universe.hpp revision 3465:d2a62e0f25eb
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/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
39class CollectedHeap;
40class DeferredObjAllocEvent;
41
42
43// Common parts of a methodOop cache. This cache safely interacts with
44// the RedefineClasses API.
45//
46class CommonMethodOopCache : public CHeapObj<mtClass> {
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//
69class 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//
92class 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.
100struct 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
112enum VerifyOption {
113      VerifyOption_Default = 0,
114
115      // G1
116      VerifyOption_G1UsePrevMarking = VerifyOption_Default,
117      VerifyOption_G1UseNextMarking = VerifyOption_G1UsePrevMarking + 1,
118      VerifyOption_G1UseMarkWord    = VerifyOption_G1UseNextMarking + 1
119};
120
121class Universe: AllStatic {
122  // Ugh.  Universe is much too friendly.
123  friend class MarkSweep;
124  friend class oopDesc;
125  friend class ClassLoader;
126  friend class Arguments;
127  friend class SystemDictionary;
128  friend class VMStructs;
129  friend class CompactingPermGenGen;
130  friend class VM_PopulateDumpSharedSpace;
131
132  friend jint  universe_init();
133  friend void  universe2_init();
134  friend bool  universe_post_init();
135
136 private:
137  // Known classes in the VM
138  static klassOop _boolArrayKlassObj;
139  static klassOop _byteArrayKlassObj;
140  static klassOop _charArrayKlassObj;
141  static klassOop _intArrayKlassObj;
142  static klassOop _shortArrayKlassObj;
143  static klassOop _longArrayKlassObj;
144  static klassOop _singleArrayKlassObj;
145  static klassOop _doubleArrayKlassObj;
146  static klassOop _typeArrayKlassObjs[T_VOID+1];
147
148  static klassOop _objectArrayKlassObj;
149
150  static klassOop _methodKlassObj;
151  static klassOop _constMethodKlassObj;
152  static klassOop _methodDataKlassObj;
153  static klassOop _klassKlassObj;
154  static klassOop _arrayKlassKlassObj;
155  static klassOop _objArrayKlassKlassObj;
156  static klassOop _typeArrayKlassKlassObj;
157  static klassOop _instanceKlassKlassObj;
158  static klassOop _constantPoolKlassObj;
159  static klassOop _constantPoolCacheKlassObj;
160  static klassOop _compiledICHolderKlassObj;
161  static klassOop _systemObjArrayKlassObj;
162
163  // Known objects in the VM
164
165  // Primitive objects
166  static oop _int_mirror;
167  static oop _float_mirror;
168  static oop _double_mirror;
169  static oop _byte_mirror;
170  static oop _bool_mirror;
171  static oop _char_mirror;
172  static oop _long_mirror;
173  static oop _short_mirror;
174  static oop _void_mirror;
175
176  static oop          _main_thread_group;             // Reference to the main thread group object
177  static oop          _system_thread_group;           // Reference to the system thread group object
178
179  static typeArrayOop _the_empty_byte_array;          // Canonicalized byte array
180  static typeArrayOop _the_empty_short_array;         // Canonicalized short array
181  static typeArrayOop _the_empty_int_array;           // Canonicalized int array
182  static objArrayOop  _the_empty_system_obj_array;    // Canonicalized system obj array
183  static objArrayOop  _the_empty_class_klass_array;   // Canonicalized obj array of type java.lang.Class
184  static objArrayOop  _the_array_interfaces_array;    // Canonicalized 2-array of cloneable & serializable klasses
185  static oop          _the_null_string;               // A cache of "null" as a Java string
186  static oop          _the_min_jint_string;          // A cache of "-2147483648" as a Java string
187  static LatestMethodOopCache* _finalizer_register_cache; // static method for registering finalizable objects
188  static LatestMethodOopCache* _loader_addClass_cache;    // method for registering loaded classes in class loader vector
189  static ActiveMethodOopsCache* _reflect_invoke_cache;    // method for security checks
190  static oop          _out_of_memory_error_java_heap; // preallocated error object (no backtrace)
191  static oop          _out_of_memory_error_perm_gen;  // preallocated error object (no backtrace)
192  static oop          _out_of_memory_error_array_size;// preallocated error object (no backtrace)
193  static oop          _out_of_memory_error_gc_overhead_limit; // preallocated error object (no backtrace)
194
195  // array of preallocated error objects with backtrace
196  static objArrayOop   _preallocated_out_of_memory_error_array;
197
198  // number of preallocated error objects available for use
199  static volatile jint _preallocated_out_of_memory_error_avail_count;
200
201  static oop          _null_ptr_exception_instance;   // preallocated exception object
202  static oop          _arithmetic_exception_instance; // preallocated exception object
203  static oop          _virtual_machine_error_instance; // preallocated exception object
204  // The object used as an exception dummy when exceptions are thrown for
205  // the vm thread.
206  static oop          _vm_exception;
207
208  // The particular choice of collected heap.
209  static CollectedHeap* _collectedHeap;
210
211  // For UseCompressedOops.
212  static struct NarrowOopStruct _narrow_oop;
213
214  // array of dummy objects used with +FullGCAlot
215  debug_only(static objArrayOop _fullgc_alot_dummy_array;)
216  // index of next entry to clear
217  debug_only(static int         _fullgc_alot_dummy_next;)
218
219  // Compiler/dispatch support
220  static int  _base_vtable_size;                      // Java vtbl size of klass Object (in words)
221
222  // Initialization
223  static bool _bootstrapping;                         // true during genesis
224  static bool _fully_initialized;                     // true after universe_init and initialize_vtables called
225
226  // the array of preallocated errors with backtraces
227  static objArrayOop  preallocated_out_of_memory_errors()     { return _preallocated_out_of_memory_error_array; }
228
229  // generate an out of memory error; if possible using an error with preallocated backtrace;
230  // otherwise return the given default error.
231  static oop        gen_out_of_memory_error(oop default_err);
232
233  // Historic gc information
234  static size_t _heap_capacity_at_last_gc;
235  static size_t _heap_used_at_last_gc;
236
237  static jint initialize_heap();
238  static void initialize_basic_type_mirrors(TRAPS);
239  static void fixup_mirrors(TRAPS);
240
241  static void reinitialize_vtable_of(KlassHandle h_k, TRAPS);
242  static void reinitialize_itables(TRAPS);
243  static void compute_base_vtable_size();             // compute vtable size of class Object
244
245  static void genesis(TRAPS);                         // Create the initial world
246
247  // Mirrors for primitive classes (created eagerly)
248  static oop check_mirror(oop m) {
249    assert(m != NULL, "mirror not initialized");
250    return m;
251  }
252
253  // Debugging
254  static int _verify_count;                           // number of verifies done
255  // True during call to verify().  Should only be set/cleared in verify().
256  static bool _verify_in_progress;
257
258  static void compute_verify_oop_data();
259
260 public:
261  // Known classes in the VM
262  static klassOop boolArrayKlassObj()                 { return _boolArrayKlassObj;   }
263  static klassOop byteArrayKlassObj()                 { return _byteArrayKlassObj;   }
264  static klassOop charArrayKlassObj()                 { return _charArrayKlassObj;   }
265  static klassOop intArrayKlassObj()                  { return _intArrayKlassObj;    }
266  static klassOop shortArrayKlassObj()                { return _shortArrayKlassObj;  }
267  static klassOop longArrayKlassObj()                 { return _longArrayKlassObj;   }
268  static klassOop singleArrayKlassObj()               { return _singleArrayKlassObj; }
269  static klassOop doubleArrayKlassObj()               { return _doubleArrayKlassObj; }
270
271  static klassOop objectArrayKlassObj() {
272    return _objectArrayKlassObj;
273  }
274
275  static klassOop typeArrayKlassObj(BasicType t) {
276    assert((uint)t < T_VOID+1, "range check");
277    assert(_typeArrayKlassObjs[t] != NULL, "domain check");
278    return _typeArrayKlassObjs[t];
279  }
280
281  static klassOop methodKlassObj()                    { return _methodKlassObj;            }
282  static klassOop constMethodKlassObj()               { return _constMethodKlassObj;         }
283  static klassOop methodDataKlassObj()                { return _methodDataKlassObj;        }
284  static klassOop klassKlassObj()                     { return _klassKlassObj;             }
285  static klassOop arrayKlassKlassObj()                { return _arrayKlassKlassObj;        }
286  static klassOop objArrayKlassKlassObj()             { return _objArrayKlassKlassObj;     }
287  static klassOop typeArrayKlassKlassObj()            { return _typeArrayKlassKlassObj;    }
288  static klassOop instanceKlassKlassObj()             { return _instanceKlassKlassObj;     }
289  static klassOop constantPoolKlassObj()              { return _constantPoolKlassObj;      }
290  static klassOop constantPoolCacheKlassObj()         { return _constantPoolCacheKlassObj; }
291  static klassOop compiledICHolderKlassObj()          { return _compiledICHolderKlassObj;  }
292  static klassOop systemObjArrayKlassObj()            { return _systemObjArrayKlassObj;    }
293
294  // Known objects in the VM
295  static oop int_mirror()                   { return check_mirror(_int_mirror); }
296  static oop float_mirror()                 { return check_mirror(_float_mirror); }
297  static oop double_mirror()                { return check_mirror(_double_mirror); }
298  static oop byte_mirror()                  { return check_mirror(_byte_mirror); }
299  static oop bool_mirror()                  { return check_mirror(_bool_mirror); }
300  static oop char_mirror()                  { return check_mirror(_char_mirror); }
301  static oop long_mirror()                  { return check_mirror(_long_mirror); }
302  static oop short_mirror()                 { return check_mirror(_short_mirror); }
303  static oop void_mirror()                  { return check_mirror(_void_mirror); }
304
305  // table of same
306  static oop _mirrors[T_VOID+1];
307
308  static oop java_mirror(BasicType t) {
309    assert((uint)t < T_VOID+1, "range check");
310    return check_mirror(_mirrors[t]);
311  }
312  static oop      main_thread_group()                 { return _main_thread_group; }
313  static void set_main_thread_group(oop group)        { _main_thread_group = group;}
314
315  static oop      system_thread_group()               { return _system_thread_group; }
316  static void set_system_thread_group(oop group)      { _system_thread_group = group;}
317
318  static typeArrayOop the_empty_byte_array()          { return _the_empty_byte_array;          }
319  static typeArrayOop the_empty_short_array()         { return _the_empty_short_array;         }
320  static typeArrayOop the_empty_int_array()           { return _the_empty_int_array;           }
321  static objArrayOop  the_empty_system_obj_array ()   { return _the_empty_system_obj_array;    }
322  static objArrayOop  the_empty_class_klass_array ()  { return _the_empty_class_klass_array;   }
323  static objArrayOop  the_array_interfaces_array()    { return _the_array_interfaces_array;    }
324  static oop          the_null_string()               { return _the_null_string;               }
325  static oop          the_min_jint_string()          { return _the_min_jint_string;          }
326  static methodOop    finalizer_register_method()     { return _finalizer_register_cache->get_methodOop(); }
327  static methodOop    loader_addClass_method()        { return _loader_addClass_cache->get_methodOop(); }
328  static ActiveMethodOopsCache* reflect_invoke_cache() { return _reflect_invoke_cache; }
329  static oop          null_ptr_exception_instance()   { return _null_ptr_exception_instance;   }
330  static oop          arithmetic_exception_instance() { return _arithmetic_exception_instance; }
331  static oop          virtual_machine_error_instance() { return _virtual_machine_error_instance; }
332  static oop          vm_exception()                  { return _vm_exception; }
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 klassOop* boolArrayKlassObj_addr()           { return &_boolArrayKlassObj;   }
344  static klassOop* byteArrayKlassObj_addr()           { return &_byteArrayKlassObj;   }
345  static klassOop* charArrayKlassObj_addr()           { return &_charArrayKlassObj;   }
346  static klassOop* intArrayKlassObj_addr()            { return &_intArrayKlassObj;    }
347  static klassOop* shortArrayKlassObj_addr()          { return &_shortArrayKlassObj;  }
348  static klassOop* longArrayKlassObj_addr()           { return &_longArrayKlassObj;   }
349  static klassOop* singleArrayKlassObj_addr()         { return &_singleArrayKlassObj; }
350  static klassOop* doubleArrayKlassObj_addr()         { return &_doubleArrayKlassObj; }
351  static klassOop* systemObjArrayKlassObj_addr()      { return &_systemObjArrayKlassObj; }
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 void     set_narrow_oop_base(address base)   { _narrow_oop._base  = base; }
362  static void     set_narrow_oop_shift(int shift)     { _narrow_oop._shift = shift; }
363  static bool     narrow_oop_use_implicit_null_checks()             { return  _narrow_oop._use_implicit_null_checks; }
364  static void     set_narrow_oop_use_implicit_null_checks(bool use) { _narrow_oop._use_implicit_null_checks = use; }
365  // Narrow Oop encoding mode:
366  // 0 - Use 32-bits oops without encoding when
367  //     NarrowOopHeapBaseMin + heap_size < 4Gb
368  // 1 - Use zero based compressed oops with encoding when
369  //     NarrowOopHeapBaseMin + heap_size < 32Gb
370  // 2 - Use compressed oops with heap base + encoding.
371  enum NARROW_OOP_MODE {
372    UnscaledNarrowOop  = 0,
373    ZeroBasedNarrowOop = 1,
374    HeapBasedNarrowOop = 2
375  };
376  static char* preferred_heap_base(size_t heap_size, NARROW_OOP_MODE mode);
377
378  // Historic gc information
379  static size_t get_heap_capacity_at_last_gc()         { return _heap_capacity_at_last_gc; }
380  static size_t get_heap_free_at_last_gc()             { return _heap_capacity_at_last_gc - _heap_used_at_last_gc; }
381  static size_t get_heap_used_at_last_gc()             { return _heap_used_at_last_gc; }
382  static void update_heap_info_at_gc();
383
384  // Testers
385  static bool is_bootstrapping()                      { return _bootstrapping; }
386  static bool is_fully_initialized()                  { return _fully_initialized; }
387
388  static inline bool element_type_should_be_aligned(BasicType type);
389  static inline bool field_type_should_be_aligned(BasicType type);
390  static bool        on_page_boundary(void* addr);
391  static bool        should_fill_in_stack_trace(Handle throwable);
392  static void check_alignment(uintx size, uintx alignment, const char* name);
393
394  // Finalizer support.
395  static void run_finalizers_on_exit();
396
397  // Iteration
398
399  // Apply "f" to the addresses of all the direct heap pointers maintained
400  // as static fields of "Universe".
401  static void oops_do(OopClosure* f, bool do_all = false);
402
403  // Apply "f" to all klasses for basic types (classes not present in
404  // SystemDictionary).
405  static void basic_type_classes_do(void f(klassOop));
406
407  // Apply "f" to all system klasses (classes not present in SystemDictionary).
408  static void system_classes_do(void f(klassOop));
409
410  // For sharing -- fill in a list of known vtable pointers.
411  static void init_self_patching_vtbl_list(void** list, int count);
412
413  // Debugging
414  static bool verify_in_progress() { return _verify_in_progress; }
415  static void verify(bool silent = false,
416                     VerifyOption option = VerifyOption_Default );
417  static int  verify_count()       { return _verify_count; }
418  // The default behavior is to call print_on() on gclog_or_tty.
419  static void print();
420  // The extended parameter determines which method on the heap will
421  // be called: print_on() (extended == false) or print_extended_on()
422  // (extended == true).
423  static void print_on(outputStream* st, bool extended = false);
424  static void print_heap_at_SIGBREAK();
425  static void print_heap_before_gc() { print_heap_before_gc(gclog_or_tty); }
426  static void print_heap_after_gc()  { print_heap_after_gc(gclog_or_tty); }
427  static void print_heap_before_gc(outputStream* st, bool ignore_extended = false);
428  static void print_heap_after_gc(outputStream* st, bool ignore_extended = false);
429
430  // Change the number of dummy objects kept reachable by the full gc dummy
431  // array; this should trigger relocation in a sliding compaction collector.
432  debug_only(static bool release_fullgc_alot_dummy();)
433  // The non-oop pattern (see compiledIC.hpp, etc)
434  static void*   non_oop_word();
435
436  // Oop verification (see MacroAssembler::verify_oop)
437  static uintptr_t verify_oop_mask()          PRODUCT_RETURN0;
438  static uintptr_t verify_oop_bits()          PRODUCT_RETURN0;
439  static uintptr_t verify_mark_bits()         PRODUCT_RETURN0;
440  static uintptr_t verify_mark_mask()         PRODUCT_RETURN0;
441  static uintptr_t verify_klass_mask()        PRODUCT_RETURN0;
442  static uintptr_t verify_klass_bits()        PRODUCT_RETURN0;
443
444  // Flushing and deoptimization
445  static void flush_dependents_on(instanceKlassHandle dependee);
446  static void flush_dependents_on(Handle call_site, Handle method_handle);
447#ifdef HOTSWAP
448  // Flushing and deoptimization in case of evolution
449  static void flush_evol_dependents_on(instanceKlassHandle dependee);
450#endif // HOTSWAP
451  // Support for fullspeed debugging
452  static void flush_dependents_on_method(methodHandle dependee);
453
454  // Compiler support
455  static int base_vtable_size()               { return _base_vtable_size; }
456};
457
458class DeferredObjAllocEvent : public CHeapObj<mtInternal> {
459  private:
460    oop    _oop;
461    size_t _bytesize;
462    jint   _arena_id;
463
464  public:
465    DeferredObjAllocEvent(const oop o, const size_t s, const jint id) {
466      _oop      = o;
467      _bytesize = s;
468      _arena_id = id;
469    }
470
471    ~DeferredObjAllocEvent() {
472    }
473
474    jint   arena_id() { return _arena_id; }
475    size_t bytesize() { return _bytesize; }
476    oop    get_oop()  { return _oop; }
477};
478
479#endif // SHARE_VM_MEMORY_UNIVERSE_HPP
480