1 /*
   2  * Copyright (c) 1997, 2018, 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 "oops/array.hpp"
  29 #include "runtime/handles.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 // A helper class for caching a Method* when the user of the cache
  45 // only cares about the latest version of the Method*.  This cache safely
  46 // interacts with the RedefineClasses API.
  47 
  48 class LatestMethodCache : public CHeapObj<mtClass> {
  49   // We save the Klass* and the idnum of Method* in order to get
  50   // the current cached Method*.
  51  private:
  52   Klass*                _klass;
  53   int                   _method_idnum;
  54 
  55  public:
  56   LatestMethodCache()   { _klass = NULL; _method_idnum = -1; }
  57   ~LatestMethodCache()  { _klass = NULL; _method_idnum = -1; }
  58 
  59   void   init(Klass* k, Method* m);
  60   Klass* klass() const           { return _klass; }
  61   int    method_idnum() const    { return _method_idnum; }
  62 
  63   Method* get_method();
  64 
  65   // CDS support.  Replace the klass in this with the archive version
  66   // could use this for Enhanced Class Redefinition also.
  67   void serialize(SerializeClosure* f) {
  68     f->do_ptr((void**)&_klass);
  69   }
  70   void metaspace_pointers_do(MetaspaceClosure* it);
  71 };
  72 
  73 
  74 // For UseCompressedOops.
  75 struct NarrowPtrStruct {
  76   // Base address for oop-within-java-object materialization.
  77   // NULL if using wide oops or zero based narrow oops.
  78   address _base;
  79   // Number of shift bits for encoding/decoding narrow ptrs.
  80   // 0 if using wide ptrs or zero based unscaled narrow ptrs,
  81   // LogMinObjAlignmentInBytes/LogKlassAlignmentInBytes otherwise.
  82   int     _shift;
  83   // Generate code with implicit null checks for narrow ptrs.
  84   bool    _use_implicit_null_checks;
  85 };
  86 
  87 enum VerifyOption {
  88       VerifyOption_Default = 0,
  89 
  90       // G1
  91       VerifyOption_G1UsePrevMarking = VerifyOption_Default,
  92       VerifyOption_G1UseNextMarking = VerifyOption_G1UsePrevMarking + 1,
  93       VerifyOption_G1UseFullMarking = VerifyOption_G1UseNextMarking + 1
  94 };
  95 
  96 class Universe: AllStatic {
  97   // Ugh.  Universe is much too friendly.
  98   friend class MarkSweep;
  99   friend class oopDesc;
 100   friend class ClassLoader;
 101   friend class SystemDictionary;
 102   friend class ReservedHeapSpace;
 103   friend class VMStructs;
 104   friend class VM_PopulateDumpSharedSpace;
 105   friend class Metaspace;
 106   friend class MetaspaceShared;
 107 
 108   friend jint  universe_init();
 109   friend void  universe2_init();
 110   friend bool  universe_post_init();
 111   friend void  universe_post_module_init();
 112 
 113  private:
 114   // Known classes in the VM
 115   static Klass* _boolArrayKlassObj;
 116   static Klass* _byteArrayKlassObj;
 117   static Klass* _charArrayKlassObj;
 118   static Klass* _intArrayKlassObj;
 119   static Klass* _shortArrayKlassObj;
 120   static Klass* _longArrayKlassObj;
 121   static Klass* _singleArrayKlassObj;
 122   static Klass* _doubleArrayKlassObj;
 123   static Klass* _typeArrayKlassObjs[T_VOID+1];
 124 
 125   static Klass* _objectArrayKlassObj;
 126 
 127   // Known objects in the VM
 128 
 129   // Primitive objects
 130   static oop _int_mirror;
 131   static oop _float_mirror;
 132   static oop _double_mirror;
 133   static oop _byte_mirror;
 134   static oop _bool_mirror;
 135   static oop _char_mirror;
 136   static oop _long_mirror;
 137   static oop _short_mirror;
 138   static oop _void_mirror;
 139 
 140   static oop          _main_thread_group;             // Reference to the main thread group object
 141   static oop          _system_thread_group;           // Reference to the system thread group object
 142 
 143   static objArrayOop  _the_empty_class_klass_array;   // Canonicalized obj array of type java.lang.Class
 144   static oop          _the_null_sentinel;             // A unique object pointer unused except as a sentinel for null.
 145   static oop          _the_null_string;               // A cache of "null" as a Java string
 146   static oop          _the_min_jint_string;          // A cache of "-2147483648" as a Java string
 147   static LatestMethodCache* _finalizer_register_cache; // static method for registering finalizable objects
 148   static LatestMethodCache* _loader_addClass_cache;    // method for registering loaded classes in class loader vector
 149   static LatestMethodCache* _pd_implies_cache;         // method for checking protection domain attributes
 150   static LatestMethodCache* _throw_illegal_access_error_cache; // Unsafe.throwIllegalAccessError() method
 151   static LatestMethodCache* _throw_no_such_method_error_cache; // Unsafe.throwNoSuchMethodError() method
 152   static LatestMethodCache* _do_stack_walk_cache;      // method for stack walker callback
 153 
 154   // preallocated error objects (no backtrace)
 155   static oop          _out_of_memory_error_java_heap;
 156   static oop          _out_of_memory_error_metaspace;
 157   static oop          _out_of_memory_error_class_metaspace;
 158   static oop          _out_of_memory_error_array_size;
 159   static oop          _out_of_memory_error_gc_overhead_limit;
 160   static oop          _out_of_memory_error_realloc_objects;
 161 
 162   // preallocated cause message for delayed StackOverflowError
 163   static oop          _delayed_stack_overflow_error_message;
 164 
 165   static Array<int>*       _the_empty_int_array;    // Canonicalized int array
 166   static Array<u2>*        _the_empty_short_array;  // Canonicalized short array
 167   static Array<Klass*>*  _the_empty_klass_array;  // Canonicalized klass obj array
 168   static Array<Method*>* _the_empty_method_array; // Canonicalized method obj array
 169 
 170   static Array<Klass*>*  _the_array_interfaces_array;
 171 
 172   // array of preallocated error objects with backtrace
 173   static objArrayOop   _preallocated_out_of_memory_error_array;
 174 
 175   // number of preallocated error objects available for use
 176   static volatile jint _preallocated_out_of_memory_error_avail_count;
 177 
 178   static oop          _null_ptr_exception_instance;   // preallocated exception object
 179   static oop          _arithmetic_exception_instance; // preallocated exception object
 180   static oop          _virtual_machine_error_instance; // preallocated exception object
 181   // The object used as an exception dummy when exceptions are thrown for
 182   // the vm thread.
 183   static oop          _vm_exception;
 184 
 185   // References waiting to be transferred to the ReferenceHandler
 186   static oop          _reference_pending_list;
 187 
 188   // The particular choice of collected heap.
 189   static CollectedHeap* _collectedHeap;
 190 
 191   static intptr_t _non_oop_bits;
 192 
 193   // For UseCompressedOops.
 194   static struct NarrowPtrStruct _narrow_oop;
 195   // For UseCompressedClassPointers.
 196   static struct NarrowPtrStruct _narrow_klass;
 197   static address _narrow_ptrs_base;
 198   // CompressedClassSpaceSize set to 1GB, but appear 3GB away from _narrow_ptrs_base during CDS dump.
 199   static uint64_t _narrow_klass_range;
 200   // array of dummy objects used with +FullGCAlot
 201   debug_only(static objArrayOop _fullgc_alot_dummy_array;)
 202   // index of next entry to clear
 203   debug_only(static int         _fullgc_alot_dummy_next;)
 204 
 205   // Compiler/dispatch support
 206   static int  _base_vtable_size;                      // Java vtbl size of klass Object (in words)
 207 
 208   // Initialization
 209   static bool _bootstrapping;                         // true during genesis
 210   static bool _module_initialized;                    // true after call_initPhase2 called
 211   static bool _fully_initialized;                     // true after universe_init and initialize_vtables called
 212 
 213   // the array of preallocated errors with backtraces
 214   static objArrayOop  preallocated_out_of_memory_errors()     { return _preallocated_out_of_memory_error_array; }
 215 
 216   // generate an out of memory error; if possible using an error with preallocated backtrace;
 217   // otherwise return the given default error.
 218   static oop        gen_out_of_memory_error(oop default_err);
 219 
 220   // Historic gc information
 221   static size_t _heap_capacity_at_last_gc;
 222   static size_t _heap_used_at_last_gc;
 223 
 224   static CollectedHeap* create_heap();
 225   static jint initialize_heap();
 226   static void initialize_basic_type_mirrors(TRAPS);
 227   static void fixup_mirrors(TRAPS);
 228 
 229   static void reinitialize_vtable_of(Klass* k, TRAPS);
 230   static void reinitialize_itables(TRAPS);
 231   static void compute_base_vtable_size();             // compute vtable size of class Object
 232 
 233   static void genesis(TRAPS);                         // Create the initial world
 234 
 235   // Mirrors for primitive classes (created eagerly)
 236   static oop check_mirror(oop m) {
 237     assert(m != NULL, "mirror not initialized");
 238     return m;
 239   }
 240 
 241   static void     set_narrow_oop_base(address base) {
 242     assert(UseCompressedOops, "no compressed oops?");
 243     _narrow_oop._base    = base;
 244   }
 245   static void     set_narrow_klass_base(address base) {
 246     assert(UseCompressedClassPointers, "no compressed klass ptrs?");
 247     _narrow_klass._base   = base;
 248   }
 249   static void     set_narrow_klass_range(uint64_t range) {
 250      assert(UseCompressedClassPointers, "no compressed klass ptrs?");
 251      _narrow_klass_range = range;
 252   }
 253   static void     set_narrow_oop_use_implicit_null_checks(bool use) {
 254     assert(UseCompressedOops, "no compressed ptrs?");
 255     _narrow_oop._use_implicit_null_checks   = use;
 256   }
 257 
 258   // Debugging
 259   static int _verify_count;                           // number of verifies done
 260 
 261   // True during call to verify().  Should only be set/cleared in verify().
 262   static bool _verify_in_progress;
 263   static long verify_flags;
 264 
 265   static uintptr_t _verify_oop_mask;
 266   static uintptr_t _verify_oop_bits;
 267 
 268   static void calculate_verify_data(HeapWord* low_boundary, HeapWord* high_boundary) PRODUCT_RETURN;
 269   static void compute_verify_oop_data();
 270 
 271  public:
 272   // Known classes in the VM
 273   static Klass* boolArrayKlassObj()                 { return _boolArrayKlassObj;   }
 274   static Klass* byteArrayKlassObj()                 { return _byteArrayKlassObj;   }
 275   static Klass* charArrayKlassObj()                 { return _charArrayKlassObj;   }
 276   static Klass* intArrayKlassObj()                  { return _intArrayKlassObj;    }
 277   static Klass* shortArrayKlassObj()                { return _shortArrayKlassObj;  }
 278   static Klass* longArrayKlassObj()                 { return _longArrayKlassObj;   }
 279   static Klass* singleArrayKlassObj()               { return _singleArrayKlassObj; }
 280   static Klass* doubleArrayKlassObj()               { return _doubleArrayKlassObj; }
 281 
 282   static Klass* objectArrayKlassObj() {
 283     return _objectArrayKlassObj;
 284   }
 285 
 286   static Klass* typeArrayKlassObj(BasicType t) {
 287     assert((uint)t < T_VOID+1, "range check for type: %s", type2name(t));
 288     assert(_typeArrayKlassObjs[t] != NULL, "domain check");
 289     return _typeArrayKlassObjs[t];
 290   }
 291 
 292   // Known objects in the VM
 293   static oop int_mirror()                   { return check_mirror(_int_mirror); }
 294   static oop float_mirror()                 { return check_mirror(_float_mirror); }
 295   static oop double_mirror()                { return check_mirror(_double_mirror); }
 296   static oop byte_mirror()                  { return check_mirror(_byte_mirror); }
 297   static oop bool_mirror()                  { return check_mirror(_bool_mirror); }
 298   static oop char_mirror()                  { return check_mirror(_char_mirror); }
 299   static oop long_mirror()                  { return check_mirror(_long_mirror); }
 300   static oop short_mirror()                 { return check_mirror(_short_mirror); }
 301   static oop void_mirror()                  { return check_mirror(_void_mirror); }
 302 
 303   static void set_int_mirror(oop m)         { _int_mirror = m;    }
 304   static void set_float_mirror(oop m)       { _float_mirror = m;  }
 305   static void set_double_mirror(oop m)      { _double_mirror = m; }
 306   static void set_byte_mirror(oop m)        { _byte_mirror = m;   }
 307   static void set_bool_mirror(oop m)        { _bool_mirror = m;   }
 308   static void set_char_mirror(oop m)        { _char_mirror = m;   }
 309   static void set_long_mirror(oop m)        { _long_mirror = m;   }
 310   static void set_short_mirror(oop m)       { _short_mirror = m;  }
 311   static void set_void_mirror(oop m)        { _void_mirror = m;   }
 312 
 313   // table of same
 314   static oop _mirrors[T_VOID+1];
 315 
 316   static oop java_mirror(BasicType t) {
 317     assert((uint)t < T_VOID+1, "range check");
 318     return check_mirror(_mirrors[t]);
 319   }
 320   static oop      main_thread_group()                 { return _main_thread_group; }
 321   static void set_main_thread_group(oop group)        { _main_thread_group = group;}
 322 
 323   static oop      system_thread_group()               { return _system_thread_group; }
 324   static void set_system_thread_group(oop group)      { _system_thread_group = group;}
 325 
 326   static objArrayOop  the_empty_class_klass_array ()  { return _the_empty_class_klass_array;   }
 327   static Array<Klass*>* the_array_interfaces_array() { return _the_array_interfaces_array;   }
 328   static oop          the_null_string()               { return _the_null_string;               }
 329   static oop          the_min_jint_string()          { return _the_min_jint_string;          }
 330 
 331   static Method*      finalizer_register_method()     { return _finalizer_register_cache->get_method(); }
 332   static Method*      loader_addClass_method()        { return _loader_addClass_cache->get_method(); }
 333 
 334   static Method*      protection_domain_implies_method() { return _pd_implies_cache->get_method(); }
 335   static Method*      throw_illegal_access_error()    { return _throw_illegal_access_error_cache->get_method(); }
 336   static Method*      throw_no_such_method_error()    { return _throw_no_such_method_error_cache->get_method(); }
 337 
 338   static Method*      do_stack_walk_method()          { return _do_stack_walk_cache->get_method(); }
 339 
 340   static oop          the_null_sentinel()             { return _the_null_sentinel;             }
 341   static address      the_null_sentinel_addr()        { return (address) &_the_null_sentinel;  }
 342 
 343   // Function to initialize these
 344   static void initialize_known_methods(TRAPS);
 345 
 346   static oop          null_ptr_exception_instance()   { return _null_ptr_exception_instance;   }
 347   static oop          arithmetic_exception_instance() { return _arithmetic_exception_instance; }
 348   static oop          virtual_machine_error_instance() { return _virtual_machine_error_instance; }
 349   static oop          vm_exception()                  { return _vm_exception; }
 350 
 351   // Reference pending list manipulation.  Access is protected by
 352   // Heap_lock.  The getter, setter and predicate require the caller
 353   // owns the lock.  Swap is used by parallel non-concurrent reference
 354   // processing threads, where some higher level controller owns
 355   // Heap_lock, so requires the lock is locked, but not necessarily by
 356   // the current thread.
 357   static oop          reference_pending_list();
 358   static void         set_reference_pending_list(oop list);
 359   static bool         has_reference_pending_list();
 360   static oop          swap_reference_pending_list(oop list);
 361 
 362   static Array<int>*       the_empty_int_array()    { return _the_empty_int_array; }
 363   static Array<u2>*        the_empty_short_array()  { return _the_empty_short_array; }
 364   static Array<Method*>* the_empty_method_array() { return _the_empty_method_array; }
 365   static Array<Klass*>*  the_empty_klass_array()  { return _the_empty_klass_array; }
 366 
 367   // OutOfMemoryError support. Returns an error with the required message. The returned error
 368   // may or may not have a backtrace. If error has a backtrace then the stack trace is already
 369   // filled in.
 370   static oop out_of_memory_error_java_heap()          { return gen_out_of_memory_error(_out_of_memory_error_java_heap);  }
 371   static oop out_of_memory_error_metaspace()          { return gen_out_of_memory_error(_out_of_memory_error_metaspace);   }
 372   static oop out_of_memory_error_class_metaspace()    { return gen_out_of_memory_error(_out_of_memory_error_class_metaspace);   }
 373   static oop out_of_memory_error_array_size()         { return gen_out_of_memory_error(_out_of_memory_error_array_size); }
 374   static oop out_of_memory_error_gc_overhead_limit()  { return gen_out_of_memory_error(_out_of_memory_error_gc_overhead_limit);  }
 375   static oop out_of_memory_error_realloc_objects()    { return gen_out_of_memory_error(_out_of_memory_error_realloc_objects);  }
 376   static oop delayed_stack_overflow_error_message()   { return _delayed_stack_overflow_error_message; }
 377 
 378   // Accessors needed for fast allocation
 379   static Klass** boolArrayKlassObj_addr()           { return &_boolArrayKlassObj;   }
 380   static Klass** byteArrayKlassObj_addr()           { return &_byteArrayKlassObj;   }
 381   static Klass** charArrayKlassObj_addr()           { return &_charArrayKlassObj;   }
 382   static Klass** intArrayKlassObj_addr()            { return &_intArrayKlassObj;    }
 383   static Klass** shortArrayKlassObj_addr()          { return &_shortArrayKlassObj;  }
 384   static Klass** longArrayKlassObj_addr()           { return &_longArrayKlassObj;   }
 385   static Klass** singleArrayKlassObj_addr()         { return &_singleArrayKlassObj; }
 386   static Klass** doubleArrayKlassObj_addr()         { return &_doubleArrayKlassObj; }
 387   static Klass** objectArrayKlassObj_addr()         { return &_objectArrayKlassObj; }
 388 
 389   // The particular choice of collected heap.
 390   static CollectedHeap* heap() { return _collectedHeap; }
 391 
 392   // For UseCompressedOops
 393   // Narrow Oop encoding mode:
 394   // 0 - Use 32-bits oops without encoding when
 395   //     NarrowOopHeapBaseMin + heap_size < 4Gb
 396   // 1 - Use zero based compressed oops with encoding when
 397   //     NarrowOopHeapBaseMin + heap_size < 32Gb
 398   // 2 - Use compressed oops with disjoint heap base if
 399   //     base is 32G-aligned and base > 0. This allows certain
 400   //     optimizations in encoding/decoding.
 401   //     Disjoint: Bits used in base are disjoint from bits used
 402   //     for oops ==> oop = (cOop << 3) | base.  One can disjoint
 403   //     the bits of an oop into base and compressed oop.
 404   // 3 - Use compressed oops with heap base + encoding.
 405   enum NARROW_OOP_MODE {
 406     UnscaledNarrowOop  = 0,
 407     ZeroBasedNarrowOop = 1,
 408     DisjointBaseNarrowOop = 2,
 409     HeapBasedNarrowOop = 3,
 410     AnyNarrowOopMode = 4
 411   };
 412   static NARROW_OOP_MODE narrow_oop_mode();
 413   static const char* narrow_oop_mode_to_string(NARROW_OOP_MODE mode);
 414   static char*    preferred_heap_base(size_t heap_size, size_t alignment, NARROW_OOP_MODE mode);
 415   static char*    preferred_metaspace_base(size_t heap_size, NARROW_OOP_MODE mode);
 416   static address  narrow_oop_base()                  { return  _narrow_oop._base; }
 417   // Test whether bits of addr and possible offsets into the heap overlap.
 418   static bool     is_disjoint_heap_base_address(address addr) {
 419     return (((uint64_t)(intptr_t)addr) &
 420             (((uint64_t)UCONST64(0xFFFFffffFFFFffff)) >> (32-LogMinObjAlignmentInBytes))) == 0;
 421   }
 422   // Check for disjoint base compressed oops.
 423   static bool     narrow_oop_base_disjoint()        {
 424     return _narrow_oop._base != NULL && is_disjoint_heap_base_address(_narrow_oop._base);
 425   }
 426   // Check for real heapbased compressed oops.
 427   // We must subtract the base as the bits overlap.
 428   // If we negate above function, we also get unscaled and zerobased.
 429   static bool     narrow_oop_base_overlaps()          {
 430     return _narrow_oop._base != NULL && !is_disjoint_heap_base_address(_narrow_oop._base);
 431   }
 432   static bool  is_narrow_oop_base(void* addr)             { return (narrow_oop_base() == (address)addr); }
 433   static int      narrow_oop_shift()                      { return  _narrow_oop._shift; }
 434   static bool     narrow_oop_use_implicit_null_checks()   { return  _narrow_oop._use_implicit_null_checks; }
 435 
 436   // For UseCompressedClassPointers
 437   static address  narrow_klass_base()                     { return  _narrow_klass._base; }
 438   static bool  is_narrow_klass_base(void* addr)           { return (narrow_klass_base() == (address)addr); }
 439   static uint64_t narrow_klass_range()                    { return  _narrow_klass_range; }
 440   static int      narrow_klass_shift()                    { return  _narrow_klass._shift; }
 441   static bool     narrow_klass_use_implicit_null_checks() { return  _narrow_klass._use_implicit_null_checks; }
 442 
 443   static address* narrow_ptrs_base_addr()                 { return &_narrow_ptrs_base; }
 444   static void     set_narrow_ptrs_base(address a)         { _narrow_ptrs_base = a; }
 445   static address  narrow_ptrs_base()                      { return _narrow_ptrs_base; }
 446 
 447   static void     print_compressed_oops_mode(outputStream* st);
 448 
 449   // this is set in vm_version on sparc (and then reset in universe afaict)
 450   static void     set_narrow_oop_shift(int shift)         {
 451     _narrow_oop._shift   = shift;
 452   }
 453 
 454   static void     set_narrow_klass_shift(int shift)       {
 455     assert(shift == 0 || shift == LogKlassAlignmentInBytes, "invalid shift for klass ptrs");
 456     _narrow_klass._shift   = shift;
 457   }
 458 
 459   // Reserve Java heap and determine CompressedOops mode
 460   static ReservedSpace reserve_heap(size_t heap_size, size_t alignment);
 461 
 462   // Historic gc information
 463   static size_t get_heap_capacity_at_last_gc()         { return _heap_capacity_at_last_gc; }
 464   static size_t get_heap_free_at_last_gc()             { return _heap_capacity_at_last_gc - _heap_used_at_last_gc; }
 465   static size_t get_heap_used_at_last_gc()             { return _heap_used_at_last_gc; }
 466   static void update_heap_info_at_gc();
 467 
 468   // Testers
 469   static bool is_bootstrapping()                      { return _bootstrapping; }
 470   static bool is_module_initialized()                 { return _module_initialized; }
 471   static bool is_fully_initialized()                  { return _fully_initialized; }
 472 
 473   static bool        on_page_boundary(void* addr);
 474   static bool        should_fill_in_stack_trace(Handle throwable);
 475   static void check_alignment(uintx size, uintx alignment, const char* name);
 476 
 477   // Iteration
 478 
 479   // Apply "f" to the addresses of all the direct heap pointers maintained
 480   // as static fields of "Universe".
 481   static void oops_do(OopClosure* f, bool do_all = false);
 482 
 483   // CDS support
 484   static void serialize(SerializeClosure* f, bool do_all = false);
 485 
 486   // Apply "f" to all klasses for basic types (classes not present in
 487   // SystemDictionary).
 488   static void basic_type_classes_do(void f(Klass*));
 489   static void metaspace_pointers_do(MetaspaceClosure* it);
 490 
 491   // Debugging
 492   enum VERIFY_FLAGS {
 493     Verify_Threads = 1,
 494     Verify_Heap = 2,
 495     Verify_SymbolTable = 4,
 496     Verify_StringTable = 8,
 497     Verify_CodeCache = 16,
 498     Verify_SystemDictionary = 32,
 499     Verify_ClassLoaderDataGraph = 64,
 500     Verify_MetaspaceUtils = 128,
 501     Verify_JNIHandles = 256,
 502     Verify_CodeCacheOops = 512,
 503     Verify_All = -1
 504   };
 505   static void initialize_verify_flags();
 506   static bool should_verify_subset(uint subset);
 507   static bool verify_in_progress() { return _verify_in_progress; }
 508   static void verify(VerifyOption option, const char* prefix);
 509   static void verify(const char* prefix) {
 510     verify(VerifyOption_Default, prefix);
 511   }
 512   static void verify() {
 513     verify("");
 514   }
 515 
 516   static int  verify_count()       { return _verify_count; }
 517   static void print_on(outputStream* st);
 518   static void print_heap_at_SIGBREAK();
 519   static void print_heap_before_gc();
 520   static void print_heap_after_gc();
 521 
 522   // Change the number of dummy objects kept reachable by the full gc dummy
 523   // array; this should trigger relocation in a sliding compaction collector.
 524   debug_only(static bool release_fullgc_alot_dummy();)
 525   // The non-oop pattern (see compiledIC.hpp, etc)
 526   static void*   non_oop_word();
 527 
 528   // Oop verification (see MacroAssembler::verify_oop)
 529   static uintptr_t verify_oop_mask()          PRODUCT_RETURN0;
 530   static uintptr_t verify_oop_bits()          PRODUCT_RETURN0;
 531   static uintptr_t verify_mark_bits()         PRODUCT_RETURN0;
 532   static uintptr_t verify_mark_mask()         PRODUCT_RETURN0;
 533 
 534   // Compiler support
 535   static int base_vtable_size()               { return _base_vtable_size; }
 536 };
 537 
 538 class DeferredObjAllocEvent : public CHeapObj<mtInternal> {
 539   private:
 540     oop    _oop;
 541     size_t _bytesize;
 542     jint   _arena_id;
 543 
 544   public:
 545     DeferredObjAllocEvent(const oop o, const size_t s, const jint id) {
 546       _oop      = o;
 547       _bytesize = s;
 548       _arena_id = id;
 549     }
 550 
 551     ~DeferredObjAllocEvent() {
 552     }
 553 
 554     jint   arena_id() { return _arena_id; }
 555     size_t bytesize() { return _bytesize; }
 556     oop    get_oop()  { return _oop; }
 557 };
 558 
 559 #endif // SHARE_VM_MEMORY_UNIVERSE_HPP