1 /*
2 * Copyright (c) 1997, 2019, 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_MEMORY_UNIVERSE_HPP
26 #define SHARE_MEMORY_UNIVERSE_HPP
27
28 #include "gc/shared/verifyOption.hpp"
29 #include "oops/array.hpp"
30 #include "oops/oopHandle.hpp"
31 #include "runtime/handles.hpp"
32 #include "utilities/growableArray.hpp"
33
34 // Universe is a name space holding known system classes and objects in the VM.
35 //
36 // Loaded classes are accessible through the SystemDictionary.
37 //
38 // The object heap is allocated and accessed through Universe, and various allocation
39 // support is provided. Allocation by the interpreter and compiled code is done inline
40 // and bails out to Scavenge::invoke_and_allocate.
41
42 class CollectedHeap;
43 class DeferredObjAllocEvent;
44 class OopStorage;
45
46 // A helper class for caching a Method* when the user of the cache
47 // only cares about the latest version of the Method*. This cache safely
48 // interacts with the RedefineClasses API.
49
50 class LatestMethodCache : public CHeapObj<mtClass> {
51 // We save the Klass* and the idnum of Method* in order to get
52 // the current cached Method*.
53 private:
54 Klass* _klass;
55 int _method_idnum;
56
57 public:
58 LatestMethodCache() { _klass = NULL; _method_idnum = -1; }
59 ~LatestMethodCache() { _klass = NULL; _method_idnum = -1; }
60
61 void init(Klass* k, Method* m);
62 Klass* klass() const { return _klass; }
63 int method_idnum() const { return _method_idnum; }
64
65 Method* get_method();
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 void metaspace_pointers_do(MetaspaceClosure* it);
73 };
74
75 class Universe: AllStatic {
76 // Ugh. Universe is much too friendly.
77 friend class MarkSweep;
78 friend class oopDesc;
79 friend class ClassLoader;
80 friend class SystemDictionary;
81 friend class ReservedHeapSpace;
82 friend class VMStructs;
83 friend class VM_PopulateDumpSharedSpace;
84 friend class Metaspace;
85 friend class MetaspaceShared;
86
87 friend jint universe_init();
88 friend void universe2_init();
89 friend bool universe_post_init();
90 friend void universe_post_module_init();
91
92 private:
93 // Known classes in the VM
94 static Klass* _typeArrayKlassObjs[T_LONG+1];
95 static Klass* _objectArrayKlassObj;
96
97 // Known objects in the VM
98
99 // Primitive objects
100 static oop _int_mirror;
101 static oop _float_mirror;
102 static oop _double_mirror;
103 static oop _byte_mirror;
104 static oop _bool_mirror;
105 static oop _char_mirror;
106 static oop _long_mirror;
107 static oop _short_mirror;
108 static oop _void_mirror;
109
110 static OopHandle _main_thread_group; // Reference to the main thread group object
111 static OopHandle _system_thread_group; // Reference to the system thread group object
112
113 static OopHandle _the_empty_class_array; // Canonicalized obj array of type java.lang.Class
114 static OopHandle _the_null_string; // A cache of "null" as a Java string
115 static OopHandle _the_min_jint_string; // A cache of "-2147483648" as a Java string
116
117 static OopHandle _the_null_sentinel; // A unique object pointer unused except as a sentinel for null.
118
119 // preallocated error objects (no backtrace)
120 static OopHandle _out_of_memory_errors;
121
122 // preallocated cause message for delayed StackOverflowError
123 static OopHandle _delayed_stack_overflow_error_message;
124
125 static LatestMethodCache* _finalizer_register_cache; // static method for registering finalizable objects
126 static LatestMethodCache* _loader_addClass_cache; // method for registering loaded classes in class loader vector
127 static LatestMethodCache* _throw_illegal_access_error_cache; // Unsafe.throwIllegalAccessError() method
128 static LatestMethodCache* _throw_no_such_method_error_cache; // Unsafe.throwNoSuchMethodError() method
129 static LatestMethodCache* _do_stack_walk_cache; // method for stack walker callback
130
131 static Array<int>* _the_empty_int_array; // Canonicalized int array
132 static Array<u2>* _the_empty_short_array; // Canonicalized short array
133 static Array<Klass*>* _the_empty_klass_array; // Canonicalized klass array
134 static Array<InstanceKlass*>* _the_empty_instance_klass_array; // Canonicalized instance klass array
135 static Array<Method*>* _the_empty_method_array; // Canonicalized method array
136
137 static Array<Klass*>* _the_array_interfaces_array;
138
139 // array of preallocated error objects with backtrace
140 static OopHandle _preallocated_out_of_memory_error_array;
141
142 // number of preallocated error objects available for use
143 static volatile jint _preallocated_out_of_memory_error_avail_count;
144
145 static OopHandle _null_ptr_exception_instance; // preallocated exception object
146 static OopHandle _arithmetic_exception_instance; // preallocated exception object
147 static OopHandle _virtual_machine_error_instance; // preallocated exception object
148
149 // References waiting to be transferred to the ReferenceHandler
150 static oop _reference_pending_list;
151
152 // The particular choice of collected heap.
153 static CollectedHeap* _collectedHeap;
154
155 static intptr_t _non_oop_bits;
156
157 // array of dummy objects used with +FullGCAlot
158 debug_only(static OopHandle _fullgc_alot_dummy_array;)
159 debug_only(static int _fullgc_alot_dummy_next;)
160
161 // Compiler/dispatch support
162 static int _base_vtable_size; // Java vtbl size of klass Object (in words)
163
164 // Initialization
165 static bool _bootstrapping; // true during genesis
166 static bool _module_initialized; // true after call_initPhase2 called
167 static bool _fully_initialized; // true after universe_init and initialize_vtables called
168
169 // the array of preallocated errors with backtraces
170 static objArrayOop preallocated_out_of_memory_errors();
171
172 static objArrayOop out_of_memory_errors();
173 // generate an out of memory error; if possible using an error with preallocated backtrace;
174 // otherwise return the given default error.
175 static oop gen_out_of_memory_error(oop default_err);
176
177 // Historic gc information
178 static size_t _heap_capacity_at_last_gc;
179 static size_t _heap_used_at_last_gc;
180
181 static OopStorage* _vm_weak;
182 static OopStorage* _vm_global;
183
184 static jint initialize_heap();
185 static void initialize_tlab();
186 static void initialize_basic_type_mirrors(TRAPS);
187 static void fixup_mirrors(TRAPS);
188
189 static void reinitialize_vtable_of(Klass* k, TRAPS);
190 static void reinitialize_vtables(TRAPS);
191 static void reinitialize_itables(TRAPS);
192 static void compute_base_vtable_size(); // compute vtable size of class Object
193
194 static void genesis(TRAPS); // Create the initial world
195
196 // Mirrors for primitive classes (created eagerly)
197 static oop check_mirror(oop m) {
198 assert(m != NULL, "mirror not initialized");
199 return m;
200 }
201
202 // Debugging
203 static int _verify_count; // number of verifies done
204
205 // True during call to verify(). Should only be set/cleared in verify().
206 static bool _verify_in_progress;
207 static long verify_flags;
208
209 static uintptr_t _verify_oop_mask;
210 static uintptr_t _verify_oop_bits;
211
212 public:
213 static void calculate_verify_data(HeapWord* low_boundary, HeapWord* high_boundary) PRODUCT_RETURN;
214
215 // Known classes in the VM
216 static Klass* boolArrayKlassObj() { return typeArrayKlassObj(T_BOOLEAN); }
217 static Klass* byteArrayKlassObj() { return typeArrayKlassObj(T_BYTE); }
218 static Klass* charArrayKlassObj() { return typeArrayKlassObj(T_CHAR); }
219 static Klass* intArrayKlassObj() { return typeArrayKlassObj(T_INT); }
220 static Klass* shortArrayKlassObj() { return typeArrayKlassObj(T_SHORT); }
221 static Klass* longArrayKlassObj() { return typeArrayKlassObj(T_LONG); }
222 static Klass* floatArrayKlassObj() { return typeArrayKlassObj(T_FLOAT); }
223 static Klass* doubleArrayKlassObj() { return typeArrayKlassObj(T_DOUBLE); }
224
225 static Klass* objectArrayKlassObj() { return _objectArrayKlassObj; }
226
227 static Klass* typeArrayKlassObj(BasicType t) {
228 assert((uint)t >= T_BOOLEAN, "range check for type: %s", type2name(t));
229 assert((uint)t < T_LONG+1, "range check for type: %s", type2name(t));
230 assert(_typeArrayKlassObjs[t] != NULL, "domain check");
231 return _typeArrayKlassObjs[t];
232 }
233
234 // Known objects in the VM
235 static oop int_mirror() { return check_mirror(_int_mirror); }
236 static oop float_mirror() { return check_mirror(_float_mirror); }
237 static oop double_mirror() { return check_mirror(_double_mirror); }
238 static oop byte_mirror() { return check_mirror(_byte_mirror); }
239 static oop bool_mirror() { return check_mirror(_bool_mirror); }
240 static oop char_mirror() { return check_mirror(_char_mirror); }
241 static oop long_mirror() { return check_mirror(_long_mirror); }
242 static oop short_mirror() { return check_mirror(_short_mirror); }
243 static oop void_mirror() { return check_mirror(_void_mirror); }
244
245 static void set_int_mirror(oop m) { _int_mirror = m; }
246 static void set_float_mirror(oop m) { _float_mirror = m; }
247 static void set_double_mirror(oop m) { _double_mirror = m; }
248 static void set_byte_mirror(oop m) { _byte_mirror = m; }
249 static void set_bool_mirror(oop m) { _bool_mirror = m; }
250 static void set_char_mirror(oop m) { _char_mirror = m; }
251 static void set_long_mirror(oop m) { _long_mirror = m; }
252 static void set_short_mirror(oop m) { _short_mirror = m; }
253 static void set_void_mirror(oop m) { _void_mirror = m; }
254
255 // table of same
256 static oop _mirrors[T_VOID+1];
257
258 static oop java_mirror(BasicType t) {
259 assert((uint)t < T_VOID+1, "range check");
260 return check_mirror(_mirrors[t]);
261 }
262 static oop main_thread_group();
263 static void set_main_thread_group(oop group);
264
265 static oop system_thread_group();
266 static void set_system_thread_group(oop group);
267
268 static objArrayOop the_empty_class_array ();
269
270 static oop the_null_string();
271 static oop the_min_jint_string();
272
273 static oop null_ptr_exception_instance();
274 static oop arithmetic_exception_instance();
275 static oop virtual_machine_error_instance();
276 static oop vm_exception() { return virtual_machine_error_instance(); }
277
278 static Array<Klass*>* the_array_interfaces_array() { return _the_array_interfaces_array; }
279 static Method* finalizer_register_method() { return _finalizer_register_cache->get_method(); }
280 static Method* loader_addClass_method() { return _loader_addClass_cache->get_method(); }
281
282 static Method* throw_illegal_access_error() { return _throw_illegal_access_error_cache->get_method(); }
283 static Method* throw_no_such_method_error() { return _throw_no_such_method_error_cache->get_method(); }
284
285 static Method* do_stack_walk_method() { return _do_stack_walk_cache->get_method(); }
286
287 static oop the_null_sentinel();
288 static address the_null_sentinel_addr() { return (address) &_the_null_sentinel; }
289
290 // Function to initialize these
291 static void initialize_known_methods(TRAPS);
292
293 static void create_preallocated_out_of_memory_errors(TRAPS);
294
295 // Reference pending list manipulation. Access is protected by
296 // Heap_lock. The getter, setter and predicate require the caller
297 // owns the lock. Swap is used by parallel non-concurrent reference
298 // processing threads, where some higher level controller owns
299 // Heap_lock, so requires the lock is locked, but not necessarily by
300 // the current thread.
301 static oop reference_pending_list();
302 static void clear_reference_pending_list();
303 static bool has_reference_pending_list();
304 static oop swap_reference_pending_list(oop list);
305
306 static Array<int>* the_empty_int_array() { return _the_empty_int_array; }
307 static Array<u2>* the_empty_short_array() { return _the_empty_short_array; }
308 static Array<Method*>* the_empty_method_array() { return _the_empty_method_array; }
309 static Array<Klass*>* the_empty_klass_array() { return _the_empty_klass_array; }
310 static Array<InstanceKlass*>* the_empty_instance_klass_array() { return _the_empty_instance_klass_array; }
311
312 // OutOfMemoryError support. Returns an error with the required message. The returned error
313 // may or may not have a backtrace. If error has a backtrace then the stack trace is already
314 // filled in.
315 static oop out_of_memory_error_java_heap();
316 static oop out_of_memory_error_metaspace();
317 static oop out_of_memory_error_class_metaspace();
318 static oop out_of_memory_error_array_size();
319 static oop out_of_memory_error_gc_overhead_limit();
320 static oop out_of_memory_error_realloc_objects();
321
322 // Throw default _out_of_memory_error_retry object as it will never propagate out of the VM
323 static oop out_of_memory_error_retry();
324 static oop delayed_stack_overflow_error_message();
325
326 // The particular choice of collected heap.
327 static CollectedHeap* heap() { return _collectedHeap; }
328
329 // Reserve Java heap and determine CompressedOops mode
330 static ReservedHeapSpace reserve_heap(size_t heap_size, size_t alignment);
331
332 // Historic gc information
333 static size_t get_heap_free_at_last_gc() { return _heap_capacity_at_last_gc - _heap_used_at_last_gc; }
334 static size_t get_heap_used_at_last_gc() { return _heap_used_at_last_gc; }
335 static void update_heap_info_at_gc();
336
337 // Global OopStorages
338 static OopStorage* vm_weak();
339 static OopStorage* vm_global();
340 static void oopstorage_init();
341
342 // Testers
343 static bool is_bootstrapping() { return _bootstrapping; }
344 static bool is_module_initialized() { return _module_initialized; }
345 static bool is_fully_initialized() { return _fully_initialized; }
346
347 static bool on_page_boundary(void* addr);
348 static bool should_fill_in_stack_trace(Handle throwable);
349 static void check_alignment(uintx size, uintx alignment, const char* name);
350
351 // Iteration
352
353 // Apply "f" to the addresses of all the direct heap pointers maintained
354 // as static fields of "Universe".
355 static void oops_do(OopClosure* f);
356
357 // CDS support
358 static void serialize(SerializeClosure* f);
359
360 // Apply "f" to all klasses for basic types (classes not present in
361 // SystemDictionary).
362 static void basic_type_classes_do(void f(Klass*));
363 static void basic_type_classes_do(KlassClosure* closure);
364 static void metaspace_pointers_do(MetaspaceClosure* it);
365
366 // Debugging
367 enum VERIFY_FLAGS {
368 Verify_Threads = 1,
369 Verify_Heap = 2,
370 Verify_SymbolTable = 4,
371 Verify_StringTable = 8,
372 Verify_CodeCache = 16,
373 Verify_SystemDictionary = 32,
374 Verify_ClassLoaderDataGraph = 64,
375 Verify_MetaspaceUtils = 128,
376 Verify_JNIHandles = 256,
377 Verify_CodeCacheOops = 512,
378 Verify_ResolvedMethodTable = 1024,
379 Verify_All = -1
380 };
381 static void initialize_verify_flags();
382 static bool should_verify_subset(uint subset);
383 static bool verify_in_progress() { return _verify_in_progress; }
384 static void verify(VerifyOption option, const char* prefix);
385 static void verify(const char* prefix) {
386 verify(VerifyOption_Default, prefix);
387 }
388 static void verify() {
389 verify("");
390 }
391
392 static int verify_count() { return _verify_count; }
393 static void print_on(outputStream* st);
394 static void print_heap_at_SIGBREAK();
395 static void print_heap_before_gc();
396 static void print_heap_after_gc();
397
398 // Change the number of dummy objects kept reachable by the full gc dummy
399 // array; this should trigger relocation in a sliding compaction collector.
400 debug_only(static bool release_fullgc_alot_dummy();)
401 // The non-oop pattern (see compiledIC.hpp, etc)
402 static void* non_oop_word();
403
404 // Oop verification (see MacroAssembler::verify_oop)
405 static uintptr_t verify_oop_mask() PRODUCT_RETURN0;
406 static uintptr_t verify_oop_bits() PRODUCT_RETURN0;
407 static uintptr_t verify_mark_bits() PRODUCT_RETURN0;
408 static uintptr_t verify_mark_mask() PRODUCT_RETURN0;
409
410 // Compiler support
411 static int base_vtable_size() { return _base_vtable_size; }
412 };
413
414 #endif // SHARE_MEMORY_UNIVERSE_HPP