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