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.
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 "gc/shared/gc.hpp"
29 #include "runtime/handles.hpp"
30 #include "utilities/array.hpp"
31 #include "utilities/growableArray.hpp"
32
33 // Universe is a name space holding known system classes and objects in the VM.
34 //
35 // Loaded classes are accessible through the SystemDictionary.
36 //
37 // The object heap is allocated and accessed through Universe, and various allocation
38 // support is provided. Allocation by the interpreter and compiled code is done inline
39 // and bails out to Scavenge::invoke_and_allocate.
40
41 class CollectedHeap;
42 class DeferredObjAllocEvent;
43
44
45 // A helper class for caching a Method* when the user of the cache
46 // only cares about the latest version of the Method*. This cache safely
47 // interacts with the RedefineClasses API.
48
49 class LatestMethodCache : public CHeapObj<mtClass> {
50 // We save the Klass* and the idnum of Method* in order to get
51 // the current cached Method*.
52 private:
53 Klass* _klass;
54 int _method_idnum;
55
56 public:
57 LatestMethodCache() { _klass = NULL; _method_idnum = -1; }
58 ~LatestMethodCache() { _klass = NULL; _method_idnum = -1; }
59
60 void init(Klass* k, Method* m);
61 Klass* klass() const { return _klass; }
62 int method_idnum() const { return _method_idnum; }
63
64 Method* get_method();
65
66 // CDS support. Replace the klass in this with the archive version
67 // could use this for Enhanced Class Redefinition also.
68 void serialize(SerializeClosure* f) {
69 f->do_ptr((void**)&_klass);
70 }
71 };
72
73
74 // For UseCompressedOops.
75 struct NarrowPtrStruct {
76 // Base address for oop-within-java-object materialization.
77 // NULL if using wide oops or zero based narrow oops.
78 address _base;
79 // Number of shift bits for encoding/decoding narrow ptrs.
80 // 0 if using wide ptrs or zero based unscaled narrow ptrs,
81 // LogMinObjAlignmentInBytes/LogKlassAlignmentInBytes otherwise.
82 int _shift;
83 // Generate code with implicit null checks for narrow ptrs.
84 bool _use_implicit_null_checks;
85 };
86
87 enum VerifyOption {
88 VerifyOption_Default = 0,
89
90 // G1
91 VerifyOption_G1UsePrevMarking = VerifyOption_Default,
92 VerifyOption_G1UseNextMarking = VerifyOption_G1UsePrevMarking + 1,
93 VerifyOption_G1UseMarkWord = VerifyOption_G1UseNextMarking + 1
94 };
95
96 class Universe: AllStatic {
97 // Ugh. Universe is much too friendly.
98 friend class MarkSweep;
99 friend class oopDesc;
100 friend class ClassLoader;
101 friend class SystemDictionary;
102 friend class ReservedHeapSpace;
103 friend class VMStructs;
104 friend class VM_PopulateDumpSharedSpace;
105 friend class Metaspace;
106
107 friend jint universe_init();
108 friend void universe2_init();
109 friend bool universe_post_init();
110 friend void universe_post_module_init();
111
112 private:
113 // Known classes in the VM
114 static Klass* _boolArrayKlassObj;
115 static Klass* _byteArrayKlassObj;
116 static Klass* _charArrayKlassObj;
117 static Klass* _intArrayKlassObj;
118 static Klass* _shortArrayKlassObj;
119 static Klass* _longArrayKlassObj;
120 static Klass* _singleArrayKlassObj;
121 static Klass* _doubleArrayKlassObj;
122 static Klass* _typeArrayKlassObjs[T_VOID+1];
123
124 static Klass* _objectArrayKlassObj;
125
126 // Known objects in the VM
127
128 // Primitive objects
129 static oop _int_mirror;
130 static oop _float_mirror;
131 static oop _double_mirror;
132 static oop _byte_mirror;
133 static oop _bool_mirror;
134 static oop _char_mirror;
135 static oop _long_mirror;
136 static oop _short_mirror;
137 static oop _void_mirror;
138
139 static oop _main_thread_group; // Reference to the main thread group object
140 static oop _system_thread_group; // Reference to the system thread group object
141
142 static objArrayOop _the_empty_class_klass_array; // Canonicalized obj array of type java.lang.Class
143 static oop _the_null_string; // A cache of "null" as a Java string
144 static oop _the_min_jint_string; // A cache of "-2147483648" as a Java string
145 static LatestMethodCache* _finalizer_register_cache; // static method for registering finalizable objects
146 static LatestMethodCache* _loader_addClass_cache; // method for registering loaded classes in class loader vector
147 static LatestMethodCache* _pd_implies_cache; // method for checking protection domain attributes
148 static LatestMethodCache* _throw_illegal_access_error_cache; // Unsafe.throwIllegalAccessError() method
149 static LatestMethodCache* _do_stack_walk_cache; // method for stack walker callback
150
151 // preallocated error objects (no backtrace)
152 static oop _out_of_memory_error_java_heap;
153 static oop _out_of_memory_error_metaspace;
154 static oop _out_of_memory_error_class_metaspace;
155 static oop _out_of_memory_error_array_size;
156 static oop _out_of_memory_error_gc_overhead_limit;
157 static oop _out_of_memory_error_realloc_objects;
158
159 // preallocated cause message for delayed StackOverflowError
160 static oop _delayed_stack_overflow_error_message;
161
162 static Array<int>* _the_empty_int_array; // Canonicalized int array
163 static Array<u2>* _the_empty_short_array; // Canonicalized short array
164 static Array<Klass*>* _the_empty_klass_array; // Canonicalized klass obj array
165 static Array<Method*>* _the_empty_method_array; // Canonicalized method obj array
166
167 static Array<Klass*>* _the_array_interfaces_array;
168
169 // array of preallocated error objects with backtrace
170 static objArrayOop _preallocated_out_of_memory_error_array;
171
172 // number of preallocated error objects available for use
173 static volatile jint _preallocated_out_of_memory_error_avail_count;
174
175 static oop _null_ptr_exception_instance; // preallocated exception object
176 static oop _arithmetic_exception_instance; // preallocated exception object
177 static oop _virtual_machine_error_instance; // preallocated exception object
178 // The object used as an exception dummy when exceptions are thrown for
179 // the vm thread.
180 static oop _vm_exception;
181
182 static oop _allocation_context_notification_obj;
183
184 // References waiting to be transferred to the ReferenceHandler
185 static oop _reference_pending_list;
186
187 static intptr_t _non_oop_bits;
188
189 // For UseCompressedOops.
190 static struct NarrowPtrStruct _narrow_oop;
191 // For UseCompressedClassPointers.
192 static struct NarrowPtrStruct _narrow_klass;
193 static address _narrow_ptrs_base;
194
195 // array of dummy objects used with +FullGCAlot
196 debug_only(static objArrayOop _fullgc_alot_dummy_array;)
197 // index of next entry to clear
198 debug_only(static int _fullgc_alot_dummy_next;)
199
200 // Compiler/dispatch support
201 static int _base_vtable_size; // Java vtbl size of klass Object (in words)
202
203 // Initialization
204 static bool _bootstrapping; // true during genesis
205 static bool _module_initialized; // true after call_initPhase2 called
206 static bool _fully_initialized; // true after universe_init and initialize_vtables called
207
208 // the array of preallocated errors with backtraces
209 static objArrayOop preallocated_out_of_memory_errors() { return _preallocated_out_of_memory_error_array; }
210
211 // generate an out of memory error; if possible using an error with preallocated backtrace;
212 // otherwise return the given default error.
213 static oop gen_out_of_memory_error(oop default_err);
214
215 // Historic gc information
216 static size_t _heap_capacity_at_last_gc;
217 static size_t _heap_used_at_last_gc;
218
219 static jint initialize_heap();
220 static void initialize_basic_type_mirrors(TRAPS);
221 static void fixup_mirrors(TRAPS);
222
223 static void reinitialize_vtable_of(Klass* k, TRAPS);
224 static void reinitialize_itables(TRAPS);
225 static void compute_base_vtable_size(); // compute vtable size of class Object
226
227 static void genesis(TRAPS); // Create the initial world
228
229 // Mirrors for primitive classes (created eagerly)
230 static oop check_mirror(oop m) {
231 assert(m != NULL, "mirror not initialized");
232 return m;
233 }
234
235 static void set_narrow_oop_base(address base) {
236 assert(UseCompressedOops, "no compressed oops?");
237 _narrow_oop._base = base;
238 }
239 static void set_narrow_klass_base(address base) {
240 assert(UseCompressedClassPointers, "no compressed klass ptrs?");
241 _narrow_klass._base = base;
242 }
243 static void set_narrow_oop_use_implicit_null_checks(bool use) {
244 assert(UseCompressedOops, "no compressed ptrs?");
245 _narrow_oop._use_implicit_null_checks = use;
246 }
247
248 // Debugging
249 static int _verify_count; // number of verifies done
250
251 // True during call to verify(). Should only be set/cleared in verify().
252 static bool _verify_in_progress;
253 static long verify_flags;
254
255 static uintptr_t _verify_oop_mask;
256 static uintptr_t _verify_oop_bits;
257
258 static void calculate_verify_data(HeapWord* low_boundary, HeapWord* high_boundary) PRODUCT_RETURN;
259 static void compute_verify_oop_data();
260
261 public:
262 // Known classes in the VM
263 static Klass* boolArrayKlassObj() { return _boolArrayKlassObj; }
264 static Klass* byteArrayKlassObj() { return _byteArrayKlassObj; }
265 static Klass* charArrayKlassObj() { return _charArrayKlassObj; }
266 static Klass* intArrayKlassObj() { return _intArrayKlassObj; }
267 static Klass* shortArrayKlassObj() { return _shortArrayKlassObj; }
268 static Klass* longArrayKlassObj() { return _longArrayKlassObj; }
269 static Klass* singleArrayKlassObj() { return _singleArrayKlassObj; }
270 static Klass* doubleArrayKlassObj() { return _doubleArrayKlassObj; }
271
272 static Klass* objectArrayKlassObj() {
273 return _objectArrayKlassObj;
274 }
275
276 static Klass* typeArrayKlassObj(BasicType t) {
277 assert((uint)t < T_VOID+1, "range check for type: %s", type2name(t));
278 assert(_typeArrayKlassObjs[t] != NULL, "domain check");
279 return _typeArrayKlassObjs[t];
280 }
281
282 // Known objects in the VM
283 static oop int_mirror() { return check_mirror(_int_mirror); }
284 static oop float_mirror() { return check_mirror(_float_mirror); }
285 static oop double_mirror() { return check_mirror(_double_mirror); }
286 static oop byte_mirror() { return check_mirror(_byte_mirror); }
287 static oop bool_mirror() { return check_mirror(_bool_mirror); }
288 static oop char_mirror() { return check_mirror(_char_mirror); }
289 static oop long_mirror() { return check_mirror(_long_mirror); }
290 static oop short_mirror() { return check_mirror(_short_mirror); }
291 static oop void_mirror() { return check_mirror(_void_mirror); }
292
293 // table of same
294 static oop _mirrors[T_VOID+1];
295
296 static oop java_mirror(BasicType t) {
297 assert((uint)t < T_VOID+1, "range check");
298 return check_mirror(_mirrors[t]);
299 }
300 static oop main_thread_group() { return _main_thread_group; }
301 static void set_main_thread_group(oop group) { _main_thread_group = group;}
302
303 static oop system_thread_group() { return _system_thread_group; }
304 static void set_system_thread_group(oop group) { _system_thread_group = group;}
305
306 static objArrayOop the_empty_class_klass_array () { return _the_empty_class_klass_array; }
307 static Array<Klass*>* the_array_interfaces_array() { return _the_array_interfaces_array; }
308 static oop the_null_string() { return _the_null_string; }
309 static oop the_min_jint_string() { return _the_min_jint_string; }
310
311 static Method* finalizer_register_method() { return _finalizer_register_cache->get_method(); }
312 static Method* loader_addClass_method() { return _loader_addClass_cache->get_method(); }
313
314 static Method* protection_domain_implies_method() { return _pd_implies_cache->get_method(); }
315 static Method* throw_illegal_access_error() { return _throw_illegal_access_error_cache->get_method(); }
316
317 static Method* do_stack_walk_method() { return _do_stack_walk_cache->get_method(); }
318
319 // Function to initialize these
320 static void initialize_known_methods(TRAPS);
321
322 static oop null_ptr_exception_instance() { return _null_ptr_exception_instance; }
323 static oop arithmetic_exception_instance() { return _arithmetic_exception_instance; }
324 static oop virtual_machine_error_instance() { return _virtual_machine_error_instance; }
325 static oop vm_exception() { return _vm_exception; }
326
327 static inline oop allocation_context_notification_obj();
328 static inline void set_allocation_context_notification_obj(oop obj);
329
330 // Reference pending list manipulation. Access is protected by
331 // Heap_lock. The getter, setter and predicate require the caller
332 // owns the lock. Swap is used by parallel non-concurrent reference
333 // processing threads, where some higher level controller owns
334 // Heap_lock, so requires the lock is locked, but not necessarily by
335 // the current thread.
336 static oop reference_pending_list();
337 static void set_reference_pending_list(oop list);
338 static bool has_reference_pending_list();
339 static oop swap_reference_pending_list(oop list);
340
341 static Array<int>* the_empty_int_array() { return _the_empty_int_array; }
342 static Array<u2>* the_empty_short_array() { return _the_empty_short_array; }
343 static Array<Method*>* the_empty_method_array() { return _the_empty_method_array; }
344 static Array<Klass*>* the_empty_klass_array() { return _the_empty_klass_array; }
345
346 // OutOfMemoryError support. Returns an error with the required message. The returned error
347 // may or may not have a backtrace. If error has a backtrace then the stack trace is already
348 // filled in.
349 static oop out_of_memory_error_java_heap() { return gen_out_of_memory_error(_out_of_memory_error_java_heap); }
350 static oop out_of_memory_error_metaspace() { return gen_out_of_memory_error(_out_of_memory_error_metaspace); }
351 static oop out_of_memory_error_class_metaspace() { return gen_out_of_memory_error(_out_of_memory_error_class_metaspace); }
352 static oop out_of_memory_error_array_size() { return gen_out_of_memory_error(_out_of_memory_error_array_size); }
353 static oop out_of_memory_error_gc_overhead_limit() { return gen_out_of_memory_error(_out_of_memory_error_gc_overhead_limit); }
354 static oop out_of_memory_error_realloc_objects() { return gen_out_of_memory_error(_out_of_memory_error_realloc_objects); }
355 static oop delayed_stack_overflow_error_message() { return _delayed_stack_overflow_error_message; }
356
357 // Accessors needed for fast allocation
358 static Klass** boolArrayKlassObj_addr() { return &_boolArrayKlassObj; }
359 static Klass** byteArrayKlassObj_addr() { return &_byteArrayKlassObj; }
360 static Klass** charArrayKlassObj_addr() { return &_charArrayKlassObj; }
361 static Klass** intArrayKlassObj_addr() { return &_intArrayKlassObj; }
362 static Klass** shortArrayKlassObj_addr() { return &_shortArrayKlassObj; }
363 static Klass** longArrayKlassObj_addr() { return &_longArrayKlassObj; }
364 static Klass** singleArrayKlassObj_addr() { return &_singleArrayKlassObj; }
365 static Klass** doubleArrayKlassObj_addr() { return &_doubleArrayKlassObj; }
366 static Klass** objectArrayKlassObj_addr() { return &_objectArrayKlassObj; }
367
368 // The particular choice of collected heap.
369 /*
370 static CollectedHeap* heap() {
371 GC* gc = GC::gc();
372 if (gc != NULL) return gc->heap();
373 else return NULL;
374 }
375 */
376
377 // For UseCompressedOops
378 // Narrow Oop encoding mode:
379 // 0 - Use 32-bits oops without encoding when
380 // NarrowOopHeapBaseMin + heap_size < 4Gb
381 // 1 - Use zero based compressed oops with encoding when
382 // NarrowOopHeapBaseMin + heap_size < 32Gb
383 // 2 - Use compressed oops with disjoint heap base if
384 // base is 32G-aligned and base > 0. This allows certain
385 // optimizations in encoding/decoding.
386 // Disjoint: Bits used in base are disjoint from bits used
387 // for oops ==> oop = (cOop << 3) | base. One can disjoint
388 // the bits of an oop into base and compressed oop.
389 // 3 - Use compressed oops with heap base + encoding.
390 enum NARROW_OOP_MODE {
391 UnscaledNarrowOop = 0,
392 ZeroBasedNarrowOop = 1,
393 DisjointBaseNarrowOop = 2,
394 HeapBasedNarrowOop = 3,
395 AnyNarrowOopMode = 4
396 };
397 static NARROW_OOP_MODE narrow_oop_mode();
398 static const char* narrow_oop_mode_to_string(NARROW_OOP_MODE mode);
399 static char* preferred_heap_base(size_t heap_size, size_t alignment, NARROW_OOP_MODE mode);
400 static char* preferred_metaspace_base(size_t heap_size, NARROW_OOP_MODE mode);
401 static address narrow_oop_base() { return _narrow_oop._base; }
402 // Test whether bits of addr and possible offsets into the heap overlap.
403 static bool is_disjoint_heap_base_address(address addr) {
404 return (((uint64_t)(intptr_t)addr) &
405 (((uint64_t)UCONST64(0xFFFFffffFFFFffff)) >> (32-LogMinObjAlignmentInBytes))) == 0;
406 }
407 // Check for disjoint base compressed oops.
408 static bool narrow_oop_base_disjoint() {
409 return _narrow_oop._base != NULL && is_disjoint_heap_base_address(_narrow_oop._base);
410 }
411 // Check for real heapbased compressed oops.
412 // We must subtract the base as the bits overlap.
413 // If we negate above function, we also get unscaled and zerobased.
414 static bool narrow_oop_base_overlaps() {
415 return _narrow_oop._base != NULL && !is_disjoint_heap_base_address(_narrow_oop._base);
416 }
417 static bool is_narrow_oop_base(void* addr) { return (narrow_oop_base() == (address)addr); }
418 static int narrow_oop_shift() { return _narrow_oop._shift; }
419 static bool narrow_oop_use_implicit_null_checks() { return _narrow_oop._use_implicit_null_checks; }
420
421 // For UseCompressedClassPointers
422 static address narrow_klass_base() { return _narrow_klass._base; }
423 static bool is_narrow_klass_base(void* addr) { return (narrow_klass_base() == (address)addr); }
424 static int narrow_klass_shift() { return _narrow_klass._shift; }
425 static bool narrow_klass_use_implicit_null_checks() { return _narrow_klass._use_implicit_null_checks; }
426
427 static address* narrow_ptrs_base_addr() { return &_narrow_ptrs_base; }
428 static void set_narrow_ptrs_base(address a) { _narrow_ptrs_base = a; }
429 static address narrow_ptrs_base() { return _narrow_ptrs_base; }
430
431 static void print_compressed_oops_mode(outputStream* st);
432
433 // this is set in vm_version on sparc (and then reset in universe afaict)
434 static void set_narrow_oop_shift(int shift) {
435 _narrow_oop._shift = shift;
436 }
437
438 static void set_narrow_klass_shift(int shift) {
439 assert(shift == 0 || shift == LogKlassAlignmentInBytes, "invalid shift for klass ptrs");
440 _narrow_klass._shift = shift;
441 }
442
443 // Reserve Java heap and determine CompressedOops mode
444 static ReservedSpace reserve_heap(size_t heap_size, size_t alignment);
445
446 // Historic gc information
447 static size_t get_heap_capacity_at_last_gc() { return _heap_capacity_at_last_gc; }
448 static size_t get_heap_free_at_last_gc() { return _heap_capacity_at_last_gc - _heap_used_at_last_gc; }
449 static size_t get_heap_used_at_last_gc() { return _heap_used_at_last_gc; }
450 static void update_heap_info_at_gc();
451
452 // Testers
453 static bool is_bootstrapping() { return _bootstrapping; }
454 static bool is_module_initialized() { return _module_initialized; }
455 static bool is_fully_initialized() { return _fully_initialized; }
456
457 static inline bool element_type_should_be_aligned(BasicType type);
458 static inline bool field_type_should_be_aligned(BasicType type);
459 static bool on_page_boundary(void* addr);
460 static bool should_fill_in_stack_trace(Handle throwable);
461 static void check_alignment(uintx size, uintx alignment, const char* name);
462
463 // Finalizer support.
464 static void run_finalizers_on_exit();
465
466 // Iteration
467
468 // Apply "f" to the addresses of all the direct heap pointers maintained
469 // as static fields of "Universe".
470 static void oops_do(OopClosure* f, bool do_all = false);
471
472 // CDS support
473 static void serialize(SerializeClosure* f, bool do_all = false);
474
475 // Apply "f" to all klasses for basic types (classes not present in
476 // SystemDictionary).
477 static void basic_type_classes_do(void f(Klass*));
478
479 // Debugging
480 enum VERIFY_FLAGS {
481 Verify_Threads = 1,
482 Verify_Heap = 2,
483 Verify_SymbolTable = 4,
484 Verify_StringTable = 8,
485 Verify_CodeCache = 16,
486 Verify_SystemDictionary = 32,
487 Verify_ClassLoaderDataGraph = 64,
488 Verify_MetaspaceAux = 128,
489 Verify_JNIHandles = 256,
490 Verify_CodeCacheOops = 512,
491 Verify_All = -1
492 };
493 static void initialize_verify_flags();
494 static bool should_verify_subset(uint subset);
495 static bool verify_in_progress() { return _verify_in_progress; }
496 static void verify(VerifyOption option, const char* prefix);
497 static void verify(const char* prefix) {
498 verify(VerifyOption_Default, prefix);
499 }
500 static void verify() {
501 verify("");
502 }
503
504 static int verify_count() { return _verify_count; }
505 static void print_on(outputStream* st);
506 static void print_heap_at_SIGBREAK();
507 static void print_heap_before_gc();
508 static void print_heap_after_gc();
509
510 // Change the number of dummy objects kept reachable by the full gc dummy
511 // array; this should trigger relocation in a sliding compaction collector.
512 debug_only(static bool release_fullgc_alot_dummy();)
513 // The non-oop pattern (see compiledIC.hpp, etc)
514 static void* non_oop_word();
515
516 // Oop verification (see MacroAssembler::verify_oop)
517 static uintptr_t verify_oop_mask() PRODUCT_RETURN0;
518 static uintptr_t verify_oop_bits() PRODUCT_RETURN0;
519 static uintptr_t verify_mark_bits() PRODUCT_RETURN0;
520 static uintptr_t verify_mark_mask() PRODUCT_RETURN0;
521
522 // Compiler support
523 static int base_vtable_size() { return _base_vtable_size; }
524 };
525
526 class DeferredObjAllocEvent : public CHeapObj<mtInternal> {
527 private:
528 oop _oop;
529 size_t _bytesize;
530 jint _arena_id;
531
532 public:
533 DeferredObjAllocEvent(const oop o, const size_t s, const jint id) {
534 _oop = o;
535 _bytesize = s;
536 _arena_id = id;
537 }
538
539 ~DeferredObjAllocEvent() {
540 }
541
542 jint arena_id() { return _arena_id; }
543 size_t bytesize() { return _bytesize; }
544 oop get_oop() { return _oop; }
545 };
546
547 #endif // SHARE_VM_MEMORY_UNIVERSE_HPP