1 /*
2 * Copyright (c) 1998, 2019, 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_OOPS_CPCACHE_HPP
26 #define SHARE_OOPS_CPCACHE_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/handles.hpp"
33 #include "utilities/align.hpp"
34 #include "utilities/constantTag.hpp"
35 #include "utilities/growableArray.hpp"
36
37 class PSPromotionManager;
38
39 // The ConstantPoolCache is not a cache! It is the resolution table that the
40 // interpreter uses to avoid going into the runtime and a way to access resolved
41 // values.
42
43 // A ConstantPoolCacheEntry describes an individual entry of the constant
44 // pool cache. There's 2 principal kinds of entries: field entries for in-
45 // stance & static field access, and method entries for invokes. Some of
46 // the entry layout is shared and looks as follows:
47 //
48 // bit number |31 0|
49 // bit length |-8--|-8--|---16----|
50 // --------------------------------
51 // _indices [ b2 | b1 | index ] index = constant_pool_index
52 // _f1 [ entry specific ] metadata ptr (method or klass)
53 // _f2 [ entry specific ] vtable or res_ref index, or vfinal method ptr
54 // _flags [tos|0|F=1|0|0|0|f|v|0 |0000|field_index] (for field entries)
55 // bit length [ 4 |1| 1 |1|1|1|1|1|1 |1 |-3-|----16-----]
56 // _flags [tos|0|F=0|S|A|I|f|0|vf|indy_rf|000|00000|psize] (for method entries)
57 // bit length [ 4 |1| 1 |1|1|1|1|1|1 |-4--|--8--|--8--]
58
59 // --------------------------------
60 //
61 // with:
62 // index = original constant pool index
63 // b1 = bytecode 1
64 // b2 = bytecode 2
65 // psize = parameters size (method entries only)
66 // field_index = index into field information in holder InstanceKlass
67 // The index max is 0xffff (max number of fields in constant pool)
68 // and is multiplied by (InstanceKlass::next_offset) when accessing.
69 // tos = TosState
70 // F = the entry is for a field (or F=0 for a method)
71 // A = call site has an appendix argument (loaded from resolved references)
72 // I = interface call is forced virtual (must use a vtable index or vfinal)
73 // f = field or method is final
74 // v = field is volatile
75 // vf = virtual but final (method entries only: is_vfinal())
76 // indy_rf = call site specifier method resolution failed
77 //
78 // The flags after TosState have the following interpretation:
79 // bit 27: 0 for fields, 1 for methods
80 // f flag true if field is marked final
81 // v flag true if field is volatile (only for fields)
82 // f2 flag true if f2 contains an oop (e.g., virtual final method)
83 // fv flag true if invokeinterface used for method in class Object
84 //
85 // The flags 31, 30, 29, 28 together build a 4 bit number 0 to 16 with the
86 // following mapping to the TosState states:
87 //
88 // btos: 0
89 // ztos: 1
90 // ctos: 2
91 // stos: 3
92 // itos: 4
93 // ltos: 5
94 // ftos: 6
95 // dtos: 7
96 // atos: 8
97 // vtos: 9
98 //
99 // Entry specific: field entries:
100 // _indices = get (b1 section) and put (b2 section) bytecodes, original constant pool index
101 // _f1 = field holder (as a java.lang.Class, not a Klass*)
102 // _f2 = field offset in bytes
103 // _flags = field type information, original FieldInfo index in field holder
104 // (field_index section)
105 //
106 // Entry specific: method entries:
107 // _indices = invoke code for f1 (b1 section), invoke code for f2 (b2 section),
108 // original constant pool index
109 // _f1 = Method* for non-virtual calls, unused by virtual calls.
110 // for interface calls, which are essentially virtual but need a klass,
111 // contains Klass* for the corresponding interface.
112 // for invokedynamic and invokehandle, f1 contains the adapter method which
113 // manages the actual call. The appendix is stored in the ConstantPool
114 // resolved_references array.
115 // (upcoming metadata changes will move the appendix to a separate array)
116 // _f2 = vtable/itable index (or final Method*) for virtual calls only,
117 // unused by non-virtual. The is_vfinal flag indicates this is a
118 // method pointer for a final method, not an index.
119 // _flags = has local signature (MHs and indy),
120 // virtual final bit (vfinal),
121 // parameter size (psize section)
122 //
123 // Note: invokevirtual & invokespecial bytecodes can share the same constant
124 // pool entry and thus the same constant pool cache entry. All invoke
125 // bytecodes but invokevirtual use only _f1 and the corresponding b1
126 // bytecode, while invokevirtual uses only _f2 and the corresponding
127 // b2 bytecode. The value of _flags is shared for both types of entries.
128 //
129 // The fields are volatile so that they are stored in the order written in the
130 // source code. The _indices field with the bytecode must be written last.
131
132 class CallInfo;
133
134 class ConstantPoolCacheEntry {
135 friend class VMStructs;
136 friend class constantPoolCacheKlass;
137 friend class ConstantPool;
138 friend class InterpreterRuntime;
139
140 private:
141 volatile intx _indices; // constant pool index & rewrite bytecodes
142 Metadata* volatile _f1; // entry specific metadata field
143 volatile intx _f2; // entry specific int/metadata field
144 volatile intx _flags; // flags
145
146
147 void set_bytecode_1(Bytecodes::Code code);
148 void set_bytecode_2(Bytecodes::Code code);
149 void set_f1(Metadata* f1) {
150 Metadata* existing_f1 = _f1; // read once
151 assert(existing_f1 == NULL || existing_f1 == f1, "illegal field change");
152 _f1 = f1;
153 }
154 void release_set_f1(Metadata* f1);
155 void set_f2(intx f2) {
156 intx existing_f2 = _f2; // read once
157 assert(existing_f2 == 0 || existing_f2 == f2, "illegal field change");
158 _f2 = f2;
159 }
160 void set_f2_as_vfinal_method(Method* f2) {
161 assert(is_vfinal(), "flags must be set");
162 set_f2((intx)f2);
163 }
164 int make_flags(TosState state, int option_bits, int field_index_or_method_params);
165 void set_flags(intx flags) { _flags = flags; }
166 void set_field_flags(TosState field_type, int option_bits, int field_index) {
167 assert((field_index & field_index_mask) == field_index, "field_index in range");
168 set_flags(make_flags(field_type, option_bits | (1 << is_field_entry_shift), field_index));
169 }
170 void set_method_flags(TosState return_type, int option_bits, int method_params) {
171 assert((method_params & parameter_size_mask) == method_params, "method_params in range");
172 set_flags(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_tsan_ignore_shift = 27, // Should the field be ignored by TSAN?
185 is_field_entry_shift = 26, // (F) is it a field or a method?
186 has_local_signature_shift = 25, // (S) does the call site have a per-site signature (sig-poly methods)?
187 has_appendix_shift = 24, // (A) does the call site have an appendix argument?
188 is_forced_virtual_shift = 23, // (I) is the interface reference forced to virtual mode?
189 is_final_shift = 22, // (f) is the field or method final?
190 is_volatile_shift = 21, // (v) is the field volatile?
191 is_vfinal_shift = 20, // (vf) did the call resolve to a final method?
192 indy_resolution_failed_shift= 19, // (indy_rf) did call site specifier resolution fail ?
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 bool is_tsan_ignore, // the field should be ignored by TSAN
229 Klass* root_klass // needed by the GC to dirty the klass
230 );
231
232 private:
233 void set_direct_or_vtable_call(
234 Bytecodes::Code invoke_code, // the bytecode used for invoking the method
235 const methodHandle& method, // the method/prototype if any (NULL, otherwise)
236 int vtable_index, // the vtable index if any, else negative
237 bool sender_is_interface
238 );
239
240 public:
241 void set_direct_call( // sets entry to exact concrete method entry
242 Bytecodes::Code invoke_code, // the bytecode used for invoking the method
243 const methodHandle& method, // the method to call
244 bool sender_is_interface
245 );
246
247 void set_vtable_call( // sets entry to vtable index
248 Bytecodes::Code invoke_code, // the bytecode used for invoking the method
249 const methodHandle& method, // resolved method which declares the vtable index
250 int vtable_index // the vtable index
251 );
252
253 void set_itable_call(
254 Bytecodes::Code invoke_code, // the bytecode used; must be invokeinterface
255 Klass* referenced_klass, // the referenced klass in the InterfaceMethodref
256 const methodHandle& method, // the resolved interface method
257 int itable_index // index into itable for the method
258 );
259
260 void set_method_handle(
261 const constantPoolHandle& cpool, // holding constant pool (required for locking)
262 const CallInfo &call_info // Call link information
263 );
264
265 void set_dynamic_call(
266 const constantPoolHandle& cpool, // holding constant pool (required for locking)
267 const CallInfo &call_info // Call link information
268 );
269
270 // Common code for invokedynamic and MH invocations.
271
272 // The "appendix" is an optional call-site-specific parameter which is
273 // pushed by the JVM at the end of the argument list. This argument may
274 // be a MethodType for the MH.invokes and a CallSite for an invokedynamic
275 // instruction. However, its exact type and use depends on the Java upcall,
276 // which simply returns a compiled LambdaForm along with any reference
277 // that LambdaForm needs to complete the call. If the upcall returns a
278 // null appendix, the argument is not passed at all.
279 //
280 // The appendix is *not* represented in the signature of the symbolic
281 // reference for the call site, but (if present) it *is* represented in
282 // the Method* bound to the site. This means that static and dynamic
283 // resolution logic needs to make slightly different assessments about the
284 // number and types of arguments.
285 void set_method_handle_common(
286 const constantPoolHandle& cpool, // holding constant pool (required for locking)
287 Bytecodes::Code invoke_code, // _invokehandle or _invokedynamic
288 const CallInfo &call_info // Call link information
289 );
290
291 // Return TRUE if resolution failed and this thread got to record the failure
292 // status. Return FALSE if another thread succeeded or failed in resolving
293 // the method and recorded the success or failure before this thread had a
294 // chance to record its failure.
295 bool save_and_throw_indy_exc(const constantPoolHandle& cpool, int cpool_index,
296 int index, constantTag tag, TRAPS);
297
298 // invokedynamic and invokehandle call sites have an "appendix" item in the
299 // resolved references array.
300 Method* method_if_resolved(const constantPoolHandle& cpool);
301 oop appendix_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
327 // Accessors
328 int indices() const { return _indices; }
329 int indices_ord() const;
330 int constant_pool_index() const { return (indices() & cp_index_mask); }
331 Bytecodes::Code bytecode_1() const;
332 Bytecodes::Code bytecode_2() const;
333 Metadata* f1_ord() const;
334 Method* f1_as_method() const;
335 Klass* f1_as_klass() const;
336 // Use the accessor f1() to acquire _f1's value. This is needed for
337 // example in BytecodeInterpreter::run(), where is_f1_null() is
338 // called to check if an invokedynamic call is resolved. This load
339 // of _f1 must be ordered with the loads performed by
340 // cache->main_entry_index().
341 bool is_f1_null() const; // classifies a CPC entry as unbound
342 int f2_as_index() const { assert(!is_vfinal(), ""); return (int) _f2; }
343 Method* f2_as_vfinal_method() const { assert(is_vfinal(), ""); return (Method*)_f2; }
344 Method* f2_as_interface_method() const;
345 intx flags_ord() const;
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 indy_resolution_failed() const;
353 bool has_appendix() const;
354 bool has_local_signature() const;
355 bool is_method_entry() const { return (_flags & (1 << is_field_entry_shift)) == 0; }
356 bool is_field_entry() const { return (_flags & (1 << is_field_entry_shift)) != 0; }
357 bool is_long() const { return flag_state() == ltos; }
358 bool is_double() const { return flag_state() == dtos; }
359 TosState flag_state() const { assert((uint)number_of_states <= (uint)tos_state_mask+1, "");
360 return (TosState)((_flags >> tos_state_shift) & tos_state_mask); }
361 void set_indy_resolution_failed();
362
363 // Code generation support
364 static WordSize size() {
365 return in_WordSize(align_up((int)sizeof(ConstantPoolCacheEntry), wordSize) / wordSize);
366 }
367 static ByteSize size_in_bytes() { return in_ByteSize(sizeof(ConstantPoolCacheEntry)); }
368 static ByteSize indices_offset() { return byte_offset_of(ConstantPoolCacheEntry, _indices); }
369 static ByteSize f1_offset() { return byte_offset_of(ConstantPoolCacheEntry, _f1); }
370 static ByteSize f2_offset() { return byte_offset_of(ConstantPoolCacheEntry, _f2); }
371 static ByteSize flags_offset() { return byte_offset_of(ConstantPoolCacheEntry, _flags); }
372
373 #if INCLUDE_JVMTI
374 // RedefineClasses() API support:
375 // If this ConstantPoolCacheEntry refers to old_method then update it
376 // to refer to new_method.
377 // trace_name_printed is set to true if the current call has
378 // printed the klass name so that other routines in the adjust_*
379 // group don't print the klass name.
380 void adjust_method_entry(Method* old_method, Method* new_method,
381 bool* trace_name_printed);
382 bool check_no_old_or_obsolete_entries();
383 Method* get_interesting_method_entry();
384 #endif // INCLUDE_JVMTI
385
386 // Debugging & Printing
387 void print (outputStream* st, int index) const;
388 void verify(outputStream* st) const;
389
390 static void verify_tos_state_shift() {
391 // When shifting flags as a 32-bit int, make sure we don't need an extra mask for tos_state:
392 assert((((u4)-1 >> tos_state_shift) & ~tos_state_mask) == 0, "no need for tos_state mask");
393 }
394
395 void verify_just_initialized(bool f2_used);
396 void reinitialize(bool f2_used);
397 };
398
399
400 // A constant pool cache is a runtime data structure set aside to a constant pool. The cache
401 // holds interpreter runtime information for all field access and invoke bytecodes. The cache
402 // is created and initialized before a class is actively used (i.e., initialized), the indivi-
403 // dual cache entries are filled at resolution (i.e., "link") time (see also: rewriter.*).
404
405 class ConstantPoolCache: public MetaspaceObj {
406 friend class VMStructs;
407 friend class MetadataFactory;
408 private:
409 // If you add a new field that points to any metaspace object, you
410 // must add this field to ConstantPoolCache::metaspace_pointers_do().
411 int _length;
412 ConstantPool* _constant_pool; // the corresponding constant pool
413
414 // The following fields need to be modified at runtime, so they cannot be
415 // stored in the ConstantPool, which is read-only.
416 // Array of resolved objects from the constant pool and map from resolved
417 // object index to original constant pool index
418 OopHandle _resolved_references;
419 Array<u2>* _reference_map;
420 // The narrowOop pointer to the archived resolved_references. Set at CDS dump
421 // time when caching java heap object is supported.
422 CDS_JAVA_HEAP_ONLY(narrowOop _archived_references;)
423
424 // Sizing
425 debug_only(friend class ClassVerifier;)
426
427 // Constructor
428 ConstantPoolCache(int length,
429 const intStack& inverse_index_map,
430 const intStack& invokedynamic_inverse_index_map,
431 const intStack& invokedynamic_references_map);
432
433 // Initialization
434 void initialize(const intArray& inverse_index_map,
435 const intArray& invokedynamic_inverse_index_map,
436 const intArray& invokedynamic_references_map);
437 public:
438 static ConstantPoolCache* allocate(ClassLoaderData* loader_data,
439 const intStack& cp_cache_map,
440 const intStack& invokedynamic_cp_cache_map,
441 const intStack& invokedynamic_references_map, TRAPS);
442
443 int length() const { return _length; }
444 void metaspace_pointers_do(MetaspaceClosure* it);
445 MetaspaceObj::Type type() const { return ConstantPoolCacheType; }
446
447 oop archived_references() NOT_CDS_JAVA_HEAP_RETURN_(NULL);
448 void set_archived_references(oop o) NOT_CDS_JAVA_HEAP_RETURN;
449
450 inline oop resolved_references();
451 void set_resolved_references(OopHandle s) { _resolved_references = s; }
452 Array<u2>* reference_map() const { return _reference_map; }
453 void set_reference_map(Array<u2>* o) { _reference_map = o; }
454
455 // Assembly code support
456 static int resolved_references_offset_in_bytes() { return offset_of(ConstantPoolCache, _resolved_references); }
457
458 // CDS support
459 void remove_unshareable_info();
460 void verify_just_initialized();
461 private:
462 void walk_entries_for_initialization(bool check_only);
463 void set_length(int length) { _length = length; }
464
465 static int header_size() { return sizeof(ConstantPoolCache) / wordSize; }
466 static int size(int length) { return align_metadata_size(header_size() + length * in_words(ConstantPoolCacheEntry::size())); }
467 public:
468 int size() const { return size(length()); }
469 private:
470
471 // Helpers
472 ConstantPool** constant_pool_addr() { return &_constant_pool; }
473 ConstantPoolCacheEntry* base() const { return (ConstantPoolCacheEntry*)((address)this + in_bytes(base_offset())); }
474
475 friend class constantPoolCacheKlass;
476 friend class ConstantPoolCacheEntry;
477
478 public:
479 // Accessors
480 void set_constant_pool(ConstantPool* pool) { _constant_pool = pool; }
481 ConstantPool* constant_pool() const { return _constant_pool; }
482 // Fetches the entry at the given index.
483 // In either case the index must not be encoded or byte-swapped in any way.
484 ConstantPoolCacheEntry* entry_at(int i) const {
485 assert(0 <= i && i < length(), "index out of bounds");
486 return base() + i;
487 }
488
489 // Code generation
490 static ByteSize base_offset() { return in_ByteSize(sizeof(ConstantPoolCache)); }
491 static ByteSize entry_offset(int raw_index) {
492 int index = raw_index;
493 return (base_offset() + ConstantPoolCacheEntry::size_in_bytes() * index);
494 }
495
496 #if INCLUDE_JVMTI
497 // RedefineClasses() API support:
498 // If any entry of this ConstantPoolCache points to any of
499 // old_methods, replace it with the corresponding new_method.
500 // trace_name_printed is set to true if the current call has
501 // printed the klass name so that other routines in the adjust_*
502 // group don't print the klass name.
503 void adjust_method_entries(bool* trace_name_printed);
504 bool check_no_old_or_obsolete_entries();
505 void dump_cache();
506 #endif // INCLUDE_JVMTI
507
508 // RedefineClasses support
509 DEBUG_ONLY(bool on_stack() { return false; })
510 void deallocate_contents(ClassLoaderData* data);
511 bool is_klass() const { return false; }
512
513 // Printing
514 void print_on(outputStream* st) const;
515 void print_value_on(outputStream* st) const;
516
517 const char* internal_name() const { return "{constant pool cache}"; }
518
519 // Verify
520 void verify_on(outputStream* st);
521 };
522
523 #endif // SHARE_OOPS_CPCACHE_HPP