1 /*
2 * Copyright (c) 1998, 2017, 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_OOPS_CPCACHEOOP_HPP
26 #define SHARE_VM_OOPS_CPCACHEOOP_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/orderAccess.hpp"
33 #include "utilities/align.hpp"
34 #include "utilities/constantTag.hpp"
35
36 class PSPromotionManager;
37
38 // The ConstantPoolCache is not a cache! It is the resolution table that the
39 // interpreter uses to avoid going into the runtime and a way to access resolved
40 // values.
41
42 // A ConstantPoolCacheEntry describes an individual entry of the constant
43 // pool cache. There's 2 principal kinds of entries: field entries for in-
44 // stance & static field access, and method entries for invokes. Some of
45 // the entry layout is shared and looks as follows:
46 //
47 // bit number |31 0|
48 // bit length |-8--|-8--|---16----|
49 // --------------------------------
50 // _indices [ b2 | b1 | index ] index = constant_pool_index
51 // _f1 [ entry specific ] metadata ptr (method or klass)
52 // _f2 [ entry specific ] vtable or res_ref index, or vfinal method ptr
53 // _flags [tos|0|F=1|0|N|i|f|v|0 |0000|field_index] (for field entries)
54 // bit length [ 4 |1| 1 |1|1|1|1|1|1 |1 |-3-|----16-----]
55 // _flags [tos|0|F=0|M|A|I|f|0|vf|indy_rf|000|00000|psize] (for method entries)
56 // bit length [ 4 |1| 1 |1|1|1|1|1|1 |-4--|--8--|--8--]
57
58 // --------------------------------
59 //
60 // with:
61 // index = original constant pool index
62 // b1 = bytecode 1
63 // b2 = bytecode 2
64 // psize = parameters size (method entries only)
65 // field_index = index into field information in holder InstanceKlass
66 // The index max is 0xffff (max number of fields in constant pool)
67 // and is multiplied by (InstanceKlass::next_offset) when accessing.
68 // tos = TosState
69 // F = the entry is for a field (or F=0 for a method)
70 // A = call site has an appendix argument (loaded from resolved references)
71 // I = interface call is forced virtual (must use a vtable index or vfinal)
72 // f = field or method is final
73 // v = field is volatile
74 // vf = virtual but final (method entries only: is_vfinal())
75 // indy_rf = call site specifier method resolution failed
76 //
77 // The flags after TosState have the following interpretation:
78 // bit 27: 0 for fields, 1 for methods
79 // N flag true if field is marked flattenable (must never be null)
80 // i flag true if field is inlined (flatten)
81 // f flag true if field is marked final
82 // v flag true if field is volatile (only for fields)
83 // f2 flag true if f2 contains an oop (e.g., virtual final method)
84 // fv flag true if invokeinterface used for method in class Object
85 //
86 // The flags 31, 30, 29, 28 together build a 4 bit number 0 to 16 with the
87 // following mapping to the TosState states:
88 //
89 // btos: 0
90 // ztos: 1
91 // ctos: 2
92 // stos: 3
93 // itos: 4
94 // ltos: 5
95 // ftos: 6
96 // dtos: 7
97 // atos: 8
98 // vtos: 9
99 //
100 // Entry specific: field entries:
101 // _indices = get (b1 section) and put (b2 section) bytecodes, original constant pool index
102 // _f1 = field holder (as a java.lang.Class, not a Klass*)
103 // _f2 = field offset in bytes
104 // _flags = field type information, original FieldInfo index in field holder
105 // (field_index section)
106 //
107 // Entry specific: method entries:
108 // _indices = invoke code for f1 (b1 section), invoke code for f2 (b2 section),
109 // original constant pool index
110 // _f1 = Method* for non-virtual calls, unused by virtual calls.
111 // for interface calls, which are essentially virtual but need a klass,
112 // contains Klass* for the corresponding interface.
113 // for invokedynamic and invokehandle, f1 contains the adapter method which
114 // manages the actual call. The appendix is stored in the ConstantPool
115 // resolved_references array.
116 // (upcoming metadata changes will move the appendix to a separate array)
117 // _f2 = vtable/itable index (or final Method*) for virtual calls only,
118 // unused by non-virtual. The is_vfinal flag indicates this is a
119 // method pointer for a final method, not an index.
120 // _flags = method type info (t section),
121 // virtual final bit (vfinal),
122 // parameter size (psize section)
123 //
124 // Note: invokevirtual & invokespecial bytecodes can share the same constant
125 // pool entry and thus the same constant pool cache entry. All invoke
126 // bytecodes but invokevirtual use only _f1 and the corresponding b1
127 // bytecode, while invokevirtual uses only _f2 and the corresponding
128 // b2 bytecode. The value of _flags is shared for both types of entries.
129 //
130 // The fields are volatile so that they are stored in the order written in the
131 // source code. The _indices field with the bytecode must be written last.
132
133 class CallInfo;
134
135 class ConstantPoolCacheEntry VALUE_OBJ_CLASS_SPEC {
136 friend class VMStructs;
137 friend class constantPoolCacheKlass;
138 friend class ConstantPool;
139 friend class InterpreterRuntime;
140
141 private:
142 volatile intx _indices; // constant pool index & rewrite bytecodes
143 Metadata* volatile _f1; // entry specific metadata field
144 volatile intx _f2; // entry specific int/metadata field
145 volatile intx _flags; // flags
146
147
148 void set_bytecode_1(Bytecodes::Code code);
149 void set_bytecode_2(Bytecodes::Code code);
150 void set_f1(Metadata* f1) {
151 Metadata* existing_f1 = _f1; // read once
152 assert(existing_f1 == NULL || existing_f1 == f1, "illegal field change");
153 _f1 = f1;
154 }
155 void release_set_f1(Metadata* f1);
156 void set_f2(intx f2) {
157 intx existing_f2 = _f2; // read once
158 assert(existing_f2 == 0 || existing_f2 == f2, "illegal field change");
159 _f2 = f2;
160 }
161 void set_f2_as_vfinal_method(Method* f2) {
162 assert(is_vfinal(), "flags must be set");
163 set_f2((intx)f2);
164 }
165 int make_flags(TosState state, int option_bits, int field_index_or_method_params);
166 void set_flags(intx flags) { _flags = flags; }
167 void set_field_flags(TosState field_type, int option_bits, int field_index) {
168 assert((field_index & field_index_mask) == field_index, "field_index in range");
169 set_flags(make_flags(field_type, option_bits | (1 << is_field_entry_shift), field_index));
170 }
171 void set_method_flags(TosState return_type, int option_bits, int method_params) {
172 assert((method_params & parameter_size_mask) == method_params, "method_params in range");
173 set_flags(make_flags(return_type, option_bits, method_params));
174 }
175
176 public:
177 // specific bit definitions for the flags field:
178 // (Note: the interpreter must use these definitions to access the CP cache.)
179 enum {
180 // high order bits are the TosState corresponding to field type or method return type
181 tos_state_bits = 4,
182 tos_state_mask = right_n_bits(tos_state_bits),
183 tos_state_shift = BitsPerInt - tos_state_bits, // see verify_tos_state_shift below
184 // misc. option bits; can be any bit position in [16..27]
185 is_field_entry_shift = 26, // (F) is it a field or a method?
186 has_method_type_shift = 25, // (M) does the call site have a MethodType?
187 has_appendix_shift = 24, // (A) does the call site have an appendix argument?
188 is_flattenable_field = 24, // (N) is the field flattenable (must never be null)
189 is_forced_virtual_shift = 23, // (I) is the interface reference forced to virtual mode?
190 is_flatten_field = 23, // (i) is the value field flatten?
191 is_final_shift = 22, // (f) is the field or method final?
192 is_volatile_shift = 21, // (v) is the field volatile?
193 is_vfinal_shift = 20, // (vf) did the call resolve to a final method?
194 indy_resolution_failed_shift= 19, // (indy_rf) did call site specifier resolution fail ?
195 // low order bits give field index (for FieldInfo) or method parameter size:
196 field_index_bits = 16,
197 field_index_mask = right_n_bits(field_index_bits),
198 parameter_size_bits = 8, // subset of field_index_mask, range is 0..255
199 parameter_size_mask = right_n_bits(parameter_size_bits),
200 option_bits_mask = ~(((~0u) << tos_state_shift) | (field_index_mask | parameter_size_mask))
201 };
202
203 // specific bit definitions for the indices field:
204 enum {
205 cp_index_bits = 2*BitsPerByte,
206 cp_index_mask = right_n_bits(cp_index_bits),
207 bytecode_1_shift = cp_index_bits,
208 bytecode_1_mask = right_n_bits(BitsPerByte), // == (u1)0xFF
209 bytecode_2_shift = cp_index_bits + BitsPerByte,
210 bytecode_2_mask = right_n_bits(BitsPerByte) // == (u1)0xFF
211 };
212
213
214 // Initialization
215 void initialize_entry(int original_index); // initialize primary entry
216 void initialize_resolved_reference_index(int ref_index) {
217 assert(_f2 == 0, "set once"); // note: ref_index might be zero also
218 _f2 = ref_index;
219 }
220
221 void set_field( // sets entry to resolved field state
222 Bytecodes::Code get_code, // the bytecode used for reading the field
223 Bytecodes::Code put_code, // the bytecode used for writing the field
224 Klass* field_holder, // the object/klass holding the field
225 int orig_field_index, // the original field index in the field holder
226 int field_offset, // the field offset in words in the field holder
227 TosState field_type, // the (machine) field type
228 bool is_final, // the field is final
229 bool is_volatile, // the field is volatile
230 bool is_flatten, // the field is flatten (value field)
231 bool is_flattenable, // the field is flattenable (must never be null)
232 Klass* root_klass // needed by the GC to dirty the klass
233 );
234
235 private:
236 void set_direct_or_vtable_call(
237 Bytecodes::Code invoke_code, // the bytecode used for invoking the method
238 const methodHandle& method, // the method/prototype if any (NULL, otherwise)
239 int vtable_index, // the vtable index if any, else negative
240 bool sender_is_interface
241 );
242
243 public:
244 void set_direct_call( // sets entry to exact concrete method entry
245 Bytecodes::Code invoke_code, // the bytecode used for invoking the method
246 const methodHandle& method, // the method to call
247 bool sender_is_interface
248 );
249
250 void set_vtable_call( // sets entry to vtable index
251 Bytecodes::Code invoke_code, // the bytecode used for invoking the method
252 const methodHandle& method, // resolved method which declares the vtable index
253 int vtable_index // the vtable index
254 );
255
256 void set_itable_call(
257 Bytecodes::Code invoke_code, // the bytecode used; must be invokeinterface
258 Klass* referenced_klass, // the referenced klass in the InterfaceMethodref
259 const methodHandle& method, // the resolved interface method
260 int itable_index // index into itable for the method
261 );
262
263 void set_method_handle(
264 const constantPoolHandle& cpool, // holding constant pool (required for locking)
265 const CallInfo &call_info // Call link information
266 );
267
268 void set_dynamic_call(
269 const constantPoolHandle& cpool, // holding constant pool (required for locking)
270 const CallInfo &call_info // Call link information
271 );
272
273 // Common code for invokedynamic and MH invocations.
274
275 // The "appendix" is an optional call-site-specific parameter which is
276 // pushed by the JVM at the end of the argument list. This argument may
277 // be a MethodType for the MH.invokes and a CallSite for an invokedynamic
278 // instruction. However, its exact type and use depends on the Java upcall,
279 // which simply returns a compiled LambdaForm along with any reference
280 // that LambdaForm needs to complete the call. If the upcall returns a
281 // null appendix, the argument is not passed at all.
282 //
283 // The appendix is *not* represented in the signature of the symbolic
284 // reference for the call site, but (if present) it *is* represented in
285 // the Method* bound to the site. This means that static and dynamic
286 // resolution logic needs to make slightly different assessments about the
287 // number and types of arguments.
288 void set_method_handle_common(
289 const constantPoolHandle& cpool, // holding constant pool (required for locking)
290 Bytecodes::Code invoke_code, // _invokehandle or _invokedynamic
291 const CallInfo &call_info // Call link information
292 );
293
294 // Return TRUE if resolution failed and this thread got to record the failure
295 // status. Return FALSE if another thread succeeded or failed in resolving
296 // the method and recorded the success or failure before this thread had a
297 // chance to record its failure.
298 bool save_and_throw_indy_exc(const constantPoolHandle& cpool, int cpool_index,
299 int index, constantTag tag, TRAPS);
300
301 // invokedynamic and invokehandle call sites have two entries in the
302 // resolved references array:
303 // appendix (at index+0)
304 // MethodType (at index+1)
305 enum {
306 _indy_resolved_references_appendix_offset = 0,
307 _indy_resolved_references_method_type_offset = 1,
308 _indy_resolved_references_entries
309 };
310
311 Method* method_if_resolved(const constantPoolHandle& cpool);
312 oop appendix_if_resolved(const constantPoolHandle& cpool);
313 oop method_type_if_resolved(const constantPoolHandle& cpool);
314
315 void set_parameter_size(int value);
316
317 // Which bytecode number (1 or 2) in the index field is valid for this bytecode?
318 // Returns -1 if neither is valid.
319 static int bytecode_number(Bytecodes::Code code) {
320 switch (code) {
321 case Bytecodes::_getstatic : // fall through
322 case Bytecodes::_getfield : // fall through
323 case Bytecodes::_invokespecial : // fall through
324 case Bytecodes::_invokestatic : // fall through
325 case Bytecodes::_invokehandle : // fall through
326 case Bytecodes::_invokedynamic : // fall through
327 case Bytecodes::_invokeinterface : return 1;
328 case Bytecodes::_putstatic : // fall through
329 case Bytecodes::_putfield : // fall through
330 case Bytecodes::_withfield : // fall through
331 case Bytecodes::_invokevirtual : return 2;
332 default : break;
333 }
334 return -1;
335 }
336
337 // Has this bytecode been resolved? Only valid for invokes and get/put field/static.
338 bool is_resolved(Bytecodes::Code code) const {
339 switch (bytecode_number(code)) {
340 case 1: return (bytecode_1() == code);
341 case 2: return (bytecode_2() == code);
342 }
343 return false; // default: not resolved
344 }
345
346 // Accessors
347 int indices() const { return _indices; }
348 int indices_ord() const { return OrderAccess::load_acquire(&_indices); }
349 int constant_pool_index() const { return (indices() & cp_index_mask); }
350 Bytecodes::Code bytecode_1() const { return Bytecodes::cast((indices_ord() >> bytecode_1_shift) & bytecode_1_mask); }
351 Bytecodes::Code bytecode_2() const { return Bytecodes::cast((indices_ord() >> bytecode_2_shift) & bytecode_2_mask); }
352 Metadata* f1_ord() const { return (Metadata *)OrderAccess::load_acquire(&_f1); }
353 Method* f1_as_method() const { Metadata* f1 = f1_ord(); assert(f1 == NULL || f1->is_method(), ""); return (Method*)f1; }
354 Klass* f1_as_klass() const { Metadata* f1 = f1_ord(); assert(f1 == NULL || f1->is_klass(), ""); return (Klass*)f1; }
355 // Use the accessor f1() to acquire _f1's value. This is needed for
356 // example in BytecodeInterpreter::run(), where is_f1_null() is
357 // called to check if an invokedynamic call is resolved. This load
358 // of _f1 must be ordered with the loads performed by
359 // cache->main_entry_index().
360 bool is_f1_null() const { Metadata* f1 = f1_ord(); return f1 == NULL; } // classifies a CPC entry as unbound
361 int f2_as_index() const { assert(!is_vfinal(), ""); return (int) _f2; }
362 Method* f2_as_vfinal_method() const { assert(is_vfinal(), ""); return (Method*)_f2; }
363 Method* f2_as_interface_method() const { assert(bytecode_1() == Bytecodes::_invokeinterface, ""); return (Method*)_f2; }
364 int f2_as_offset() const { assert(is_field_entry(), ""); return (int)_f2; }
365 intx flags_ord() const { return (intx)OrderAccess::load_acquire(&_flags); }
366 int field_index() const { assert(is_field_entry(), ""); return (_flags & field_index_mask); }
367 int parameter_size() const { assert(is_method_entry(), ""); return (_flags & parameter_size_mask); }
368 bool is_volatile() const { return (_flags & (1 << is_volatile_shift)) != 0; }
369 bool is_final() const { return (_flags & (1 << is_final_shift)) != 0; }
370 bool is_flatten() const { return (_flags & (1 << is_flatten_field)) != 0; }
371 bool is_forced_virtual() const { return (_flags & (1 << is_forced_virtual_shift)) != 0; }
372 bool is_vfinal() const { return (_flags & (1 << is_vfinal_shift)) != 0; }
373 bool indy_resolution_failed() const { intx flags = flags_ord(); return (flags & (1 << indy_resolution_failed_shift)) != 0; }
374 bool has_appendix() const { return (!is_f1_null()) && (_flags & (1 << has_appendix_shift)) != 0; }
375 bool has_method_type() const { return (!is_f1_null()) && (_flags & (1 << has_method_type_shift)) != 0; }
376 bool is_method_entry() const { return (_flags & (1 << is_field_entry_shift)) == 0; }
377 bool is_field_entry() const { return (_flags & (1 << is_field_entry_shift)) != 0; }
378 bool is_long() const { return flag_state() == ltos; }
379 bool is_double() const { return flag_state() == dtos; }
380 bool is_flattenable() const { return (_flags & (1 << is_flattenable_field)) != 0; }
381 TosState flag_state() const { assert((uint)number_of_states <= (uint)tos_state_mask+1, "");
382 return (TosState)((_flags >> tos_state_shift) & tos_state_mask); }
383 void set_indy_resolution_failed();
384
385 // Code generation support
386 static WordSize size() {
387 return in_WordSize(align_up((int)sizeof(ConstantPoolCacheEntry), wordSize) / wordSize);
388 }
389 static ByteSize size_in_bytes() { return in_ByteSize(sizeof(ConstantPoolCacheEntry)); }
390 static ByteSize indices_offset() { return byte_offset_of(ConstantPoolCacheEntry, _indices); }
391 static ByteSize f1_offset() { return byte_offset_of(ConstantPoolCacheEntry, _f1); }
392 static ByteSize f2_offset() { return byte_offset_of(ConstantPoolCacheEntry, _f2); }
393 static ByteSize flags_offset() { return byte_offset_of(ConstantPoolCacheEntry, _flags); }
394
395 #if INCLUDE_JVMTI
396 // RedefineClasses() API support:
397 // If this ConstantPoolCacheEntry refers to old_method then update it
398 // to refer to new_method.
399 // trace_name_printed is set to true if the current call has
400 // printed the klass name so that other routines in the adjust_*
401 // group don't print the klass name.
402 void adjust_method_entry(Method* old_method, Method* new_method,
403 bool* trace_name_printed);
404 bool check_no_old_or_obsolete_entries();
405 Method* get_interesting_method_entry(Klass* k);
406 #endif // INCLUDE_JVMTI
407
408 // Debugging & Printing
409 void print (outputStream* st, int index) const;
410 void verify(outputStream* st) const;
411
412 static void verify_tos_state_shift() {
413 // When shifting flags as a 32-bit int, make sure we don't need an extra mask for tos_state:
414 assert((((u4)-1 >> tos_state_shift) & ~tos_state_mask) == 0, "no need for tos_state mask");
415 }
416
417 void verify_just_initialized(bool f2_used);
418 void reinitialize(bool f2_used);
419 };
420
421
422 // A constant pool cache is a runtime data structure set aside to a constant pool. The cache
423 // holds interpreter runtime information for all field access and invoke bytecodes. The cache
424 // is created and initialized before a class is actively used (i.e., initialized), the indivi-
425 // dual cache entries are filled at resolution (i.e., "link") time (see also: rewriter.*).
426
427 class ConstantPoolCache: public MetaspaceObj {
428 friend class VMStructs;
429 friend class MetadataFactory;
430 private:
431 // If you add a new field that points to any metaspace object, you
432 // must add this field to ConstantPoolCache::metaspace_pointers_do().
433 int _length;
434 ConstantPool* _constant_pool; // the corresponding constant pool
435
436 // The following fields need to be modified at runtime, so they cannot be
437 // stored in the ConstantPool, which is read-only.
438 // Array of resolved objects from the constant pool and map from resolved
439 // object index to original constant pool index
440 OopHandle _resolved_references;
441 Array<u2>* _reference_map;
442 // The narrowOop pointer to the archived resolved_references. Set at CDS dump
443 // time when caching java heap object is supported.
444 CDS_JAVA_HEAP_ONLY(narrowOop _archived_references;)
445
446 // Sizing
447 debug_only(friend class ClassVerifier;)
448
449 // Constructor
450 ConstantPoolCache(int length,
451 const intStack& inverse_index_map,
452 const intStack& invokedynamic_inverse_index_map,
453 const intStack& invokedynamic_references_map) :
454 _length(length),
455 _constant_pool(NULL) {
456 CDS_JAVA_HEAP_ONLY(_archived_references = 0;)
457 initialize(inverse_index_map, invokedynamic_inverse_index_map,
458 invokedynamic_references_map);
459 for (int i = 0; i < length; i++) {
460 assert(entry_at(i)->is_f1_null(), "Failed to clear?");
461 }
462 }
463
464 // Initialization
465 void initialize(const intArray& inverse_index_map,
466 const intArray& invokedynamic_inverse_index_map,
467 const intArray& invokedynamic_references_map);
468 public:
469 static ConstantPoolCache* allocate(ClassLoaderData* loader_data,
470 const intStack& cp_cache_map,
471 const intStack& invokedynamic_cp_cache_map,
472 const intStack& invokedynamic_references_map, TRAPS);
473 bool is_constantPoolCache() const { return true; }
474
475 int length() const { return _length; }
476 void metaspace_pointers_do(MetaspaceClosure* it);
477 MetaspaceObj::Type type() const { return ConstantPoolCacheType; }
478
479 oop archived_references() NOT_CDS_JAVA_HEAP_RETURN_(NULL);
480 void set_archived_references(oop o) NOT_CDS_JAVA_HEAP_RETURN;
481
482 oop resolved_references() { return _resolved_references.resolve(); }
483 void set_resolved_references(OopHandle s) { _resolved_references = s; }
484 Array<u2>* reference_map() const { return _reference_map; }
485 void set_reference_map(Array<u2>* o) { _reference_map = o; }
486
487 // Assembly code support
488 static int resolved_references_offset_in_bytes() { return offset_of(ConstantPoolCache, _resolved_references); }
489
490 // CDS support
491 void remove_unshareable_info();
492 void verify_just_initialized();
493 private:
494 void walk_entries_for_initialization(bool check_only);
495 void set_length(int length) { _length = length; }
496
497 static int header_size() { return sizeof(ConstantPoolCache) / wordSize; }
498 static int size(int length) { return align_metadata_size(header_size() + length * in_words(ConstantPoolCacheEntry::size())); }
499 public:
500 int size() const { return size(length()); }
501 private:
502
503 // Helpers
504 ConstantPool** constant_pool_addr() { return &_constant_pool; }
505 ConstantPoolCacheEntry* base() const { return (ConstantPoolCacheEntry*)((address)this + in_bytes(base_offset())); }
506
507 friend class constantPoolCacheKlass;
508 friend class ConstantPoolCacheEntry;
509
510 public:
511 // Accessors
512 void set_constant_pool(ConstantPool* pool) { _constant_pool = pool; }
513 ConstantPool* constant_pool() const { return _constant_pool; }
514 // Fetches the entry at the given index.
515 // In either case the index must not be encoded or byte-swapped in any way.
516 ConstantPoolCacheEntry* entry_at(int i) const {
517 assert(0 <= i && i < length(), "index out of bounds");
518 return base() + i;
519 }
520
521 // Code generation
522 static ByteSize base_offset() { return in_ByteSize(sizeof(ConstantPoolCache)); }
523 static ByteSize entry_offset(int raw_index) {
524 int index = raw_index;
525 return (base_offset() + ConstantPoolCacheEntry::size_in_bytes() * index);
526 }
527
528 #if INCLUDE_JVMTI
529 // RedefineClasses() API support:
530 // If any entry of this ConstantPoolCache points to any of
531 // old_methods, replace it with the corresponding new_method.
532 // trace_name_printed is set to true if the current call has
533 // printed the klass name so that other routines in the adjust_*
534 // group don't print the klass name.
535 void adjust_method_entries(InstanceKlass* holder, bool* trace_name_printed);
536 bool check_no_old_or_obsolete_entries();
537 void dump_cache();
538 #endif // INCLUDE_JVMTI
539
540 // RedefineClasses support
541 DEBUG_ONLY(bool on_stack() { return false; })
542 void deallocate_contents(ClassLoaderData* data);
543 bool is_klass() const { return false; }
544
545 // Printing
546 void print_on(outputStream* st) const;
547 void print_value_on(outputStream* st) const;
548
549 const char* internal_name() const { return "{constant pool cache}"; }
550
551 // Verify
552 void verify_on(outputStream* st);
553 };
554
555 #endif // SHARE_VM_OOPS_CPCACHEOOP_HPP