1 /*
2  * Copyright (c) 1998, 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_OOPS_CPCACHE_HPP
26 #define SHARE_OOPS_CPCACHE_HPP
27 
28 #include "interpreter/bytecodes.hpp"
29 #include "memory/allocation.hpp"
30 #include "oops/array.hpp"
31 #include "oops/oopHandle.hpp"
32 #include "runtime/handles.hpp"
33 #include "utilities/align.hpp"
34 #include "utilities/constantTag.hpp"
35 #include "utilities/growableArray.hpp"
36 
37 class PSPromotionManager;
38 
39 // The ConstantPoolCache is not a cache! It is the resolution table that the
40 // interpreter uses to avoid going into the runtime and a way to access resolved
41 // values.
42 
43 // A ConstantPoolCacheEntry describes an individual entry of the constant
44 // pool cache. There's 2 principal kinds of entries: field entries for in-
45 // stance & static field access, and method entries for invokes. Some of
46 // the entry layout is shared and looks as follows:
47 //
48 // bit number |31                0|
49 // bit length |-8--|-8--|---16----|
50 // --------------------------------
51 // _indices   [ b2 | b1 |  index  ]  index = constant_pool_index
52 // _f1        [  entry specific   ]  metadata ptr (method or klass)
53 // _f2        [  entry specific   ]  vtable or res_ref index, or vfinal method ptr
54 // _flags     [tos|0|F=1|0|0|0|f|v|0 |0000|field_index] (for field entries)
55 // bit length [ 4 |1| 1 |1|1|1|1|1|1 |1     |-3-|----16-----]
56 // _flags     [tos|0|F=0|S|A|I|f|0|vf|indy_rf|000|00000|psize] (for method entries)
57 // bit length [ 4 |1| 1 |1|1|1|1|1|1 |-4--|--8--|--8--]
58 
59 // --------------------------------
60 //
61 // with:
62 // index  = original constant pool index
63 // b1     = bytecode 1
64 // b2     = bytecode 2
65 // psize  = parameters size (method entries only)
66 // field_index = index into field information in holder InstanceKlass
67 //          The index max is 0xffff (max number of fields in constant pool)
68 //          and is multiplied by (InstanceKlass::next_offset) when accessing.
69 // tos    = TosState
70 // F      = the entry is for a field (or F=0 for a method)
71 // A      = call site has an appendix argument (loaded from resolved references)
72 // I      = interface call is forced virtual (must use a vtable index or vfinal)
73 // f      = field or method is final
74 // v      = field is volatile
75 // vf     = virtual but final (method entries only: is_vfinal())
76 // indy_rf = call site specifier method resolution failed
77 //
78 // The flags after TosState have the following interpretation:
79 // bit 27: 0 for fields, 1 for methods
80 // f  flag true if field is marked final
81 // v  flag true if field is volatile (only for fields)
82 // f2 flag true if f2 contains an oop (e.g., virtual final method)
83 // fv flag true if invokeinterface used for method in class Object
84 //
85 // The flags 31, 30, 29, 28 together build a 4 bit number 0 to 16 with the
86 // following mapping to the TosState states:
87 //
88 // btos: 0
89 // ztos: 1
90 // ctos: 2
91 // stos: 3
92 // itos: 4
93 // ltos: 5
94 // ftos: 6
95 // dtos: 7
96 // atos: 8
97 // vtos: 9
98 //
99 // Entry specific: field entries:
100 // _indices = get (b1 section) and put (b2 section) bytecodes, original constant pool index
101 // _f1      = field holder (as a java.lang.Class, not a Klass*)
102 // _f2      = field offset in bytes
103 // _flags   = field type information, original FieldInfo index in field holder
104 //            (field_index section)
105 //
106 // Entry specific: method entries:
107 // _indices = invoke code for f1 (b1 section), invoke code for f2 (b2 section),
108 //            original constant pool index
109 // _f1      = Method* for non-virtual calls, unused by virtual calls.
110 //            for interface calls, which are essentially virtual but need a klass,
111 //            contains Klass* for the corresponding interface.
112 //            for invokedynamic and invokehandle, f1 contains the adapter method which
113 //            manages the actual call. The appendix is stored in the ConstantPool
114 //            resolved_references array.
115 //            (upcoming metadata changes will move the appendix to a separate array)
116 // _f2      = vtable/itable index (or final Method*) for virtual calls only,
117 //            unused by non-virtual.  The is_vfinal flag indicates this is a
118 //            method pointer for a final method, not an index.
119 // _flags   = has local signature (MHs and indy),
120 //            virtual final bit (vfinal),
121 //            parameter size (psize section)
122 //
123 // Note: invokevirtual & invokespecial bytecodes can share the same constant
124 //       pool entry and thus the same constant pool cache entry. All invoke
125 //       bytecodes but invokevirtual use only _f1 and the corresponding b1
126 //       bytecode, while invokevirtual uses only _f2 and the corresponding
127 //       b2 bytecode.  The value of _flags is shared for both types of entries.
128 //
129 // The fields are volatile so that they are stored in the order written in the
130 // source code.  The _indices field with the bytecode must be written last.
131 
132 class CallInfo;
133 
134 class ConstantPoolCacheEntry {
135   friend class VMStructs;
136   friend class constantPoolCacheKlass;
137   friend class ConstantPool;
138   friend class InterpreterRuntime;
139 
140  private:
141   volatile intx     _indices;  // constant pool index & rewrite bytecodes
142   Metadata* volatile   _f1;       // entry specific metadata field
143   volatile intx        _f2;       // entry specific int/metadata field
144   volatile intx     _flags;    // flags
145 
146 
147   void set_bytecode_1(Bytecodes::Code code);
148   void set_bytecode_2(Bytecodes::Code code);
set_f1(Metadata * f1)149   void set_f1(Metadata* f1) {
150     Metadata* existing_f1 = _f1; // read once
151     assert(existing_f1 == NULL || existing_f1 == f1, "illegal field change");
152     _f1 = f1;
153   }
154   void release_set_f1(Metadata* f1);
set_f2(intx f2)155   void set_f2(intx f2) {
156     intx existing_f2 = _f2; // read once
157     assert(existing_f2 == 0 || existing_f2 == f2, "illegal field change");
158     _f2 = f2;
159   }
set_f2_as_vfinal_method(Method * f2)160   void set_f2_as_vfinal_method(Method* f2) {
161     assert(is_vfinal(), "flags must be set");
162     set_f2((intx)f2);
163   }
164   int make_flags(TosState state, int option_bits, int field_index_or_method_params);
set_flags(intx flags)165   void set_flags(intx flags)                     { _flags = flags; }
set_field_flags(TosState field_type,int option_bits,int field_index)166   void set_field_flags(TosState field_type, int option_bits, int field_index) {
167     assert((field_index & field_index_mask) == field_index, "field_index in range");
168     set_flags(make_flags(field_type, option_bits | (1 << is_field_entry_shift), field_index));
169   }
set_method_flags(TosState return_type,int option_bits,int method_params)170   void set_method_flags(TosState return_type, int option_bits, int method_params) {
171     assert((method_params & parameter_size_mask) == method_params, "method_params in range");
172     set_flags(make_flags(return_type, option_bits, method_params));
173   }
174 
175  public:
176   // specific bit definitions for the flags field:
177   // (Note: the interpreter must use these definitions to access the CP cache.)
178   enum {
179     // high order bits are the TosState corresponding to field type or method return type
180     tos_state_bits             = 4,
181     tos_state_mask             = right_n_bits(tos_state_bits),
182     tos_state_shift            = BitsPerInt - tos_state_bits,  // see verify_tos_state_shift below
183     // misc. option bits; can be any bit position in [16..27]
184     is_field_entry_shift       = 26,  // (F) is it a field or a method?
185     has_local_signature_shift  = 25,  // (S) does the call site have a per-site signature (sig-poly methods)?
186     has_appendix_shift         = 24,  // (A) does the call site have an appendix argument?
187     is_forced_virtual_shift    = 23,  // (I) is the interface reference forced to virtual mode?
188     is_final_shift             = 22,  // (f) is the field or method final?
189     is_volatile_shift          = 21,  // (v) is the field volatile?
190     is_vfinal_shift            = 20,  // (vf) did the call resolve to a final method?
191     indy_resolution_failed_shift= 19, // (indy_rf) did call site specifier resolution fail ?
192     // low order bits give field index (for FieldInfo) or method parameter size:
193     field_index_bits           = 16,
194     field_index_mask           = right_n_bits(field_index_bits),
195     parameter_size_bits        = 8,  // subset of field_index_mask, range is 0..255
196     parameter_size_mask        = right_n_bits(parameter_size_bits),
197     option_bits_mask           = ~(((~0u) << tos_state_shift) | (field_index_mask | parameter_size_mask))
198   };
199 
200   // specific bit definitions for the indices field:
201   enum {
202     cp_index_bits              = 2*BitsPerByte,
203     cp_index_mask              = right_n_bits(cp_index_bits),
204     bytecode_1_shift           = cp_index_bits,
205     bytecode_1_mask            = right_n_bits(BitsPerByte), // == (u1)0xFF
206     bytecode_2_shift           = cp_index_bits + BitsPerByte,
207     bytecode_2_mask            = right_n_bits(BitsPerByte)  // == (u1)0xFF
208   };
209 
210 
211   // Initialization
212   void initialize_entry(int original_index);     // initialize primary entry
initialize_resolved_reference_index(int ref_index)213   void initialize_resolved_reference_index(int ref_index) {
214     assert(_f2 == 0, "set once");  // note: ref_index might be zero also
215     _f2 = ref_index;
216   }
217 
218   void set_field(                                // sets entry to resolved field state
219     Bytecodes::Code get_code,                    // the bytecode used for reading the field
220     Bytecodes::Code put_code,                    // the bytecode used for writing the field
221     Klass*          field_holder,                // the object/klass holding the field
222     int             orig_field_index,            // the original field index in the field holder
223     int             field_offset,                // the field offset in words in the field holder
224     TosState        field_type,                  // the (machine) field type
225     bool            is_final,                    // the field is final
226     bool            is_volatile,                 // the field is volatile
227     Klass*          root_klass                   // needed by the GC to dirty the klass
228   );
229 
230  private:
231   void set_direct_or_vtable_call(
232     Bytecodes::Code invoke_code,                 // the bytecode used for invoking the method
233     const methodHandle& method,                  // the method/prototype if any (NULL, otherwise)
234     int             vtable_index,                // the vtable index if any, else negative
235     bool            sender_is_interface
236   );
237 
238  public:
239   void set_direct_call(                          // sets entry to exact concrete method entry
240     Bytecodes::Code invoke_code,                 // the bytecode used for invoking the method
241     const methodHandle& method,                  // the method to call
242     bool            sender_is_interface
243   );
244 
245   void set_vtable_call(                          // sets entry to vtable index
246     Bytecodes::Code invoke_code,                 // the bytecode used for invoking the method
247     const methodHandle& method,                  // resolved method which declares the vtable index
248     int             vtable_index                 // the vtable index
249   );
250 
251   void set_itable_call(
252     Bytecodes::Code invoke_code,                 // the bytecode used; must be invokeinterface
253     Klass* referenced_klass,                     // the referenced klass in the InterfaceMethodref
254     const methodHandle& method,                  // the resolved interface method
255     int itable_index                             // index into itable for the method
256   );
257 
258   void set_method_handle(
259     const constantPoolHandle& cpool,             // holding constant pool (required for locking)
260     const CallInfo &call_info                    // Call link information
261   );
262 
263   void set_dynamic_call(
264     const constantPoolHandle& cpool,             // holding constant pool (required for locking)
265     const CallInfo &call_info                    // Call link information
266   );
267 
268   // Common code for invokedynamic and MH invocations.
269 
270   // The "appendix" is an optional call-site-specific parameter which is
271   // pushed by the JVM at the end of the argument list.  This argument may
272   // be a MethodType for the MH.invokes and a CallSite for an invokedynamic
273   // instruction.  However, its exact type and use depends on the Java upcall,
274   // which simply returns a compiled LambdaForm along with any reference
275   // that LambdaForm needs to complete the call.  If the upcall returns a
276   // null appendix, the argument is not passed at all.
277   //
278   // The appendix is *not* represented in the signature of the symbolic
279   // reference for the call site, but (if present) it *is* represented in
280   // the Method* bound to the site.  This means that static and dynamic
281   // resolution logic needs to make slightly different assessments about the
282   // number and types of arguments.
283   void set_method_handle_common(
284     const constantPoolHandle& cpool,                    // holding constant pool (required for locking)
285     Bytecodes::Code invoke_code,                 // _invokehandle or _invokedynamic
286     const CallInfo &call_info                    // Call link information
287   );
288 
289   // Return TRUE if resolution failed and this thread got to record the failure
290   // status.  Return FALSE if another thread succeeded or failed in resolving
291   // the method and recorded the success or failure before this thread had a
292   // chance to record its failure.
293   bool save_and_throw_indy_exc(const constantPoolHandle& cpool, int cpool_index,
294                                int index, constantTag tag, TRAPS);
295 
296   // invokedynamic and invokehandle call sites have an "appendix" item in the
297   // resolved references array.
298   Method*      method_if_resolved(const constantPoolHandle& cpool);
299   oop        appendix_if_resolved(const constantPoolHandle& cpool);
300 
301   void set_parameter_size(int value);
302 
303   // Which bytecode number (1 or 2) in the index field is valid for this bytecode?
304   // Returns -1 if neither is valid.
bytecode_number(Bytecodes::Code code)305   static int bytecode_number(Bytecodes::Code code) {
306     switch (code) {
307       case Bytecodes::_getstatic       :    // fall through
308       case Bytecodes::_getfield        :    // fall through
309       case Bytecodes::_invokespecial   :    // fall through
310       case Bytecodes::_invokestatic    :    // fall through
311       case Bytecodes::_invokehandle    :    // fall through
312       case Bytecodes::_invokedynamic   :    // fall through
313       case Bytecodes::_invokeinterface : return 1;
314       case Bytecodes::_putstatic       :    // fall through
315       case Bytecodes::_putfield        :    // fall through
316       case Bytecodes::_invokevirtual   : return 2;
317       default                          : break;
318     }
319     return -1;
320   }
321 
322   // Has this bytecode been resolved? Only valid for invokes and get/put field/static.
323   bool is_resolved(Bytecodes::Code code) const;
324 
325   // Accessors
indices() const326   int indices() const                            { return _indices; }
327   int indices_ord() const;
constant_pool_index() const328   int constant_pool_index() const                { return (indices() & cp_index_mask); }
329   Bytecodes::Code bytecode_1() const;
330   Bytecodes::Code bytecode_2() const;
331   Metadata* f1_ord() const;
332   Method*   f1_as_method() const;
333   Klass*    f1_as_klass() const;
334   // Use the accessor f1() to acquire _f1's value. This is needed for
335   // example in BytecodeInterpreter::run(), where is_f1_null() is
336   // called to check if an invokedynamic call is resolved. This load
337   // of _f1 must be ordered with the loads performed by
338   // cache->main_entry_index().
339   bool      is_f1_null() const;  // classifies a CPC entry as unbound
f2_as_index() const340   int       f2_as_index() const                  { assert(!is_vfinal(), ""); return (int) _f2; }
f2_as_vfinal_method() const341   Method*   f2_as_vfinal_method() const          { assert(is_vfinal(), ""); return (Method*)_f2; }
342   Method*   f2_as_interface_method() const;
343   intx flags_ord() const;
field_index() const344   int  field_index() const                       { assert(is_field_entry(),  ""); return (_flags & field_index_mask); }
parameter_size() const345   int  parameter_size() const                    { assert(is_method_entry(), ""); return (_flags & parameter_size_mask); }
is_volatile() const346   bool is_volatile() const                       { return (_flags & (1 << is_volatile_shift))       != 0; }
is_final() const347   bool is_final() const                          { return (_flags & (1 << is_final_shift))          != 0; }
is_forced_virtual() const348   bool is_forced_virtual() const                 { return (_flags & (1 << is_forced_virtual_shift)) != 0; }
is_vfinal() const349   bool is_vfinal() const                         { return (_flags & (1 << is_vfinal_shift))         != 0; }
350   bool indy_resolution_failed() const;
351   bool has_appendix() const;
352   bool has_local_signature() const;
is_method_entry() const353   bool is_method_entry() const                   { return (_flags & (1 << is_field_entry_shift))    == 0; }
is_field_entry() const354   bool is_field_entry() const                    { return (_flags & (1 << is_field_entry_shift))    != 0; }
is_long() const355   bool is_long() const                           { return flag_state() == ltos; }
is_double() const356   bool is_double() const                         { return flag_state() == dtos; }
flag_state() const357   TosState flag_state() const                    { assert((uint)number_of_states <= (uint)tos_state_mask+1, "");
358                                                    return (TosState)((_flags >> tos_state_shift) & tos_state_mask); }
359   void set_indy_resolution_failed();
360 
361   // Code generation support
size()362   static WordSize size()                         {
363     return in_WordSize(align_up((int)sizeof(ConstantPoolCacheEntry), wordSize) / wordSize);
364   }
size_in_bytes()365   static ByteSize size_in_bytes()                { return in_ByteSize(sizeof(ConstantPoolCacheEntry)); }
indices_offset()366   static ByteSize indices_offset()               { return byte_offset_of(ConstantPoolCacheEntry, _indices); }
f1_offset()367   static ByteSize f1_offset()                    { return byte_offset_of(ConstantPoolCacheEntry, _f1); }
f2_offset()368   static ByteSize f2_offset()                    { return byte_offset_of(ConstantPoolCacheEntry, _f2); }
flags_offset()369   static ByteSize flags_offset()                 { return byte_offset_of(ConstantPoolCacheEntry, _flags); }
370 
371 #if INCLUDE_JVMTI
372   // RedefineClasses() API support:
373   // If this ConstantPoolCacheEntry refers to old_method then update it
374   // to refer to new_method.
375   // trace_name_printed is set to true if the current call has
376   // printed the klass name so that other routines in the adjust_*
377   // group don't print the klass name.
378   void adjust_method_entry(Method* old_method, Method* new_method,
379          bool* trace_name_printed);
380   bool check_no_old_or_obsolete_entries();
381   Method* get_interesting_method_entry();
382 #endif // INCLUDE_JVMTI
383 
384   // Debugging & Printing
385   void print (outputStream* st, int index) const;
386   void verify(outputStream* st) const;
387 
verify_tos_state_shift()388   static void verify_tos_state_shift() {
389     // When shifting flags as a 32-bit int, make sure we don't need an extra mask for tos_state:
390     assert((((u4)-1 >> tos_state_shift) & ~tos_state_mask) == 0, "no need for tos_state mask");
391   }
392 
393   void verify_just_initialized(bool f2_used);
394   void reinitialize(bool f2_used);
395 };
396 
397 
398 // A constant pool cache is a runtime data structure set aside to a constant pool. The cache
399 // holds interpreter runtime information for all field access and invoke bytecodes. The cache
400 // is created and initialized before a class is actively used (i.e., initialized), the indivi-
401 // dual cache entries are filled at resolution (i.e., "link") time (see also: rewriter.*).
402 
403 class ConstantPoolCache: public MetaspaceObj {
404   friend class VMStructs;
405   friend class MetadataFactory;
406  private:
407   // If you add a new field that points to any metaspace object, you
408   // must add this field to ConstantPoolCache::metaspace_pointers_do().
409   int             _length;
410   ConstantPool*   _constant_pool;          // the corresponding constant pool
411 
412   // The following fields need to be modified at runtime, so they cannot be
413   // stored in the ConstantPool, which is read-only.
414   // Array of resolved objects from the constant pool and map from resolved
415   // object index to original constant pool index
416   OopHandle            _resolved_references;
417   Array<u2>*           _reference_map;
418   // The narrowOop pointer to the archived resolved_references. Set at CDS dump
419   // time when caching java heap object is supported.
420   CDS_JAVA_HEAP_ONLY(narrowOop _archived_references;)
421 
422   // Sizing
423   debug_only(friend class ClassVerifier;)
424 
425   // Constructor
426   ConstantPoolCache(int length,
427                     const intStack& inverse_index_map,
428                     const intStack& invokedynamic_inverse_index_map,
429                     const intStack& invokedynamic_references_map);
430 
431   // Initialization
432   void initialize(const intArray& inverse_index_map,
433                   const intArray& invokedynamic_inverse_index_map,
434                   const intArray& invokedynamic_references_map);
435  public:
436   static ConstantPoolCache* allocate(ClassLoaderData* loader_data,
437                                      const intStack& cp_cache_map,
438                                      const intStack& invokedynamic_cp_cache_map,
439                                      const intStack& invokedynamic_references_map, TRAPS);
440 
length() const441   int length() const                      { return _length; }
442   void metaspace_pointers_do(MetaspaceClosure* it);
type() const443   MetaspaceObj::Type type() const         { return ConstantPoolCacheType; }
444 
445   oop  archived_references() NOT_CDS_JAVA_HEAP_RETURN_(NULL);
446   void set_archived_references(oop o) NOT_CDS_JAVA_HEAP_RETURN;
447 
448   inline oop resolved_references();
set_resolved_references(OopHandle s)449   void set_resolved_references(OopHandle s) { _resolved_references = s; }
reference_map() const450   Array<u2>* reference_map() const        { return _reference_map; }
set_reference_map(Array<u2> * o)451   void set_reference_map(Array<u2>* o)    { _reference_map = o; }
452 
453   // Assembly code support
resolved_references_offset_in_bytes()454   static int resolved_references_offset_in_bytes() { return offset_of(ConstantPoolCache, _resolved_references); }
455 
456   // CDS support
457   void remove_unshareable_info();
458   void verify_just_initialized();
459  private:
460   void walk_entries_for_initialization(bool check_only);
set_length(int length)461   void set_length(int length)                    { _length = length; }
462 
header_size()463   static int header_size()                       { return sizeof(ConstantPoolCache) / wordSize; }
size(int length)464   static int size(int length)                    { return align_metadata_size(header_size() + length * in_words(ConstantPoolCacheEntry::size())); }
465  public:
size() const466   int size() const                               { return size(length()); }
467  private:
468 
469   // Helpers
constant_pool_addr()470   ConstantPool**        constant_pool_addr()     { return &_constant_pool; }
base() const471   ConstantPoolCacheEntry* base() const           { return (ConstantPoolCacheEntry*)((address)this + in_bytes(base_offset())); }
472 
473   friend class constantPoolCacheKlass;
474   friend class ConstantPoolCacheEntry;
475 
476  public:
477   // Accessors
set_constant_pool(ConstantPool * pool)478   void set_constant_pool(ConstantPool* pool)   { _constant_pool = pool; }
constant_pool() const479   ConstantPool* constant_pool() const          { return _constant_pool; }
480   // Fetches the entry at the given index.
481   // In either case the index must not be encoded or byte-swapped in any way.
entry_at(int i) const482   ConstantPoolCacheEntry* entry_at(int i) const {
483     assert(0 <= i && i < length(), "index out of bounds");
484     return base() + i;
485   }
486 
487   // Code generation
base_offset()488   static ByteSize base_offset()                  { return in_ByteSize(sizeof(ConstantPoolCache)); }
entry_offset(int raw_index)489   static ByteSize entry_offset(int raw_index) {
490     int index = raw_index;
491     return (base_offset() + ConstantPoolCacheEntry::size_in_bytes() * index);
492   }
493 
494 #if INCLUDE_JVMTI
495   // RedefineClasses() API support:
496   // If any entry of this ConstantPoolCache points to any of
497   // old_methods, replace it with the corresponding new_method.
498   // trace_name_printed is set to true if the current call has
499   // printed the klass name so that other routines in the adjust_*
500   // group don't print the klass name.
501   void adjust_method_entries(bool* trace_name_printed);
502   bool check_no_old_or_obsolete_entries();
503   void dump_cache();
504 #endif // INCLUDE_JVMTI
505 
506   // RedefineClasses support
507   DEBUG_ONLY(bool on_stack() { return false; })
508   void deallocate_contents(ClassLoaderData* data);
is_klass() const509   bool is_klass() const { return false; }
510 
511   // Printing
512   void print_on(outputStream* st) const;
513   void print_value_on(outputStream* st) const;
514 
internal_name() const515   const char* internal_name() const { return "{constant pool cache}"; }
516 
517   // Verify
518   void verify_on(outputStream* st);
519 };
520 
521 #endif // SHARE_OOPS_CPCACHE_HPP
522