1 /*
2 * Copyright (c) 1998, 2013, 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.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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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 "utilities/array.hpp"
31
32 class PSPromotionManager;
33
34 // The ConstantPoolCache is not a cache! It is the resolution table that the
35 // interpreter uses to avoid going into the runtime and a way to access resolved
36 // values.
37
38 // A ConstantPoolCacheEntry describes an individual entry of the constant
39 // pool cache. There's 2 principal kinds of entries: field entries for in-
40 // stance & static field access, and method entries for invokes. Some of
41 // the entry layout is shared and looks as follows:
42 //
43 // bit number |31 0|
44 // bit length |-8--|-8--|---16----|
45 // --------------------------------
46 // _indices [ b2 | b1 | index ] index = constant_pool_index
47 // _f1 [ entry specific ] metadata ptr (method or klass)
48 // _f2 [ entry specific ] vtable or res_ref index, or vfinal method ptr
49 // _flags [tos|0|F=1|0|0|0|f|v|0 |0000|field_index] (for field entries)
50 // bit length [ 4 |1| 1 |1|1|1|1|1|1 |-4--|----16-----]
51 // _flags [tos|0|F=0|M|A|I|f|0|vf|0000|00000|psize] (for method entries)
52 // bit length [ 4 |1| 1 |1|1|1|1|1|1 |-4--|--8--|--8--]
53
54 // --------------------------------
55 //
56 // with:
57 // index = original constant pool index
58 // b1 = bytecode 1
59 // b2 = bytecode 2
60 // psize = parameters size (method entries only)
61 // field_index = index into field information in holder InstanceKlass
62 // The index max is 0xffff (max number of fields in constant pool)
63 // and is multiplied by (InstanceKlass::next_offset) when accessing.
64 // tos = TosState
65 // F = the entry is for a field (or F=0 for a method)
66 // A = call site has an appendix argument (loaded from resolved references)
67 // I = interface call is forced virtual (must use a vtable index or vfinal)
68 // f = field or method is final
69 // v = field is volatile
70 // vf = virtual but final (method entries only: is_vfinal())
71 //
72 // The flags after TosState have the following interpretation:
73 // bit 27: 0 for fields, 1 for methods
74 // f flag true if field is marked final
75 // v flag true if field is volatile (only for fields)
76 // f2 flag true if f2 contains an oop (e.g., virtual final method)
77 // fv flag true if invokeinterface used for method in class Object
78 //
79 // The flags 31, 30, 29, 28 together build a 4 bit number 0 to 8 with the
80 // following mapping to the TosState states:
81 //
82 // btos: 0
83 // ctos: 1
84 // stos: 2
85 // itos: 3
86 // ltos: 4
87 // ftos: 5
88 // dtos: 6
89 // atos: 7
90 // vtos: 8
91 //
92 // Entry specific: field entries:
93 // _indices = get (b1 section) and put (b2 section) bytecodes, original constant pool index
94 // _f1 = field holder (as a java.lang.Class, not a Klass*)
95 // _f2 = field offset in bytes
96 // _flags = field type information, original FieldInfo index in field holder
97 // (field_index section)
98 //
99 // Entry specific: method entries:
100 // _indices = invoke code for f1 (b1 section), invoke code for f2 (b2 section),
101 // original constant pool index
102 // _f1 = Method* for non-virtual calls, unused by virtual calls.
103 // for interface calls, which are essentially virtual but need a klass,
104 // contains Klass* for the corresponding interface.
105 // for invokedynamic, f1 contains a site-specific CallSite object (as an appendix)
106 // for invokehandle, f1 contains a site-specific MethodType object (as an appendix)
107 // (upcoming metadata changes will move the appendix to a separate array)
108 // _f2 = vtable/itable index (or final Method*) for virtual calls only,
109 // unused by non-virtual. The is_vfinal flag indicates this is a
110 // method pointer for a final method, not an index.
111 // _flags = method type info (t section),
112 // virtual final bit (vfinal),
113 // parameter size (psize section)
114 //
115 // Note: invokevirtual & invokespecial bytecodes can share the same constant
116 // pool entry and thus the same constant pool cache entry. All invoke
117 // bytecodes but invokevirtual use only _f1 and the corresponding b1
118 // bytecode, while invokevirtual uses only _f2 and the corresponding
119 // b2 bytecode. The value of _flags is shared for both types of entries.
120 //
121 // The fields are volatile so that they are stored in the order written in the
122 // source code. The _indices field with the bytecode must be written last.
123
124 class CallInfo;
125
126 class ConstantPoolCacheEntry VALUE_OBJ_CLASS_SPEC {
127 friend class VMStructs;
128 friend class constantPoolCacheKlass;
129 friend class ConstantPool;
130 friend class InterpreterRuntime;
131
132 private:
133 volatile intx _indices; // constant pool index & rewrite bytecodes
134 volatile Metadata* _f1; // entry specific metadata field
135 volatile intx _f2; // entry specific int/metadata field
136 volatile intx _flags; // flags
137
138
139 void set_bytecode_1(Bytecodes::Code code);
140 void set_bytecode_2(Bytecodes::Code code);
141 void set_f1(Metadata* f1) {
142 Metadata* existing_f1 = (Metadata*)_f1; // read once
143 assert(existing_f1 == NULL || existing_f1 == f1, "illegal field change");
144 _f1 = f1;
145 }
146 void release_set_f1(Metadata* f1);
147 void set_f2(intx f2) {
148 intx existing_f2 = _f2; // read once
149 assert(existing_f2 == 0 || existing_f2 == f2, "illegal field change");
150 _f2 = f2;
151 }
152 void set_f2_as_vfinal_method(Method* f2) {
153 assert(is_vfinal(), "flags must be set");
154 set_f2((intx)f2);
155 }
156 int make_flags(TosState state, int option_bits, int field_index_or_method_params);
157 void set_flags(intx flags) { _flags = flags; }
158 bool init_flags_atomic(intx flags);
159 void set_field_flags(TosState field_type, int option_bits, int field_index) {
160 assert((field_index & field_index_mask) == field_index, "field_index in range");
161 set_flags(make_flags(field_type, option_bits | (1 << is_field_entry_shift), field_index));
162 }
163 void set_method_flags(TosState return_type, int option_bits, int method_params) {
164 assert((method_params & parameter_size_mask) == method_params, "method_params in range");
165 set_flags(make_flags(return_type, option_bits, method_params));
166 }
167 bool init_method_flags_atomic(TosState return_type, int option_bits, int method_params) {
168 assert((method_params & parameter_size_mask) == method_params, "method_params in range");
169 return init_flags_atomic(make_flags(return_type, option_bits, method_params));
170 }
171
172 public:
173 // specific bit definitions for the flags field:
174 // (Note: the interpreter must use these definitions to access the CP cache.)
175 enum {
176 // high order bits are the TosState corresponding to field type or method return type
177 tos_state_bits = 4,
178 tos_state_mask = right_n_bits(tos_state_bits),
179 tos_state_shift = BitsPerInt - tos_state_bits, // see verify_tos_state_shift below
180 // misc. option bits; can be any bit position in [16..27]
181 is_field_entry_shift = 26, // (F) is it a field or a method?
182 has_method_type_shift = 25, // (M) does the call site have a MethodType?
183 has_appendix_shift = 24, // (A) does the call site have an appendix argument?
184 is_forced_virtual_shift = 23, // (I) is the interface reference forced to virtual mode?
185 is_final_shift = 22, // (f) is the field or method final?
186 is_volatile_shift = 21, // (v) is the field volatile?
187 is_vfinal_shift = 20, // (vf) did the call resolve to a final method?
188 // low order bits give field index (for FieldInfo) or method parameter size:
189 field_index_bits = 16,
190 field_index_mask = right_n_bits(field_index_bits),
191 parameter_size_bits = 8, // subset of field_index_mask, range is 0..255
192 parameter_size_mask = right_n_bits(parameter_size_bits),
193 option_bits_mask = ~(((-1) << tos_state_shift) | (field_index_mask | parameter_size_mask))
194 };
195
196 // specific bit definitions for the indices field:
197 enum {
198 cp_index_bits = 2*BitsPerByte,
199 cp_index_mask = right_n_bits(cp_index_bits),
200 bytecode_1_shift = cp_index_bits,
201 bytecode_1_mask = right_n_bits(BitsPerByte), // == (u1)0xFF
202 bytecode_2_shift = cp_index_bits + BitsPerByte,
203 bytecode_2_mask = right_n_bits(BitsPerByte) // == (u1)0xFF
204 };
205
206
207 // Initialization
208 void initialize_entry(int original_index); // initialize primary entry
209 void initialize_resolved_reference_index(int ref_index) {
210 assert(_f2 == 0, "set once"); // note: ref_index might be zero also
211 _f2 = ref_index;
212 }
213
214 void set_field( // sets entry to resolved field state
215 Bytecodes::Code get_code, // the bytecode used for reading the field
216 Bytecodes::Code put_code, // the bytecode used for writing the field
217 KlassHandle field_holder, // the object/klass holding the field
218 int orig_field_index, // the original field index in the field holder
219 int field_offset, // the field offset in words in the field holder
220 TosState field_type, // the (machine) field type
221 bool is_final, // the field is final
222 bool is_volatile, // the field is volatile
223 Klass* root_klass // needed by the GC to dirty the klass
224 );
225
226 private:
227 void set_direct_or_vtable_call(
228 Bytecodes::Code invoke_code, // the bytecode used for invoking the method
229 methodHandle method, // the method/prototype if any (NULL, otherwise)
230 int vtable_index // the vtable index if any, else negative
231 );
232
233 public:
234 void set_direct_call( // sets entry to exact concrete method entry
235 Bytecodes::Code invoke_code, // the bytecode used for invoking the method
236 methodHandle method // the method to call
237 );
238
239 void set_vtable_call( // sets entry to vtable index
240 Bytecodes::Code invoke_code, // the bytecode used for invoking the method
241 methodHandle method, // resolved method which declares the vtable index
242 int vtable_index // the vtable index
243 );
244
245 void set_itable_call(
246 Bytecodes::Code invoke_code, // the bytecode used; must be invokeinterface
247 methodHandle method, // the resolved interface method
248 int itable_index // index into itable for the method
249 );
250
251 void set_method_handle(
252 constantPoolHandle cpool, // holding constant pool (required for locking)
253 const CallInfo &call_info // Call link information
254 );
255
256 void set_dynamic_call(
257 constantPoolHandle cpool, // holding constant pool (required for locking)
258 const CallInfo &call_info // Call link information
259 );
260
261 // Common code for invokedynamic and MH invocations.
262
263 // The "appendix" is an optional call-site-specific parameter which is
264 // pushed by the JVM at the end of the argument list. This argument may
265 // be a MethodType for the MH.invokes and a CallSite for an invokedynamic
266 // instruction. However, its exact type and use depends on the Java upcall,
267 // which simply returns a compiled LambdaForm along with any reference
268 // that LambdaForm needs to complete the call. If the upcall returns a
269 // null appendix, the argument is not passed at all.
270 //
271 // The appendix is *not* represented in the signature of the symbolic
272 // reference for the call site, but (if present) it *is* represented in
273 // the Method* bound to the site. This means that static and dynamic
274 // resolution logic needs to make slightly different assessments about the
275 // number and types of arguments.
276 void set_method_handle_common(
277 constantPoolHandle cpool, // holding constant pool (required for locking)
278 Bytecodes::Code invoke_code, // _invokehandle or _invokedynamic
279 const CallInfo &call_info // Call link information
280 );
281
282 // invokedynamic and invokehandle call sites have two entries in the
283 // resolved references array:
284 // appendix (at index+0)
285 // MethodType (at index+1)
286 enum {
287 _indy_resolved_references_appendix_offset = 0,
288 _indy_resolved_references_method_type_offset = 1,
289 _indy_resolved_references_entries
290 };
291
292 Method* method_if_resolved(constantPoolHandle cpool);
293 oop appendix_if_resolved(constantPoolHandle cpool);
294 oop method_type_if_resolved(constantPoolHandle cpool);
295
296 void set_parameter_size(int value);
297
298 // Which bytecode number (1 or 2) in the index field is valid for this bytecode?
299 // Returns -1 if neither is valid.
300 static int bytecode_number(Bytecodes::Code code) {
301 switch (code) {
302 case Bytecodes::_getstatic : // fall through
303 case Bytecodes::_getfield : // fall through
304 case Bytecodes::_invokespecial : // fall through
305 case Bytecodes::_invokestatic : // fall through
306 case Bytecodes::_invokehandle : // fall through
307 case Bytecodes::_invokedynamic : // fall through
308 case Bytecodes::_invokeinterface : return 1;
309 case Bytecodes::_putstatic : // fall through
310 case Bytecodes::_putfield : // fall through
311 case Bytecodes::_invokevirtual : return 2;
312 default : break;
313 }
314 return -1;
315 }
316
317 // Has this bytecode been resolved? Only valid for invokes and get/put field/static.
318 bool is_resolved(Bytecodes::Code code) const {
319 switch (bytecode_number(code)) {
320 case 1: return (bytecode_1() == code);
321 case 2: return (bytecode_2() == code);
322 }
323 return false; // default: not resolved
324 }
325
326 // Accessors
327 int indices() const { return _indices; }
328 int indices_ord() const { return (intx)OrderAccess::load_ptr_acquire(&_indices); }
329 int constant_pool_index() const { return (indices() & cp_index_mask); }
330 Bytecodes::Code bytecode_1() const { return Bytecodes::cast((indices_ord() >> bytecode_1_shift) & bytecode_1_mask); }
331 Bytecodes::Code bytecode_2() const { return Bytecodes::cast((indices_ord() >> bytecode_2_shift) & bytecode_2_mask); }
332 Metadata* f1_ord() const { return (Metadata *)OrderAccess::load_ptr_acquire(&_f1); }
333 Method* f1_as_method() const { Metadata* f1 = f1_ord(); assert(f1 == NULL || f1->is_method(), ""); return (Method*)f1; }
334 Klass* f1_as_klass() const { Metadata* f1 = f1_ord(); assert(f1 == NULL || f1->is_klass(), ""); return (Klass*)f1; }
335 // Use the accessor f1() to acquire _f1's value. This is needed for
336 // example in BytecodeInterpreter::run(), where is_f1_null() is
337 // called to check if an invokedynamic call is resolved. This load
338 // of _f1 must be ordered with the loads performed by
339 // cache->main_entry_index().
340 bool is_f1_null() const { Metadata* f1 = f1_ord(); return f1 == NULL; } // classifies a CPC entry as unbound
341 int f2_as_index() const { assert(!is_vfinal(), ""); return (int) _f2; }
342 Method* f2_as_vfinal_method() const { assert(is_vfinal(), ""); return (Method*)_f2; }
343 int field_index() const { assert(is_field_entry(), ""); return (_flags & field_index_mask); }
344 int parameter_size() const { assert(is_method_entry(), ""); return (_flags & parameter_size_mask); }
345 bool is_volatile() const { return (_flags & (1 << is_volatile_shift)) != 0; }
346 bool is_final() const { return (_flags & (1 << is_final_shift)) != 0; }
347 bool is_forced_virtual() const { return (_flags & (1 << is_forced_virtual_shift)) != 0; }
348 bool is_vfinal() const { return (_flags & (1 << is_vfinal_shift)) != 0; }
349 bool has_appendix() const { return (_flags & (1 << has_appendix_shift)) != 0; }
350 bool has_method_type() const { return (_flags & (1 << has_method_type_shift)) != 0; }
351 bool is_method_entry() const { return (_flags & (1 << is_field_entry_shift)) == 0; }
352 bool is_field_entry() const { return (_flags & (1 << is_field_entry_shift)) != 0; }
353 bool is_byte() const { return flag_state() == btos; }
354 bool is_char() const { return flag_state() == ctos; }
355 bool is_short() const { return flag_state() == stos; }
356 bool is_int() const { return flag_state() == itos; }
357 bool is_long() const { return flag_state() == ltos; }
358 bool is_float() const { return flag_state() == ftos; }
359 bool is_double() const { return flag_state() == dtos; }
360 bool is_object() const { return flag_state() == atos; }
361 TosState flag_state() const { assert((uint)number_of_states <= (uint)tos_state_mask+1, "");
362 return (TosState)((_flags >> tos_state_shift) & tos_state_mask); }
363
364 // Code generation support
365 static WordSize size() { return in_WordSize(sizeof(ConstantPoolCacheEntry) / HeapWordSize); }
366 static ByteSize size_in_bytes() { return in_ByteSize(sizeof(ConstantPoolCacheEntry)); }
367 static ByteSize indices_offset() { return byte_offset_of(ConstantPoolCacheEntry, _indices); }
368 static ByteSize f1_offset() { return byte_offset_of(ConstantPoolCacheEntry, _f1); }
369 static ByteSize f2_offset() { return byte_offset_of(ConstantPoolCacheEntry, _f2); }
370 static ByteSize flags_offset() { return byte_offset_of(ConstantPoolCacheEntry, _flags); }
371
372 #if INCLUDE_JVMTI
373 // RedefineClasses() API support:
374 // If this ConstantPoolCacheEntry refers to old_method then update it
375 // to refer to new_method.
376 // trace_name_printed is set to true if the current call has
377 // printed the klass name so that other routines in the adjust_*
378 // group don't print the klass name.
379 bool adjust_method_entry(Method* old_method, Method* new_method,
380 bool * trace_name_printed);
381 bool check_no_old_or_obsolete_entries();
382 bool is_interesting_method_entry(Klass* k);
383 #endif // INCLUDE_JVMTI
384
385 // Debugging & Printing
386 void print (outputStream* st, int index) const;
387 void verify(outputStream* st) const;
388
389 static void verify_tos_state_shift() {
390 // When shifting flags as a 32-bit int, make sure we don't need an extra mask for tos_state:
391 assert((((u4)-1 >> tos_state_shift) & ~tos_state_mask) == 0, "no need for tos_state mask");
392 }
393 };
394
395
396 // A constant pool cache is a runtime data structure set aside to a constant pool. The cache
397 // holds interpreter runtime information for all field access and invoke bytecodes. The cache
398 // is created and initialized before a class is actively used (i.e., initialized), the indivi-
399 // dual cache entries are filled at resolution (i.e., "link") time (see also: rewriter.*).
400
401 class ConstantPoolCache: public MetaspaceObj {
402 friend class VMStructs;
403 friend class MetadataFactory;
404 private:
405 int _length;
406 ConstantPool* _constant_pool; // the corresponding constant pool
407
408 // Sizing
409 debug_only(friend class ClassVerifier;)
410
411 // Constructor
412 ConstantPoolCache(int length,
413 const intStack& inverse_index_map,
414 const intStack& invokedynamic_inverse_index_map,
415 const intStack& invokedynamic_references_map) :
416 _length(length),
417 _constant_pool(NULL) {
418 initialize(inverse_index_map, invokedynamic_inverse_index_map,
419 invokedynamic_references_map);
420 for (int i = 0; i < length; i++) {
421 assert(entry_at(i)->is_f1_null(), "Failed to clear?");
422 }
423 }
424
425 // Initialization
426 void initialize(const intArray& inverse_index_map,
427 const intArray& invokedynamic_inverse_index_map,
428 const intArray& invokedynamic_references_map);
429 public:
430 static ConstantPoolCache* allocate(ClassLoaderData* loader_data,
431 const intStack& cp_cache_map,
432 const intStack& invokedynamic_cp_cache_map,
433 const intStack& invokedynamic_references_map, TRAPS);
434 bool is_constantPoolCache() const { return true; }
435
436 int length() const { return _length; }
437 private:
438 void set_length(int length) { _length = length; }
439
440 static int header_size() { return sizeof(ConstantPoolCache) / HeapWordSize; }
441 static int size(int length) { return align_object_size(header_size() + length * in_words(ConstantPoolCacheEntry::size())); }
442 public:
443 int size() const { return size(length()); }
444 private:
445
446 // Helpers
447 ConstantPool** constant_pool_addr() { return &_constant_pool; }
448 ConstantPoolCacheEntry* base() const { return (ConstantPoolCacheEntry*)((address)this + in_bytes(base_offset())); }
449
450 friend class constantPoolCacheKlass;
451 friend class ConstantPoolCacheEntry;
452
453 public:
454 // Accessors
455 void set_constant_pool(ConstantPool* pool) { _constant_pool = pool; }
456 ConstantPool* constant_pool() const { return _constant_pool; }
457 // Fetches the entry at the given index.
458 // In either case the index must not be encoded or byte-swapped in any way.
459 ConstantPoolCacheEntry* entry_at(int i) const {
460 assert(0 <= i && i < length(), "index out of bounds");
461 return base() + i;
462 }
463
464 // Code generation
465 static ByteSize base_offset() { return in_ByteSize(sizeof(ConstantPoolCache)); }
466 static ByteSize entry_offset(int raw_index) {
467 int index = raw_index;
468 return (base_offset() + ConstantPoolCacheEntry::size_in_bytes() * index);
469 }
470
471 #if INCLUDE_JVMTI
472 // RedefineClasses() API support:
473 // If any entry of this ConstantPoolCache points to any of
474 // old_methods, replace it with the corresponding new_method.
475 // trace_name_printed is set to true if the current call has
476 // printed the klass name so that other routines in the adjust_*
477 // group don't print the klass name.
478 void adjust_method_entries(Method** old_methods, Method** new_methods,
479 int methods_length, bool * trace_name_printed);
480 bool check_no_old_or_obsolete_entries();
481 void dump_cache();
482 #endif // INCLUDE_JVMTI
483
484 // Deallocate - no fields to deallocate
485 DEBUG_ONLY(bool on_stack() { return false; })
486 void deallocate_contents(ClassLoaderData* data) {}
487 bool is_klass() const { return false; }
488
489 // Printing
490 void print_on(outputStream* st) const;
491 void print_value_on(outputStream* st) const;
492
493 const char* internal_name() const { return "{constant pool cache}"; }
494
495 // Verify
496 void verify_on(outputStream* st);
497 };
498
499 #endif // SHARE_VM_OOPS_CPCACHEOOP_HPP