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.
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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 16 with the
81 // following mapping to the TosState states:
82 //
83 // btos: 0
84 // ztos: 1
85 // ctos: 2
86 // stos: 3
87 // itos: 4
88 // ltos: 5
89 // ftos: 6
90 // dtos: 7
91 // atos: 8
92 // vtos: 9
93 //
94 // Entry specific: field entries:
95 // _indices = get (b1 section) and put (b2 section) bytecodes, original constant pool index
96 // _f1 = field holder (as a java.lang.Class, not a Klass*)
97 // _f2 = field offset in bytes
98 // _flags = field type information, original FieldInfo index in field holder
99 // (field_index section)
100 //
101 // Entry specific: method entries:
102 // _indices = invoke code for f1 (b1 section), invoke code for f2 (b2 section),
103 // original constant pool index
104 // _f1 = Method* for non-virtual calls, unused by virtual calls.
105 // for interface calls, which are essentially virtual but need a klass,
106 // contains Klass* for the corresponding interface.
107 // for invokedynamic and invokehandle, f1 contains the adapter method which
108 // manages the actual call. The appendix is stored in the ConstantPool
109 // resolved_references array.
110 // (upcoming metadata changes will move the appendix to a separate array)
111 // _f2 = vtable/itable index (or final Method*) for virtual calls only,
112 // unused by non-virtual. The is_vfinal flag indicates this is a
113 // method pointer for a final method, not an index.
114 // _flags = method type info (t section),
115 // virtual final bit (vfinal),
116 // parameter size (psize section)
117 //
118 // Note: invokevirtual & invokespecial bytecodes can share the same constant
119 // pool entry and thus the same constant pool cache entry. All invoke
120 // bytecodes but invokevirtual use only _f1 and the corresponding b1
121 // bytecode, while invokevirtual uses only _f2 and the corresponding
122 // b2 bytecode. The value of _flags is shared for both types of entries.
123 //
124 // The fields are volatile so that they are stored in the order written in the
125 // source code. The _indices field with the bytecode must be written last.
126
127 class CallInfo;
128
129 class ConstantPoolCacheEntry VALUE_OBJ_CLASS_SPEC {
130 friend class VMStructs;
131 friend class constantPoolCacheKlass;
132 friend class ConstantPool;
133 friend class InterpreterRuntime;
134
135 private:
136 volatile intx _indices; // constant pool index & rewrite bytecodes
137 volatile Metadata* _f1; // entry specific metadata field
138 volatile intx _f2; // entry specific int/metadata field
139 volatile intx _flags; // flags
140
141
142 void set_bytecode_1(Bytecodes::Code code);
143 void set_bytecode_2(Bytecodes::Code code);
144 void set_f1(Metadata* f1) {
145 Metadata* existing_f1 = (Metadata*)_f1; // read once
146 assert(existing_f1 == NULL || existing_f1 == f1, "illegal field change");
147 _f1 = f1;
148 }
149 void release_set_f1(Metadata* f1);
150 void set_f2(intx f2) {
151 intx existing_f2 = _f2; // read once
152 assert(existing_f2 == 0 || existing_f2 == f2, "illegal field change");
153 _f2 = f2;
154 }
155 void set_f2_as_vfinal_method(Method* f2) {
156 assert(is_vfinal(), "flags must be set");
157 set_f2((intx)f2);
158 }
159 int make_flags(TosState state, int option_bits, int field_index_or_method_params);
160 void set_flags(intx flags) { _flags = flags; }
161 bool init_flags_atomic(intx flags);
162 void set_field_flags(TosState field_type, int option_bits, int field_index) {
163 assert((field_index & field_index_mask) == field_index, "field_index in range");
164 set_flags(make_flags(field_type, option_bits | (1 << is_field_entry_shift), field_index));
165 }
166 void set_method_flags(TosState return_type, int option_bits, int method_params) {
167 assert((method_params & parameter_size_mask) == method_params, "method_params in range");
168 set_flags(make_flags(return_type, option_bits, method_params));
169 }
170 bool init_method_flags_atomic(TosState return_type, int option_bits, int method_params) {
171 assert((method_params & parameter_size_mask) == method_params, "method_params in range");
172 return init_flags_atomic(make_flags(return_type, option_bits, method_params));
173 }
174
175 public:
176 // specific bit definitions for the flags field:
177 // (Note: the interpreter must use these definitions to access the CP cache.)
178 enum {
179 // high order bits are the TosState corresponding to field type or method return type
180 tos_state_bits = 4,
181 tos_state_mask = right_n_bits(tos_state_bits),
182 tos_state_shift = BitsPerInt - tos_state_bits, // see verify_tos_state_shift below
183 // misc. option bits; can be any bit position in [16..27]
184 is_field_entry_shift = 26, // (F) is it a field or a method?
185 has_method_type_shift = 25, // (M) does the call site have a MethodType?
186 has_appendix_shift = 24, // (A) does the call site have an appendix argument?
187 is_forced_virtual_shift = 23, // (I) is the interface reference forced to virtual mode?
188 is_final_shift = 22, // (f) is the field or method final?
189 is_volatile_shift = 21, // (v) is the field volatile?
190 is_vfinal_shift = 20, // (vf) did the call resolve to a final method?
191 // low order bits give field index (for FieldInfo) or method parameter size:
192 field_index_bits = 16,
193 field_index_mask = right_n_bits(field_index_bits),
194 parameter_size_bits = 8, // subset of field_index_mask, range is 0..255
195 parameter_size_mask = right_n_bits(parameter_size_bits),
196 option_bits_mask = ~(((~0u) << tos_state_shift) | (field_index_mask | parameter_size_mask))
197 };
198
199 // specific bit definitions for the indices field:
200 enum {
201 cp_index_bits = 2*BitsPerByte,
202 cp_index_mask = right_n_bits(cp_index_bits),
203 bytecode_1_shift = cp_index_bits,
204 bytecode_1_mask = right_n_bits(BitsPerByte), // == (u1)0xFF
205 bytecode_2_shift = cp_index_bits + BitsPerByte,
206 bytecode_2_mask = right_n_bits(BitsPerByte) // == (u1)0xFF
207 };
208
209
210 // Initialization
211 void initialize_entry(int original_index); // initialize primary entry
212 void initialize_resolved_reference_index(int ref_index) {
213 assert(_f2 == 0, "set once"); // note: ref_index might be zero also
214 _f2 = ref_index;
215 }
216
217 void set_field( // sets entry to resolved field state
218 Bytecodes::Code get_code, // the bytecode used for reading the field
219 Bytecodes::Code put_code, // the bytecode used for writing the field
220 Klass* field_holder, // the object/klass holding the field
221 int orig_field_index, // the original field index in the field holder
222 int field_offset, // the field offset in words in the field holder
223 TosState field_type, // the (machine) field type
224 bool is_final, // the field is final
225 bool is_volatile, // the field is volatile
226 Klass* root_klass // needed by the GC to dirty the klass
227 );
228
229 private:
230 void set_direct_or_vtable_call(
231 Bytecodes::Code invoke_code, // the bytecode used for invoking the method
232 methodHandle method, // the method/prototype if any (NULL, otherwise)
233 int vtable_index // the vtable index if any, else negative
234 );
235
236 public:
237 void set_direct_call( // sets entry to exact concrete method entry
238 Bytecodes::Code invoke_code, // the bytecode used for invoking the method
239 methodHandle method // the method to call
240 );
241
242 void set_vtable_call( // sets entry to vtable index
243 Bytecodes::Code invoke_code, // the bytecode used for invoking the method
244 methodHandle method, // resolved method which declares the vtable index
245 int vtable_index // the vtable index
246 );
247
248 void set_itable_call(
249 Bytecodes::Code invoke_code, // the bytecode used; must be invokeinterface
250 const methodHandle& method, // the resolved interface method
251 int itable_index // index into itable for the method
252 );
253
254 void set_method_handle(
255 const constantPoolHandle& cpool, // holding constant pool (required for locking)
256 const CallInfo &call_info // Call link information
257 );
258
259 void set_dynamic_call(
260 const constantPoolHandle& cpool, // holding constant pool (required for locking)
261 const CallInfo &call_info // Call link information
262 );
263
264 // Common code for invokedynamic and MH invocations.
265
266 // The "appendix" is an optional call-site-specific parameter which is
267 // pushed by the JVM at the end of the argument list. This argument may
268 // be a MethodType for the MH.invokes and a CallSite for an invokedynamic
269 // instruction. However, its exact type and use depends on the Java upcall,
270 // which simply returns a compiled LambdaForm along with any reference
271 // that LambdaForm needs to complete the call. If the upcall returns a
272 // null appendix, the argument is not passed at all.
273 //
274 // The appendix is *not* represented in the signature of the symbolic
275 // reference for the call site, but (if present) it *is* represented in
276 // the Method* bound to the site. This means that static and dynamic
277 // resolution logic needs to make slightly different assessments about the
278 // number and types of arguments.
279 void set_method_handle_common(
280 const constantPoolHandle& cpool, // holding constant pool (required for locking)
281 Bytecodes::Code invoke_code, // _invokehandle or _invokedynamic
282 const CallInfo &call_info // Call link information
283 );
284
285 // invokedynamic and invokehandle call sites have two entries in the
286 // resolved references array:
287 // appendix (at index+0)
288 // MethodType (at index+1)
289 enum {
290 _indy_resolved_references_appendix_offset = 0,
291 _indy_resolved_references_method_type_offset = 1,
292 _indy_resolved_references_entries
293 };
294
295 Method* method_if_resolved(const constantPoolHandle& cpool);
296 oop appendix_if_resolved(const constantPoolHandle& cpool);
297 oop method_type_if_resolved(const constantPoolHandle& cpool);
298
299 void set_parameter_size(int value);
300
301 // Which bytecode number (1 or 2) in the index field is valid for this bytecode?
302 // Returns -1 if neither is valid.
303 static int bytecode_number(Bytecodes::Code code) {
304 switch (code) {
305 case Bytecodes::_getstatic : // fall through
306 case Bytecodes::_getfield : // fall through
307 case Bytecodes::_invokespecial : // fall through
308 case Bytecodes::_invokestatic : // fall through
309 case Bytecodes::_invokehandle : // fall through
310 case Bytecodes::_invokedynamic : // fall through
311 case Bytecodes::_invokeinterface : return 1;
312 case Bytecodes::_putstatic : // fall through
313 case Bytecodes::_putfield : // fall through
314 case Bytecodes::_invokevirtual : return 2;
315 default : break;
316 }
317 return -1;
318 }
319
320 // Has this bytecode been resolved? Only valid for invokes and get/put field/static.
321 bool is_resolved(Bytecodes::Code code) const {
322 switch (bytecode_number(code)) {
323 case 1: return (bytecode_1() == code);
324 case 2: return (bytecode_2() == code);
325 }
326 return false; // default: not resolved
327 }
328
329 // Accessors
330 int indices() const { return _indices; }
331 int indices_ord() const { return (intx)OrderAccess::load_ptr_acquire(&_indices); }
332 int constant_pool_index() const { return (indices() & cp_index_mask); }
333 Bytecodes::Code bytecode_1() const { return Bytecodes::cast((indices_ord() >> bytecode_1_shift) & bytecode_1_mask); }
334 Bytecodes::Code bytecode_2() const { return Bytecodes::cast((indices_ord() >> bytecode_2_shift) & bytecode_2_mask); }
335 Metadata* f1_ord() const { return (Metadata *)OrderAccess::load_ptr_acquire(&_f1); }
336 Method* f1_as_method() const { Metadata* f1 = f1_ord(); assert(f1 == NULL || f1->is_method(), ""); return (Method*)f1; }
337 Klass* f1_as_klass() const { Metadata* f1 = f1_ord(); assert(f1 == NULL || f1->is_klass(), ""); return (Klass*)f1; }
338 // Use the accessor f1() to acquire _f1's value. This is needed for
339 // example in BytecodeInterpreter::run(), where is_f1_null() is
340 // called to check if an invokedynamic call is resolved. This load
341 // of _f1 must be ordered with the loads performed by
342 // cache->main_entry_index().
343 bool is_f1_null() const { Metadata* f1 = f1_ord(); return f1 == NULL; } // classifies a CPC entry as unbound
344 int f2_as_index() const { assert(!is_vfinal(), ""); return (int) _f2; }
345 Method* f2_as_vfinal_method() const { assert(is_vfinal(), ""); return (Method*)_f2; }
346 int field_index() const { assert(is_field_entry(), ""); return (_flags & field_index_mask); }
347 int parameter_size() const { assert(is_method_entry(), ""); return (_flags & parameter_size_mask); }
348 bool is_volatile() const { return (_flags & (1 << is_volatile_shift)) != 0; }
349 bool is_final() const { return (_flags & (1 << is_final_shift)) != 0; }
350 bool is_forced_virtual() const { return (_flags & (1 << is_forced_virtual_shift)) != 0; }
351 bool is_vfinal() const { return (_flags & (1 << is_vfinal_shift)) != 0; }
352 bool has_appendix() const { return (!is_f1_null()) && (_flags & (1 << has_appendix_shift)) != 0; }
353 bool has_method_type() const { return (!is_f1_null()) && (_flags & (1 << has_method_type_shift)) != 0; }
354 bool is_method_entry() const { return (_flags & (1 << is_field_entry_shift)) == 0; }
355 bool is_field_entry() const { return (_flags & (1 << is_field_entry_shift)) != 0; }
356 bool is_long() const { return flag_state() == ltos; }
357 bool is_double() const { return flag_state() == dtos; }
358 TosState flag_state() const { assert((uint)number_of_states <= (uint)tos_state_mask+1, "");
359 return (TosState)((_flags >> tos_state_shift) & tos_state_mask); }
360
361 // Code generation support
362 static WordSize size() { return in_WordSize(sizeof(ConstantPoolCacheEntry) / wordSize); }
363 static ByteSize size_in_bytes() { return in_ByteSize(sizeof(ConstantPoolCacheEntry)); }
364 static ByteSize indices_offset() { return byte_offset_of(ConstantPoolCacheEntry, _indices); }
365 static ByteSize f1_offset() { return byte_offset_of(ConstantPoolCacheEntry, _f1); }
366 static ByteSize f2_offset() { return byte_offset_of(ConstantPoolCacheEntry, _f2); }
367 static ByteSize flags_offset() { return byte_offset_of(ConstantPoolCacheEntry, _flags); }
368
369 #if INCLUDE_JVMTI
370 // RedefineClasses() API support:
371 // If this ConstantPoolCacheEntry refers to old_method then update it
372 // to refer to new_method.
373 // trace_name_printed is set to true if the current call has
374 // printed the klass name so that other routines in the adjust_*
375 // group don't print the klass name.
376 bool adjust_method_entry(Method* old_method, Method* new_method,
377 bool* trace_name_printed);
378 bool check_no_old_or_obsolete_entries();
379 Method* get_interesting_method_entry(Klass* k);
380 #endif // INCLUDE_JVMTI
381
382 // Debugging & Printing
383 void print (outputStream* st, int index) const;
384 void verify(outputStream* st) const;
385
386 static void verify_tos_state_shift() {
387 // When shifting flags as a 32-bit int, make sure we don't need an extra mask for tos_state:
388 assert((((u4)-1 >> tos_state_shift) & ~tos_state_mask) == 0, "no need for tos_state mask");
389 }
390 };
391
392
393 // A constant pool cache is a runtime data structure set aside to a constant pool. The cache
394 // holds interpreter runtime information for all field access and invoke bytecodes. The cache
395 // is created and initialized before a class is actively used (i.e., initialized), the indivi-
396 // dual cache entries are filled at resolution (i.e., "link") time (see also: rewriter.*).
397
398 class ConstantPoolCache: public MetaspaceObj {
399 friend class VMStructs;
400 friend class MetadataFactory;
401 private:
402 int _length;
403 ConstantPool* _constant_pool; // the corresponding constant pool
404
405 // Sizing
406 debug_only(friend class ClassVerifier;)
407
408 // Constructor
409 ConstantPoolCache(int length,
410 const intStack& inverse_index_map,
411 const intStack& invokedynamic_inverse_index_map,
412 const intStack& invokedynamic_references_map) :
413 _length(length),
414 _constant_pool(NULL) {
415 initialize(inverse_index_map, invokedynamic_inverse_index_map,
416 invokedynamic_references_map);
417 for (int i = 0; i < length; i++) {
418 assert(entry_at(i)->is_f1_null(), "Failed to clear?");
419 }
420 }
421
422 // Initialization
423 void initialize(const intArray& inverse_index_map,
424 const intArray& invokedynamic_inverse_index_map,
425 const intArray& invokedynamic_references_map);
426 public:
427 static ConstantPoolCache* allocate(ClassLoaderData* loader_data,
428 const intStack& cp_cache_map,
429 const intStack& invokedynamic_cp_cache_map,
430 const intStack& invokedynamic_references_map, TRAPS);
431 bool is_constantPoolCache() const { return true; }
432
433 int length() const { return _length; }
434 private:
435 void set_length(int length) { _length = length; }
436
437 static int header_size() { return sizeof(ConstantPoolCache) / wordSize; }
438 static int size(int length) { return align_metadata_size(header_size() + length * in_words(ConstantPoolCacheEntry::size())); }
439 public:
440 int size() const { return size(length()); }
441 private:
442
443 // Helpers
444 ConstantPool** constant_pool_addr() { return &_constant_pool; }
445 ConstantPoolCacheEntry* base() const { return (ConstantPoolCacheEntry*)((address)this + in_bytes(base_offset())); }
446
447 friend class constantPoolCacheKlass;
448 friend class ConstantPoolCacheEntry;
449
450 public:
451 // Accessors
452 void set_constant_pool(ConstantPool* pool) { _constant_pool = pool; }
453 ConstantPool* constant_pool() const { return _constant_pool; }
454 // Fetches the entry at the given index.
455 // In either case the index must not be encoded or byte-swapped in any way.
456 ConstantPoolCacheEntry* entry_at(int i) const {
457 assert(0 <= i && i < length(), "index out of bounds");
458 return base() + i;
459 }
460
461 // Code generation
462 static ByteSize base_offset() { return in_ByteSize(sizeof(ConstantPoolCache)); }
463 static ByteSize entry_offset(int raw_index) {
464 int index = raw_index;
465 return (base_offset() + ConstantPoolCacheEntry::size_in_bytes() * index);
466 }
467
468 #if INCLUDE_JVMTI
469 // RedefineClasses() API support:
470 // If any entry of this ConstantPoolCache points to any of
471 // old_methods, replace it with the corresponding new_method.
472 // trace_name_printed is set to true if the current call has
473 // printed the klass name so that other routines in the adjust_*
474 // group don't print the klass name.
475 void adjust_method_entries(InstanceKlass* holder, bool* trace_name_printed);
476 bool check_no_old_or_obsolete_entries();
477 void dump_cache();
478 #endif // INCLUDE_JVMTI
479
480 // Deallocate - no fields to deallocate
481 DEBUG_ONLY(bool on_stack() { return false; })
482 void deallocate_contents(ClassLoaderData* data) {}
483 bool is_klass() const { return false; }
484
485 // Printing
486 void print_on(outputStream* st) const;
487 void print_value_on(outputStream* st) const;
488
489 const char* internal_name() const { return "{constant pool cache}"; }
490
491 // Verify
492 void verify_on(outputStream* st);
493 };
494
495 #endif // SHARE_VM_OOPS_CPCACHEOOP_HPP