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. 22 * 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