1 /*
2 * Copyright (c) 1997, 2015, 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 SystemDictionary;
106 friend class ReservedHeapSpace;
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 static LatestMethodCache* _throw_illegal_access_error_cache; // Unsafe.throwIllegalAccessError() method
152 static LatestMethodCache* _do_stack_walk_cache; // method for stack walker callback
153
154 // preallocated error objects (no backtrace)
155 static oop _out_of_memory_error_java_heap;
156 static oop _out_of_memory_error_metaspace;
157 static oop _out_of_memory_error_class_metaspace;
158 static oop _out_of_memory_error_array_size;
159 static oop _out_of_memory_error_gc_overhead_limit;
160 static oop _out_of_memory_error_realloc_objects;
161
162 // preallocated cause message for delayed StackOverflowError
163 static oop _delayed_stack_overflow_error_message;
164
165 static Array<int>* _the_empty_int_array; // Canonicalized int array
166 static Array<u2>* _the_empty_short_array; // Canonicalized short array
167 static Array<Klass*>* _the_empty_klass_array; // Canonicalized klass obj array
168 static Array<Method*>* _the_empty_method_array; // Canonicalized method obj array
169
170 static Array<Klass*>* _the_array_interfaces_array;
171
172 // array of preallocated error objects with backtrace
173 static objArrayOop _preallocated_out_of_memory_error_array;
174
175 // number of preallocated error objects available for use
176 static volatile jint _preallocated_out_of_memory_error_avail_count;
177
178 static oop _null_ptr_exception_instance; // preallocated exception object
179 static oop _arithmetic_exception_instance; // preallocated exception object
180 static oop _virtual_machine_error_instance; // preallocated exception object
181 // The object used as an exception dummy when exceptions are thrown for
182 // the vm thread.
183 static oop _vm_exception;
184
185 static oop _allocation_context_notification_obj;
186
187 // The particular choice of collected heap.
188 static CollectedHeap* _collectedHeap;
189
190 static intptr_t _non_oop_bits;
191
192 // For UseCompressedOops.
193 static struct NarrowPtrStruct _narrow_oop;
194 // For UseCompressedClassPointers.
195 static struct NarrowPtrStruct _narrow_klass;
196 static address _narrow_ptrs_base;
197
198 // array of dummy objects used with +FullGCAlot
199 debug_only(static objArrayOop _fullgc_alot_dummy_array;)
200 // index of next entry to clear
201 debug_only(static int _fullgc_alot_dummy_next;)
202
203 // Compiler/dispatch support
204 static int _base_vtable_size; // Java vtbl size of klass Object (in words)
205
206 // Initialization
207 static bool _bootstrapping; // true during genesis
208 static bool _fully_initialized; // true after universe_init and initialize_vtables called
209
210 // the array of preallocated errors with backtraces
211 static objArrayOop preallocated_out_of_memory_errors() { return _preallocated_out_of_memory_error_array; }
212
213 // generate an out of memory error; if possible using an error with preallocated backtrace;
214 // otherwise return the given default error.
215 static oop gen_out_of_memory_error(oop default_err);
216
217 // Historic gc information
218 static size_t _heap_capacity_at_last_gc;
219 static size_t _heap_used_at_last_gc;
220
221 template <class Heap, class Policy> static CollectedHeap* create_heap_with_policy();
222 static CollectedHeap* create_heap();
223 static CollectedHeap* create_heap_ext();
224 static jint initialize_heap();
225 static void initialize_basic_type_mirrors(TRAPS);
226 static void fixup_mirrors(TRAPS);
227
228 static void reinitialize_vtable_of(KlassHandle h_k, TRAPS);
229 static void reinitialize_itables(TRAPS);
230 static void compute_base_vtable_size(); // compute vtable size of class Object
231
232 static void genesis(TRAPS); // Create the initial world
233
234 // Mirrors for primitive classes (created eagerly)
235 static oop check_mirror(oop m) {
236 assert(m != NULL, "mirror not initialized");
237 return m;
238 }
239
240 static void set_narrow_oop_base(address base) {
241 assert(UseCompressedOops, "no compressed oops?");
242 _narrow_oop._base = base;
243 }
244 static void set_narrow_klass_base(address base) {
245 assert(UseCompressedClassPointers, "no compressed klass ptrs?");
246 _narrow_klass._base = base;
247 }
248 static void set_narrow_oop_use_implicit_null_checks(bool use) {
249 assert(UseCompressedOops, "no compressed ptrs?");
250 _narrow_oop._use_implicit_null_checks = use;
251 }
252
253 // Debugging
254 static int _verify_count; // number of verifies done
255
256 // True during call to verify(). Should only be set/cleared in verify().
257 static bool _verify_in_progress;
258 static long verify_flags;
259
260 static uintptr_t _verify_oop_mask;
261 static uintptr_t _verify_oop_bits;
262
263 static void calculate_verify_data(HeapWord* low_boundary, HeapWord* high_boundary) PRODUCT_RETURN;
264 static void compute_verify_oop_data();
265
266 public:
267 // Known classes in the VM
268 static Klass* boolArrayKlassObj() { return _boolArrayKlassObj; }
269 static Klass* byteArrayKlassObj() { return _byteArrayKlassObj; }
270 static Klass* charArrayKlassObj() { return _charArrayKlassObj; }
271 static Klass* intArrayKlassObj() { return _intArrayKlassObj; }
272 static Klass* shortArrayKlassObj() { return _shortArrayKlassObj; }
273 static Klass* longArrayKlassObj() { return _longArrayKlassObj; }
274 static Klass* singleArrayKlassObj() { return _singleArrayKlassObj; }
275 static Klass* doubleArrayKlassObj() { return _doubleArrayKlassObj; }
276
277 static Klass* objectArrayKlassObj() {
278 return _objectArrayKlassObj;
279 }
280
281 static Klass* typeArrayKlassObj(BasicType t) {
282 assert((uint)t < T_VOID+1, "range check for type: %s", type2name(t));
283 assert(_typeArrayKlassObjs[t] != NULL, "domain check");
284 return _typeArrayKlassObjs[t];
285 }
286
287 // Known objects in the VM
288 static oop int_mirror() { return check_mirror(_int_mirror); }
289 static oop float_mirror() { return check_mirror(_float_mirror); }
290 static oop double_mirror() { return check_mirror(_double_mirror); }
291 static oop byte_mirror() { return check_mirror(_byte_mirror); }
292 static oop bool_mirror() { return check_mirror(_bool_mirror); }
293 static oop char_mirror() { return check_mirror(_char_mirror); }
294 static oop long_mirror() { return check_mirror(_long_mirror); }
295 static oop short_mirror() { return check_mirror(_short_mirror); }
296 static oop void_mirror() { return check_mirror(_void_mirror); }
297
298 // table of same
299 static oop _mirrors[T_VOID+1];
300
301 static oop java_mirror(BasicType t) {
302 assert((uint)t < T_VOID+1, "range check");
303 return check_mirror(_mirrors[t]);
304 }
305 static oop main_thread_group() { return _main_thread_group; }
306 static void set_main_thread_group(oop group) { _main_thread_group = group;}
307
308 static oop system_thread_group() { return _system_thread_group; }
309 static void set_system_thread_group(oop group) { _system_thread_group = group;}
310
311 static objArrayOop the_empty_class_klass_array () { return _the_empty_class_klass_array; }
312 static Array<Klass*>* the_array_interfaces_array() { return _the_array_interfaces_array; }
313 static oop the_null_string() { return _the_null_string; }
314 static oop the_min_jint_string() { return _the_min_jint_string; }
315
316 static Method* finalizer_register_method() { return _finalizer_register_cache->get_method(); }
317 static Method* loader_addClass_method() { return _loader_addClass_cache->get_method(); }
318
319 static Method* protection_domain_implies_method() { return _pd_implies_cache->get_method(); }
320 static Method* throw_illegal_access_error() { return _throw_illegal_access_error_cache->get_method(); }
321
322 static Method* do_stack_walk_method() { return _do_stack_walk_cache->get_method(); }
323
324 static oop null_ptr_exception_instance() { return _null_ptr_exception_instance; }
325 static oop arithmetic_exception_instance() { return _arithmetic_exception_instance; }
326 static oop virtual_machine_error_instance() { return _virtual_machine_error_instance; }
327 static oop vm_exception() { return _vm_exception; }
328
329 static inline oop allocation_context_notification_obj();
330 static inline void set_allocation_context_notification_obj(oop obj);
331
332 static Array<int>* the_empty_int_array() { return _the_empty_int_array; }
333 static Array<u2>* the_empty_short_array() { return _the_empty_short_array; }
334 static Array<Method*>* the_empty_method_array() { return _the_empty_method_array; }
335 static Array<Klass*>* the_empty_klass_array() { return _the_empty_klass_array; }
336
337 // OutOfMemoryError support. Returns an error with the required message. The returned error
338 // may or may not have a backtrace. If error has a backtrace then the stack trace is already
339 // filled in.
340 static oop out_of_memory_error_java_heap() { return gen_out_of_memory_error(_out_of_memory_error_java_heap); }
341 static oop out_of_memory_error_metaspace() { return gen_out_of_memory_error(_out_of_memory_error_metaspace); }
342 static oop out_of_memory_error_class_metaspace() { return gen_out_of_memory_error(_out_of_memory_error_class_metaspace); }
343 static oop out_of_memory_error_array_size() { return gen_out_of_memory_error(_out_of_memory_error_array_size); }
344 static oop out_of_memory_error_gc_overhead_limit() { return gen_out_of_memory_error(_out_of_memory_error_gc_overhead_limit); }
345 static oop out_of_memory_error_realloc_objects() { return gen_out_of_memory_error(_out_of_memory_error_realloc_objects); }
346 static oop delayed_stack_overflow_error_message() { return _delayed_stack_overflow_error_message; }
347
348 // Accessors needed for fast allocation
349 static Klass** boolArrayKlassObj_addr() { return &_boolArrayKlassObj; }
350 static Klass** byteArrayKlassObj_addr() { return &_byteArrayKlassObj; }
351 static Klass** charArrayKlassObj_addr() { return &_charArrayKlassObj; }
352 static Klass** intArrayKlassObj_addr() { return &_intArrayKlassObj; }
353 static Klass** shortArrayKlassObj_addr() { return &_shortArrayKlassObj; }
354 static Klass** longArrayKlassObj_addr() { return &_longArrayKlassObj; }
355 static Klass** singleArrayKlassObj_addr() { return &_singleArrayKlassObj; }
356 static Klass** doubleArrayKlassObj_addr() { return &_doubleArrayKlassObj; }
357 static Klass** objectArrayKlassObj_addr() { return &_objectArrayKlassObj; }
358
359 // The particular choice of collected heap.
360 static CollectedHeap* heap() { return _collectedHeap; }
361
362 // For UseCompressedOops
363 // Narrow Oop encoding mode:
364 // 0 - Use 32-bits oops without encoding when
365 // NarrowOopHeapBaseMin + heap_size < 4Gb
366 // 1 - Use zero based compressed oops with encoding when
367 // NarrowOopHeapBaseMin + heap_size < 32Gb
368 // 2 - Use compressed oops with disjoint heap base if
369 // base is 32G-aligned and base > 0. This allows certain
370 // optimizations in encoding/decoding.
371 // Disjoint: Bits used in base are disjoint from bits used
372 // for oops ==> oop = (cOop << 3) | base. One can disjoint
373 // the bits of an oop into base and compressed oop.
374 // 3 - Use compressed oops with heap base + encoding.
375 enum NARROW_OOP_MODE {
376 UnscaledNarrowOop = 0,
377 ZeroBasedNarrowOop = 1,
378 DisjointBaseNarrowOop = 2,
379 HeapBasedNarrowOop = 3,
380 AnyNarrowOopMode = 4
381 };
382 static NARROW_OOP_MODE narrow_oop_mode();
383 static const char* narrow_oop_mode_to_string(NARROW_OOP_MODE mode);
384 static char* preferred_heap_base(size_t heap_size, size_t alignment, NARROW_OOP_MODE mode);
385 static char* preferred_metaspace_base(size_t heap_size, NARROW_OOP_MODE mode);
386 static address narrow_oop_base() { return _narrow_oop._base; }
387 // Test whether bits of addr and possible offsets into the heap overlap.
388 static bool is_disjoint_heap_base_address(address addr) {
389 return (((uint64_t)(intptr_t)addr) &
390 (((uint64_t)UCONST64(0xFFFFffffFFFFffff)) >> (32-LogMinObjAlignmentInBytes))) == 0;
391 }
392 // Check for disjoint base compressed oops.
393 static bool narrow_oop_base_disjoint() {
394 return _narrow_oop._base != NULL && is_disjoint_heap_base_address(_narrow_oop._base);
395 }
396 // Check for real heapbased compressed oops.
397 // We must subtract the base as the bits overlap.
398 // If we negate above function, we also get unscaled and zerobased.
399 static bool narrow_oop_base_overlaps() {
400 return _narrow_oop._base != NULL && !is_disjoint_heap_base_address(_narrow_oop._base);
401 }
402 static bool is_narrow_oop_base(void* addr) { return (narrow_oop_base() == (address)addr); }
403 static int narrow_oop_shift() { return _narrow_oop._shift; }
404 static bool narrow_oop_use_implicit_null_checks() { return _narrow_oop._use_implicit_null_checks; }
405
406 // For UseCompressedClassPointers
407 static address narrow_klass_base() { return _narrow_klass._base; }
408 static bool is_narrow_klass_base(void* addr) { return (narrow_klass_base() == (address)addr); }
409 static int narrow_klass_shift() { return _narrow_klass._shift; }
410 static bool narrow_klass_use_implicit_null_checks() { return _narrow_klass._use_implicit_null_checks; }
411
412 static address* narrow_ptrs_base_addr() { return &_narrow_ptrs_base; }
413 static void set_narrow_ptrs_base(address a) { _narrow_ptrs_base = a; }
414 static address narrow_ptrs_base() { return _narrow_ptrs_base; }
415
416 static void print_compressed_oops_mode(outputStream* st);
417
418 // this is set in vm_version on sparc (and then reset in universe afaict)
419 static void set_narrow_oop_shift(int shift) {
420 _narrow_oop._shift = shift;
421 }
422
423 static void set_narrow_klass_shift(int shift) {
424 assert(shift == 0 || shift == LogKlassAlignmentInBytes, "invalid shift for klass ptrs");
425 _narrow_klass._shift = shift;
426 }
427
428 // Reserve Java heap and determine CompressedOops mode
429 static ReservedSpace reserve_heap(size_t heap_size, size_t alignment);
430
431 // Historic gc information
432 static size_t get_heap_capacity_at_last_gc() { return _heap_capacity_at_last_gc; }
433 static size_t get_heap_free_at_last_gc() { return _heap_capacity_at_last_gc - _heap_used_at_last_gc; }
434 static size_t get_heap_used_at_last_gc() { return _heap_used_at_last_gc; }
435 static void update_heap_info_at_gc();
436
437 // Testers
438 static bool is_bootstrapping() { return _bootstrapping; }
439 static bool is_fully_initialized() { return _fully_initialized; }
440
441 static inline bool element_type_should_be_aligned(BasicType type);
442 static inline bool field_type_should_be_aligned(BasicType type);
443 static bool on_page_boundary(void* addr);
444 static bool should_fill_in_stack_trace(Handle throwable);
445 static void check_alignment(uintx size, uintx alignment, const char* name);
446
447 // Finalizer support.
448 static void run_finalizers_on_exit();
449
450 // Iteration
451
452 // Apply "f" to the addresses of all the direct heap pointers maintained
453 // as static fields of "Universe".
454 static void oops_do(OopClosure* f, bool do_all = false);
455
456 // CDS support
457 static void serialize(SerializeClosure* f, bool do_all = false);
458
459 // Apply "f" to all klasses for basic types (classes not present in
460 // SystemDictionary).
461 static void basic_type_classes_do(void f(Klass*));
462
463 // For sharing -- fill in a list of known vtable pointers.
464 static void init_self_patching_vtbl_list(void** list, int count);
465
466 // Debugging
467 enum VERIFY_FLAGS {
468 Verify_Threads = 1,
469 Verify_Heap = 2,
470 Verify_SymbolTable = 4,
471 Verify_StringTable = 8,
472 Verify_CodeCache = 16,
473 Verify_SystemDictionary = 32,
474 Verify_ClassLoaderDataGraph = 64,
475 Verify_MetaspaceAux = 128,
476 Verify_JNIHandles = 256,
477 Verify_CHeap = 512,
478 Verify_CodeCacheOops = 1024,
479 Verify_All = -1
480 };
481 static void initialize_verify_flags();
482 static bool should_verify_subset(uint subset);
483 static bool verify_in_progress() { return _verify_in_progress; }
484 static void verify(VerifyOption option, const char* prefix);
485 static void verify(const char* prefix) {
486 verify(VerifyOption_Default, prefix);
487 }
488 static void verify() {
489 verify("");
490 }
491
492 static int verify_count() { return _verify_count; }
493 static void print_on(outputStream* st);
494 static void print_heap_at_SIGBREAK();
495 static void print_heap_before_gc();
496 static void print_heap_after_gc();
497
498 // Change the number of dummy objects kept reachable by the full gc dummy
499 // array; this should trigger relocation in a sliding compaction collector.
500 debug_only(static bool release_fullgc_alot_dummy();)
501 // The non-oop pattern (see compiledIC.hpp, etc)
502 static void* non_oop_word();
503
504 // Oop verification (see MacroAssembler::verify_oop)
505 static uintptr_t verify_oop_mask() PRODUCT_RETURN0;
506 static uintptr_t verify_oop_bits() PRODUCT_RETURN0;
507 static uintptr_t verify_mark_bits() PRODUCT_RETURN0;
508 static uintptr_t verify_mark_mask() PRODUCT_RETURN0;
509
510 // Compiler support
511 static int base_vtable_size() { return _base_vtable_size; }
512 };
513
514 class DeferredObjAllocEvent : public CHeapObj<mtInternal> {
515 private:
516 oop _oop;
517 size_t _bytesize;
518 jint _arena_id;
519
520 public:
521 DeferredObjAllocEvent(const oop o, const size_t s, const jint id) {
522 _oop = o;
523 _bytesize = s;
524 _arena_id = id;
525 }
526
527 ~DeferredObjAllocEvent() {
528 }
529
530 jint arena_id() { return _arena_id; }
531 size_t bytesize() { return _bytesize; }
532 oop get_oop() { return _oop; }
533 };
534
535 #endif // SHARE_VM_MEMORY_UNIVERSE_HPP