1 /*
2 * Copyright (c) 1997, 2012, 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 // Common parts of a Method* cache. This cache safely interacts with
45 // the RedefineClasses API.
46 //
47 class CommonMethodOopCache : public CHeapObj<mtClass> {
48 // We save the Klass* and the idnum of Method* in order to get
49 // the current cached Method*.
50 private:
51 Klass* _klass;
52 int _method_idnum;
53
54 public:
55 CommonMethodOopCache() { _klass = NULL; _method_idnum = -1; }
56 ~CommonMethodOopCache() { _klass = NULL; _method_idnum = -1; }
57
58 void init(Klass* k, Method* m, TRAPS);
59 Klass* klass() const { return _klass; }
60 int method_idnum() const { return _method_idnum; }
61
62 // Enhanced Class Redefinition support
63 void classes_do(void f(Klass*)) {
64 f(_klass);
65 }
66
67 // CDS support. Replace the klass in this with the archive version
68 // could use this for Enhanced Class Redefinition also.
69 void serialize(SerializeClosure* f) {
70 f->do_ptr((void**)&_klass);
71 }
72 };
73
74
75 // A helper class for caching a Method* when the user of the cache
76 // cares about all versions of the Method*.
77 //
78 class ActiveMethodOopsCache : public CommonMethodOopCache {
79 // This subclass adds weak references to older versions of the
80 // Method* and a query method for a Method*.
81
82 private:
83 // If the cached Method* has not been redefined, then
84 // _prev_methods will be NULL. If all of the previous
85 // versions of the method have been collected, then
86 // _prev_methods can have a length of zero.
87 GrowableArray<Method*>* _prev_methods;
88
89 public:
90 ActiveMethodOopsCache() { _prev_methods = NULL; }
91 ~ActiveMethodOopsCache();
92
93 void add_previous_version(Method* const method);
94 bool is_same_method(Method* const method) const;
95 };
96
97
98 // A helper class for caching a Method* when the user of the cache
99 // only cares about the latest version of the Method*.
100 //
101 class LatestMethodOopCache : public CommonMethodOopCache {
102 // This subclass adds a getter method for the latest Method*.
103
104 public:
105 Method* get_Method();
106 };
107
108 // For UseCompressedOops.
109 struct NarrowOopStruct {
110 // Base address for oop-within-java-object materialization.
111 // NULL if using wide oops or zero based narrow oops.
112 address _base;
113 // Number of shift bits for encoding/decoding narrow oops.
114 // 0 if using wide oops or zero based unscaled narrow oops,
115 // LogMinObjAlignmentInBytes otherwise.
116 int _shift;
117 // Generate code with implicit null checks for narrow oops.
118 bool _use_implicit_null_checks;
119 };
120
121 enum VerifyOption {
122 VerifyOption_Default = 0,
123
124 // G1
125 VerifyOption_G1UsePrevMarking = VerifyOption_Default,
126 VerifyOption_G1UseNextMarking = VerifyOption_G1UsePrevMarking + 1,
127 VerifyOption_G1UseMarkWord = VerifyOption_G1UseNextMarking + 1
128 };
129
130 class Universe: AllStatic {
131 // Ugh. Universe is much too friendly.
132 friend class MarkSweep;
133 friend class oopDesc;
134 friend class ClassLoader;
135 friend class Arguments;
136 friend class SystemDictionary;
137 friend class VMStructs;
138 friend class VM_PopulateDumpSharedSpace;
139
140 friend jint universe_init();
141 friend void universe2_init();
142 friend bool universe_post_init();
143
144 private:
145 // Known classes in the VM
146 static Klass* _boolArrayKlassObj;
147 static Klass* _byteArrayKlassObj;
148 static Klass* _charArrayKlassObj;
149 static Klass* _intArrayKlassObj;
150 static Klass* _shortArrayKlassObj;
151 static Klass* _longArrayKlassObj;
152 static Klass* _singleArrayKlassObj;
153 static Klass* _doubleArrayKlassObj;
154 static Klass* _typeArrayKlassObjs[T_VOID+1];
155
156 static Klass* _objectArrayKlassObj;
157
158 // Known objects in the VM
159
160 // Primitive objects
161 static oop _int_mirror;
162 static oop _float_mirror;
163 static oop _double_mirror;
164 static oop _byte_mirror;
165 static oop _bool_mirror;
166 static oop _char_mirror;
167 static oop _long_mirror;
168 static oop _short_mirror;
169 static oop _void_mirror;
170
171 static oop _main_thread_group; // Reference to the main thread group object
172 static oop _system_thread_group; // Reference to the system thread group object
173
174 static objArrayOop _the_empty_class_klass_array; // Canonicalized obj array of type java.lang.Class
175 static oop _the_null_string; // A cache of "null" as a Java string
176 static oop _the_min_jint_string; // A cache of "-2147483648" as a Java string
177 static LatestMethodOopCache* _finalizer_register_cache; // static method for registering finalizable objects
178 static LatestMethodOopCache* _loader_addClass_cache; // method for registering loaded classes in class loader vector
179 static ActiveMethodOopsCache* _reflect_invoke_cache; // method for security checks
180 static oop _out_of_memory_error_java_heap; // preallocated error object (no backtrace)
181 static oop _out_of_memory_error_perm_gen; // preallocated error object (no backtrace)
182 static oop _out_of_memory_error_array_size;// preallocated error object (no backtrace)
183 static oop _out_of_memory_error_gc_overhead_limit; // preallocated error object (no backtrace)
184
185 static Array<int>* _the_empty_int_array; // Canonicalized int array
186 static Array<u2>* _the_empty_short_array; // Canonicalized short array
187 static Array<Klass*>* _the_empty_klass_array; // Canonicalized klass obj array
188 static Array<Method*>* _the_empty_method_array; // Canonicalized method obj array
189
190 static Array<Klass*>* _the_array_interfaces_array;
191
192 // array of preallocated error objects with backtrace
193 static objArrayOop _preallocated_out_of_memory_error_array;
194
195 // number of preallocated error objects available for use
196 static volatile jint _preallocated_out_of_memory_error_avail_count;
197
198 static oop _null_ptr_exception_instance; // preallocated exception object
199 static oop _arithmetic_exception_instance; // preallocated exception object
200 static oop _virtual_machine_error_instance; // preallocated exception object
201 // The object used as an exception dummy when exceptions are thrown for
202 // the vm thread.
203 static oop _vm_exception;
204
205 // The particular choice of collected heap.
206 static CollectedHeap* _collectedHeap;
207
208 // For UseCompressedOops.
209 static struct NarrowOopStruct _narrow_oop;
210
211 // array of dummy objects used with +FullGCAlot
212 debug_only(static objArrayOop _fullgc_alot_dummy_array;)
213 // index of next entry to clear
214 debug_only(static int _fullgc_alot_dummy_next;)
215
216 // Compiler/dispatch support
217 static int _base_vtable_size; // Java vtbl size of klass Object (in words)
218
219 // Initialization
220 static bool _bootstrapping; // true during genesis
221 static bool _fully_initialized; // true after universe_init and initialize_vtables called
222
223 // the array of preallocated errors with backtraces
224 static objArrayOop preallocated_out_of_memory_errors() { return _preallocated_out_of_memory_error_array; }
225
226 // generate an out of memory error; if possible using an error with preallocated backtrace;
227 // otherwise return the given default error.
228 static oop gen_out_of_memory_error(oop default_err);
229
230 // Historic gc information
231 static size_t _heap_capacity_at_last_gc;
232 static size_t _heap_used_at_last_gc;
233
234 static jint initialize_heap();
235 static void initialize_basic_type_mirrors(TRAPS);
236 static void fixup_mirrors(TRAPS);
237
238 static void reinitialize_vtable_of(KlassHandle h_k, TRAPS);
239 static void reinitialize_itables(TRAPS);
240 static void compute_base_vtable_size(); // compute vtable size of class Object
241
242 static void genesis(TRAPS); // Create the initial world
243
244 // Mirrors for primitive classes (created eagerly)
245 static oop check_mirror(oop m) {
246 assert(m != NULL, "mirror not initialized");
247 return m;
248 }
249
250 // Narrow Oop encoding mode:
251 // 0 - Use 32-bits oops without encoding when
252 // NarrowOopHeapBaseMin + heap_size < 4Gb
253 // 1 - Use zero based compressed oops with encoding when
254 // NarrowOopHeapBaseMin + heap_size < 32Gb
255 // 2 - Use compressed oops with heap base + encoding.
256 enum NARROW_OOP_MODE {
257 UnscaledNarrowOop = 0,
258 ZeroBasedNarrowOop = 1,
259 HeapBasedNarrowOop = 2
260 };
261 static char* preferred_heap_base(size_t heap_size, NARROW_OOP_MODE mode);
262 static void set_narrow_oop_base(address base) { _narrow_oop._base = base; }
263 static void set_narrow_oop_use_implicit_null_checks(bool use) { _narrow_oop._use_implicit_null_checks = use; }
264
265 // Debugging
266 static int _verify_count; // number of verifies done
267 // True during call to verify(). Should only be set/cleared in verify().
268 static bool _verify_in_progress;
269
270 static void compute_verify_oop_data();
271
272 public:
273 // Known classes in the VM
274 static Klass* boolArrayKlassObj() { return _boolArrayKlassObj; }
275 static Klass* byteArrayKlassObj() { return _byteArrayKlassObj; }
276 static Klass* charArrayKlassObj() { return _charArrayKlassObj; }
277 static Klass* intArrayKlassObj() { return _intArrayKlassObj; }
278 static Klass* shortArrayKlassObj() { return _shortArrayKlassObj; }
279 static Klass* longArrayKlassObj() { return _longArrayKlassObj; }
280 static Klass* singleArrayKlassObj() { return _singleArrayKlassObj; }
281 static Klass* doubleArrayKlassObj() { return _doubleArrayKlassObj; }
282
283 static Klass* objectArrayKlassObj() {
284 return _objectArrayKlassObj;
285 }
286
287 static Klass* typeArrayKlassObj(BasicType t) {
288 assert((uint)t < T_VOID+1, err_msg("range check for type: %s", type2name(t)));
289 assert(_typeArrayKlassObjs[t] != NULL, "domain check");
290 return _typeArrayKlassObjs[t];
291 }
292
293 // Known objects in the VM
294 static oop int_mirror() { return check_mirror(_int_mirror); }
295 static oop float_mirror() { return check_mirror(_float_mirror); }
296 static oop double_mirror() { return check_mirror(_double_mirror); }
297 static oop byte_mirror() { return check_mirror(_byte_mirror); }
298 static oop bool_mirror() { return check_mirror(_bool_mirror); }
299 static oop char_mirror() { return check_mirror(_char_mirror); }
300 static oop long_mirror() { return check_mirror(_long_mirror); }
301 static oop short_mirror() { return check_mirror(_short_mirror); }
302 static oop void_mirror() { return check_mirror(_void_mirror); }
303
304 // table of same
305 static oop _mirrors[T_VOID+1];
306
307 static oop java_mirror(BasicType t) {
308 assert((uint)t < T_VOID+1, "range check");
309 return check_mirror(_mirrors[t]);
310 }
311 static oop main_thread_group() { return _main_thread_group; }
312 static void set_main_thread_group(oop group) { _main_thread_group = group;}
313
314 static oop system_thread_group() { return _system_thread_group; }
315 static void set_system_thread_group(oop group) { _system_thread_group = group;}
316
317 static objArrayOop the_empty_class_klass_array () { return _the_empty_class_klass_array; }
318 static Array<Klass*>* the_array_interfaces_array() { return _the_array_interfaces_array; }
319 static oop the_null_string() { return _the_null_string; }
320 static oop the_min_jint_string() { return _the_min_jint_string; }
321 static Method* finalizer_register_method() { return _finalizer_register_cache->get_Method(); }
322 static Method* loader_addClass_method() { return _loader_addClass_cache->get_Method(); }
323 static ActiveMethodOopsCache* reflect_invoke_cache() { return _reflect_invoke_cache; }
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 Array<int>* the_empty_int_array() { return _the_empty_int_array; }
330 static Array<u2>* the_empty_short_array() { return _the_empty_short_array; }
331 static Array<Method*>* the_empty_method_array() { return _the_empty_method_array; }
332 static Array<Klass*>* the_empty_klass_array() { return _the_empty_klass_array; }
333
334 // OutOfMemoryError support. Returns an error with the required message. The returned error
335 // may or may not have a backtrace. If error has a backtrace then the stack trace is already
336 // filled in.
337 static oop out_of_memory_error_java_heap() { return gen_out_of_memory_error(_out_of_memory_error_java_heap); }
338 static oop out_of_memory_error_perm_gen() { return gen_out_of_memory_error(_out_of_memory_error_perm_gen); }
339 static oop out_of_memory_error_array_size() { return gen_out_of_memory_error(_out_of_memory_error_array_size); }
340 static oop out_of_memory_error_gc_overhead_limit() { return gen_out_of_memory_error(_out_of_memory_error_gc_overhead_limit); }
341
342 // Accessors needed for fast allocation
343 static Klass** boolArrayKlassObj_addr() { return &_boolArrayKlassObj; }
344 static Klass** byteArrayKlassObj_addr() { return &_byteArrayKlassObj; }
345 static Klass** charArrayKlassObj_addr() { return &_charArrayKlassObj; }
346 static Klass** intArrayKlassObj_addr() { return &_intArrayKlassObj; }
347 static Klass** shortArrayKlassObj_addr() { return &_shortArrayKlassObj; }
348 static Klass** longArrayKlassObj_addr() { return &_longArrayKlassObj; }
349 static Klass** singleArrayKlassObj_addr() { return &_singleArrayKlassObj; }
350 static Klass** doubleArrayKlassObj_addr() { return &_doubleArrayKlassObj; }
351 static Klass** objectArrayKlassObj_addr() { return &_objectArrayKlassObj; }
352
353 // The particular choice of collected heap.
354 static CollectedHeap* heap() { return _collectedHeap; }
355
356 // For UseCompressedOops
357 static address* narrow_oop_base_addr() { return &_narrow_oop._base; }
358 static address narrow_oop_base() { return _narrow_oop._base; }
359 static bool is_narrow_oop_base(void* addr) { return (narrow_oop_base() == (address)addr); }
360 static int narrow_oop_shift() { return _narrow_oop._shift; }
361 static bool narrow_oop_use_implicit_null_checks() { return _narrow_oop._use_implicit_null_checks; }
362
363 // this is set in vm_version on sparc (and then reset in universe afaict)
364 static void set_narrow_oop_shift(int shift) { _narrow_oop._shift = shift; }
365
366 // Reserve Java heap and determine CompressedOops mode
367 static ReservedSpace reserve_heap(size_t heap_size, size_t alignment);
368
369 // Historic gc information
370 static size_t get_heap_capacity_at_last_gc() { return _heap_capacity_at_last_gc; }
371 static size_t get_heap_free_at_last_gc() { return _heap_capacity_at_last_gc - _heap_used_at_last_gc; }
372 static size_t get_heap_used_at_last_gc() { return _heap_used_at_last_gc; }
373 static void update_heap_info_at_gc();
374
375 // Testers
376 static bool is_bootstrapping() { return _bootstrapping; }
377 static bool is_fully_initialized() { return _fully_initialized; }
378
379 static inline bool element_type_should_be_aligned(BasicType type);
380 static inline bool field_type_should_be_aligned(BasicType type);
381 static bool on_page_boundary(void* addr);
382 static bool should_fill_in_stack_trace(Handle throwable);
383 static void check_alignment(uintx size, uintx alignment, const char* name);
384
385 // Finalizer support.
386 static void run_finalizers_on_exit();
387
388 // Iteration
389
390 // Apply "f" to the addresses of all the direct heap pointers maintained
391 // as static fields of "Universe".
392 static void oops_do(OopClosure* f, bool do_all = false);
393
394 // CDS support
395 static void serialize(SerializeClosure* f, bool do_all = false);
396
397 // Apply "f" to all klasses for basic types (classes not present in
398 // SystemDictionary).
399 static void basic_type_classes_do(void f(Klass*));
400
401 // For sharing -- fill in a list of known vtable pointers.
402 static void init_self_patching_vtbl_list(void** list, int count);
403
404 // Debugging
405 static bool verify_in_progress() { return _verify_in_progress; }
406 static void verify(bool silent = false,
407 VerifyOption option = VerifyOption_Default );
408 static int verify_count() { return _verify_count; }
409 // The default behavior is to call print_on() on gclog_or_tty.
410 static void print();
411 // The extended parameter determines which method on the heap will
412 // be called: print_on() (extended == false) or print_extended_on()
413 // (extended == true).
414 static void print_on(outputStream* st, bool extended = false);
415 static void print_heap_at_SIGBREAK();
416 static void print_heap_before_gc() { print_heap_before_gc(gclog_or_tty); }
417 static void print_heap_after_gc() { print_heap_after_gc(gclog_or_tty); }
418 static void print_heap_before_gc(outputStream* st, bool ignore_extended = false);
419 static void print_heap_after_gc(outputStream* st, bool ignore_extended = false);
420
421 // Change the number of dummy objects kept reachable by the full gc dummy
422 // array; this should trigger relocation in a sliding compaction collector.
423 debug_only(static bool release_fullgc_alot_dummy();)
424 // The non-oop pattern (see compiledIC.hpp, etc)
425 static void* non_oop_word();
426
427 // Oop verification (see MacroAssembler::verify_oop)
428 static uintptr_t verify_oop_mask() PRODUCT_RETURN0;
429 static uintptr_t verify_oop_bits() PRODUCT_RETURN0;
430 static uintptr_t verify_mark_bits() PRODUCT_RETURN0;
431 static uintptr_t verify_mark_mask() PRODUCT_RETURN0;
432
433 // Flushing and deoptimization
434 static void flush_dependents_on(instanceKlassHandle dependee);
435 static void flush_dependents_on(Handle call_site, Handle method_handle);
436 #ifdef HOTSWAP
437 // Flushing and deoptimization in case of evolution
438 static void flush_evol_dependents_on(instanceKlassHandle dependee);
439 #endif // HOTSWAP
440 // Support for fullspeed debugging
441 static void flush_dependents_on_method(methodHandle dependee);
442
443 // Compiler support
444 static int base_vtable_size() { return _base_vtable_size; }
445 };
446
447 class DeferredObjAllocEvent : public CHeapObj<mtInternal> {
448 private:
449 oop _oop;
450 size_t _bytesize;
451 jint _arena_id;
452
453 public:
454 DeferredObjAllocEvent(const oop o, const size_t s, const jint id) {
455 _oop = o;
456 _bytesize = s;
457 _arena_id = id;
458 }
459
460 ~DeferredObjAllocEvent() {
461 }
462
463 jint arena_id() { return _arena_id; }
464 size_t bytesize() { return _bytesize; }
465 oop get_oop() { return _oop; }
466 };
467
468 #endif // SHARE_VM_MEMORY_UNIVERSE_HPP