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