1 /*
2 * Copyright (c) 1998, 2014, 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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20 * or visit www.oracle.com if you need additional information or have any
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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 "runtime/orderAccess.hpp"
31 #include "utilities/array.hpp"
32
33 class PSPromotionManager;
34
35 // The ConstantPoolCache is not a cache! It is the resolution table that the
36 // interpreter uses to avoid going into the runtime and a way to access resolved
37 // values.
38
39 // A ConstantPoolCacheEntry describes an individual entry of the constant
40 // pool cache. There's 2 principal kinds of entries: field entries for in-
41 // stance & static field access, and method entries for invokes. Some of
42 // the entry layout is shared and looks as follows:
43 //
44 // bit number |31 0|
45 // bit length |-8--|-8--|---16----|
46 // --------------------------------
47 // _indices [ b2 | b1 | index ] index = constant_pool_index
48 // _f1 [ entry specific ] metadata ptr (method or klass)
49 // _f2 [ entry specific ] vtable or res_ref index, or vfinal method ptr
50 // _flags [tos|0|F=1|0|0|0|f|v|0 |0000|field_index] (for field entries)
51 // bit length [ 4 |1| 1 |1|1|1|1|1|1 |-4--|----16-----]
52 // _flags [tos|0|F=0|M|A|I|f|0|vf|0000|00000|psize] (for method entries)
53 // bit length [ 4 |1| 1 |1|1|1|1|1|1 |-4--|--8--|--8--]
54
55 // --------------------------------
56 //
57 // with:
58 // index = original constant pool index
59 // b1 = bytecode 1
60 // b2 = bytecode 2
61 // psize = parameters size (method entries only)
62 // field_index = index into field information in holder InstanceKlass
63 // The index max is 0xffff (max number of fields in constant pool)
64 // and is multiplied by (InstanceKlass::next_offset) when accessing.
65 // tos = TosState
66 // F = the entry is for a field (or F=0 for a method)
67 // A = call site has an appendix argument (loaded from resolved references)
68 // I = interface call is forced virtual (must use a vtable index or vfinal)
69 // f = field or method is final
70 // v = field is volatile
71 // vf = virtual but final (method entries only: is_vfinal())
72 //
73 // The flags after TosState have the following interpretation:
74 // bit 27: 0 for fields, 1 for methods
75 // f flag true if field is marked final
76 // v flag true if field is volatile (only for fields)
77 // f2 flag true if f2 contains an oop (e.g., virtual final method)
78 // fv flag true if invokeinterface used for method in class Object
79 //
80 // The flags 31, 30, 29, 28 together build a 4 bit number 0 to 8 with the
81 // following mapping to the TosState states:
82 //
83 // btos: 0
84 // ctos: 1
85 // stos: 2
86 // itos: 3
87 // ltos: 4
88 // ftos: 5
89 // dtos: 6
90 // atos: 7
91 // vtos: 8
92 //
93 // Entry specific: field entries:
94 // _indices = get (b1 section) and put (b2 section) bytecodes, original constant pool index
95 // _f1 = field holder (as a java.lang.Class, not a Klass*)
96 // _f2 = field offset in bytes
97 // _flags = field type information, original FieldInfo index in field holder
98 // (field_index section)
99 //
100 // Entry specific: method entries:
101 // _indices = invoke code for f1 (b1 section), invoke code for f2 (b2 section),
102 // original constant pool index
103 // _f1 = Method* for non-virtual calls, unused by virtual calls.
104 // for interface calls, which are essentially virtual but need a klass,
105 // contains Klass* for the corresponding interface.
106 // for invokedynamic and invokehandle, f1 contains the adapter method which
107 // manages the actual call. The appendix is stored in the ConstantPool
108 // resolved_references array.
109 // (upcoming metadata changes will move the appendix to a separate array)
110 // _f2 = vtable/itable index (or final Method*) for virtual calls only,
111 // unused by non-virtual. The is_vfinal flag indicates this is a
112 // method pointer for a final method, not an index.
113 // _flags = method type info (t section),
114 // virtual final bit (vfinal),
115 // parameter size (psize section)
116 //
117 // Note: invokevirtual & invokespecial bytecodes can share the same constant
118 // pool entry and thus the same constant pool cache entry. All invoke
119 // bytecodes but invokevirtual use only _f1 and the corresponding b1
120 // bytecode, while invokevirtual uses only _f2 and the corresponding
121 // b2 bytecode. The value of _flags is shared for both types of entries.
122 //
123 // The fields are volatile so that they are stored in the order written in the
124 // source code. The _indices field with the bytecode must be written last.
125
126 class CallInfo;
127
128 class ConstantPoolCacheEntry VALUE_OBJ_CLASS_SPEC {
129 friend class VMStructs;
130 friend class constantPoolCacheKlass;
131 friend class ConstantPool;
132 friend class InterpreterRuntime;
133
134 private:
135 volatile intx _indices; // constant pool index & rewrite bytecodes
136 volatile Metadata* _f1; // entry specific metadata field
137 volatile intx _f2; // entry specific int/metadata field
138 volatile intx _flags; // flags
139
140
141 void set_bytecode_1(Bytecodes::Code code);
142 void set_bytecode_2(Bytecodes::Code code);
143 void set_f1(Metadata* f1) {
144 Metadata* existing_f1 = (Metadata*)_f1; // read once
145 assert(existing_f1 == NULL || existing_f1 == f1, "illegal field change");
146 _f1 = f1;
147 }
148 void release_set_f1(Metadata* f1);
149 void set_f2(intx f2) {
150 intx existing_f2 = _f2; // read once
151 assert(existing_f2 == 0 || existing_f2 == f2, "illegal field change");
152 _f2 = f2;
153 }
154 void set_f2_as_vfinal_method(Method* f2) {
155 assert(is_vfinal(), "flags must be set");
156 set_f2((intx)f2);
157 }
158 int make_flags(TosState state, int option_bits, int field_index_or_method_params);
159 void set_flags(intx flags) { _flags = flags; }
160 bool init_flags_atomic(intx flags);
161 void set_field_flags(TosState field_type, int option_bits, int field_index) {
162 assert((field_index & field_index_mask) == field_index, "field_index in range");
163 set_flags(make_flags(field_type, option_bits | (1 << is_field_entry_shift), field_index));
164 }
165 void set_method_flags(TosState return_type, int option_bits, int method_params) {
166 assert((method_params & parameter_size_mask) == method_params, "method_params in range");
167 set_flags(make_flags(return_type, option_bits, method_params));
168 }
169 bool init_method_flags_atomic(TosState return_type, int option_bits, int method_params) {
170 assert((method_params & parameter_size_mask) == method_params, "method_params in range");
171 return init_flags_atomic(make_flags(return_type, option_bits, method_params));
172 }
173
174 public:
175 // specific bit definitions for the flags field:
176 // (Note: the interpreter must use these definitions to access the CP cache.)
177 enum {
178 // high order bits are the TosState corresponding to field type or method return type
179 tos_state_bits = 4,
180 tos_state_mask = right_n_bits(tos_state_bits),
181 tos_state_shift = BitsPerInt - tos_state_bits, // see verify_tos_state_shift below
182 // misc. option bits; can be any bit position in [16..27]
183 is_field_entry_shift = 26, // (F) is it a field or a method?
184 has_method_type_shift = 25, // (M) does the call site have a MethodType?
185 has_appendix_shift = 24, // (A) does the call site have an appendix argument?
186 is_forced_virtual_shift = 23, // (I) is the interface reference forced to virtual mode?
187 is_final_shift = 22, // (f) is the field or method final?
188 is_volatile_shift = 21, // (v) is the field volatile?
189 is_vfinal_shift = 20, // (vf) did the call resolve to a final method?
190 // low order bits give field index (for FieldInfo) or method parameter size:
191 field_index_bits = 16,
192 field_index_mask = right_n_bits(field_index_bits),
193 parameter_size_bits = 8, // subset of field_index_mask, range is 0..255
194 parameter_size_mask = right_n_bits(parameter_size_bits),
195 option_bits_mask = ~(((-1) << tos_state_shift) | (field_index_mask | parameter_size_mask))
196 };
197
198 // specific bit definitions for the indices field:
199 enum {
200 cp_index_bits = 2*BitsPerByte,
201 cp_index_mask = right_n_bits(cp_index_bits),
202 bytecode_1_shift = cp_index_bits,
203 bytecode_1_mask = right_n_bits(BitsPerByte), // == (u1)0xFF
204 bytecode_2_shift = cp_index_bits + BitsPerByte,
205 bytecode_2_mask = right_n_bits(BitsPerByte) // == (u1)0xFF
206 };
207
208
209 // Initialization
210 void initialize_entry(int original_index); // initialize primary entry
211 void initialize_resolved_reference_index(int ref_index) {
212 assert(_f2 == 0, "set once"); // note: ref_index might be zero also
213 _f2 = ref_index;
214 }
215
216 void set_field( // sets entry to resolved field state
217 Bytecodes::Code get_code, // the bytecode used for reading the field
218 Bytecodes::Code put_code, // the bytecode used for writing the field
219 KlassHandle field_holder, // the object/klass holding the field
220 int orig_field_index, // the original field index in the field holder
221 int field_offset, // the field offset in words in the field holder
222 TosState field_type, // the (machine) field type
223 bool is_final, // the field is final
224 bool is_volatile, // the field is volatile
225 Klass* root_klass // needed by the GC to dirty the klass
226 );
227
228 private:
229 void set_direct_or_vtable_call(
230 Bytecodes::Code invoke_code, // the bytecode used for invoking the method
231 methodHandle method, // the method/prototype if any (NULL, otherwise)
232 int vtable_index // the vtable index if any, else negative
233 );
234
235 public:
236 void set_direct_call( // sets entry to exact concrete method entry
237 Bytecodes::Code invoke_code, // the bytecode used for invoking the method
238 methodHandle method // the method to call
239 );
240
241 void set_vtable_call( // sets entry to vtable index
242 Bytecodes::Code invoke_code, // the bytecode used for invoking the method
243 methodHandle method, // resolved method which declares the vtable index
244 int vtable_index // the vtable index
245 );
246
247 void set_itable_call(
248 Bytecodes::Code invoke_code, // the bytecode used; must be invokeinterface
249 methodHandle method, // the resolved interface method
250 int itable_index // index into itable for the method
251 );
252
253 void set_method_handle(
254 constantPoolHandle cpool, // holding constant pool (required for locking)
255 const CallInfo &call_info // Call link information
256 );
257
258 void set_dynamic_call(
259 constantPoolHandle cpool, // holding constant pool (required for locking)
260 const CallInfo &call_info // Call link information
261 );
262
263 // Common code for invokedynamic and MH invocations.
264
265 // The "appendix" is an optional call-site-specific parameter which is
266 // pushed by the JVM at the end of the argument list. This argument may
267 // be a MethodType for the MH.invokes and a CallSite for an invokedynamic
268 // instruction. However, its exact type and use depends on the Java upcall,
269 // which simply returns a compiled LambdaForm along with any reference
270 // that LambdaForm needs to complete the call. If the upcall returns a
271 // null appendix, the argument is not passed at all.
272 //
273 // The appendix is *not* represented in the signature of the symbolic
274 // reference for the call site, but (if present) it *is* represented in
275 // the Method* bound to the site. This means that static and dynamic
276 // resolution logic needs to make slightly different assessments about the
277 // number and types of arguments.
278 void set_method_handle_common(
279 constantPoolHandle cpool, // holding constant pool (required for locking)
280 Bytecodes::Code invoke_code, // _invokehandle or _invokedynamic
281 const CallInfo &call_info // Call link information
282 );
283
284 // invokedynamic and invokehandle call sites have two entries in the
285 // resolved references array:
286 // appendix (at index+0)
287 // MethodType (at index+1)
288 enum {
289 _indy_resolved_references_appendix_offset = 0,
290 _indy_resolved_references_method_type_offset = 1,
291 _indy_resolved_references_entries
292 };
293
294 Method* method_if_resolved(constantPoolHandle cpool);
295 oop appendix_if_resolved(constantPoolHandle cpool);
296 oop method_type_if_resolved(constantPoolHandle cpool);
297
298 void set_parameter_size(int value);
299
300 // Which bytecode number (1 or 2) in the index field is valid for this bytecode?
301 // Returns -1 if neither is valid.
302 static int bytecode_number(Bytecodes::Code code) {
303 switch (code) {
304 case Bytecodes::_getstatic : // fall through
305 case Bytecodes::_getfield : // fall through
306 case Bytecodes::_invokespecial : // fall through
307 case Bytecodes::_invokestatic : // fall through
308 case Bytecodes::_invokehandle : // fall through
309 case Bytecodes::_invokedynamic : // fall through
310 case Bytecodes::_invokeinterface : return 1;
311 case Bytecodes::_putstatic : // fall through
312 case Bytecodes::_putfield : // fall through
313 case Bytecodes::_invokevirtual : return 2;
314 default : break;
315 }
316 return -1;
317 }
318
319 // Has this bytecode been resolved? Only valid for invokes and get/put field/static.
320 bool is_resolved(Bytecodes::Code code) const {
321 switch (bytecode_number(code)) {
322 case 1: return (bytecode_1() == code);
323 case 2: return (bytecode_2() == code);
324 }
325 return false; // default: not resolved
326 }
327
328 // Accessors
329 int indices() const { return _indices; }
330 int indices_ord() const { return (intx)OrderAccess::load_ptr_acquire(&_indices); }
331 int constant_pool_index() const { return (indices() & cp_index_mask); }
332 Bytecodes::Code bytecode_1() const { return Bytecodes::cast((indices_ord() >> bytecode_1_shift) & bytecode_1_mask); }
333 Bytecodes::Code bytecode_2() const { return Bytecodes::cast((indices_ord() >> bytecode_2_shift) & bytecode_2_mask); }
334 Metadata* f1_ord() const { return (Metadata *)OrderAccess::load_ptr_acquire(&_f1); }
335 Method* f1_as_method() const { Metadata* f1 = f1_ord(); assert(f1 == NULL || f1->is_method(), ""); return (Method*)f1; }
336 Klass* f1_as_klass() const { Metadata* f1 = f1_ord(); assert(f1 == NULL || f1->is_klass(), ""); return (Klass*)f1; }
337 // Use the accessor f1() to acquire _f1's value. This is needed for
338 // example in BytecodeInterpreter::run(), where is_f1_null() is
339 // called to check if an invokedynamic call is resolved. This load
340 // of _f1 must be ordered with the loads performed by
341 // cache->main_entry_index().
342 bool is_f1_null() const { Metadata* f1 = f1_ord(); return f1 == NULL; } // classifies a CPC entry as unbound
343 int f2_as_index() const { assert(!is_vfinal(), ""); return (int) _f2; }
344 Method* f2_as_vfinal_method() const { assert(is_vfinal(), ""); return (Method*)_f2; }
345 int field_index() const { assert(is_field_entry(), ""); return (_flags & field_index_mask); }
346 int parameter_size() const { assert(is_method_entry(), ""); return (_flags & parameter_size_mask); }
347 bool is_volatile() const { return (_flags & (1 << is_volatile_shift)) != 0; }
348 bool is_final() const { return (_flags & (1 << is_final_shift)) != 0; }
349 bool is_forced_virtual() const { return (_flags & (1 << is_forced_virtual_shift)) != 0; }
350 bool is_vfinal() const { return (_flags & (1 << is_vfinal_shift)) != 0; }
351 bool has_appendix() const { return (_flags & (1 << has_appendix_shift)) != 0; }
352 bool has_method_type() const { return (_flags & (1 << has_method_type_shift)) != 0; }
353 bool is_method_entry() const { return (_flags & (1 << is_field_entry_shift)) == 0; }
354 bool is_field_entry() const { return (_flags & (1 << is_field_entry_shift)) != 0; }
355 bool is_byte() const { return flag_state() == btos; }
356 bool is_char() const { return flag_state() == ctos; }
357 bool is_short() const { return flag_state() == stos; }
358 bool is_int() const { return flag_state() == itos; }
359 bool is_long() const { return flag_state() == ltos; }
360 bool is_float() const { return flag_state() == ftos; }
361 bool is_double() const { return flag_state() == dtos; }
362 bool is_object() const { return flag_state() == atos; }
363 TosState flag_state() const { assert((uint)number_of_states <= (uint)tos_state_mask+1, "");
364 return (TosState)((_flags >> tos_state_shift) & tos_state_mask); }
365
366 // Code generation support
367 static WordSize size() { return in_WordSize(sizeof(ConstantPoolCacheEntry) / HeapWordSize); }
368 static ByteSize size_in_bytes() { return in_ByteSize(sizeof(ConstantPoolCacheEntry)); }
369 static ByteSize indices_offset() { return byte_offset_of(ConstantPoolCacheEntry, _indices); }
370 static ByteSize f1_offset() { return byte_offset_of(ConstantPoolCacheEntry, _f1); }
371 static ByteSize f2_offset() { return byte_offset_of(ConstantPoolCacheEntry, _f2); }
372 static ByteSize flags_offset() { return byte_offset_of(ConstantPoolCacheEntry, _flags); }
373
374 #if INCLUDE_JVMTI
375 // RedefineClasses() API support:
376 // If this ConstantPoolCacheEntry refers to old_method then update it
377 // to refer to new_method.
378 // trace_name_printed is set to true if the current call has
379 // printed the klass name so that other routines in the adjust_*
380 // group don't print the klass name.
381 bool adjust_method_entry(Method* old_method, Method* new_method,
382 bool * trace_name_printed);
383 bool check_no_old_or_obsolete_entries();
384 bool is_interesting_method_entry(Klass* k);
385 #endif // INCLUDE_JVMTI
386
387 // Debugging & Printing
388 void print (outputStream* st, int index) const;
389 void verify(outputStream* st) const;
390
391 static void verify_tos_state_shift() {
392 // When shifting flags as a 32-bit int, make sure we don't need an extra mask for tos_state:
393 assert((((u4)-1 >> tos_state_shift) & ~tos_state_mask) == 0, "no need for tos_state mask");
394 }
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 int _length;
408 ConstantPool* _constant_pool; // the corresponding constant pool
409
410 // Sizing
411 debug_only(friend class ClassVerifier;)
412
413 // Constructor
414 ConstantPoolCache(int length,
415 const intStack& inverse_index_map,
416 const intStack& invokedynamic_inverse_index_map,
417 const intStack& invokedynamic_references_map) :
418 _length(length),
419 _constant_pool(NULL) {
420 initialize(inverse_index_map, invokedynamic_inverse_index_map,
421 invokedynamic_references_map);
422 for (int i = 0; i < length; i++) {
423 assert(entry_at(i)->is_f1_null(), "Failed to clear?");
424 }
425 }
426
427 // Initialization
428 void initialize(const intArray& inverse_index_map,
429 const intArray& invokedynamic_inverse_index_map,
430 const intArray& invokedynamic_references_map);
431 public:
432 static ConstantPoolCache* allocate(ClassLoaderData* loader_data,
433 const intStack& cp_cache_map,
434 const intStack& invokedynamic_cp_cache_map,
435 const intStack& invokedynamic_references_map, TRAPS);
436 bool is_constantPoolCache() const { return true; }
437
438 int length() const { return _length; }
439 private:
440 void set_length(int length) { _length = length; }
441
442 static int header_size() { return sizeof(ConstantPoolCache) / HeapWordSize; }
443 static int size(int length) { return align_object_size(header_size() + length * in_words(ConstantPoolCacheEntry::size())); }
444 public:
445 int size() const { return size(length()); }
446 private:
447
448 // Helpers
449 ConstantPool** constant_pool_addr() { return &_constant_pool; }
450 ConstantPoolCacheEntry* base() const { return (ConstantPoolCacheEntry*)((address)this + in_bytes(base_offset())); }
451
452 friend class constantPoolCacheKlass;
453 friend class ConstantPoolCacheEntry;
454
455 public:
456 // Accessors
457 void set_constant_pool(ConstantPool* pool) { _constant_pool = pool; }
458 ConstantPool* constant_pool() const { return _constant_pool; }
459 // Fetches the entry at the given index.
460 // In either case the index must not be encoded or byte-swapped in any way.
461 ConstantPoolCacheEntry* entry_at(int i) const {
462 assert(0 <= i && i < length(), "index out of bounds");
463 return base() + i;
464 }
465
466 // Code generation
467 static ByteSize base_offset() { return in_ByteSize(sizeof(ConstantPoolCache)); }
468 static ByteSize entry_offset(int raw_index) {
469 int index = raw_index;
470 return (base_offset() + ConstantPoolCacheEntry::size_in_bytes() * index);
471 }
472
473 #if INCLUDE_JVMTI
474 // RedefineClasses() API support:
475 // If any entry of this ConstantPoolCache points to any of
476 // old_methods, replace it with the corresponding new_method.
477 // trace_name_printed is set to true if the current call has
478 // printed the klass name so that other routines in the adjust_*
479 // group don't print the klass name.
480 void adjust_method_entries(Method** old_methods, Method** new_methods,
481 int methods_length, bool * trace_name_printed);
482 bool check_no_old_or_obsolete_entries();
483 void dump_cache();
484 #endif // INCLUDE_JVMTI
485
486 // Deallocate - no fields to deallocate
487 DEBUG_ONLY(bool on_stack() { return false; })
488 void deallocate_contents(ClassLoaderData* data) {}
489 bool is_klass() const { return false; }
490
491 // Printing
492 void print_on(outputStream* st) const;
493 void print_value_on(outputStream* st) const;
494
495 const char* internal_name() const { return "{constant pool cache}"; }
496
497 // Verify
498 void verify_on(outputStream* st);
499 };
500
501 #endif // SHARE_VM_OOPS_CPCACHEOOP_HPP