);
247 _shortArrayKlassObj = typeArrayKlass::create_klass(T_SHORT, sizeof(jshort), CHECK);
248 _intArrayKlassObj = typeArrayKlass::create_klass(T_INT, sizeof(jint), CHECK);
249 _longArrayKlassObj = typeArrayKlass::create_klass(T_LONG, sizeof(jlong), CHECK);
251 _typeArrayKlassObjs[T_BOOLEAN] = _boolArrayKlassObj;
252 _typeArrayKlassObjs[T_CHAR] = _charArrayKlassObj;
253 _typeArrayKlassObjs[T_FLOAT] = _singleArrayKlassObj;
254 _typeArrayKlassObjs[T_DOUBLE] = _doubleArrayKlassObj;
255 _typeArrayKlassObjs[T_BYTE] = _byteArrayKlassObj;
256 _typeArrayKlassObjs[T_SHORT] = _shortArrayKlassObj;
257 _typeArrayKlassObjs[T_INT] = _intArrayKlassObj;
258 _typeArrayKlassObjs[T_LONG] = _longArrayKlassObj;
260 _methodKlassObj = methodKlass::create_klass(CHECK);
261 _constMethodKlassObj = constMethodKlass::create_klass(CHECK);
262 _methodDataKlassObj = methodDataKlass::create_klass(CHECK);
263 _constantPoolKlassObj = constantPoolKlass::create_klass(CHECK);
264 _constantPoolCacheKlassObj = constantPoolCacheKlass::create_klass(CHECK);
266 _compiledICHolderKlassObj = compiledICHolderKlass::create_klass(CHECK);
267 _systemObjArrayKlassObj = objArrayKlassKlass::cast(objArrayKlassKlassObj())->allocate_system_objArray_klass(CHECK);
269 _the_empty_byte_array = oopFactory::new_permanent_byteArray(0, CHECK);
270 _the_empty_short_array = oopFactory::new_permanent_shortArray(0, CHECK);
271 _the_empty_int_array = oopFactory::new_permanent_intArray(0, CHECK);
272 _the_empty_system_obj_array = oopFactory::new_system_objArray(0, CHECK);
274 _the_array_interfaces_array = oopFactory::new_system_objArray(2, CHECK);
275 _vm_exception = oopFactory::new_symbol("vm exception holder", CHECK);
276 } else {
277 FileMapInfo *mapinfo = FileMapInfo::current_info();
278 char* buffer = mapinfo->region_base(CompactingPermGenGen::md);
279 void** vtbl_list = (void**)buffer;
280 init_self_patching_vtbl_list(vtbl_list,
281 CompactingPermGenGen::vtbl_list_size);
282 }
283 }
285 vmSymbols::initialize(CHECK);
287 SystemDictionary::initialize(CHECK);
289 klassOop ok = SystemDictionary::object_klass();
291 if (UseSharedSpaces) {
292 // Verify shared interfaces array.
293 assert(_the_array_interfaces_array->obj_at(0) ==
294 SystemDictionary::cloneable_klass(), "u3");
295 assert(_the_array_interfaces_array->obj_at(1) ==
296 SystemDictionary::serializable_klass(), "u3");
298 // Verify element klass for system obj array klass
299 assert(objArrayKlass::cast(_systemObjArrayKlassObj)->element_klass() == ok, "u1");
300 assert(objArrayKlass::cast(_systemObjArrayKlassObj)->bottom_klass() == ok, "u2");
302 // Verify super class for the classes created above
303 assert(Klass::cast(boolArrayKlassObj() )->super() == ok, "u3");
304 assert(Klass::cast(charArrayKlassObj() )->super() == ok, "u3");
305 assert(Klass::cast(singleArrayKlassObj() )->super() == ok, "u3");
306 assert(Klass::cast(doubleArrayKlassObj() )->super() == ok, "u3");
307 assert(Klass::cast(byteArrayKlassObj() )->super() == ok, "u3");
308 assert(Klass::cast(shortArrayKlassObj() )->super() == ok, "u3");
309 assert(Klass::cast(intArrayKlassObj() )->super() == ok, "u3");
310 assert(Klass::cast(longArrayKlassObj() )->super() == ok, "u3");
311 assert(Klass::cast(constantPoolKlassObj() )->super() == ok, "u3");
312 assert(Klass::cast(systemObjArrayKlassObj())->super() == ok, "u3");
313 } else {
314 // Set up shared interfaces array. (Do this before supers are set up.)
315 _the_array_interfaces_array->obj_at_put(0, SystemDictionary::cloneable_klass());
316 _the_array_interfaces_array->obj_at_put(1, SystemDictionary::serializable_klass());
318 // Set element klass for system obj array klass
319 objArrayKlass::cast(_systemObjArrayKlassObj)->set_element_klass(ok);
320 objArrayKlass::cast(_systemObjArrayKlassObj)->set_bottom_klass(ok);
322 // Set super class for the classes created above
323 Klass::cast(boolArrayKlassObj() )->initialize_supers(ok, CHECK);
324 Klass::cast(charArrayKlassObj() )->initialize_supers(ok, CHECK);
325 Klass::cast(singleArrayKlassObj() )->initialize_supers(ok, CHECK);
326 Klass::cast(doubleArrayKlassObj() )->initialize_supers(ok, CHECK);
327 Klass::cast(byteArrayKlassObj() )->initialize_supers(ok, CHECK);
328 Klass::cast(shortArrayKlassObj() )->initialize_supers(ok, CHECK);
329 Klass::cast(intArrayKlassObj() )->initialize_supers(ok, CHECK);
330 Klass::cast(longArrayKlassObj() )->initialize_supers(ok, CHECK);
331 Klass::cast(constantPoolKlassObj() )->initialize_supers(ok, CHECK);
332 Klass::cast(systemObjArrayKlassObj())->initialize_supers(ok, CHECK);
333 Klass::cast(boolArrayKlassObj() )->set_super(ok);
334 Klass::cast(charArrayKlassObj() )->set_super(ok);
335 Klass::cast(singleArrayKlassObj() )->set_super(ok);
336 Klass::cast(doubleArrayKlassObj() )->set_super(ok);
337 Klass::cast(byteArrayKlassObj() )->set_super(ok);
338 Klass::cast(shortArrayKlassObj() )->set_super(ok);
339 Klass::cast(intArrayKlassObj() )->set_super(ok);
340 Klass::cast(longArrayKlassObj() )->set_super(ok);
341 Klass::cast(constantPoolKlassObj() )->set_super(ok);
342 Klass::cast(systemObjArrayKlassObj())->set_super(ok);
343 }
345 Klass::cast(boolArrayKlassObj() )->append_to_sibling_list();
346 Klass::cast(charArrayKlassObj() )->append_to_sibling_list();
347 Klass::cast(singleArrayKlassObj() )->append_to_sibling_list();
348 Klass::cast(doubleArrayKlassObj() )->append_to_sibling_list();
349 Klass::cast(byteArrayKlassObj() )->append_to_sibling_list();
350 Klass::cast(shortArrayKlassObj() )->append_to_sibling_list();
351 Klass::cast(intArrayKlassObj() )->append_to_sibling_list();
352 Klass::cast(longArrayKlassObj() )->append_to_sibling_list();
353 Klass::cast(constantPoolKlassObj() )->append_to_sibling_list();
354 Klass::cast(systemObjArrayKlassObj())->append_to_sibling_list();
355 } // end of core bootstrapping
357 // Initialize _objectArrayKlass after core bootstraping to make
358 // sure the super class is set up properly for _objectArrayKlass.
359 _objectArrayKlassObj = instanceKlass::
360 cast(SystemDictionary::object_klass())->array_klass(1, CHECK);
361 // Add the class to the class hierarchy manually to make sure that
362 // its vtable is initialized after core bootstrapping is completed.
363 Klass::cast(_objectArrayKlassObj)->append_to_sibling_list();
365 // Compute is_jdk version flags.
366 // Only 1.3 or later has the java.lang.Shutdown class.
367 // Only 1.4 or later has the java.lang.CharSequence interface.
368 // Only 1.5 or later has the java.lang.management.MemoryUsage class.
369 if (JDK_Version::is_partially_initialized()) {
370 uint8_t jdk_version;
371 klassOop k = SystemDictionary::resolve_or_null(
372 vmSymbolHandles::java_lang_management_MemoryUsage(), THREAD);
373 CLEAR_PENDING_EXCEPTION; // ignore exceptions
374 if (k == NULL) {
375 k = SystemDictionary::resolve_or_null(
376 vmSymbolHandles::java_lang_CharSequence(), THREAD);
377 CLEAR_PENDING_EXCEPTION; // ignore exceptions
378 if (k == NULL) {
379 k = SystemDictionary::resolve_or_null(
380 vmSymbolHandles::java_lang_Shutdown(), THREAD);
381 CLEAR_PENDING_EXCEPTION; // ignore exceptions
382 if (k == NULL) {
383 jdk_version = 2;
384 } else {
385 jdk_version = 3;
386 }
387 } else {
388 jdk_version = 4;
389 }
390 } else {
391 jdk_version = 5;
392 }
393 JDK_Version::fully_initialize(jdk_version);
394 }
396 #ifdef ASSERT
397 if (FullGCALot) {
398 // Allocate an array of dummy objects.
399 // We'd like these to be at the bottom of the old generation,
400 // so that when we free one and then collect,
401 // (almost) the whole heap moves
402 // and we find out if we actually update all the oops correctly.
403 // But we can't allocate directly in the old generation,
404 // so we allocate wherever, and hope that the first collection
405 // moves these objects to the bottom of the old generation.
406 // We can allocate directly in the permanent generation, so we do.
407 int size;
408 if (UseConcMarkSweepGC) {
409 warning("Using +FullGCALot with concurrent mark sweep gc "
410 "will not force all objects to relocate");
411 size = FullGCALotDummies;
412 } else {
413 size = FullGCALotDummies * 2;
414 }
415 objArrayOop naked_array = oopFactory::new_system_objArray(size, CHECK);
416 objArrayHandle dummy_array(THREAD, naked_array);
417 int i = 0;
418 while (i < size) {
419 if (!UseConcMarkSweepGC) {
420 // Allocate dummy in old generation
421 oop dummy = instanceKlass::cast(SystemDictionary::object_klass())->allocate_instance(CHECK);
422 dummy_array->obj_at_put(i++, dummy);
423 }
424 // Allocate dummy in permanent generation
425 oop dummy = instanceKlass::cast(SystemDictionary::object_klass())->allocate_permanent_instance(CHECK);
426 dummy_array->obj_at_put(i++, dummy);
427 }
428 {
429 // Only modify the global variable inside the mutex.
430 // If we had a race to here, the other dummy_array instances
431 // and their elements just get dropped on the floor, which is fine.
432 MutexLocker ml(FullGCALot_lock);
433 if (_fullgc_alot_dummy_array == NULL) {
434 _fullgc_alot_dummy_array = dummy_array();
435 }
436 }
437 assert(i == _fullgc_alot_dummy_array->length(), "just checking");
438 }
439 #endif
440 }
443 static inline void add_vtable(void** list, int* n, Klass* o, int count) {
444 list[(*n)++] = *(void**)&o->vtbl_value();
445 guarantee((*n) <= count, "vtable list too small.");
446 }
449 void Universe::init_self_patching_vtbl_list(void** list, int count) {
450 int n = 0;
451 { klassKlass o; add_vtable(list, &n, &o, count); }
452 { arrayKlassKlass o; add_vtable(list, &n, &o, count); }
453 { objArrayKlassKlass o; add_vtable(list, &n, &o, count); }
454 { instanceKlassKlass o; add_vtable(list, &n, &o, count); }
455 { instanceKlass o; add_vtable(list, &n, &o, count); }
456 { instanceRefKlass o; add_vtable(list, &n, &o, count); }
457 { typeArrayKlassKlass o; add_vtable(list, &n, &o, count); }
458 { symbolKlass o; add_vtable(list, &n, &o, count); }
459 { typeArrayKlass o; add_vtable(list, &n, &o, count); }
460 { methodKlass o; add_vtable(list, &n, &o, count); }
461 { constMethodKlass o; add_vtable(list, &n, &o, count); }
462 { constantPoolKlass o; add_vtable(list, &n, &o, count); }
463 { constantPoolCacheKlass o; add_vtable(list, &n, &o, count); }
464 { objArrayKlass o; add_vtable(list, &n, &o, count); }
465 { methodDataKlass o; add_vtable(list, &n, &o, count); }
466 { compiledICHolderKlass o; add_vtable(list, &n, &o, count); }
467 }
470 class FixupMirrorClosure: public ObjectClosure {
471 public:
472 virtual void do_object(oop obj) {
473 if (obj->is_klass()) {
474 EXCEPTION_MARK;
475 KlassHandle k(THREAD, klassOop(obj));
476 // We will never reach the CATCH below since Exceptions::_throw will cause
477 // the VM to exit if an exception is thrown during initialization
478 java_lang_Class::create_mirror(k, CATCH);
479 // This call unconditionally creates a new mirror for k,
480 // and links in k's component_mirror field if k is an array.
481 // If k is an objArray, k's element type must already have
482 // a mirror. In other words, this closure must process
483 // the component type of an objArray k before it processes k.
484 // This works because the permgen iterator presents arrays
485 // and their component types in order of creation.
486 }
487 }
488 };
490 void Universe::initialize_basic_type_mirrors(TRAPS) {
491 if (UseSharedSpaces) {
492 assert(_int_mirror != NULL, "already loaded");
493 assert(_void_mirror == _mirrors[T_VOID], "consistently loaded");
494 } else {
496 assert(_int_mirror==NULL, "basic type mirrors already initialized");
497 _int_mirror =
498 java_lang_Class::create_basic_type_mirror("int", T_INT, CHECK);
499 _float_mirror =
500 java_lang_Class::create_basic_type_mirror("float", T_FLOAT, CHECK);
501 _double_mirror =
502 java_lang_Class::create_basic_type_mirror("double", T_DOUBLE, CHECK);
503 _byte_mirror =
504 java_lang_Class::create_basic_type_mirror("byte", T_BYTE, CHECK);
505 _bool_mirror =
506 java_lang_Class::create_basic_type_mirror("boolean",T_BOOLEAN, CHECK);
507 _char_mirror =
508 java_lang_Class::create_basic_type_mirror("char", T_CHAR, CHECK);
509 _long_mirror =
510 java_lang_Class::create_basic_type_mirror("long", T_LONG, CHECK);
511 _short_mirror =
512 java_lang_Class::create_basic_type_mirror("short", T_SHORT, CHECK);
513 _void_mirror =
514 java_lang_Class::create_basic_type_mirror("void", T_VOID, CHECK);
516 _mirrors[T_INT] = _int_mirror;
517 _mirrors[T_FLOAT] = _float_mirror;
518 _mirrors[T_DOUBLE] = _double_mirror;
519 _mirrors[T_BYTE] = _byte_mirror;
520 _mirrors[T_BOOLEAN] = _bool_mirror;
521 _mirrors[T_CHAR] = _char_mirror;
522 _mirrors[T_LONG] = _long_mirror;
523 _mirrors[T_SHORT] = _short_mirror;
524 _mirrors[T_VOID] = _void_mirror;
525 //_mirrors[T_OBJECT] = instanceKlass::cast(_object_klass)->java_mirror();
526 //_mirrors[T_ARRAY] = instanceKlass::cast(_object_klass)->java_mirror();
527 }
528 }
530 void Universe::fixup_mirrors(TRAPS) {
531 // Bootstrap problem: all classes gets a mirror (java.lang.Class instance) assigned eagerly,
532 // but we cannot do that for classes created before java.lang.Class is loaded. Here we simply
533 // walk over permanent objects created so far (mostly classes) and fixup their mirrors. Note
534 // that the number of objects allocated at this point is very small.
535 assert(SystemDictionary::class_klass_loaded(), "java.lang.Class should be loaded");
536 FixupMirrorClosure blk;
537 Universe::heap()->permanent_object_iterate(&blk);
538 }
541 static bool has_run_finalizers_on_exit = false;
543 void Universe::run_finalizers_on_exit() {
544 if (has_run_finalizers_on_exit) return;
545 has_run_finalizers_on_exit = true;
547 // Called on VM exit. This ought to be run in a separate thread.
548 if (TraceReferenceGC) tty->print_cr("Callback to run finalizers on exit");
549 {
550 PRESERVE_EXCEPTION_MARK;
551 KlassHandle finalizer_klass(THREAD, SystemDictionary::finalizer_klass());
552 JavaValue result(T_VOID);
553 JavaCalls::call_static(
554 &result,
555 finalizer_klass,
556 vmSymbolHandles::run_finalizers_on_exit_name(),
557 vmSymbolHandles::void_method_signature(),
558 THREAD
559 );
560 // Ignore any pending exceptions
561 CLEAR_PENDING_EXCEPTION;
562 }
563 }
566 // initialize_vtable could cause gc if
567 // 1) we specified true to initialize_vtable and
568 // 2) this ran after gc was enabled
569 // In case those ever change we use handles for oops
570 void Universe::reinitialize_vtable_of(KlassHandle k_h, TRAPS) {
571 // init vtable of k and all subclasses
572 Klass* ko = k_h()->klass_part();
573 klassVtable* vt = ko->vtable();
574 if (vt) vt->initialize_vtable(false, CHECK);
575 if (ko->oop_is_instance()) {
576 instanceKlass* ik = (instanceKlass*)ko;
577 for (KlassHandle s_h(THREAD, ik->subklass()); s_h() != NULL; s_h = (THREAD, s_h()->klass_part()->next_sibling())) {
578 reinitialize_vtable_of(s_h, CHECK);
579 }
580 }
581 }
584 void initialize_itable_for_klass(klassOop k, TRAPS) {
585 instanceKlass::cast(k)->itable()->initialize_itable(false, CHECK);
586 }
589 void Universe::reinitialize_itables(TRAPS) {
590 SystemDictionary::classes_do(initialize_itable_for_klass, CHECK);
592 }
595 bool Universe::on_page_boundary(void* addr) {
596 return ((uintptr_t) addr) % os::vm_page_size() == 0;
597 }
600 bool Universe::should_fill_in_stack_trace(Handle throwable) {
601 // never attempt to fill in the stack trace of preallocated errors that do not have
602 // backtrace. These errors are kept alive forever and may be "re-used" when all
603 // preallocated errors with backtrace have been consumed. Also need to avoid
604 // a potential loop which could happen if an out of memory occurs when attempting
605 // to allocate the backtrace.
606 return ((throwable() != Universe::_out_of_memory_error_java_heap) &&
607 (throwable() != Universe::_out_of_memory_error_perm_gen) &&
608 (throwable() != Universe::_out_of_memory_error_array_size) &&
609 (throwable() != Universe::_out_of_memory_error_gc_overhead_limit));
610 }
613 oop Universe::gen_out_of_memory_error(oop default_err) {
614 // generate an out of memory error:
615 // - if there is a preallocated error with backtrace available then return it wth
616 // a filled in stack trace.
617 // - if there are no preallocated errors with backtrace available then return
618 // an error without backtrace.
619 int next;
620 if (_preallocated_out_of_memory_error_avail_count > 0) {
621 next = (int)Atomic::add(-1, &_preallocated_out_of_memory_error_avail_count);
622 assert(next < (int)PreallocatedOutOfMemoryErrorCount, "avail count is corrupt");
623 } else {
624 next = -1;
625 }
626 if (next < 0) {
627 // all preallocated errors have been used.
628 // return default
629 return default_err;
630 } else {
631 // get the error object at the slot and set set it to NULL so that the
632 // array isn't keeping it alive anymore.
633 oop exc = preallocated_out_of_memory_errors()->obj_at(next);
634 assert(exc != NULL, "slot has been used already");
635 preallocated_out_of_memory_errors()->obj_at_put(next, NULL);
637 // use the message from the default error
638 oop msg = java_lang_Throwable::message(default_err);
639 assert(msg != NULL, "no message");
640 java_lang_Throwable::set_message(exc, msg);
642 // populate the stack trace and return it.
643 java_lang_Throwable::fill_in_stack_trace_of_preallocated_backtrace(exc);
644 return exc;
645 }
646 }
648 static intptr_t non_oop_bits = 0;
650 void* Universe::non_oop_word() {
651 // Neither the high bits nor the low bits of this value is allowed
652 // to look like (respectively) the high or low bits of a real oop.
653 //
654 // High and low are CPU-specific notions, but low always includes
655 // the low-order bit. Since oops are always aligned at least mod 4,
656 // setting the low-order bit will ensure that the low half of the
657 // word will never look like that of a real oop.
658 //
659 // Using the OS-supplied non-memory-address word (usually 0 or -1)
660 // will take care of the high bits, however many there are.
662 if (non_oop_bits == 0) {
663 non_oop_bits = (intptr_t)os::non_memory_address_word() | 1;
664 }
666 return (void*)non_oop_bits;
667 }
669 jint universe_init() {
670 assert(!Universe::_fully_initialized, "called after initialize_vtables");
671 guarantee(1 << LogHeapWordSize == sizeof(HeapWord),
672 "LogHeapWordSize is incorrect.");
673 guarantee(sizeof(oop) >= sizeof(HeapWord), "HeapWord larger than oop?");
674 guarantee(sizeof(oop) % sizeof(HeapWord) == 0,
675 "oop size is not not a multiple of HeapWord size");
676 TraceTime timer("Genesis", TraceStartupTime);
677 GC_locker::lock(); // do not allow gc during bootstrapping
678 JavaClasses::compute_hard_coded_offsets();
680 // Get map info from shared archive file.
681 if (DumpSharedSpaces)
682 UseSharedSpaces = false;
684 FileMapInfo* mapinfo = NULL;
685 if (UseSharedSpaces) {
686 mapinfo = NEW_C_HEAP_OBJ(FileMapInfo);
687 memset(mapinfo, 0, sizeof(FileMapInfo));
689 // Open the shared archive file, read and validate the header. If
690 // initialization files, shared spaces [UseSharedSpaces] are
691 // disabled and the file is closed.
693 if (mapinfo->initialize()) {
694 FileMapInfo::set_current_info(mapinfo);
695 } else {
696 assert(!mapinfo->is_open() && !UseSharedSpaces,
697 "archive file not closed or shared spaces not disabled.");
698 }
699 }
701 jint status = Universe::initialize_heap();
702 if (status != JNI_OK) {
703 return status;
704 }
706 // We have a heap so create the methodOop caches before
707 // CompactingPermGenGen::initialize_oops() tries to populate them.
708 Universe::_finalizer_register_cache = new LatestMethodOopCache();
709 Universe::_loader_addClass_cache = new LatestMethodOopCache();
710 Universe::_reflect_invoke_cache = new ActiveMethodOopsCache();
712 if (UseSharedSpaces) {
714 // Read the data structures supporting the shared spaces (shared
715 // system dictionary, symbol table, etc.). After that, access to
716 // the file (other than the mapped regions) is no longer needed, and
717 // the file is closed. Closing the file does not affect the
718 // currently mapped regions.
720 CompactingPermGenGen::initialize_oops();
721 mapinfo->close();
723 } else {
724 SymbolTable::create_table();
725 StringTable::create_table();
726 ClassLoader::create_package_info_table();
727 }
729 return JNI_OK;
730 }
732 jint Universe::initialize_heap() {
734 if (UseParallelGC) {
735 #ifndef SERIALGC
736 Universe::_collectedHeap = new ParallelScavengeHeap();
737 #else // SERIALGC
738 fatal("UseParallelGC not supported in java kernel vm.");
739 #endif // SERIALGC
741 } else if (UseG1GC) {
742 #ifndef SERIALGC
743 G1CollectorPolicy* g1p = new G1CollectorPolicy_BestRegionsFirst();
744 G1CollectedHeap* g1h = new G1CollectedHeap(g1p);
745 Universe::_collectedHeap = g1h;
746 #else // SERIALGC
747 fatal("UseG1GC not supported in java kernel vm.");
748 #endif // SERIALGC
750 } else {
751 GenCollectorPolicy *gc_policy;
753 if (UseSerialGC) {
754 gc_policy = new MarkSweepPolicy();
755 } else if (UseConcMarkSweepGC) {
756 #ifndef SERIALGC
757 if (UseAdaptiveSizePolicy) {
758 gc_policy = new ASConcurrentMarkSweepPolicy();
759 } else {
760 gc_policy = new ConcurrentMarkSweepPolicy();
761 }
762 #else // SERIALGC
763 fatal("UseConcMarkSweepGC not supported in java kernel vm.");
764 #endif // SERIALGC
765 } else { // default old generation
766 gc_policy = new MarkSweepPolicy();
767 }
769 Universe::_collectedHeap = new GenCollectedHeap(gc_policy);
770 }
772 jint status = Universe::heap()->initialize();
773 if (status != JNI_OK) {
774 return status;
775 }
776 if (UseCompressedOops) {
777 // Subtract a page because something can get allocated at heap base.
778 // This also makes implicit null checking work, because the
779 // memory+1 page below heap_base needs to cause a signal.
780 // See needs_explicit_null_check.
781 // Only set the heap base for compressed oops because it indicates
782 // compressed oops for pstack code.
783 Universe::_heap_base = Universe::heap()->base() - os::vm_page_size();
784 }
786 // We will never reach the CATCH below since Exceptions::_throw will cause
787 // the VM to exit if an exception is thrown during initialization
789 if (UseTLAB) {
790 assert(Universe::heap()->supports_tlab_allocation(),
791 "Should support thread-local allocation buffers");
792 ThreadLocalAllocBuffer::startup_initialization();
793 }
794 return JNI_OK;
795 }
797 // It's the caller's repsonsibility to ensure glitch-freedom
798 // (if required).
799 void Universe::update_heap_info_at_gc() {
800 _heap_capacity_at_last_gc = heap()->capacity();
801 _heap_used_at_last_gc = heap()->used();
802 }
806 void universe2_init() {
807 EXCEPTION_MARK;
808 Universe::genesis(CATCH);
809 // Although we'd like to verify here that the state of the heap
810 // is good, we can't because the main thread has not yet added
811 // itself to the threads list (so, using current interfaces
812 // we can't "fill" its TLAB), unless TLABs are disabled.
813 if (VerifyBeforeGC && !UseTLAB &&
814 Universe::heap()->total_collections() >= VerifyGCStartAt) {
815 Universe::heap()->prepare_for_verify();
816 Universe::verify(); // make sure we're starting with a clean slate
817 }
818 }
821 // This function is defined in JVM.cpp
822 extern void initialize_converter_functions();
824 bool universe_post_init() {
825 Universe::_fully_initialized = true;
826 EXCEPTION_MARK;
827 { ResourceMark rm;
828 Interpreter::initialize(); // needed for interpreter entry points
829 if (!UseSharedSpaces) {
830 KlassHandle ok_h(THREAD, SystemDictionary::object_klass());
831 Universe::reinitialize_vtable_of(ok_h, CHECK_false);
832 Universe::reinitialize_itables(CHECK_false);
833 }
834 }
836 klassOop k;
837 instanceKlassHandle k_h;
838 if (!UseSharedSpaces) {
839 // Setup preallocated empty java.lang.Class array
840 Universe::_the_empty_class_klass_array = oopFactory::new_objArray(SystemDictionary::class_klass(), 0, CHECK_false);
841 // Setup preallocated OutOfMemoryError errors
842 k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_OutOfMemoryError(), true, CHECK_false);
843 k_h = instanceKlassHandle(THREAD, k);
844 Universe::_out_of_memory_error_java_heap = k_h->allocate_permanent_instance(CHECK_false);
845 Universe::_out_of_memory_error_perm_gen = k_h->allocate_permanent_instance(CHECK_false);
846 Universe::_out_of_memory_error_array_size = k_h->allocate_permanent_instance(CHECK_false);
847 Universe::_out_of_memory_error_gc_overhead_limit =
848 k_h->allocate_permanent_instance(CHECK_false);
850 // Setup preallocated NullPointerException
851 // (this is currently used for a cheap & dirty solution in compiler exception handling)
852 k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_NullPointerException(), true, CHECK_false);
853 Universe::_null_ptr_exception_instance = instanceKlass::cast(k)->allocate_permanent_instance(CHECK_false);
854 // Setup preallocated ArithmeticException
855 // (this is currently used for a cheap & dirty solution in compiler exception handling)
856 k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_ArithmeticException(), true, CHECK_false);
857 Universe::_arithmetic_exception_instance = instanceKlass::cast(k)->allocate_permanent_instance(CHECK_false);
858 // Virtual Machine Error for when we get into a situation we can't resolve
859 k = SystemDictionary::resolve_or_fail(
860 vmSymbolHandles::java_lang_VirtualMachineError(), true, CHECK_false);
861 bool linked = instanceKlass::cast(k)->link_class_or_fail(CHECK_false);
862 if (!linked) {
863 tty->print_cr("Unable to link/verify VirtualMachineError class");
864 return false; // initialization failed
865 }
866 Universe::_virtual_machine_error_instance =
867 instanceKlass::cast(k)->allocate_permanent_instance(CHECK_false);
868 }
869 if (!DumpSharedSpaces) {
870 // These are the only Java fields that are currently set during shared space dumping.
871 // We prefer to not handle this generally, so we always reinitialize these detail messages.
872 Handle msg = java_lang_String::create_from_str("Java heap space", CHECK_false);
873 java_lang_Throwable::set_message(Universe::_out_of_memory_error_java_heap, msg());
875 msg = java_lang_String::create_from_str("PermGen space", CHECK_false);
876 java_lang_Throwable::set_message(Universe::_out_of_memory_error_perm_gen, msg());
878 msg = java_lang_String::create_from_str("Requested array size exceeds VM limit", CHECK_false);
879 java_lang_Throwable::set_message(Universe::_out_of_memory_error_array_size, msg());
881 msg = java_lang_String::create_from_str("GC overhead limit exceeded", CHECK_false);
882 java_lang_Throwable::set_message(Universe::_out_of_memory_error_gc_overhead_limit, msg());
884 msg = java_lang_String::create_from_str("/ by zero", CHECK_false);
885 java_lang_Throwable::set_message(Universe::_arithmetic_exception_instance, msg());
887 // Setup the array of errors that have preallocated backtrace
888 k = Universe::_out_of_memory_error_java_heap->klass();
889 assert(k->klass_part()->name() == vmSymbols::java_lang_OutOfMemoryError(), "should be out of memory error");
890 k_h = instanceKlassHandle(THREAD, k);
892 int len = (StackTraceInThrowable) ? (int)PreallocatedOutOfMemoryErrorCount : 0;
893 Universe::_preallocated_out_of_memory_error_array = oopFactory::new_objArray(k_h(), len, CHECK_false);
894 for (int i=0; i<len; i++) {
895 oop err = k_h->allocate_permanent_instance(CHECK_false);
896 Handle err_h = Handle(THREAD, err);
897 java_lang_Throwable::allocate_backtrace(err_h, CHECK_false);
898 Universe::preallocated_out_of_memory_errors()->obj_at_put(i, err_h());
899 }
900 Universe::_preallocated_out_of_memory_error_avail_count = (jint)len;
901 }
904 // Setup static method for registering finalizers
905 // The finalizer klass must be linked before looking up the method, in
906 // case it needs to get rewritten.
907 instanceKlass::cast(SystemDictionary::finalizer_klass())->link_class(CHECK_false);
908 methodOop m = instanceKlass::cast(SystemDictionary::finalizer_klass())->find_method(
909 vmSymbols::register_method_name(),
910 vmSymbols::register_method_signature());
911 if (m == NULL || !m->is_static()) {
912 THROW_MSG_(vmSymbols::java_lang_NoSuchMethodException(),
913 "java.lang.ref.Finalizer.register", false);
914 }
915 Universe::_finalizer_register_cache->init(
916 SystemDictionary::finalizer_klass(), m, CHECK_false);
918 // Resolve on first use and initialize class.
919 // Note: No race-condition here, since a resolve will always return the same result
921 // Setup method for security checks
922 k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_reflect_Method(), true, CHECK_false);
923 k_h = instanceKlassHandle(THREAD, k);
924 k_h->link_class(CHECK_false);
925 m = k_h->find_method(vmSymbols::invoke_name(), vmSymbols::object_array_object_object_signature());
926 if (m == NULL || m->is_static()) {
927 THROW_MSG_(vmSymbols::java_lang_NoSuchMethodException(),
928 "java.lang.reflect.Method.invoke", false);
929 }
930 Universe::_reflect_invoke_cache->init(k_h(), m, CHECK_false);
932 // Setup method for registering loaded classes in class loader vector
933 instanceKlass::cast(SystemDictionary::classloader_klass())->link_class(CHECK_false);
934 m = instanceKlass::cast(SystemDictionary::classloader_klass())->find_method(vmSymbols::addClass_name(), vmSymbols::class_void_signature());
935 if (m == NULL || m->is_static()) {
936 THROW_MSG_(vmSymbols::java_lang_NoSuchMethodException(),
937 "java.lang.ClassLoader.addClass", false);
938 }
939 Universe::_loader_addClass_cache->init(
940 SystemDictionary::classloader_klass(), m, CHECK_false);
942 // The folowing is initializing converter functions for serialization in
943 // JVM.cpp. If we clean up the StrictMath code above we may want to find
944 // a better solution for this as well.
945 initialize_converter_functions();
947 // This needs to be done before the first scavenge/gc, since
948 // it's an input to soft ref clearing policy.
949 {
950 MutexLocker x(Heap_lock);
951 Universe::update_heap_info_at_gc();
952 }
954 // ("weak") refs processing infrastructure initialization
955 Universe::heap()->post_initialize();
957 GC_locker::unlock(); // allow gc after bootstrapping
959 MemoryService::set_universe_heap(Universe::_collectedHeap);
960 return true;
961 }
964 void Universe::compute_base_vtable_size() {
965 _base_vtable_size = ClassLoader::compute_Object_vtable();
966 }
969 // %%% The Universe::flush_foo methods belong in CodeCache.
971 // Flushes compiled methods dependent on dependee.
972 void Universe::flush_dependents_on(instanceKlassHandle dependee) {
973 assert_lock_strong(Compile_lock);
975 if (CodeCache::number_of_nmethods_with_dependencies() == 0) return;
977 // CodeCache can only be updated by a thread_in_VM and they will all be
978 // stopped dring the safepoint so CodeCache will be safe to update without
979 // holding the CodeCache_lock.
981 DepChange changes(dependee);
983 // Compute the dependent nmethods
984 if (CodeCache::mark_for_deoptimization(changes) > 0) {
985 // At least one nmethod has been marked for deoptimization
986 VM_Deoptimize op;
987 VMThread::execute(&op);
988 }
989 }
991 #ifdef HOTSWAP
992 // Flushes compiled methods dependent on dependee in the evolutionary sense
993 void Universe::flush_evol_dependents_on(instanceKlassHandle ev_k_h) {
994 // --- Compile_lock is not held. However we are at a safepoint.
995 assert_locked_or_safepoint(Compile_lock);
996 if (CodeCache::number_of_nmethods_with_dependencies() == 0) return;
998 // CodeCache can only be updated by a thread_in_VM and they will all be
999 // stopped dring the safepoint so CodeCache will be safe to update without
1000 // holding the CodeCache_lock.
1002 // Compute the dependent nmethods
1003 if (CodeCache::mark_for_evol_deoptimization(ev_k_h) > 0) {
1004 // At least one nmethod has been marked for deoptimization
1006 // All this already happens inside a VM_Operation, so we'll do all the work here.
1007 // Stuff copied from VM_Deoptimize and modified slightly.
1009 // We do not want any GCs to happen while we are in the middle of this VM operation
1010 ResourceMark rm;
1011 DeoptimizationMarker dm;
1013 // Deoptimize all activations depending on marked nmethods
1014 Deoptimization::deoptimize_dependents();
1016 // Make the dependent methods not entrant (in VM_Deoptimize they are made zombies)
1017 CodeCache::make_marked_nmethods_not_entrant();
1018 }
1019 }
1020 #endif // HOTSWAP
1023 // Flushes compiled methods dependent on dependee
1024 void Universe::flush_dependents_on_method(methodHandle m_h) {
1025 // --- Compile_lock is not held. However we are at a safepoint.
1026 assert_locked_or_safepoint(Compile_lock);
1028 // CodeCache can only be updated by a thread_in_VM and they will all be
1029 // stopped dring the safepoint so CodeCache will be safe to update without
1030 // holding the CodeCache_lock.
1032 // Compute the dependent nmethods
1033 if (CodeCache::mark_for_deoptimization(m_h()) > 0) {
1034 // At least one nmethod has been marked for deoptimization
1036 // All this already happens inside a VM_Operation, so we'll do all the work here.
1037 // Stuff copied from VM_Deoptimize and modified slightly.
1039 // We do not want any GCs to happen while we are in the middle of this VM operation
1040 ResourceMark rm;
1041 DeoptimizationMarker dm;
1043 // Deoptimize all activations depending on marked nmethods
1044 Deoptimization::deoptimize_dependents();
1046 // Make the dependent methods not entrant (in VM_Deoptimize they are made zombies)
1047 CodeCache::make_marked_nmethods_not_entrant();
1048 }
1049 }
1051 void Universe::print() { print_on(gclog_or_tty); }
1053 void Universe::print_on(outputStream* st) {
1054 st->print_cr("Heap");
1055 heap()->print_on(st);
1056 }
1058 void Universe::print_heap_at_SIGBREAK() {
1059 if (PrintHeapAtSIGBREAK) {
1060 MutexLocker hl(Heap_lock);
1061 print_on(tty);
1062 tty->cr();
1063 tty->flush();
1064 }
1065 }
1067 void Universe::print_heap_before_gc(outputStream* st) {
1068 st->print_cr("{Heap before GC invocations=%u (full %u):",
1069 heap()->total_collections(),
1070 heap()->total_full_collections());
1071 heap()->print_on(st);
1072 }
1074 void Universe::print_heap_after_gc(outputStream* st) {
1075 st->print_cr("Heap after GC invocations=%u (full %u):",
1076 heap()->total_collections(),
1077 heap()->total_full_collections());
1078 heap()->print_on(st);
1079 st->print_cr("}");
1080 }
1082 void Universe::verify(bool allow_dirty, bool silent) {
1083 if (SharedSkipVerify) {
1084 return;
1085 }
1087 // The use of _verify_in_progress is a temporary work around for
1088 // 6320749. Don't bother with a creating a class to set and clear
1089 // it since it is only used in this method and the control flow is
1090 // straight forward.
1091 _verify_in_progress = true;
1093 COMPILER2_PRESENT(
1094 assert(!DerivedPointerTable::is_active(),
1095 "DPT should not be active during verification "
1096 "(of thread stacks below)");
1097 )
1099 ResourceMark rm;
1100 HandleMark hm; // Handles created during verification can be zapped
1101 _verify_count++;
1103 if (!silent) gclog_or_tty->print("[Verifying ");
1104 if (!silent) gclog_or_tty->print("threads ");
1105 Threads::verify();
1106 heap()->verify(allow_dirty, silent);
1108 if (!silent) gclog_or_tty->print("syms ");
1109 SymbolTable::verify();
1110 if (!silent) gclog_or_tty->print("strs ");
1111 StringTable::verify();
1112 {
1113 MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1114 if (!silent) gclog_or_tty->print("zone ");
1115 CodeCache::verify();
1116 }
1117 if (!silent) gclog_or_tty->print("dict ");
1118 SystemDictionary::verify();
1119 if (!silent) gclog_or_tty->print("hand ");
1120 JNIHandles::verify();
1121 if (!silent) gclog_or_tty->print("C-heap ");
1122 os::check_heap();
1123 if (!silent) gclog_or_tty->print_cr("]");
1125 _verify_in_progress = false;
1126 }
1128 // Oop verification (see MacroAssembler::verify_oop)
1130 static uintptr_t _verify_oop_data[2] = {0, (uintptr_t)-1};
1131 static uintptr_t _verify_klass_data[2] = {0, (uintptr_t)-1};
1134 static void calculate_verify_data(uintptr_t verify_data[2],
1135 HeapWord* low_boundary,
1136 HeapWord* high_boundary) {
1137 assert(low_boundary < high_boundary, "bad interval");
1139 // decide which low-order bits we require to be clear:
1140 size_t alignSize = MinObjAlignmentInBytes;
1141 size_t min_object_size = oopDesc::header_size();
1143 // make an inclusive limit:
1144 uintptr_t max = (uintptr_t)high_boundary - min_object_size*wordSize;
1145 uintptr_t min = (uintptr_t)low_boundary;
1146 assert(min < max, "bad interval");
1147 uintptr_t diff = max ^ min;
1149 // throw away enough low-order bits to make the diff vanish
1150 uintptr_t mask = (uintptr_t)(-1);
1151 while ((mask & diff) != 0)
1152 mask <<= 1;
1153 uintptr_t bits = (min & mask);
1154 assert(bits == (max & mask), "correct mask");
1155 // check an intermediate value between min and max, just to make sure:
1156 assert(bits == ((min + (max-min)/2) & mask), "correct mask");
1158 // require address alignment, too:
1159 mask |= (alignSize - 1);
1161 if (!(verify_data[0] == 0 && verify_data[1] == (uintptr_t)-1)) {
1162 assert(verify_data[0] == mask && verify_data[1] == bits, "mask stability");
1163 }
1164 verify_data[0] = mask;
1165 verify_data[1] = bits;
1166 }
1169 // Oop verification (see MacroAssembler::verify_oop)
1170 #ifndef PRODUCT
1172 uintptr_t Universe::verify_oop_mask() {
1173 MemRegion m = heap()->reserved_region();
1174 calculate_verify_data(_verify_oop_data,
1175 m.start(),
1176 m.end());
1177 return _verify_oop_data[0];
1178 }
1182 uintptr_t Universe::verify_oop_bits() {
1183 verify_oop_mask();
1184 return _verify_oop_data[1];
1185 }
1188 uintptr_t Universe::verify_klass_mask() {
1189 /* $$$
1190 // A klass can never live in the new space. Since the new and old
1191 // spaces can change size, we must settle for bounds-checking against
1192 // the bottom of the world, plus the smallest possible new and old
1193 // space sizes that may arise during execution.
1194 size_t min_new_size = Universe::new_size(); // in bytes
1195 size_t min_old_size = Universe::old_size(); // in bytes
1196 calculate_verify_data(_verify_klass_data,
1197 (HeapWord*)((uintptr_t)_new_gen->low_boundary + min_new_size + min_old_size),
1198 _perm_gen->high_boundary);
1199 */
1200 // Why doesn't the above just say that klass's always live in the perm
1201 // gen? I'll see if that seems to work...
1202 MemRegion permanent_reserved;
1203 switch (Universe::heap()->kind()) {
1204 default:
1205 // ???: What if a CollectedHeap doesn't have a permanent generation?
1206 ShouldNotReachHere();
1207 break;
1208 case CollectedHeap::GenCollectedHeap:
1209 case CollectedHeap::G1CollectedHeap: {
1210 SharedHeap* sh = (SharedHeap*) Universe::heap();
1211 permanent_reserved = sh->perm_gen()->reserved();
1212 break;
1213 }
1214 #ifndef SERIALGC
1215 case CollectedHeap::ParallelScavengeHeap: {
1216 ParallelScavengeHeap* psh = (ParallelScavengeHeap*) Universe::heap();
1217 permanent_reserved = psh->perm_gen()->reserved();
1218 break;
1219 }
1220 #endif // SERIALGC
1221 }
1222 calculate_verify_data(_verify_klass_data,
1223 permanent_reserved.start(),
1224 permanent_reserved.end());
1226 return _verify_klass_data[0];
1227 }
1231 uintptr_t Universe::verify_klass_bits() {
1232 verify_klass_mask();
1233 return _verify_klass_data[1];
1234 }
1237 uintptr_t Universe::verify_mark_mask() {
1238 return markOopDesc::lock_mask_in_place;
1239 }
1243 uintptr_t Universe::verify_mark_bits() {
1244 intptr_t mask = verify_mark_mask();
1245 intptr_t bits = (intptr_t)markOopDesc::prototype();
1246 assert((bits & ~mask) == 0, "no stray header bits");
1247 return bits;
1248 }
1249 #endif // PRODUCT
1252 void Universe::compute_verify_oop_data() {
1253 verify_oop_mask();
1254 verify_oop_bits();
1255 verify_mark_mask();
1256 verify_mark_bits();
1257 verify_klass_mask();
1258 verify_klass_bits();
1259 }
1262 void CommonMethodOopCache::init(klassOop k, methodOop m, TRAPS) {
1263 if (!UseSharedSpaces) {
1264 _klass = k;
1265 }
1266 #ifndef PRODUCT
1267 else {
1268 // sharing initilization should have already set up _klass
1269 assert(_klass != NULL, "just checking");
1270 }
1271 #endif
1273 _method_idnum = m->method_idnum();
1274 assert(_method_idnum >= 0, "sanity check");
1275 }
1278 ActiveMethodOopsCache::~ActiveMethodOopsCache() {
1279 if (_prev_methods != NULL) {
1280 for (int i = _prev_methods->length() - 1; i >= 0; i--) {
1281 jweak method_ref = _prev_methods->at(i);
1282 if (method_ref != NULL) {
1283 JNIHandles::destroy_weak_global(method_ref);
1284 }
1285 }
1286 delete _prev_methods;
1287 _prev_methods = NULL;
1288 }
1289 }
1292 void ActiveMethodOopsCache::add_previous_version(const methodOop method) {
1293 assert(Thread::current()->is_VM_thread(),
1294 "only VMThread can add previous versions");
1296 if (_prev_methods == NULL) {
1297 // This is the first previous version so make some space.
1298 // Start with 2 elements under the assumption that the class
1299 // won't be redefined much.
1300 _prev_methods = new (ResourceObj::C_HEAP) GrowableArray<jweak>(2, true);
1301 }
1303 // RC_TRACE macro has an embedded ResourceMark
1304 RC_TRACE(0x00000100,
1305 ("add: %s(%s): adding prev version ref for cached method @%d",
1306 method->name()->as_C_string(), method->signature()->as_C_string(),
1307 _prev_methods->length()));
1309 methodHandle method_h(method);
1310 jweak method_ref = JNIHandles::make_weak_global(method_h);
1311 _prev_methods->append(method_ref);
1313 // Using weak references allows previous versions of the cached
1314 // method to be GC'ed when they are no longer needed. Since the
1315 // caller is the VMThread and we are at a safepoint, this is a good
1316 // time to clear out unused weak references.
1318 for (int i = _prev_methods->length() - 1; i >= 0; i--) {
1319 jweak method_ref = _prev_methods->at(i);
1320 assert(method_ref != NULL, "weak method ref was unexpectedly cleared");
1321 if (method_ref == NULL) {
1322 _prev_methods->remove_at(i);
1323 // Since we are traversing the array backwards, we don't have to
1324 // do anything special with the index.
1325 continue; // robustness
1326 }
1328 methodOop m = (methodOop)JNIHandles::resolve(method_ref);
1329 if (m == NULL) {
1330 // this method entry has been GC'ed so remove it
1331 JNIHandles::destroy_weak_global(method_ref);
1332 _prev_methods->remove_at(i);
1333 } else {
1334 // RC_TRACE macro has an embedded ResourceMark
1335 RC_TRACE(0x00000400, ("add: %s(%s): previous cached method @%d is alive",
1336 m->name()->as_C_string(), m->signature()->as_C_string(), i));
1337 }
1338 }
1339 } // end add_previous_version()
1342 bool ActiveMethodOopsCache::is_same_method(const methodOop method) const {
1343 instanceKlass* ik = instanceKlass::cast(klass());
1344 methodOop check_method = ik->method_with_idnum(method_idnum());
1345 assert(check_method != NULL, "sanity check");
1346 if (check_method == method) {
1347 // done with the easy case
1348 return true;
1349 }
1351 if (_prev_methods != NULL) {
1352 // The cached method has been redefined at least once so search
1353 // the previous versions for a match.
1354 for (int i = 0; i < _prev_methods->length(); i++) {
1355 jweak method_ref = _prev_methods->at(i);
1356 assert(method_ref != NULL, "weak method ref was unexpectedly cleared");
1357 if (method_ref == NULL) {
1358 continue; // robustness
1359 }
1361 check_method = (methodOop)JNIHandles::resolve(method_ref);
1362 if (check_method == method) {
1363 // a previous version matches
1364 return true;
1365 }
1366 }
1367 }
1369 // either no previous versions or no previous version matched
1370 return false;
1371 }
1374 methodOop LatestMethodOopCache::get_methodOop() {
1375 instanceKlass* ik = instanceKlass::cast(klass());
1376 methodOop m = ik->method_with_idnum(method_idnum());
1377 assert(m != NULL, "sanity check");
1378 return m;
1379 }
1382 #ifdef ASSERT
1383 // Release dummy object(s) at bottom of heap
1384 bool Universe::release_fullgc_alot_dummy() {
1385 MutexLocker ml(FullGCALot_lock);
1386 if (_fullgc_alot_dummy_array != NULL) {
1387 if (_fullgc_alot_dummy_next >= _fullgc_alot_dummy_array->length()) {
1388 // No more dummies to release, release entire array instead
1389 _fullgc_alot_dummy_array = NULL;
1390 return false;
1391 }
1392 if (!UseConcMarkSweepGC) {
1393 // Release dummy at bottom of old generation
1394 _fullgc_alot_dummy_array->obj_at_put(_fullgc_alot_dummy_next++, NULL);
1395 }
1396 // Release dummy at bottom of permanent generation
1397 _fullgc_alot_dummy_array->obj_at_put(_fullgc_alot_dummy_next++, NULL);
1398 }
1399 return true;
1400 }
1402 #endif // ASSERT