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