1 /*
2 * Copyright (c) 1997, 2009, 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 // Universe is a name space holding known system classes and objects in the VM.
26 //
27 // Loaded classes are accessible through the SystemDictionary.
28 //
29 // The object heap is allocated and accessed through Universe, and various allocation
30 // support is provided. Allocation by the interpreter and compiled code is done inline
31 // and bails out to Scavenge::invoke_and_allocate.
32
33 class CollectedHeap;
34 class DeferredObjAllocEvent;
35
36
37 // Common parts of a methodOop cache. This cache safely interacts with
38 // the RedefineClasses API.
39 //
40 class CommonMethodOopCache : public CHeapObj {
41 // We save the klassOop and the idnum of methodOop in order to get
42 // the current cached methodOop.
43 private:
44 klassOop _klass;
45 int _method_idnum;
46
47 public:
48 CommonMethodOopCache() { _klass = NULL; _method_idnum = -1; }
49 ~CommonMethodOopCache() { _klass = NULL; _method_idnum = -1; }
50
51 void init(klassOop k, methodOop m, TRAPS);
52 klassOop klass() const { return _klass; }
53 int method_idnum() const { return _method_idnum; }
54
55 // GC support
56 void oops_do(OopClosure* f) { f->do_oop((oop*)&_klass); }
57 };
58
59
60 // A helper class for caching a methodOop when the user of the cache
61 // cares about all versions of the methodOop.
62 //
63 class ActiveMethodOopsCache : public CommonMethodOopCache {
64 // This subclass adds weak references to older versions of the
65 // methodOop and a query method for a methodOop.
66
67 private:
68 // If the cached methodOop has not been redefined, then
69 // _prev_methods will be NULL. If all of the previous
70 // versions of the method have been collected, then
71 // _prev_methods can have a length of zero.
72 GrowableArray<jweak>* _prev_methods;
73
74 public:
75 ActiveMethodOopsCache() { _prev_methods = NULL; }
76 ~ActiveMethodOopsCache();
77
78 void add_previous_version(const methodOop method);
79 bool is_same_method(const methodOop method) const;
80 };
81
82
83 // A helper class for caching a methodOop when the user of the cache
84 // only cares about the latest version of the methodOop.
85 //
86 class LatestMethodOopCache : public CommonMethodOopCache {
87 // This subclass adds a getter method for the latest methodOop.
88
89 public:
90 methodOop get_methodOop();
91 };
92
93 // For UseCompressedOops.
94 struct NarrowOopStruct {
95 // Base address for oop-within-java-object materialization.
96 // NULL if using wide oops or zero based narrow oops.
97 address _base;
98 // Number of shift bits for encoding/decoding narrow oops.
99 // 0 if using wide oops or zero based unscaled narrow oops,
100 // LogMinObjAlignmentInBytes otherwise.
101 int _shift;
102 // Generate code with implicit null checks for narrow oops.
103 bool _use_implicit_null_checks;
104 };
105
106
107 class Universe: AllStatic {
108 // Ugh. Universe is much too friendly.
109 friend class MarkSweep;
110 friend class oopDesc;
111 friend class ClassLoader;
112 friend class Arguments;
113 friend class SystemDictionary;
114 friend class VMStructs;
115 friend class CompactingPermGenGen;
116 friend class VM_PopulateDumpSharedSpace;
117
118 friend jint universe_init();
119 friend void universe2_init();
120 friend bool universe_post_init();
121
122 private:
123 // Known classes in the VM
124 static klassOop _boolArrayKlassObj;
125 static klassOop _byteArrayKlassObj;
126 static klassOop _charArrayKlassObj;
127 static klassOop _intArrayKlassObj;
128 static klassOop _shortArrayKlassObj;
129 static klassOop _longArrayKlassObj;
130 static klassOop _singleArrayKlassObj;
131 static klassOop _doubleArrayKlassObj;
132 static klassOop _typeArrayKlassObjs[T_VOID+1];
133
134 static klassOop _objectArrayKlassObj;
135
136 static klassOop _symbolKlassObj;
137 static klassOop _methodKlassObj;
138 static klassOop _constMethodKlassObj;
139 static klassOop _methodDataKlassObj;
140 static klassOop _klassKlassObj;
141 static klassOop _arrayKlassKlassObj;
142 static klassOop _objArrayKlassKlassObj;
143 static klassOop _typeArrayKlassKlassObj;
144 static klassOop _instanceKlassKlassObj;
145 static klassOop _constantPoolKlassObj;
146 static klassOop _constantPoolCacheKlassObj;
147 static klassOop _compiledICHolderKlassObj;
148 static klassOop _systemObjArrayKlassObj;
149
150 // Known objects in the VM
151
152 // Primitive objects
153 static oop _int_mirror;
154 static oop _float_mirror;
155 static oop _double_mirror;
156 static oop _byte_mirror;
157 static oop _bool_mirror;
158 static oop _char_mirror;
159 static oop _long_mirror;
160 static oop _short_mirror;
161 static oop _void_mirror;
162
163 static oop _main_thread_group; // Reference to the main thread group object
164 static oop _system_thread_group; // Reference to the system thread group object
165
166 static typeArrayOop _the_empty_byte_array; // Canonicalized byte array
167 static typeArrayOop _the_empty_short_array; // Canonicalized short array
168 static typeArrayOop _the_empty_int_array; // Canonicalized int array
169 static objArrayOop _the_empty_system_obj_array; // Canonicalized system obj array
170 static objArrayOop _the_empty_class_klass_array; // Canonicalized obj array of type java.lang.Class
171 static objArrayOop _the_array_interfaces_array; // Canonicalized 2-array of cloneable & serializable klasses
172 static oop _the_null_string; // A cache of "null" as a Java string
173 static oop _the_min_jint_string; // A cache of "-2147483648" as a Java string
174 static LatestMethodOopCache* _finalizer_register_cache; // static method for registering finalizable objects
175 static LatestMethodOopCache* _loader_addClass_cache; // method for registering loaded classes in class loader vector
176 static ActiveMethodOopsCache* _reflect_invoke_cache; // method for security checks
177 static oop _out_of_memory_error_java_heap; // preallocated error object (no backtrace)
178 static oop _out_of_memory_error_perm_gen; // preallocated error object (no backtrace)
179 static oop _out_of_memory_error_array_size;// preallocated error object (no backtrace)
180 static oop _out_of_memory_error_gc_overhead_limit; // preallocated error object (no backtrace)
181
182 // array of preallocated error objects with backtrace
183 static objArrayOop _preallocated_out_of_memory_error_array;
184
185 // number of preallocated error objects available for use
186 static volatile jint _preallocated_out_of_memory_error_avail_count;
187
188 static oop _null_ptr_exception_instance; // preallocated exception object
189 static oop _arithmetic_exception_instance; // preallocated exception object
190 static oop _virtual_machine_error_instance; // preallocated exception object
191 // The object used as an exception dummy when exceptions are thrown for
192 // the vm thread.
193 static oop _vm_exception;
194
195 static oop _emptySymbol; // Canonical empty string ("") symbol
196
197 // The particular choice of collected heap.
198 static CollectedHeap* _collectedHeap;
199
200 // For UseCompressedOops.
201 static struct NarrowOopStruct _narrow_oop;
202
203 // array of dummy objects used with +FullGCAlot
204 debug_only(static objArrayOop _fullgc_alot_dummy_array;)
205 // index of next entry to clear
206 debug_only(static int _fullgc_alot_dummy_next;)
207
208 // Compiler/dispatch support
209 static int _base_vtable_size; // Java vtbl size of klass Object (in words)
210
211 // Initialization
212 static bool _bootstrapping; // true during genesis
213 static bool _fully_initialized; // true after universe_init and initialize_vtables called
214
215 // the array of preallocated errors with backtraces
216 static objArrayOop preallocated_out_of_memory_errors() { return _preallocated_out_of_memory_error_array; }
217
218 // generate an out of memory error; if possible using an error with preallocated backtrace;
219 // otherwise return the given default error.
220 static oop gen_out_of_memory_error(oop default_err);
221
222 // Historic gc information
223 static size_t _heap_capacity_at_last_gc;
224 static size_t _heap_used_at_last_gc;
225
226 static jint initialize_heap();
227 static void initialize_basic_type_mirrors(TRAPS);
228 static void fixup_mirrors(TRAPS);
229
230 static void reinitialize_vtable_of(KlassHandle h_k, TRAPS);
231 static void reinitialize_itables(TRAPS);
232 static void compute_base_vtable_size(); // compute vtable size of class Object
233
234 static void genesis(TRAPS); // Create the initial world
235
236 // Mirrors for primitive classes (created eagerly)
237 static oop check_mirror(oop m) {
238 assert(m != NULL, "mirror not initialized");
239 return m;
240 }
241
242 // Debugging
243 static int _verify_count; // number of verifies done
244 // True during call to verify(). Should only be set/cleared in verify().
245 static bool _verify_in_progress;
246
247 static void compute_verify_oop_data();
248
249 public:
250 // Known classes in the VM
251 static klassOop boolArrayKlassObj() { return _boolArrayKlassObj; }
252 static klassOop byteArrayKlassObj() { return _byteArrayKlassObj; }
253 static klassOop charArrayKlassObj() { return _charArrayKlassObj; }
254 static klassOop intArrayKlassObj() { return _intArrayKlassObj; }
255 static klassOop shortArrayKlassObj() { return _shortArrayKlassObj; }
256 static klassOop longArrayKlassObj() { return _longArrayKlassObj; }
257 static klassOop singleArrayKlassObj() { return _singleArrayKlassObj; }
258 static klassOop doubleArrayKlassObj() { return _doubleArrayKlassObj; }
259
260 static klassOop objectArrayKlassObj() {
261 return _objectArrayKlassObj;
262 }
263
264 static klassOop typeArrayKlassObj(BasicType t) {
265 assert((uint)t < T_VOID+1, "range check");
266 assert(_typeArrayKlassObjs[t] != NULL, "domain check");
267 return _typeArrayKlassObjs[t];
268 }
269
270 static klassOop symbolKlassObj() { return _symbolKlassObj; }
271 static klassOop methodKlassObj() { return _methodKlassObj; }
272 static klassOop constMethodKlassObj() { return _constMethodKlassObj; }
273 static klassOop methodDataKlassObj() { return _methodDataKlassObj; }
274 static klassOop klassKlassObj() { return _klassKlassObj; }
275 static klassOop arrayKlassKlassObj() { return _arrayKlassKlassObj; }
276 static klassOop objArrayKlassKlassObj() { return _objArrayKlassKlassObj; }
277 static klassOop typeArrayKlassKlassObj() { return _typeArrayKlassKlassObj; }
278 static klassOop instanceKlassKlassObj() { return _instanceKlassKlassObj; }
279 static klassOop constantPoolKlassObj() { return _constantPoolKlassObj; }
280 static klassOop constantPoolCacheKlassObj() { return _constantPoolCacheKlassObj; }
281 static klassOop compiledICHolderKlassObj() { return _compiledICHolderKlassObj; }
282 static klassOop systemObjArrayKlassObj() { return _systemObjArrayKlassObj; }
283
284 // Known objects in tbe VM
285 static oop int_mirror() { return check_mirror(_int_mirror);
286 }
287 static oop float_mirror() { return check_mirror(_float_mirror); }
288 static oop double_mirror() { return check_mirror(_double_mirror); }
289 static oop byte_mirror() { return check_mirror(_byte_mirror); }
290 static oop bool_mirror() { return check_mirror(_bool_mirror); }
291 static oop char_mirror() { return check_mirror(_char_mirror); }
292 static oop long_mirror() { return check_mirror(_long_mirror); }
293 static oop short_mirror() { return check_mirror(_short_mirror); }
294 static oop void_mirror() { return check_mirror(_void_mirror); }
295
296 // table of same
297 static oop _mirrors[T_VOID+1];
298
299 static oop java_mirror(BasicType t) {
300 assert((uint)t < T_VOID+1, "range check");
301 return check_mirror(_mirrors[t]);
302 }
303 static oop main_thread_group() { return _main_thread_group; }
304 static void set_main_thread_group(oop group) { _main_thread_group = group;}
305
306 static oop system_thread_group() { return _system_thread_group; }
307 static void set_system_thread_group(oop group) { _system_thread_group = group;}
308
309 static typeArrayOop the_empty_byte_array() { return _the_empty_byte_array; }
310 static typeArrayOop the_empty_short_array() { return _the_empty_short_array; }
311 static typeArrayOop the_empty_int_array() { return _the_empty_int_array; }
312 static objArrayOop the_empty_system_obj_array () { return _the_empty_system_obj_array; }
313 static objArrayOop the_empty_class_klass_array () { return _the_empty_class_klass_array; }
314 static objArrayOop the_array_interfaces_array() { return _the_array_interfaces_array; }
315 static oop the_null_string() { return _the_null_string; }
316 static oop the_min_jint_string() { return _the_min_jint_string; }
317 static methodOop finalizer_register_method() { return _finalizer_register_cache->get_methodOop(); }
318 static methodOop loader_addClass_method() { return _loader_addClass_cache->get_methodOop(); }
319 static ActiveMethodOopsCache* reflect_invoke_cache() { return _reflect_invoke_cache; }
320 static oop null_ptr_exception_instance() { return _null_ptr_exception_instance; }
321 static oop arithmetic_exception_instance() { return _arithmetic_exception_instance; }
322 static oop virtual_machine_error_instance() { return _virtual_machine_error_instance; }
323 static oop vm_exception() { return _vm_exception; }
324 static oop emptySymbol() { return _emptySymbol; }
325
326 // OutOfMemoryError support. Returns an error with the required message. The returned error
327 // may or may not have a backtrace. If error has a backtrace then the stack trace is already
328 // filled in.
329 static oop out_of_memory_error_java_heap() { return gen_out_of_memory_error(_out_of_memory_error_java_heap); }
330 static oop out_of_memory_error_perm_gen() { return gen_out_of_memory_error(_out_of_memory_error_perm_gen); }
331 static oop out_of_memory_error_array_size() { return gen_out_of_memory_error(_out_of_memory_error_array_size); }
332 static oop out_of_memory_error_gc_overhead_limit() { return gen_out_of_memory_error(_out_of_memory_error_gc_overhead_limit); }
333
334 // Accessors needed for fast allocation
335 static klassOop* boolArrayKlassObj_addr() { return &_boolArrayKlassObj; }
336 static klassOop* byteArrayKlassObj_addr() { return &_byteArrayKlassObj; }
337 static klassOop* charArrayKlassObj_addr() { return &_charArrayKlassObj; }
338 static klassOop* intArrayKlassObj_addr() { return &_intArrayKlassObj; }
339 static klassOop* shortArrayKlassObj_addr() { return &_shortArrayKlassObj; }
340 static klassOop* longArrayKlassObj_addr() { return &_longArrayKlassObj; }
341 static klassOop* singleArrayKlassObj_addr() { return &_singleArrayKlassObj; }
342 static klassOop* doubleArrayKlassObj_addr() { return &_doubleArrayKlassObj; }
343
344 // The particular choice of collected heap.
345 static CollectedHeap* heap() { return _collectedHeap; }
346
347 // For UseCompressedOops
348 static address* narrow_oop_base_addr() { return &_narrow_oop._base; }
349 static address narrow_oop_base() { return _narrow_oop._base; }
350 static bool is_narrow_oop_base(void* addr) { return (narrow_oop_base() == (address)addr); }
351 static int narrow_oop_shift() { return _narrow_oop._shift; }
352 static void set_narrow_oop_base(address base) { _narrow_oop._base = base; }
353 static void set_narrow_oop_shift(int shift) { _narrow_oop._shift = shift; }
354 static bool narrow_oop_use_implicit_null_checks() { return _narrow_oop._use_implicit_null_checks; }
355 static void set_narrow_oop_use_implicit_null_checks(bool use) { _narrow_oop._use_implicit_null_checks = use; }
356 // Narrow Oop encoding mode:
357 // 0 - Use 32-bits oops without encoding when
358 // NarrowOopHeapBaseMin + heap_size < 4Gb
359 // 1 - Use zero based compressed oops with encoding when
360 // NarrowOopHeapBaseMin + heap_size < 32Gb
361 // 2 - Use compressed oops with heap base + encoding.
362 enum NARROW_OOP_MODE {
363 UnscaledNarrowOop = 0,
364 ZeroBasedNarrowOop = 1,
365 HeapBasedNarrowOop = 2
366 };
367 static char* preferred_heap_base(size_t heap_size, NARROW_OOP_MODE mode);
368
369 // Historic gc information
370 static size_t get_heap_capacity_at_last_gc() { return _heap_capacity_at_last_gc; }
371 static size_t get_heap_free_at_last_gc() { return _heap_capacity_at_last_gc - _heap_used_at_last_gc; }
372 static size_t get_heap_used_at_last_gc() { return _heap_used_at_last_gc; }
373 static void update_heap_info_at_gc();
374
375 // Testers
376 static bool is_bootstrapping() { return _bootstrapping; }
377 static bool is_fully_initialized() { return _fully_initialized; }
378
379 static inline bool element_type_should_be_aligned(BasicType type);
380 static inline bool field_type_should_be_aligned(BasicType type);
381 static bool on_page_boundary(void* addr);
382 static bool should_fill_in_stack_trace(Handle throwable);
383 static void check_alignment(uintx size, uintx alignment, const char* name);
384
385 // Finalizer support.
386 static void run_finalizers_on_exit();
387
388 // Iteration
389
390 // Apply "f" to the addresses of all the direct heap pointers maintained
391 // as static fields of "Universe".
392 static void oops_do(OopClosure* f, bool do_all = false);
393
394 // Apply "f" to all klasses for basic types (classes not present in
395 // SystemDictionary).
396 static void basic_type_classes_do(void f(klassOop));
397
398 // Apply "f" to all system klasses (classes not present in SystemDictionary).
399 static void system_classes_do(void f(klassOop));
400
401 // For sharing -- fill in a list of known vtable pointers.
402 static void init_self_patching_vtbl_list(void** list, int count);
403
404 // Debugging
405 static bool verify_in_progress() { return _verify_in_progress; }
406 static void verify(bool allow_dirty = true, bool silent = false, bool option = true);
407 static int verify_count() { return _verify_count; }
408 static void print();
409 static void print_on(outputStream* st);
410 static void print_heap_at_SIGBREAK();
411 static void print_heap_before_gc() { print_heap_before_gc(gclog_or_tty); }
412 static void print_heap_after_gc() { print_heap_after_gc(gclog_or_tty); }
413 static void print_heap_before_gc(outputStream* st);
414 static void print_heap_after_gc(outputStream* st);
415
416 // Change the number of dummy objects kept reachable by the full gc dummy
417 // array; this should trigger relocation in a sliding compaction collector.
418 debug_only(static bool release_fullgc_alot_dummy();)
419 // The non-oop pattern (see compiledIC.hpp, etc)
420 static void* non_oop_word();
421
422 // Oop verification (see MacroAssembler::verify_oop)
423 static uintptr_t verify_oop_mask() PRODUCT_RETURN0;
424 static uintptr_t verify_oop_bits() PRODUCT_RETURN0;
425 static uintptr_t verify_mark_bits() PRODUCT_RETURN0;
426 static uintptr_t verify_mark_mask() PRODUCT_RETURN0;
427 static uintptr_t verify_klass_mask() PRODUCT_RETURN0;
428 static uintptr_t verify_klass_bits() PRODUCT_RETURN0;
429
430 // Flushing and deoptimization
431 static void flush_dependents_on(instanceKlassHandle dependee);
432 #ifdef HOTSWAP
433 // Flushing and deoptimization in case of evolution
434 static void flush_evol_dependents_on(instanceKlassHandle dependee);
435 #endif // HOTSWAP
436 // Support for fullspeed debugging
437 static void flush_dependents_on_method(methodHandle dependee);
438
439 // Compiler support
440 static int base_vtable_size() { return _base_vtable_size; }
441 };
442
443 class DeferredObjAllocEvent : public CHeapObj {
444 private:
445 oop _oop;
446 size_t _bytesize;
447 jint _arena_id;
448
449 public:
450 DeferredObjAllocEvent(const oop o, const size_t s, const jint id) {
451 _oop = o;
452 _bytesize = s;
453 _arena_id = id;
454 }
455
456 ~DeferredObjAllocEvent() {
457 }
458
459 jint arena_id() { return _arena_id; }
460 size_t bytesize() { return _bytesize; }
461 oop get_oop() { return _oop; }
462 };