1 /*
2 * Copyright (c) 1997, 2016, 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.
22 *
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 // Enhanced Class Redefinition support
67 void classes_do(void f(Klass*)) {
68 f(_klass);
69 }
70
71 // CDS support. Replace the klass in this with the archive version
72 // could use this for Enhanced Class Redefinition also.
73 void serialize(SerializeClosure* f) {
74 f->do_ptr((void**)&_klass);
75 }
76 };
77
78
79 // For UseCompressedOops.
80 struct NarrowPtrStruct {
81 // Base address for oop-within-java-object materialization.
82 // NULL if using wide oops or zero based narrow oops.
83 address _base;
84 // Number of shift bits for encoding/decoding narrow ptrs.
85 // 0 if using wide ptrs or zero based unscaled narrow ptrs,
86 // LogMinObjAlignmentInBytes/LogKlassAlignmentInBytes otherwise.
87 int _shift;
88 // Generate code with implicit null checks for narrow ptrs.
89 bool _use_implicit_null_checks;
90 };
91
92 enum VerifyOption {
93 VerifyOption_Default = 0,
94
95 // G1
96 VerifyOption_G1UsePrevMarking = VerifyOption_Default,
97 VerifyOption_G1UseNextMarking = VerifyOption_G1UsePrevMarking + 1,
98 VerifyOption_G1UseMarkWord = VerifyOption_G1UseNextMarking + 1
99 };
100
101 class Universe: AllStatic {
102 // Ugh. Universe is much too friendly.
103 friend class MarkSweep;
104 friend class oopDesc;
105 friend class ClassLoader;
106 friend class SystemDictionary;
107 friend class ReservedHeapSpace;
108 friend class VMStructs;
109 friend class VM_PopulateDumpSharedSpace;
110 friend class Metaspace;
111
112 friend jint universe_init();
113 friend void universe2_init();
114 friend bool universe_post_init();
115 friend void universe_post_module_init();
116
117 private:
118 // Known classes in the VM
119 static Klass* _boolArrayKlassObj;
120 static Klass* _byteArrayKlassObj;
121 static Klass* _charArrayKlassObj;
122 static Klass* _intArrayKlassObj;
123 static Klass* _shortArrayKlassObj;
124 static Klass* _longArrayKlassObj;
125 static Klass* _singleArrayKlassObj;
126 static Klass* _doubleArrayKlassObj;
127 static Klass* _typeArrayKlassObjs[T_VOID+1];
128
129 static Klass* _objectArrayKlassObj;
130
131 // Known objects in the VM
132
133 // Primitive objects
134 static oop _int_mirror;
135 static oop _float_mirror;
136 static oop _double_mirror;
137 static oop _byte_mirror;
138 static oop _bool_mirror;
139 static oop _char_mirror;
140 static oop _long_mirror;
141 static oop _short_mirror;
142 static oop _void_mirror;
143
144 static oop _main_thread_group; // Reference to the main thread group object
145 static oop _system_thread_group; // Reference to the system thread group object
146
147 static objArrayOop _the_empty_class_klass_array; // Canonicalized obj array of type java.lang.Class
148 static oop _the_null_string; // A cache of "null" as a Java string
149 static oop _the_min_jint_string; // A cache of "-2147483648" as a Java string
150 static LatestMethodCache* _finalizer_register_cache; // static method for registering finalizable objects
151 static LatestMethodCache* _loader_addClass_cache; // method for registering loaded classes in class loader vector
152 static LatestMethodCache* _pd_implies_cache; // method for checking protection domain attributes
153 static LatestMethodCache* _throw_illegal_access_error_cache; // Unsafe.throwIllegalAccessError() method
154 static LatestMethodCache* _do_stack_walk_cache; // method for stack walker callback
155
156 // preallocated error objects (no backtrace)
157 static oop _out_of_memory_error_java_heap;
158 static oop _out_of_memory_error_metaspace;
159 static oop _out_of_memory_error_class_metaspace;
160 static oop _out_of_memory_error_array_size;
161 static oop _out_of_memory_error_gc_overhead_limit;
162 static oop _out_of_memory_error_realloc_objects;
163
164 // preallocated cause message for delayed StackOverflowError
165 static oop _delayed_stack_overflow_error_message;
166
167 static Array<int>* _the_empty_int_array; // Canonicalized int array
168 static Array<u2>* _the_empty_short_array; // Canonicalized short array
169 static Array<Klass*>* _the_empty_klass_array; // Canonicalized klass obj array
170 static Array<Method*>* _the_empty_method_array; // Canonicalized method obj array
171
172 static Array<Klass*>* _the_array_interfaces_array;
173
174 // array of preallocated error objects with backtrace
175 static objArrayOop _preallocated_out_of_memory_error_array;
176
177 // number of preallocated error objects available for use
178 static volatile jint _preallocated_out_of_memory_error_avail_count;
179
180 static oop _null_ptr_exception_instance; // preallocated exception object
181 static oop _arithmetic_exception_instance; // preallocated exception object
182 static oop _virtual_machine_error_instance; // preallocated exception object
183 // The object used as an exception dummy when exceptions are thrown for
184 // the vm thread.
185 static oop _vm_exception;
186
187 static oop _allocation_context_notification_obj;
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 static jint initialize_heap();
222 static void initialize_basic_type_mirrors(TRAPS);
223 static void fixup_mirrors(TRAPS);
224
225 static void reinitialize_vtable_of(KlassHandle h_k, TRAPS);
226 static void reinitialize_itables(TRAPS);
227 static void compute_base_vtable_size(); // compute vtable size of class Object
228
229 static void genesis(TRAPS); // Create the initial world
230
231 // Mirrors for primitive classes (created eagerly)
232 static oop check_mirror(oop m) {
233 assert(m != NULL, "mirror not initialized");
234 return m;
235 }
236
237 static void set_narrow_oop_base(address base) {
238 assert(UseCompressedOops, "no compressed oops?");
239 _narrow_oop._base = base;
240 }
241 static void set_narrow_klass_base(address base) {
242 assert(UseCompressedClassPointers, "no compressed klass ptrs?");
243 _narrow_klass._base = base;
244 }
245 static void set_narrow_oop_use_implicit_null_checks(bool use) {
246 assert(UseCompressedOops, "no compressed ptrs?");
247 _narrow_oop._use_implicit_null_checks = use;
248 }
249
250 // Debugging
251 static int _verify_count; // number of verifies done
252
253 // True during call to verify(). Should only be set/cleared in verify().
254 static bool _verify_in_progress;
255 static long verify_flags;
256
257 static uintptr_t _verify_oop_mask;
258 static uintptr_t _verify_oop_bits;
259
260 static void calculate_verify_data(HeapWord* low_boundary, HeapWord* high_boundary) PRODUCT_RETURN;
261 static void compute_verify_oop_data();
262
263 public:
264 // Known classes in the VM
265 static Klass* boolArrayKlassObj() { return _boolArrayKlassObj; }
266 static Klass* byteArrayKlassObj() { return _byteArrayKlassObj; }
267 static Klass* charArrayKlassObj() { return _charArrayKlassObj; }
268 static Klass* intArrayKlassObj() { return _intArrayKlassObj; }
269 static Klass* shortArrayKlassObj() { return _shortArrayKlassObj; }
270 static Klass* longArrayKlassObj() { return _longArrayKlassObj; }
271 static Klass* singleArrayKlassObj() { return _singleArrayKlassObj; }
272 static Klass* doubleArrayKlassObj() { return _doubleArrayKlassObj; }
273
274 static Klass* objectArrayKlassObj() {
275 return _objectArrayKlassObj;
276 }
277
278 static Klass* typeArrayKlassObj(BasicType t) {
279 assert((uint)t < T_VOID+1, "range check for type: %s", type2name(t));
280 assert(_typeArrayKlassObjs[t] != NULL, "domain check");
281 return _typeArrayKlassObjs[t];
282 }
283
284 // Known objects in the VM
285 static oop int_mirror() { return check_mirror(_int_mirror); }
286 static oop float_mirror() { return check_mirror(_float_mirror); }
287 static oop double_mirror() { return check_mirror(_double_mirror); }
288 static oop byte_mirror() { return check_mirror(_byte_mirror); }
289 static oop bool_mirror() { return check_mirror(_bool_mirror); }
290 static oop char_mirror() { return check_mirror(_char_mirror); }
291 static oop long_mirror() { return check_mirror(_long_mirror); }
292 static oop short_mirror() { return check_mirror(_short_mirror); }
293 static oop void_mirror() { return check_mirror(_void_mirror); }
294
295 // table of same
296 static oop _mirrors[T_VOID+1];
297
298 static oop java_mirror(BasicType t) {
299 assert((uint)t < T_VOID+1, "range check");
300 return check_mirror(_mirrors[t]);
301 }
302 static oop main_thread_group() { return _main_thread_group; }
303 static void set_main_thread_group(oop group) { _main_thread_group = group;}
304
305 static oop system_thread_group() { return _system_thread_group; }
306 static void set_system_thread_group(oop group) { _system_thread_group = group;}
307
308 static objArrayOop the_empty_class_klass_array () { return _the_empty_class_klass_array; }
309 static Array<Klass*>* the_array_interfaces_array() { return _the_array_interfaces_array; }
310 static oop the_null_string() { return _the_null_string; }
311 static oop the_min_jint_string() { return _the_min_jint_string; }
312
313 static Method* finalizer_register_method() { return _finalizer_register_cache->get_method(); }
314 static Method* loader_addClass_method() { return _loader_addClass_cache->get_method(); }
315
316 static Method* protection_domain_implies_method() { return _pd_implies_cache->get_method(); }
317 static Method* throw_illegal_access_error() { return _throw_illegal_access_error_cache->get_method(); }
318
319 static Method* do_stack_walk_method() { return _do_stack_walk_cache->get_method(); }
320
321 // Function to initialize these
322 static void initialize_known_methods(TRAPS);
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 /*
361 static CollectedHeap* heap() {
362 GC* gc = GC::gc();
363 if (gc != NULL) return gc->heap();
364 else return NULL;
365 }
366 */
367
368 // For UseCompressedOops
369 // Narrow Oop encoding mode:
370 // 0 - Use 32-bits oops without encoding when
371 // NarrowOopHeapBaseMin + heap_size < 4Gb
372 // 1 - Use zero based compressed oops with encoding when
373 // NarrowOopHeapBaseMin + heap_size < 32Gb
374 // 2 - Use compressed oops with disjoint heap base if
375 // base is 32G-aligned and base > 0. This allows certain
376 // optimizations in encoding/decoding.
377 // Disjoint: Bits used in base are disjoint from bits used
378 // for oops ==> oop = (cOop << 3) | base. One can disjoint
379 // the bits of an oop into base and compressed oop.
380 // 3 - Use compressed oops with heap base + encoding.
381 enum NARROW_OOP_MODE {
382 UnscaledNarrowOop = 0,
383 ZeroBasedNarrowOop = 1,
384 DisjointBaseNarrowOop = 2,
385 HeapBasedNarrowOop = 3,
386 AnyNarrowOopMode = 4
387 };
388 static NARROW_OOP_MODE narrow_oop_mode();
389 static const char* narrow_oop_mode_to_string(NARROW_OOP_MODE mode);
390 static char* preferred_heap_base(size_t heap_size, size_t alignment, NARROW_OOP_MODE mode);
391 static char* preferred_metaspace_base(size_t heap_size, NARROW_OOP_MODE mode);
392 static address narrow_oop_base() { return _narrow_oop._base; }
393 // Test whether bits of addr and possible offsets into the heap overlap.
394 static bool is_disjoint_heap_base_address(address addr) {
395 return (((uint64_t)(intptr_t)addr) &
396 (((uint64_t)UCONST64(0xFFFFffffFFFFffff)) >> (32-LogMinObjAlignmentInBytes))) == 0;
397 }
398 // Check for disjoint base compressed oops.
399 static bool narrow_oop_base_disjoint() {
400 return _narrow_oop._base != NULL && is_disjoint_heap_base_address(_narrow_oop._base);
401 }
402 // Check for real heapbased compressed oops.
403 // We must subtract the base as the bits overlap.
404 // If we negate above function, we also get unscaled and zerobased.
405 static bool narrow_oop_base_overlaps() {
406 return _narrow_oop._base != NULL && !is_disjoint_heap_base_address(_narrow_oop._base);
407 }
408 static bool is_narrow_oop_base(void* addr) { return (narrow_oop_base() == (address)addr); }
409 static int narrow_oop_shift() { return _narrow_oop._shift; }
410 static bool narrow_oop_use_implicit_null_checks() { return _narrow_oop._use_implicit_null_checks; }
411
412 // For UseCompressedClassPointers
413 static address narrow_klass_base() { return _narrow_klass._base; }
414 static bool is_narrow_klass_base(void* addr) { return (narrow_klass_base() == (address)addr); }
415 static int narrow_klass_shift() { return _narrow_klass._shift; }
416 static bool narrow_klass_use_implicit_null_checks() { return _narrow_klass._use_implicit_null_checks; }
417
418 static address* narrow_ptrs_base_addr() { return &_narrow_ptrs_base; }
419 static void set_narrow_ptrs_base(address a) { _narrow_ptrs_base = a; }
420 static address narrow_ptrs_base() { return _narrow_ptrs_base; }
421
422 static void print_compressed_oops_mode(outputStream* st);
423
424 // this is set in vm_version on sparc (and then reset in universe afaict)
425 static void set_narrow_oop_shift(int shift) {
426 _narrow_oop._shift = shift;
427 }
428
429 static void set_narrow_klass_shift(int shift) {
430 assert(shift == 0 || shift == LogKlassAlignmentInBytes, "invalid shift for klass ptrs");
431 _narrow_klass._shift = shift;
432 }
433
434 // Reserve Java heap and determine CompressedOops mode
435 static ReservedSpace reserve_heap(size_t heap_size, size_t alignment);
436
437 // Historic gc information
438 static size_t get_heap_capacity_at_last_gc() { return _heap_capacity_at_last_gc; }
439 static size_t get_heap_free_at_last_gc() { return _heap_capacity_at_last_gc - _heap_used_at_last_gc; }
440 static size_t get_heap_used_at_last_gc() { return _heap_used_at_last_gc; }
441 static void update_heap_info_at_gc();
442
443 // Testers
444 static bool is_bootstrapping() { return _bootstrapping; }
445 static bool is_module_initialized() { return _module_initialized; }
446 static bool is_fully_initialized() { return _fully_initialized; }
447
448 static inline bool element_type_should_be_aligned(BasicType type);
449 static inline bool field_type_should_be_aligned(BasicType type);
450 static bool on_page_boundary(void* addr);
451 static bool should_fill_in_stack_trace(Handle throwable);
452 static void check_alignment(uintx size, uintx alignment, const char* name);
453
454 // Finalizer support.
455 static void run_finalizers_on_exit();
456
457 // Iteration
458
459 // Apply "f" to the addresses of all the direct heap pointers maintained
460 // as static fields of "Universe".
461 static void oops_do(OopClosure* f, bool do_all = false);
462
463 // CDS support
464 static void serialize(SerializeClosure* f, bool do_all = false);
465
466 // Apply "f" to all klasses for basic types (classes not present in
467 // SystemDictionary).
468 static void basic_type_classes_do(void f(Klass*));
469
470 // For sharing -- fill in a list of known vtable pointers.
471 static void init_self_patching_vtbl_list(void** list, int count);
472
473 // Debugging
474 enum VERIFY_FLAGS {
475 Verify_Threads = 1,
476 Verify_Heap = 2,
477 Verify_SymbolTable = 4,
478 Verify_StringTable = 8,
479 Verify_CodeCache = 16,
480 Verify_SystemDictionary = 32,
481 Verify_ClassLoaderDataGraph = 64,
482 Verify_MetaspaceAux = 128,
483 Verify_JNIHandles = 256,
484 Verify_CHeap = 512,
485 Verify_CodeCacheOops = 1024,
486 Verify_All = -1
487 };
488 static void initialize_verify_flags();
489 static bool should_verify_subset(uint subset);
490 static bool verify_in_progress() { return _verify_in_progress; }
491 static void verify(VerifyOption option, const char* prefix);
492 static void verify(const char* prefix) {
493 verify(VerifyOption_Default, prefix);
494 }
495 static void verify() {
496 verify("");
497 }
498
499 static int verify_count() { return _verify_count; }
500 static void print_on(outputStream* st);
501 static void print_heap_at_SIGBREAK();
502 static void print_heap_before_gc();
503 static void print_heap_after_gc();
504
505 // Change the number of dummy objects kept reachable by the full gc dummy
506 // array; this should trigger relocation in a sliding compaction collector.
507 debug_only(static bool release_fullgc_alot_dummy();)
508 // The non-oop pattern (see compiledIC.hpp, etc)
509 static void* non_oop_word();
510
511 // Oop verification (see MacroAssembler::verify_oop)
512 static uintptr_t verify_oop_mask() PRODUCT_RETURN0;
513 static uintptr_t verify_oop_bits() PRODUCT_RETURN0;
514 static uintptr_t verify_mark_bits() PRODUCT_RETURN0;
515 static uintptr_t verify_mark_mask() PRODUCT_RETURN0;
516
517 // Compiler support
518 static int base_vtable_size() { return _base_vtable_size; }
519 };
520
521 class DeferredObjAllocEvent : public CHeapObj<mtInternal> {
522 private:
523 oop _oop;
524 size_t _bytesize;
525 jint _arena_id;
526
527 public:
528 DeferredObjAllocEvent(const oop o, const size_t s, const jint id) {
529 _oop = o;
530 _bytesize = s;
531 _arena_id = id;
532 }
533
534 ~DeferredObjAllocEvent() {
535 }
536
537 jint arena_id() { return _arena_id; }
538 size_t bytesize() { return _bytesize; }
539 oop get_oop() { return _oop; }
540 };
541
542 #endif // SHARE_VM_MEMORY_UNIVERSE_HPP