1 /*
2 * Copyright (c) 1997, 2017, 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.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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23 */
24
25 #ifndef SHARE_VM_MEMORY_UNIVERSE_HPP
26 #define SHARE_VM_MEMORY_UNIVERSE_HPP
27
28 #include "oops/array.hpp"
29 #include "runtime/handles.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 // CDS support. Replace the klass in this with the archive version
66 // could use this for Enhanced Class Redefinition also.
67 void serialize(SerializeClosure* f) {
68 f->do_ptr((void**)&_klass);
69 }
70 };
71
72
73 // For UseCompressedOops.
74 struct NarrowPtrStruct {
75 // Base address for oop-within-java-object materialization.
76 // NULL if using wide oops or zero based narrow oops.
77 address _base;
78 // Number of shift bits for encoding/decoding narrow ptrs.
79 // 0 if using wide ptrs or zero based unscaled narrow ptrs,
80 // LogMinObjAlignmentInBytes/LogKlassAlignmentInBytes otherwise.
81 int _shift;
82 // Generate code with implicit null checks for narrow ptrs.
83 bool _use_implicit_null_checks;
84 };
85
86 enum VerifyOption {
87 VerifyOption_Default = 0,
88
89 // G1
90 VerifyOption_G1UsePrevMarking = VerifyOption_Default,
91 VerifyOption_G1UseNextMarking = VerifyOption_G1UsePrevMarking + 1,
92 VerifyOption_G1UseMarkWord = VerifyOption_G1UseNextMarking + 1
93 };
94
95 class Universe: AllStatic {
96 // Ugh. Universe is much too friendly.
97 friend class MarkSweep;
98 friend class oopDesc;
99 friend class ClassLoader;
100 friend class SystemDictionary;
101 friend class ReservedHeapSpace;
102 friend class VMStructs;
103 friend class VM_PopulateDumpSharedSpace;
104 friend class Metaspace;
105
106 friend jint universe_init();
107 friend void universe2_init();
108 friend bool universe_post_init();
109 friend void universe_post_module_init();
110
111 private:
112 // Known classes in the VM
113 static Klass* _boolArrayKlassObj;
114 static Klass* _byteArrayKlassObj;
115 static Klass* _charArrayKlassObj;
116 static Klass* _intArrayKlassObj;
117 static Klass* _shortArrayKlassObj;
118 static Klass* _longArrayKlassObj;
119 static Klass* _singleArrayKlassObj;
120 static Klass* _doubleArrayKlassObj;
121 static Klass* _typeArrayKlassObjs[T_VOID+1];
122
123 static Klass* _objectArrayKlassObj;
124
125 // Known objects in the VM
126
127 // Primitive objects
128 static oop _int_mirror;
129 static oop _float_mirror;
130 static oop _double_mirror;
131 static oop _byte_mirror;
132 static oop _bool_mirror;
133 static oop _char_mirror;
134 static oop _long_mirror;
135 static oop _short_mirror;
136 static oop _void_mirror;
137
138 static oop _main_thread_group; // Reference to the main thread group object
139 static oop _system_thread_group; // Reference to the system thread group object
140
141 static objArrayOop _the_empty_class_klass_array; // Canonicalized obj array of type java.lang.Class
142 static oop _the_null_string; // A cache of "null" as a Java string
143 static oop _the_min_jint_string; // A cache of "-2147483648" as a Java string
144 static LatestMethodCache* _finalizer_register_cache; // static method for registering finalizable objects
145 static LatestMethodCache* _loader_addClass_cache; // method for registering loaded classes in class loader vector
146 static LatestMethodCache* _pd_implies_cache; // method for checking protection domain attributes
147 static LatestMethodCache* _throw_illegal_access_error_cache; // Unsafe.throwIllegalAccessError() method
148 static LatestMethodCache* _do_stack_walk_cache; // method for stack walker callback
149
150 // preallocated error objects (no backtrace)
151 static oop _out_of_memory_error_java_heap;
152 static oop _out_of_memory_error_metaspace;
153 static oop _out_of_memory_error_class_metaspace;
154 static oop _out_of_memory_error_array_size;
155 static oop _out_of_memory_error_gc_overhead_limit;
156 static oop _out_of_memory_error_realloc_objects;
157
158 // preallocated cause message for delayed StackOverflowError
159 static oop _delayed_stack_overflow_error_message;
160
161 static Array<int>* _the_empty_int_array; // Canonicalized int array
162 static Array<u2>* _the_empty_short_array; // Canonicalized short array
163 static Array<Klass*>* _the_empty_klass_array; // Canonicalized klass obj array
164 static Array<Method*>* _the_empty_method_array; // Canonicalized method obj array
165
166 static Array<Klass*>* _the_array_interfaces_array;
167
168 // array of preallocated error objects with backtrace
169 static objArrayOop _preallocated_out_of_memory_error_array;
170
171 // number of preallocated error objects available for use
172 static volatile jint _preallocated_out_of_memory_error_avail_count;
173
174 static oop _null_ptr_exception_instance; // preallocated exception object
175 static oop _arithmetic_exception_instance; // preallocated exception object
176 static oop _virtual_machine_error_instance; // preallocated exception object
177 // The object used as an exception dummy when exceptions are thrown for
178 // the vm thread.
179 static oop _vm_exception;
180
181 static oop _allocation_context_notification_obj;
182
183 // References waiting to be transferred to the ReferenceHandler
184 static oop _reference_pending_list;
185
186 // The particular choice of collected heap.
187 static CollectedHeap* _collectedHeap;
188
189 static intptr_t _non_oop_bits;
190
191 // For UseCompressedOops.
192 static struct NarrowPtrStruct _narrow_oop;
193 // For UseCompressedClassPointers.
194 static struct NarrowPtrStruct _narrow_klass;
195 static address _narrow_ptrs_base;
196
197 // array of dummy objects used with +FullGCAlot
198 debug_only(static objArrayOop _fullgc_alot_dummy_array;)
199 // index of next entry to clear
200 debug_only(static int _fullgc_alot_dummy_next;)
201
202 // Compiler/dispatch support
203 static int _base_vtable_size; // Java vtbl size of klass Object (in words)
204
205 // Initialization
206 static bool _bootstrapping; // true during genesis
207 static bool _module_initialized; // true after call_initPhase2 called
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(Klass* 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 // Function to initialize these
325 static void initialize_known_methods(TRAPS);
326
327 static oop null_ptr_exception_instance() { return _null_ptr_exception_instance; }
328 static oop arithmetic_exception_instance() { return _arithmetic_exception_instance; }
329 static oop virtual_machine_error_instance() { return _virtual_machine_error_instance; }
330 static oop vm_exception() { return _vm_exception; }
331
332 static inline oop allocation_context_notification_obj();
333 static inline void set_allocation_context_notification_obj(oop obj);
334
335 // Reference pending list manipulation. Access is protected by
336 // Heap_lock. The getter, setter and predicate require the caller
337 // owns the lock. Swap is used by parallel non-concurrent reference
338 // processing threads, where some higher level controller owns
339 // Heap_lock, so requires the lock is locked, but not necessarily by
340 // the current thread.
341 static oop reference_pending_list();
342 static void set_reference_pending_list(oop list);
343 static bool has_reference_pending_list();
344 static oop swap_reference_pending_list(oop list);
345
346 static Array<int>* the_empty_int_array() { return _the_empty_int_array; }
347 static Array<u2>* the_empty_short_array() { return _the_empty_short_array; }
348 static Array<Method*>* the_empty_method_array() { return _the_empty_method_array; }
349 static Array<Klass*>* the_empty_klass_array() { return _the_empty_klass_array; }
350
351 // OutOfMemoryError support. Returns an error with the required message. The returned error
352 // may or may not have a backtrace. If error has a backtrace then the stack trace is already
353 // filled in.
354 static oop out_of_memory_error_java_heap() { return gen_out_of_memory_error(_out_of_memory_error_java_heap); }
355 static oop out_of_memory_error_metaspace() { return gen_out_of_memory_error(_out_of_memory_error_metaspace); }
356 static oop out_of_memory_error_class_metaspace() { return gen_out_of_memory_error(_out_of_memory_error_class_metaspace); }
357 static oop out_of_memory_error_array_size() { return gen_out_of_memory_error(_out_of_memory_error_array_size); }
358 static oop out_of_memory_error_gc_overhead_limit() { return gen_out_of_memory_error(_out_of_memory_error_gc_overhead_limit); }
359 static oop out_of_memory_error_realloc_objects() { return gen_out_of_memory_error(_out_of_memory_error_realloc_objects); }
360 static oop delayed_stack_overflow_error_message() { return _delayed_stack_overflow_error_message; }
361
362 // Accessors needed for fast allocation
363 static Klass** boolArrayKlassObj_addr() { return &_boolArrayKlassObj; }
364 static Klass** byteArrayKlassObj_addr() { return &_byteArrayKlassObj; }
365 static Klass** charArrayKlassObj_addr() { return &_charArrayKlassObj; }
366 static Klass** intArrayKlassObj_addr() { return &_intArrayKlassObj; }
367 static Klass** shortArrayKlassObj_addr() { return &_shortArrayKlassObj; }
368 static Klass** longArrayKlassObj_addr() { return &_longArrayKlassObj; }
369 static Klass** singleArrayKlassObj_addr() { return &_singleArrayKlassObj; }
370 static Klass** doubleArrayKlassObj_addr() { return &_doubleArrayKlassObj; }
371 static Klass** objectArrayKlassObj_addr() { return &_objectArrayKlassObj; }
372
373 // The particular choice of collected heap.
374 static CollectedHeap* heap() { return _collectedHeap; }
375
376 // For UseCompressedOops
377 // Narrow Oop encoding mode:
378 // 0 - Use 32-bits oops without encoding when
379 // NarrowOopHeapBaseMin + heap_size < 4Gb
380 // 1 - Use zero based compressed oops with encoding when
381 // NarrowOopHeapBaseMin + heap_size < 32Gb
382 // 2 - Use compressed oops with disjoint heap base if
383 // base is 32G-aligned and base > 0. This allows certain
384 // optimizations in encoding/decoding.
385 // Disjoint: Bits used in base are disjoint from bits used
386 // for oops ==> oop = (cOop << 3) | base. One can disjoint
387 // the bits of an oop into base and compressed oop.
388 // 3 - Use compressed oops with heap base + encoding.
389 enum NARROW_OOP_MODE {
390 UnscaledNarrowOop = 0,
391 ZeroBasedNarrowOop = 1,
392 DisjointBaseNarrowOop = 2,
393 HeapBasedNarrowOop = 3,
394 AnyNarrowOopMode = 4
395 };
396 static NARROW_OOP_MODE narrow_oop_mode();
397 static const char* narrow_oop_mode_to_string(NARROW_OOP_MODE mode);
398 static char* preferred_heap_base(size_t heap_size, size_t alignment, NARROW_OOP_MODE mode);
399 static char* preferred_metaspace_base(size_t heap_size, NARROW_OOP_MODE mode);
400 static address narrow_oop_base() { return _narrow_oop._base; }
401 // Test whether bits of addr and possible offsets into the heap overlap.
402 static bool is_disjoint_heap_base_address(address addr) {
403 return (((uint64_t)(intptr_t)addr) &
404 (((uint64_t)UCONST64(0xFFFFffffFFFFffff)) >> (32-LogMinObjAlignmentInBytes))) == 0;
405 }
406 // Check for disjoint base compressed oops.
407 static bool narrow_oop_base_disjoint() {
408 return _narrow_oop._base != NULL && is_disjoint_heap_base_address(_narrow_oop._base);
409 }
410 // Check for real heapbased compressed oops.
411 // We must subtract the base as the bits overlap.
412 // If we negate above function, we also get unscaled and zerobased.
413 static bool narrow_oop_base_overlaps() {
414 return _narrow_oop._base != NULL && !is_disjoint_heap_base_address(_narrow_oop._base);
415 }
416 static bool is_narrow_oop_base(void* addr) { return (narrow_oop_base() == (address)addr); }
417 static int narrow_oop_shift() { return _narrow_oop._shift; }
418 static bool narrow_oop_use_implicit_null_checks() { return _narrow_oop._use_implicit_null_checks; }
419
420 // For UseCompressedClassPointers
421 static address narrow_klass_base() { return _narrow_klass._base; }
422 static bool is_narrow_klass_base(void* addr) { return (narrow_klass_base() == (address)addr); }
423 static int narrow_klass_shift() { return _narrow_klass._shift; }
424 static bool narrow_klass_use_implicit_null_checks() { return _narrow_klass._use_implicit_null_checks; }
425
426 static address* narrow_ptrs_base_addr() { return &_narrow_ptrs_base; }
427 static void set_narrow_ptrs_base(address a) { _narrow_ptrs_base = a; }
428 static address narrow_ptrs_base() { return _narrow_ptrs_base; }
429
430 static void print_compressed_oops_mode(outputStream* st);
431
432 // this is set in vm_version on sparc (and then reset in universe afaict)
433 static void set_narrow_oop_shift(int shift) {
434 _narrow_oop._shift = shift;
435 }
436
437 static void set_narrow_klass_shift(int shift) {
438 assert(shift == 0 || shift == LogKlassAlignmentInBytes, "invalid shift for klass ptrs");
439 _narrow_klass._shift = shift;
440 }
441
442 // Reserve Java heap and determine CompressedOops mode
443 static ReservedSpace reserve_heap(size_t heap_size, size_t alignment);
444
445 // Historic gc information
446 static size_t get_heap_capacity_at_last_gc() { return _heap_capacity_at_last_gc; }
447 static size_t get_heap_free_at_last_gc() { return _heap_capacity_at_last_gc - _heap_used_at_last_gc; }
448 static size_t get_heap_used_at_last_gc() { return _heap_used_at_last_gc; }
449 static void update_heap_info_at_gc();
450
451 // Testers
452 static bool is_bootstrapping() { return _bootstrapping; }
453 static bool is_module_initialized() { return _module_initialized; }
454 static bool is_fully_initialized() { return _fully_initialized; }
455
456 static inline bool element_type_should_be_aligned(BasicType type);
457 static inline bool field_type_should_be_aligned(BasicType type);
458 static bool on_page_boundary(void* addr);
459 static bool should_fill_in_stack_trace(Handle throwable);
460 static void check_alignment(uintx size, uintx alignment, const char* name);
461
462 // Finalizer support.
463 static void run_finalizers_on_exit();
464
465 // Iteration
466
467 // Apply "f" to the addresses of all the direct heap pointers maintained
468 // as static fields of "Universe".
469 static void oops_do(OopClosure* f, bool do_all = false);
470
471 // CDS support
472 static void serialize(SerializeClosure* f, bool do_all = false);
473
474 // Apply "f" to all klasses for basic types (classes not present in
475 // SystemDictionary).
476 static void basic_type_classes_do(void f(Klass*));
477
478 // Debugging
479 enum VERIFY_FLAGS {
480 Verify_Threads = 1,
481 Verify_Heap = 2,
482 Verify_SymbolTable = 4,
483 Verify_StringTable = 8,
484 Verify_CodeCache = 16,
485 Verify_SystemDictionary = 32,
486 Verify_ClassLoaderDataGraph = 64,
487 Verify_MetaspaceAux = 128,
488 Verify_JNIHandles = 256,
489 Verify_CodeCacheOops = 512,
490 Verify_All = -1
491 };
492 static void initialize_verify_flags();
493 static bool should_verify_subset(uint subset);
494 static bool verify_in_progress() { return _verify_in_progress; }
495 static void verify(VerifyOption option, const char* prefix);
496 static void verify(const char* prefix) {
497 verify(VerifyOption_Default, prefix);
498 }
499 static void verify() {
500 verify("");
501 }
502
503 static int verify_count() { return _verify_count; }
504 static void print_on(outputStream* st);
505 static void print_heap_at_SIGBREAK();
506 static void print_heap_before_gc();
507 static void print_heap_after_gc();
508
509 // Change the number of dummy objects kept reachable by the full gc dummy
510 // array; this should trigger relocation in a sliding compaction collector.
511 debug_only(static bool release_fullgc_alot_dummy();)
512 // The non-oop pattern (see compiledIC.hpp, etc)
513 static void* non_oop_word();
514
515 // Oop verification (see MacroAssembler::verify_oop)
516 static uintptr_t verify_oop_mask() PRODUCT_RETURN0;
517 static uintptr_t verify_oop_bits() PRODUCT_RETURN0;
518 static uintptr_t verify_mark_bits() PRODUCT_RETURN0;
519 static uintptr_t verify_mark_mask() PRODUCT_RETURN0;
520
521 // Compiler support
522 static int base_vtable_size() { return _base_vtable_size; }
523 };
524
525 class DeferredObjAllocEvent : public CHeapObj<mtInternal> {
526 private:
527 oop _oop;
528 size_t _bytesize;
529 jint _arena_id;
530
531 public:
532 DeferredObjAllocEvent(const oop o, const size_t s, const jint id) {
533 _oop = o;
534 _bytesize = s;
535 _arena_id = id;
536 }
537
538 ~DeferredObjAllocEvent() {
539 }
540
541 jint arena_id() { return _arena_id; }
542 size_t bytesize() { return _bytesize; }
543 oop get_oop() { return _oop; }
544 };
545
546 #endif // SHARE_VM_MEMORY_UNIVERSE_HPP