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.
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23 */
24
25 #ifndef SHARE_VM_MEMORY_UNIVERSE_HPP
26 #define SHARE_VM_MEMORY_UNIVERSE_HPP
27
28 #include "runtime/handles.hpp"
29 #include "utilities/array.hpp"
30 #include "utilities/growableArray.hpp"
31
32 // Universe is a name space holding known system classes and objects in the VM.
33 //
34 // Loaded classes are accessible through the SystemDictionary.
35 //
36 // The object heap is allocated and accessed through Universe, and various allocation
37 // support is provided. Allocation by the interpreter and compiled code is done inline
38 // and bails out to Scavenge::invoke_and_allocate.
39
40 class CollectedHeap;
41 class DeferredObjAllocEvent;
42
43
44 // Common parts of a Method* cache. This cache safely interacts with
45 // the RedefineClasses API.
46 //
47 class CommonMethodOopCache : public CHeapObj<mtClass> {
48 // We save the Klass* and the idnum of Method* in order to get
49 // the current cached Method*.
50 private:
51 Klass* _klass;
52 int _method_idnum;
53
54 public:
55 CommonMethodOopCache() { _klass = NULL; _method_idnum = -1; }
56 ~CommonMethodOopCache() { _klass = NULL; _method_idnum = -1; }
57
58 void init(Klass* k, Method* m, TRAPS);
59 Klass* klass() const { return _klass; }
60 int method_idnum() const { return _method_idnum; }
61
62 // Enhanced Class Redefinition support
63 void classes_do(void f(Klass*)) {
64 f(_klass);
65 }
66
67 // CDS support. Replace the klass in this with the archive version
68 // could use this for Enhanced Class Redefinition also.
69 void serialize(SerializeClosure* f) {
70 f->do_ptr((void**)&_klass);
71 }
72 };
73
74
75 // A helper class for caching a Method* when the user of the cache
76 // cares about all versions of the Method*.
77 //
78 class ActiveMethodOopsCache : public CommonMethodOopCache {
79 // This subclass adds weak references to older versions of the
80 // Method* and a query method for a Method*.
81
82 private:
83 // If the cached Method* has not been redefined, then
84 // _prev_methods will be NULL. If all of the previous
85 // versions of the method have been collected, then
86 // _prev_methods can have a length of zero.
87 GrowableArray<Method*>* _prev_methods;
88
89 public:
90 ActiveMethodOopsCache() { _prev_methods = NULL; }
91 ~ActiveMethodOopsCache();
92
93 void add_previous_version(Method* method);
94 bool is_same_method(const Method* method) const;
95 };
96
97
98 // A helper class for caching a Method* when the user of the cache
99 // only cares about the latest version of the Method*.
100 //
101 class LatestMethodOopCache : public CommonMethodOopCache {
102 // This subclass adds a getter method for the latest Method*.
103
104 public:
105 Method* get_Method();
106 };
107
108 // For UseCompressedOops.
109 struct NarrowPtrStruct {
110 // Base address for oop-within-java-object materialization.
111 // NULL if using wide oops or zero based narrow oops.
112 address _base;
113 // Number of shift bits for encoding/decoding narrow ptrs.
114 // 0 if using wide ptrs or zero based unscaled narrow ptrs,
115 // LogMinObjAlignmentInBytes/LogKlassAlignmentInBytes otherwise.
116 int _shift;
117 // Generate code with implicit null checks for narrow ptrs.
118 bool _use_implicit_null_checks;
119 };
120
121 enum VerifyOption {
122 VerifyOption_Default = 0,
123
124 // G1
125 VerifyOption_G1UsePrevMarking = VerifyOption_Default,
126 VerifyOption_G1UseNextMarking = VerifyOption_G1UsePrevMarking + 1,
127 VerifyOption_G1UseMarkWord = VerifyOption_G1UseNextMarking + 1
128 };
129
130 class Universe: AllStatic {
131 // Ugh. Universe is much too friendly.
132 friend class MarkSweep;
133 friend class oopDesc;
134 friend class ClassLoader;
135 friend class Arguments;
136 friend class SystemDictionary;
137 friend class VMStructs;
138 friend class VM_PopulateDumpSharedSpace;
139 friend class Metaspace;
140
141 friend jint universe_init();
142 friend void universe2_init();
143 friend bool universe_post_init();
144
145 private:
146 // Known classes in the VM
147 static Klass* _boolArrayKlassObj;
148 static Klass* _byteArrayKlassObj;
149 static Klass* _charArrayKlassObj;
150 static Klass* _intArrayKlassObj;
151 static Klass* _shortArrayKlassObj;
152 static Klass* _longArrayKlassObj;
153 static Klass* _singleArrayKlassObj;
154 static Klass* _doubleArrayKlassObj;
155 static Klass* _typeArrayKlassObjs[T_VOID+1];
156
157 static Klass* _objectArrayKlassObj;
158
159 // Known objects in the VM
160
161 // Primitive objects
162 static oop _int_mirror;
163 static oop _float_mirror;
164 static oop _double_mirror;
165 static oop _byte_mirror;
166 static oop _bool_mirror;
167 static oop _char_mirror;
168 static oop _long_mirror;
169 static oop _short_mirror;
170 static oop _void_mirror;
171
172 static oop _main_thread_group; // Reference to the main thread group object
173 static oop _system_thread_group; // Reference to the system thread group object
174
175 static objArrayOop _the_empty_class_klass_array; // Canonicalized obj array of type java.lang.Class
176 static oop _the_null_string; // A cache of "null" as a Java string
177 static oop _the_min_jint_string; // A cache of "-2147483648" as a Java string
178 static LatestMethodOopCache* _finalizer_register_cache; // static method for registering finalizable objects
179 static LatestMethodOopCache* _loader_addClass_cache; // method for registering loaded classes in class loader vector
180 static LatestMethodOopCache* _pd_implies_cache; // method for checking protection domain attributes
181 static ActiveMethodOopsCache* _reflect_invoke_cache; // method for security checks
182 // preallocated error objects (no backtrace)
183 static oop _out_of_memory_error_java_heap;
184 static oop _out_of_memory_error_metaspace;
185 static oop _out_of_memory_error_class_metaspace;
186 static oop _out_of_memory_error_array_size;
187 static oop _out_of_memory_error_gc_overhead_limit;
188
189 static Array<int>* _the_empty_int_array; // Canonicalized int array
190 static Array<u2>* _the_empty_short_array; // Canonicalized short array
191 static Array<Klass*>* _the_empty_klass_array; // Canonicalized klass obj array
192 static Array<Method*>* _the_empty_method_array; // Canonicalized method obj array
193
194 static Array<Klass*>* _the_array_interfaces_array;
195
196 // array of preallocated error objects with backtrace
197 static objArrayOop _preallocated_out_of_memory_error_array;
198
199 // number of preallocated error objects available for use
200 static volatile jint _preallocated_out_of_memory_error_avail_count;
201
202 static oop _null_ptr_exception_instance; // preallocated exception object
203 static oop _arithmetic_exception_instance; // preallocated exception object
204 static oop _virtual_machine_error_instance; // preallocated exception object
205 // The object used as an exception dummy when exceptions are thrown for
206 // the vm thread.
207 static oop _vm_exception;
208
209 // The particular choice of collected heap.
210 static CollectedHeap* _collectedHeap;
211
212 // For UseCompressedOops.
213 static struct NarrowPtrStruct _narrow_oop;
214 // For UseCompressedKlassPointers.
215 static struct NarrowPtrStruct _narrow_klass;
216 static address _narrow_ptrs_base;
217
218 // array of dummy objects used with +FullGCAlot
219 debug_only(static objArrayOop _fullgc_alot_dummy_array;)
220 // index of next entry to clear
221 debug_only(static int _fullgc_alot_dummy_next;)
222
223 // Compiler/dispatch support
224 static int _base_vtable_size; // Java vtbl size of klass Object (in words)
225
226 // Initialization
227 static bool _bootstrapping; // true during genesis
228 static bool _fully_initialized; // true after universe_init and initialize_vtables called
229
230 // the array of preallocated errors with backtraces
231 static objArrayOop preallocated_out_of_memory_errors() { return _preallocated_out_of_memory_error_array; }
232
233 // generate an out of memory error; if possible using an error with preallocated backtrace;
234 // otherwise return the given default error.
235 static oop gen_out_of_memory_error(oop default_err);
236
237 // Historic gc information
238 static size_t _heap_capacity_at_last_gc;
239 static size_t _heap_used_at_last_gc;
240
241 static jint initialize_heap();
242 static void initialize_basic_type_mirrors(TRAPS);
243 static void fixup_mirrors(TRAPS);
244
245 static void reinitialize_vtable_of(KlassHandle h_k, TRAPS);
246 static void reinitialize_itables(TRAPS);
247 static void compute_base_vtable_size(); // compute vtable size of class Object
248
249 static void genesis(TRAPS); // Create the initial world
250
251 // Mirrors for primitive classes (created eagerly)
252 static oop check_mirror(oop m) {
253 assert(m != NULL, "mirror not initialized");
254 return m;
255 }
256
257 static void set_narrow_oop_base(address base) {
258 assert(UseCompressedOops, "no compressed oops?");
259 _narrow_oop._base = base;
260 }
261 static void set_narrow_klass_base(address base) {
262 assert(UseCompressedKlassPointers, "no compressed klass ptrs?");
263 _narrow_klass._base = base;
264 }
265 static void set_narrow_oop_use_implicit_null_checks(bool use) {
266 assert(UseCompressedOops, "no compressed ptrs?");
267 _narrow_oop._use_implicit_null_checks = use;
268 }
269
270 // Debugging
271 static int _verify_count; // number of verifies done
272 // True during call to verify(). Should only be set/cleared in verify().
273 static bool _verify_in_progress;
274
275 static void compute_verify_oop_data();
276
277 public:
278 // Known classes in the VM
279 static Klass* boolArrayKlassObj() { return _boolArrayKlassObj; }
280 static Klass* byteArrayKlassObj() { return _byteArrayKlassObj; }
281 static Klass* charArrayKlassObj() { return _charArrayKlassObj; }
282 static Klass* intArrayKlassObj() { return _intArrayKlassObj; }
283 static Klass* shortArrayKlassObj() { return _shortArrayKlassObj; }
284 static Klass* longArrayKlassObj() { return _longArrayKlassObj; }
285 static Klass* singleArrayKlassObj() { return _singleArrayKlassObj; }
286 static Klass* doubleArrayKlassObj() { return _doubleArrayKlassObj; }
287
288 static Klass* objectArrayKlassObj() {
289 return _objectArrayKlassObj;
290 }
291
292 static Klass* typeArrayKlassObj(BasicType t) {
293 assert((uint)t < T_VOID+1, err_msg("range check for type: %s", type2name(t)));
294 assert(_typeArrayKlassObjs[t] != NULL, "domain check");
295 return _typeArrayKlassObjs[t];
296 }
297
298 // Known objects in the VM
299 static oop int_mirror() { return check_mirror(_int_mirror); }
300 static oop float_mirror() { return check_mirror(_float_mirror); }
301 static oop double_mirror() { return check_mirror(_double_mirror); }
302 static oop byte_mirror() { return check_mirror(_byte_mirror); }
303 static oop bool_mirror() { return check_mirror(_bool_mirror); }
304 static oop char_mirror() { return check_mirror(_char_mirror); }
305 static oop long_mirror() { return check_mirror(_long_mirror); }
306 static oop short_mirror() { return check_mirror(_short_mirror); }
307 static oop void_mirror() { return check_mirror(_void_mirror); }
308
309 // table of same
310 static oop _mirrors[T_VOID+1];
311
312 static oop java_mirror(BasicType t) {
313 assert((uint)t < T_VOID+1, "range check");
314 return check_mirror(_mirrors[t]);
315 }
316 static oop main_thread_group() { return _main_thread_group; }
317 static void set_main_thread_group(oop group) { _main_thread_group = group;}
318
319 static oop system_thread_group() { return _system_thread_group; }
320 static void set_system_thread_group(oop group) { _system_thread_group = group;}
321
322 static objArrayOop the_empty_class_klass_array () { return _the_empty_class_klass_array; }
323 static Array<Klass*>* the_array_interfaces_array() { return _the_array_interfaces_array; }
324 static oop the_null_string() { return _the_null_string; }
325 static oop the_min_jint_string() { return _the_min_jint_string; }
326 static Method* finalizer_register_method() { return _finalizer_register_cache->get_Method(); }
327 static Method* loader_addClass_method() { return _loader_addClass_cache->get_Method(); }
328
329 static Method* protection_domain_implies_method() { return _pd_implies_cache->get_Method(); }
330 static ActiveMethodOopsCache* reflect_invoke_cache() { return _reflect_invoke_cache; }
331
332 static oop null_ptr_exception_instance() { return _null_ptr_exception_instance; }
333 static oop arithmetic_exception_instance() { return _arithmetic_exception_instance; }
334 static oop virtual_machine_error_instance() { return _virtual_machine_error_instance; }
335 static oop vm_exception() { return _vm_exception; }
336
337 static Array<int>* the_empty_int_array() { return _the_empty_int_array; }
338 static Array<u2>* the_empty_short_array() { return _the_empty_short_array; }
339 static Array<Method*>* the_empty_method_array() { return _the_empty_method_array; }
340 static Array<Klass*>* the_empty_klass_array() { return _the_empty_klass_array; }
341
342 // OutOfMemoryError support. Returns an error with the required message. The returned error
343 // may or may not have a backtrace. If error has a backtrace then the stack trace is already
344 // filled in.
345 static oop out_of_memory_error_java_heap() { return gen_out_of_memory_error(_out_of_memory_error_java_heap); }
346 static oop out_of_memory_error_metaspace() { return gen_out_of_memory_error(_out_of_memory_error_metaspace); }
347 static oop out_of_memory_error_class_metaspace() { return gen_out_of_memory_error(_out_of_memory_error_class_metaspace); }
348 static oop out_of_memory_error_array_size() { return gen_out_of_memory_error(_out_of_memory_error_array_size); }
349 static oop out_of_memory_error_gc_overhead_limit() { return gen_out_of_memory_error(_out_of_memory_error_gc_overhead_limit); }
350
351 // Accessors needed for fast allocation
352 static Klass** boolArrayKlassObj_addr() { return &_boolArrayKlassObj; }
353 static Klass** byteArrayKlassObj_addr() { return &_byteArrayKlassObj; }
354 static Klass** charArrayKlassObj_addr() { return &_charArrayKlassObj; }
355 static Klass** intArrayKlassObj_addr() { return &_intArrayKlassObj; }
356 static Klass** shortArrayKlassObj_addr() { return &_shortArrayKlassObj; }
357 static Klass** longArrayKlassObj_addr() { return &_longArrayKlassObj; }
358 static Klass** singleArrayKlassObj_addr() { return &_singleArrayKlassObj; }
359 static Klass** doubleArrayKlassObj_addr() { return &_doubleArrayKlassObj; }
360 static Klass** objectArrayKlassObj_addr() { return &_objectArrayKlassObj; }
361
362 // The particular choice of collected heap.
363 static CollectedHeap* heap() { return _collectedHeap; }
364
365 // For UseCompressedOops
366 // Narrow Oop encoding mode:
367 // 0 - Use 32-bits oops without encoding when
368 // NarrowOopHeapBaseMin + heap_size < 4Gb
369 // 1 - Use zero based compressed oops with encoding when
370 // NarrowOopHeapBaseMin + heap_size < 32Gb
371 // 2 - Use compressed oops with heap base + encoding.
372 enum NARROW_OOP_MODE {
373 UnscaledNarrowOop = 0,
374 ZeroBasedNarrowOop = 1,
375 HeapBasedNarrowOop = 2
376 };
377 static NARROW_OOP_MODE narrow_oop_mode();
378 static const char* narrow_oop_mode_to_string(NARROW_OOP_MODE mode);
379 static char* preferred_heap_base(size_t heap_size, NARROW_OOP_MODE mode);
380 static char* preferred_metaspace_base(size_t heap_size, NARROW_OOP_MODE mode);
381 static address narrow_oop_base() { return _narrow_oop._base; }
382 static bool is_narrow_oop_base(void* addr) { return (narrow_oop_base() == (address)addr); }
383 static int narrow_oop_shift() { return _narrow_oop._shift; }
384 static bool narrow_oop_use_implicit_null_checks() { return _narrow_oop._use_implicit_null_checks; }
385
386 // For UseCompressedKlassPointers
387 static address narrow_klass_base() { return _narrow_klass._base; }
388 static bool is_narrow_klass_base(void* addr) { return (narrow_klass_base() == (address)addr); }
389 static int narrow_klass_shift() { return _narrow_klass._shift; }
390 static bool narrow_klass_use_implicit_null_checks() { return _narrow_klass._use_implicit_null_checks; }
391
392 static address* narrow_ptrs_base_addr() { return &_narrow_ptrs_base; }
393 static void set_narrow_ptrs_base(address a) { _narrow_ptrs_base = a; }
394 static address narrow_ptrs_base() { return _narrow_ptrs_base; }
395
396 // this is set in vm_version on sparc (and then reset in universe afaict)
397 static void set_narrow_oop_shift(int shift) {
398 _narrow_oop._shift = shift;
399 }
400
401 static void set_narrow_klass_shift(int shift) {
402 assert(shift == 0 || shift == LogKlassAlignmentInBytes, "invalid shift for klass ptrs");
403 _narrow_klass._shift = shift;
404 }
405
406 // Reserve Java heap and determine CompressedOops mode
407 static ReservedSpace reserve_heap(size_t heap_size, size_t alignment);
408
409 // Historic gc information
410 static size_t get_heap_capacity_at_last_gc() { return _heap_capacity_at_last_gc; }
411 static size_t get_heap_free_at_last_gc() { return _heap_capacity_at_last_gc - _heap_used_at_last_gc; }
412 static size_t get_heap_used_at_last_gc() { return _heap_used_at_last_gc; }
413 static void update_heap_info_at_gc();
414
415 // Testers
416 static bool is_bootstrapping() { return _bootstrapping; }
417 static bool is_fully_initialized() { return _fully_initialized; }
418
419 static inline bool element_type_should_be_aligned(BasicType type);
420 static inline bool field_type_should_be_aligned(BasicType type);
421 static bool on_page_boundary(void* addr);
422 static bool should_fill_in_stack_trace(Handle throwable);
423 static void check_alignment(uintx size, uintx alignment, const char* name);
424
425 // Finalizer support.
426 static void run_finalizers_on_exit();
427
428 // Iteration
429
430 // Apply "f" to the addresses of all the direct heap pointers maintained
431 // as static fields of "Universe".
432 static void oops_do(OopClosure* f, bool do_all = false);
433
434 // CDS support
435 static void serialize(SerializeClosure* f, bool do_all = false);
436
437 // Apply "f" to all klasses for basic types (classes not present in
438 // SystemDictionary).
439 static void basic_type_classes_do(void f(Klass*));
440
441 // For sharing -- fill in a list of known vtable pointers.
442 static void init_self_patching_vtbl_list(void** list, int count);
443
444 // Debugging
445 static bool verify_in_progress() { return _verify_in_progress; }
446 static void verify(VerifyOption option, const char* prefix, bool silent = VerifySilently);
447 static void verify(const char* prefix, bool silent = VerifySilently) {
448 verify(VerifyOption_Default, prefix, silent);
449 }
450 static void verify(bool silent = VerifySilently) {
451 verify("", silent);
452 }
453
454 static int verify_count() { return _verify_count; }
455 // The default behavior is to call print_on() on gclog_or_tty.
456 static void print();
457 // The extended parameter determines which method on the heap will
458 // be called: print_on() (extended == false) or print_extended_on()
459 // (extended == true).
460 static void print_on(outputStream* st, bool extended = false);
461 static void print_heap_at_SIGBREAK();
462 static void print_heap_before_gc() { print_heap_before_gc(gclog_or_tty); }
463 static void print_heap_after_gc() { print_heap_after_gc(gclog_or_tty); }
464 static void print_heap_before_gc(outputStream* st, bool ignore_extended = false);
465 static void print_heap_after_gc(outputStream* st, bool ignore_extended = false);
466
467 // Change the number of dummy objects kept reachable by the full gc dummy
468 // array; this should trigger relocation in a sliding compaction collector.
469 debug_only(static bool release_fullgc_alot_dummy();)
470 // The non-oop pattern (see compiledIC.hpp, etc)
471 static void* non_oop_word();
472
473 // Oop verification (see MacroAssembler::verify_oop)
474 static uintptr_t verify_oop_mask() PRODUCT_RETURN0;
475 static uintptr_t verify_oop_bits() PRODUCT_RETURN0;
476 static uintptr_t verify_mark_bits() PRODUCT_RETURN0;
477 static uintptr_t verify_mark_mask() PRODUCT_RETURN0;
478
479 // Flushing and deoptimization
480 static void flush_dependents_on(instanceKlassHandle dependee);
481 static void flush_dependents_on(Handle call_site, Handle method_handle);
482 #ifdef HOTSWAP
483 // Flushing and deoptimization in case of evolution
484 static void flush_evol_dependents_on(instanceKlassHandle dependee);
485 #endif // HOTSWAP
486 // Support for fullspeed debugging
487 static void flush_dependents_on_method(methodHandle dependee);
488
489 // Compiler support
490 static int base_vtable_size() { return _base_vtable_size; }
491 };
492
493 class DeferredObjAllocEvent : public CHeapObj<mtInternal> {
494 private:
495 oop _oop;
496 size_t _bytesize;
497 jint _arena_id;
498
499 public:
500 DeferredObjAllocEvent(const oop o, const size_t s, const jint id) {
501 _oop = o;
502 _bytesize = s;
503 _arena_id = id;
504 }
505
506 ~DeferredObjAllocEvent() {
507 }
508
509 jint arena_id() { return _arena_id; }
510 size_t bytesize() { return _bytesize; }
511 oop get_oop() { return _oop; }
512 };
513
514 #endif // SHARE_VM_MEMORY_UNIVERSE_HPP