1 /*
2 * Copyright (c) 1997, 2010, 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 "runtime/handles.hpp"
29 #include "utilities/growableArray.hpp"
30
31 // Universe is a name space holding known system classes and objects in the VM.
32 //
33 // Loaded classes are accessible through the SystemDictionary.
34 //
35 // The object heap is allocated and accessed through Universe, and various allocation
36 // support is provided. Allocation by the interpreter and compiled code is done inline
37 // and bails out to Scavenge::invoke_and_allocate.
38
39 class CollectedHeap;
40 class DeferredObjAllocEvent;
41
42
43 // Common parts of a methodOop cache. This cache safely interacts with
44 // the RedefineClasses API.
45 //
46 class CommonMethodOopCache : public CHeapObj {
47 // We save the klassOop and the idnum of methodOop in order to get
48 // the current cached methodOop.
49 private:
50 klassOop _klass;
51 int _method_idnum;
52
53 public:
54 CommonMethodOopCache() { _klass = NULL; _method_idnum = -1; }
55 ~CommonMethodOopCache() { _klass = NULL; _method_idnum = -1; }
56
57 void init(klassOop k, methodOop m, TRAPS);
58 klassOop klass() const { return _klass; }
59 int method_idnum() const { return _method_idnum; }
60
61 // GC support
62 void oops_do(OopClosure* f) { f->do_oop((oop*)&_klass); }
63 };
64
65
66 // A helper class for caching a methodOop when the user of the cache
67 // cares about all versions of the methodOop.
68 //
69 class ActiveMethodOopsCache : public CommonMethodOopCache {
70 // This subclass adds weak references to older versions of the
71 // methodOop and a query method for a methodOop.
72
73 private:
74 // If the cached methodOop has not been redefined, then
75 // _prev_methods will be NULL. If all of the previous
76 // versions of the method have been collected, then
77 // _prev_methods can have a length of zero.
78 GrowableArray<jweak>* _prev_methods;
79
80 public:
81 ActiveMethodOopsCache() { _prev_methods = NULL; }
82 ~ActiveMethodOopsCache();
83
84 void add_previous_version(const methodOop method);
85 bool is_same_method(const methodOop method) const;
86 };
87
88
89 // A helper class for caching a methodOop when the user of the cache
90 // only cares about the latest version of the methodOop.
91 //
92 class LatestMethodOopCache : public CommonMethodOopCache {
93 // This subclass adds a getter method for the latest methodOop.
94
95 public:
96 methodOop get_methodOop();
97 };
98
99 // For UseCompressedOops.
100 struct NarrowOopStruct {
101 // Base address for oop-within-java-object materialization.
102 // NULL if using wide oops or zero based narrow oops.
103 address _base;
104 // Number of shift bits for encoding/decoding narrow oops.
105 // 0 if using wide oops or zero based unscaled narrow oops,
106 // LogMinObjAlignmentInBytes otherwise.
107 int _shift;
108 // Generate code with implicit null checks for narrow oops.
109 bool _use_implicit_null_checks;
110 };
111
112
113 class Universe: AllStatic {
114 // Ugh. Universe is much too friendly.
115 friend class MarkSweep;
116 friend class oopDesc;
117 friend class ClassLoader;
118 friend class Arguments;
119 friend class SystemDictionary;
120 friend class VMStructs;
121 friend class CompactingPermGenGen;
122 friend class VM_PopulateDumpSharedSpace;
123
124 friend jint universe_init();
125 friend void universe2_init();
126 friend bool universe_post_init();
127
128 private:
129 // Known classes in the VM
130 static klassOop _boolArrayKlassObj;
131 static klassOop _byteArrayKlassObj;
132 static klassOop _charArrayKlassObj;
133 static klassOop _intArrayKlassObj;
134 static klassOop _shortArrayKlassObj;
135 static klassOop _longArrayKlassObj;
136 static klassOop _singleArrayKlassObj;
137 static klassOop _doubleArrayKlassObj;
138 static klassOop _typeArrayKlassObjs[T_VOID+1];
139
140 static klassOop _objectArrayKlassObj;
141
142 static klassOop _symbolKlassObj;
143 static klassOop _methodKlassObj;
144 static klassOop _constMethodKlassObj;
145 static klassOop _methodDataKlassObj;
146 static klassOop _klassKlassObj;
147 static klassOop _arrayKlassKlassObj;
148 static klassOop _objArrayKlassKlassObj;
149 static klassOop _typeArrayKlassKlassObj;
150 static klassOop _instanceKlassKlassObj;
151 static klassOop _constantPoolKlassObj;
152 static klassOop _constantPoolCacheKlassObj;
153 static klassOop _compiledICHolderKlassObj;
154 static klassOop _systemObjArrayKlassObj;
155
156 // Known objects in the VM
157
158 // Primitive objects
159 static oop _int_mirror;
160 static oop _float_mirror;
161 static oop _double_mirror;
162 static oop _byte_mirror;
163 static oop _bool_mirror;
164 static oop _char_mirror;
165 static oop _long_mirror;
166 static oop _short_mirror;
167 static oop _void_mirror;
168
169 static oop _main_thread_group; // Reference to the main thread group object
170 static oop _system_thread_group; // Reference to the system thread group object
171
172 static typeArrayOop _the_empty_byte_array; // Canonicalized byte array
173 static typeArrayOop _the_empty_short_array; // Canonicalized short array
174 static typeArrayOop _the_empty_int_array; // Canonicalized int array
175 static objArrayOop _the_empty_system_obj_array; // Canonicalized system obj array
176 static objArrayOop _the_empty_class_klass_array; // Canonicalized obj array of type java.lang.Class
177 static objArrayOop _the_array_interfaces_array; // Canonicalized 2-array of cloneable & serializable klasses
178 static oop _the_null_string; // A cache of "null" as a Java string
179 static oop _the_min_jint_string; // A cache of "-2147483648" as a Java string
180 static LatestMethodOopCache* _finalizer_register_cache; // static method for registering finalizable objects
181 static LatestMethodOopCache* _loader_addClass_cache; // method for registering loaded classes in class loader vector
182 static ActiveMethodOopsCache* _reflect_invoke_cache; // method for security checks
183 static oop _out_of_memory_error_java_heap; // preallocated error object (no backtrace)
184 static oop _out_of_memory_error_perm_gen; // preallocated error object (no backtrace)
185 static oop _out_of_memory_error_array_size;// preallocated error object (no backtrace)
186 static oop _out_of_memory_error_gc_overhead_limit; // preallocated error object (no backtrace)
187
188 // array of preallocated error objects with backtrace
189 static objArrayOop _preallocated_out_of_memory_error_array;
190
191 // number of preallocated error objects available for use
192 static volatile jint _preallocated_out_of_memory_error_avail_count;
193
194 static oop _null_ptr_exception_instance; // preallocated exception object
195 static oop _arithmetic_exception_instance; // preallocated exception object
196 static oop _virtual_machine_error_instance; // preallocated exception object
197 // The object used as an exception dummy when exceptions are thrown for
198 // the vm thread.
199 static oop _vm_exception;
200
201 static oop _emptySymbol; // Canonical empty string ("") symbol
202
203 // The particular choice of collected heap.
204 static CollectedHeap* _collectedHeap;
205
206 // For UseCompressedOops.
207 static struct NarrowOopStruct _narrow_oop;
208
209 // array of dummy objects used with +FullGCAlot
210 debug_only(static objArrayOop _fullgc_alot_dummy_array;)
211 // index of next entry to clear
212 debug_only(static int _fullgc_alot_dummy_next;)
213
214 // Compiler/dispatch support
215 static int _base_vtable_size; // Java vtbl size of klass Object (in words)
216
217 // Initialization
218 static bool _bootstrapping; // true during genesis
219 static bool _fully_initialized; // true after universe_init and initialize_vtables called
220
221 // the array of preallocated errors with backtraces
222 static objArrayOop preallocated_out_of_memory_errors() { return _preallocated_out_of_memory_error_array; }
223
224 // generate an out of memory error; if possible using an error with preallocated backtrace;
225 // otherwise return the given default error.
226 static oop gen_out_of_memory_error(oop default_err);
227
228 // Historic gc information
229 static size_t _heap_capacity_at_last_gc;
230 static size_t _heap_used_at_last_gc;
231
232 static jint initialize_heap();
233 static void initialize_basic_type_mirrors(TRAPS);
234 static void fixup_mirrors(TRAPS);
235
236 static void reinitialize_vtable_of(KlassHandle h_k, TRAPS);
237 static void reinitialize_itables(TRAPS);
238 static void compute_base_vtable_size(); // compute vtable size of class Object
239
240 static void genesis(TRAPS); // Create the initial world
241
242 // Mirrors for primitive classes (created eagerly)
243 static oop check_mirror(oop m) {
244 assert(m != NULL, "mirror not initialized");
245 return m;
246 }
247
248 // Debugging
249 static int _verify_count; // number of verifies done
250 // True during call to verify(). Should only be set/cleared in verify().
251 static bool _verify_in_progress;
252
253 static void compute_verify_oop_data();
254
255 public:
256 // Known classes in the VM
257 static klassOop boolArrayKlassObj() { return _boolArrayKlassObj; }
258 static klassOop byteArrayKlassObj() { return _byteArrayKlassObj; }
259 static klassOop charArrayKlassObj() { return _charArrayKlassObj; }
260 static klassOop intArrayKlassObj() { return _intArrayKlassObj; }
261 static klassOop shortArrayKlassObj() { return _shortArrayKlassObj; }
262 static klassOop longArrayKlassObj() { return _longArrayKlassObj; }
263 static klassOop singleArrayKlassObj() { return _singleArrayKlassObj; }
264 static klassOop doubleArrayKlassObj() { return _doubleArrayKlassObj; }
265
266 static klassOop objectArrayKlassObj() {
267 return _objectArrayKlassObj;
268 }
269
270 static klassOop typeArrayKlassObj(BasicType t) {
271 assert((uint)t < T_VOID+1, "range check");
272 assert(_typeArrayKlassObjs[t] != NULL, "domain check");
273 return _typeArrayKlassObjs[t];
274 }
275
276 static klassOop symbolKlassObj() { return _symbolKlassObj; }
277 static klassOop methodKlassObj() { return _methodKlassObj; }
278 static klassOop constMethodKlassObj() { return _constMethodKlassObj; }
279 static klassOop methodDataKlassObj() { return _methodDataKlassObj; }
280 static klassOop klassKlassObj() { return _klassKlassObj; }
281 static klassOop arrayKlassKlassObj() { return _arrayKlassKlassObj; }
282 static klassOop objArrayKlassKlassObj() { return _objArrayKlassKlassObj; }
283 static klassOop typeArrayKlassKlassObj() { return _typeArrayKlassKlassObj; }
284 static klassOop instanceKlassKlassObj() { return _instanceKlassKlassObj; }
285 static klassOop constantPoolKlassObj() { return _constantPoolKlassObj; }
286 static klassOop constantPoolCacheKlassObj() { return _constantPoolCacheKlassObj; }
287 static klassOop compiledICHolderKlassObj() { return _compiledICHolderKlassObj; }
288 static klassOop systemObjArrayKlassObj() { return _systemObjArrayKlassObj; }
289
290 // Known objects in tbe VM
291 static oop int_mirror() { return check_mirror(_int_mirror);
292 }
293 static oop float_mirror() { return check_mirror(_float_mirror); }
294 static oop double_mirror() { return check_mirror(_double_mirror); }
295 static oop byte_mirror() { return check_mirror(_byte_mirror); }
296 static oop bool_mirror() { return check_mirror(_bool_mirror); }
297 static oop char_mirror() { return check_mirror(_char_mirror); }
298 static oop long_mirror() { return check_mirror(_long_mirror); }
299 static oop short_mirror() { return check_mirror(_short_mirror); }
300 static oop void_mirror() { return check_mirror(_void_mirror); }
301
302 // table of same
303 static oop _mirrors[T_VOID+1];
304
305 static oop java_mirror(BasicType t) {
306 assert((uint)t < T_VOID+1, "range check");
307 return check_mirror(_mirrors[t]);
308 }
309 static oop main_thread_group() { return _main_thread_group; }
310 static void set_main_thread_group(oop group) { _main_thread_group = group;}
311
312 static oop system_thread_group() { return _system_thread_group; }
313 static void set_system_thread_group(oop group) { _system_thread_group = group;}
314
315 static typeArrayOop the_empty_byte_array() { return _the_empty_byte_array; }
316 static typeArrayOop the_empty_short_array() { return _the_empty_short_array; }
317 static typeArrayOop the_empty_int_array() { return _the_empty_int_array; }
318 static objArrayOop the_empty_system_obj_array () { return _the_empty_system_obj_array; }
319 static objArrayOop the_empty_class_klass_array () { return _the_empty_class_klass_array; }
320 static objArrayOop the_array_interfaces_array() { return _the_array_interfaces_array; }
321 static oop the_null_string() { return _the_null_string; }
322 static oop the_min_jint_string() { return _the_min_jint_string; }
323 static methodOop finalizer_register_method() { return _finalizer_register_cache->get_methodOop(); }
324 static methodOop loader_addClass_method() { return _loader_addClass_cache->get_methodOop(); }
325 static ActiveMethodOopsCache* reflect_invoke_cache() { return _reflect_invoke_cache; }
326 static oop null_ptr_exception_instance() { return _null_ptr_exception_instance; }
327 static oop arithmetic_exception_instance() { return _arithmetic_exception_instance; }
328 static oop virtual_machine_error_instance() { return _virtual_machine_error_instance; }
329 static oop vm_exception() { return _vm_exception; }
330 static oop emptySymbol() { return _emptySymbol; }
331
332 // OutOfMemoryError support. Returns an error with the required message. The returned error
333 // may or may not have a backtrace. If error has a backtrace then the stack trace is already
334 // filled in.
335 static oop out_of_memory_error_java_heap() { return gen_out_of_memory_error(_out_of_memory_error_java_heap); }
336 static oop out_of_memory_error_perm_gen() { return gen_out_of_memory_error(_out_of_memory_error_perm_gen); }
337 static oop out_of_memory_error_array_size() { return gen_out_of_memory_error(_out_of_memory_error_array_size); }
338 static oop out_of_memory_error_gc_overhead_limit() { return gen_out_of_memory_error(_out_of_memory_error_gc_overhead_limit); }
339
340 // Accessors needed for fast allocation
341 static klassOop* boolArrayKlassObj_addr() { return &_boolArrayKlassObj; }
342 static klassOop* byteArrayKlassObj_addr() { return &_byteArrayKlassObj; }
343 static klassOop* charArrayKlassObj_addr() { return &_charArrayKlassObj; }
344 static klassOop* intArrayKlassObj_addr() { return &_intArrayKlassObj; }
345 static klassOop* shortArrayKlassObj_addr() { return &_shortArrayKlassObj; }
346 static klassOop* longArrayKlassObj_addr() { return &_longArrayKlassObj; }
347 static klassOop* singleArrayKlassObj_addr() { return &_singleArrayKlassObj; }
348 static klassOop* doubleArrayKlassObj_addr() { return &_doubleArrayKlassObj; }
349
350 // The particular choice of collected heap.
351 static CollectedHeap* heap() { return _collectedHeap; }
352
353 // For UseCompressedOops
354 static address* narrow_oop_base_addr() { return &_narrow_oop._base; }
355 static address narrow_oop_base() { return _narrow_oop._base; }
356 static bool is_narrow_oop_base(void* addr) { return (narrow_oop_base() == (address)addr); }
357 static int narrow_oop_shift() { return _narrow_oop._shift; }
358 static void set_narrow_oop_base(address base) { _narrow_oop._base = base; }
359 static void set_narrow_oop_shift(int shift) { _narrow_oop._shift = shift; }
360 static bool narrow_oop_use_implicit_null_checks() { return _narrow_oop._use_implicit_null_checks; }
361 static void set_narrow_oop_use_implicit_null_checks(bool use) { _narrow_oop._use_implicit_null_checks = use; }
362 // Narrow Oop encoding mode:
363 // 0 - Use 32-bits oops without encoding when
364 // NarrowOopHeapBaseMin + heap_size < 4Gb
365 // 1 - Use zero based compressed oops with encoding when
366 // NarrowOopHeapBaseMin + heap_size < 32Gb
367 // 2 - Use compressed oops with heap base + encoding.
368 enum NARROW_OOP_MODE {
369 UnscaledNarrowOop = 0,
370 ZeroBasedNarrowOop = 1,
371 HeapBasedNarrowOop = 2
372 };
373 static char* preferred_heap_base(size_t heap_size, NARROW_OOP_MODE mode);
374
375 // Historic gc information
376 static size_t get_heap_capacity_at_last_gc() { return _heap_capacity_at_last_gc; }
377 static size_t get_heap_free_at_last_gc() { return _heap_capacity_at_last_gc - _heap_used_at_last_gc; }
378 static size_t get_heap_used_at_last_gc() { return _heap_used_at_last_gc; }
379 static void update_heap_info_at_gc();
380
381 // Testers
382 static bool is_bootstrapping() { return _bootstrapping; }
383 static bool is_fully_initialized() { return _fully_initialized; }
384
385 static inline bool element_type_should_be_aligned(BasicType type);
386 static inline bool field_type_should_be_aligned(BasicType type);
387 static bool on_page_boundary(void* addr);
388 static bool should_fill_in_stack_trace(Handle throwable);
389 static void check_alignment(uintx size, uintx alignment, const char* name);
390
391 // Finalizer support.
392 static void run_finalizers_on_exit();
393
394 // Iteration
395
396 // Apply "f" to the addresses of all the direct heap pointers maintained
397 // as static fields of "Universe".
398 static void oops_do(OopClosure* f, bool do_all = false);
399
400 // Apply "f" to all klasses for basic types (classes not present in
401 // SystemDictionary).
402 static void basic_type_classes_do(void f(klassOop));
403
404 // Apply "f" to all system klasses (classes not present in SystemDictionary).
405 static void system_classes_do(void f(klassOop));
406
407 // For sharing -- fill in a list of known vtable pointers.
408 static void init_self_patching_vtbl_list(void** list, int count);
409
410 // Debugging
411 static bool verify_in_progress() { return _verify_in_progress; }
412 static void verify(bool allow_dirty = true, bool silent = false, bool option = true);
413 static int verify_count() { return _verify_count; }
414 static void print();
415 static void print_on(outputStream* st);
416 static void print_heap_at_SIGBREAK();
417 static void print_heap_before_gc() { print_heap_before_gc(gclog_or_tty); }
418 static void print_heap_after_gc() { print_heap_after_gc(gclog_or_tty); }
419 static void print_heap_before_gc(outputStream* st);
420 static void print_heap_after_gc(outputStream* st);
421
422 // Change the number of dummy objects kept reachable by the full gc dummy
423 // array; this should trigger relocation in a sliding compaction collector.
424 debug_only(static bool release_fullgc_alot_dummy();)
425 // The non-oop pattern (see compiledIC.hpp, etc)
426 static void* non_oop_word();
427
428 // Oop verification (see MacroAssembler::verify_oop)
429 static uintptr_t verify_oop_mask() PRODUCT_RETURN0;
430 static uintptr_t verify_oop_bits() PRODUCT_RETURN0;
431 static uintptr_t verify_mark_bits() PRODUCT_RETURN0;
432 static uintptr_t verify_mark_mask() PRODUCT_RETURN0;
433 static uintptr_t verify_klass_mask() PRODUCT_RETURN0;
434 static uintptr_t verify_klass_bits() PRODUCT_RETURN0;
435
436 // Flushing and deoptimization
437 static void flush_dependents_on(instanceKlassHandle dependee);
438 #ifdef HOTSWAP
439 // Flushing and deoptimization in case of evolution
440 static void flush_evol_dependents_on(instanceKlassHandle dependee);
441 #endif // HOTSWAP
442 // Support for fullspeed debugging
443 static void flush_dependents_on_method(methodHandle dependee);
444
445 // Compiler support
446 static int base_vtable_size() { return _base_vtable_size; }
447 };
448
449 class DeferredObjAllocEvent : public CHeapObj {
450 private:
451 oop _oop;
452 size_t _bytesize;
453 jint _arena_id;
454
455 public:
456 DeferredObjAllocEvent(const oop o, const size_t s, const jint id) {
457 _oop = o;
458 _bytesize = s;
459 _arena_id = id;
460 }
461
462 ~DeferredObjAllocEvent() {
463 }
464
465 jint arena_id() { return _arena_id; }
466 size_t bytesize() { return _bytesize; }
467 oop get_oop() { return _oop; }
468 };
469
470 #endif // SHARE_VM_MEMORY_UNIVERSE_HPP