1/*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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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
37class 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
132class CallInfo;
133
134class 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_field_entry_shift = 26, // (F) is it a field or a method?
185 has_local_signature_shift = 25, // (S) does the call site have a per-site signature (sig-poly methods)?
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 indy_resolution_failed_shift= 19, // (indy_rf) did call site specifier resolution fail ?
192 // low order bits give field index (for FieldInfo) or method parameter size:
193 field_index_bits = 16,
194 field_index_mask = right_n_bits(field_index_bits),
195 parameter_size_bits = 8, // subset of field_index_mask, range is 0..255
196 parameter_size_mask = right_n_bits(parameter_size_bits),
197 option_bits_mask = ~(((~0u) << tos_state_shift) | (field_index_mask | parameter_size_mask))
198 };
199
200 // specific bit definitions for the indices field:
201 enum {
202 cp_index_bits = 2*BitsPerByte,
203 cp_index_mask = right_n_bits(cp_index_bits),
204 bytecode_1_shift = cp_index_bits,
205 bytecode_1_mask = right_n_bits(BitsPerByte), // == (u1)0xFF
206 bytecode_2_shift = cp_index_bits + BitsPerByte,
207 bytecode_2_mask = right_n_bits(BitsPerByte) // == (u1)0xFF
208 };
209
210
211 // Initialization
212 void initialize_entry(int original_index); // initialize primary entry
213 void initialize_resolved_reference_index(int ref_index) {
214 assert(_f2 == 0, "set once"); // note: ref_index might be zero also
215 _f2 = ref_index;
216 }
217
218 void set_field( // sets entry to resolved field state
219 Bytecodes::Code get_code, // the bytecode used for reading the field
220 Bytecodes::Code put_code, // the bytecode used for writing the field
221 Klass* field_holder, // the object/klass holding the field
222 int orig_field_index, // the original field index in the field holder
223 int field_offset, // the field offset in words in the field holder
224 TosState field_type, // the (machine) field type
225 bool is_final, // the field is final
226 bool is_volatile, // the field is volatile
227 Klass* root_klass // needed by the GC to dirty the klass
228 );
229
230 private:
231 void set_direct_or_vtable_call(
232 Bytecodes::Code invoke_code, // the bytecode used for invoking the method
233 const methodHandle& method, // the method/prototype if any (NULL, otherwise)
234 int vtable_index, // the vtable index if any, else negative
235 bool sender_is_interface
236 );
237
238 public:
239 void set_direct_call( // sets entry to exact concrete method entry
240 Bytecodes::Code invoke_code, // the bytecode used for invoking the method
241 const methodHandle& method, // the method to call
242 bool sender_is_interface
243 );
244
245 void set_vtable_call( // sets entry to vtable index
246 Bytecodes::Code invoke_code, // the bytecode used for invoking the method
247 const methodHandle& method, // resolved method which declares the vtable index
248 int vtable_index // the vtable index
249 );
250
251 void set_itable_call(
252 Bytecodes::Code invoke_code, // the bytecode used; must be invokeinterface
253 Klass* referenced_klass, // the referenced klass in the InterfaceMethodref
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 // Return TRUE if resolution failed and this thread got to record the failure
290 // status. Return FALSE if another thread succeeded or failed in resolving
291 // the method and recorded the success or failure before this thread had a
292 // chance to record its failure.
293 bool save_and_throw_indy_exc(const constantPoolHandle& cpool, int cpool_index,
294 int index, constantTag tag, TRAPS);
295
296 // invokedynamic and invokehandle call sites have an "appendix" item in the
297 // resolved references array.
298 Method* method_if_resolved(const constantPoolHandle& cpool);
299 oop appendix_if_resolved(const constantPoolHandle& cpool);
300
301 void set_parameter_size(int value);
302
303 // Which bytecode number (1 or 2) in the index field is valid for this bytecode?
304 // Returns -1 if neither is valid.
305 static int bytecode_number(Bytecodes::Code code) {
306 switch (code) {
307 case Bytecodes::_getstatic : // fall through
308 case Bytecodes::_getfield : // fall through
309 case Bytecodes::_invokespecial : // fall through
310 case Bytecodes::_invokestatic : // fall through
311 case Bytecodes::_invokehandle : // fall through
312 case Bytecodes::_invokedynamic : // fall through
313 case Bytecodes::_invokeinterface : return 1;
314 case Bytecodes::_putstatic : // fall through
315 case Bytecodes::_putfield : // fall through
316 case Bytecodes::_invokevirtual : return 2;
317 default : break;
318 }
319 return -1;
320 }
321
322 // Has this bytecode been resolved? Only valid for invokes and get/put field/static.
323 bool is_resolved(Bytecodes::Code code) const;
324
325 // Accessors
326 int indices() const { return _indices; }
327 int indices_ord() const;
328 int constant_pool_index() const { return (indices() & cp_index_mask); }
329 Bytecodes::Code bytecode_1() const;
330 Bytecodes::Code bytecode_2() const;
331 Metadata* f1_ord() const;
332 Method* f1_as_method() const;
333 Klass* f1_as_klass() const;
334 // Use the accessor f1() to acquire _f1's value. This is needed for
335 // example in BytecodeInterpreter::run(), where is_f1_null() is
336 // called to check if an invokedynamic call is resolved. This load
337 // of _f1 must be ordered with the loads performed by
338 // cache->main_entry_index().
339 bool is_f1_null() const; // classifies a CPC entry as unbound
340 int f2_as_index() const { assert(!is_vfinal(), ""); return (int) _f2; }
341 Method* f2_as_vfinal_method() const { assert(is_vfinal(), ""); return (Method*)_f2; }
342 Method* f2_as_interface_method() const;
343 intx flags_ord() const;
344 int field_index() const { assert(is_field_entry(), ""); return (_flags & field_index_mask); }
345 int parameter_size() const { assert(is_method_entry(), ""); return (_flags & parameter_size_mask); }
346 bool is_volatile() const { return (_flags & (1 << is_volatile_shift)) != 0; }
347 bool is_final() const { return (_flags & (1 << is_final_shift)) != 0; }
348 bool is_forced_virtual() const { return (_flags & (1 << is_forced_virtual_shift)) != 0; }
349 bool is_vfinal() const { return (_flags & (1 << is_vfinal_shift)) != 0; }
350 bool indy_resolution_failed() const;
351 bool has_appendix() const;
352 bool has_local_signature() const;
353 bool is_method_entry() const { return (_flags & (1 << is_field_entry_shift)) == 0; }
354 bool is_field_entry() const { return (_flags & (1 << is_field_entry_shift)) != 0; }
355 bool is_long() const { return flag_state() == ltos; }
356 bool is_double() const { return flag_state() == dtos; }
357 TosState flag_state() const { assert((uint)number_of_states <= (uint)tos_state_mask+1, "");
358 return (TosState)((_flags >> tos_state_shift) & tos_state_mask); }
359 void set_indy_resolution_failed();
360
361 // Code generation support
362 static WordSize size() {
363 return in_WordSize(align_up((int)sizeof(ConstantPoolCacheEntry), wordSize) / wordSize);
364 }
365 static ByteSize size_in_bytes() { return in_ByteSize(sizeof(ConstantPoolCacheEntry)); }
366 static ByteSize indices_offset() { return byte_offset_of(ConstantPoolCacheEntry, _indices); }
367 static ByteSize f1_offset() { return byte_offset_of(ConstantPoolCacheEntry, _f1); }
368 static ByteSize f2_offset() { return byte_offset_of(ConstantPoolCacheEntry, _f2); }
369 static ByteSize flags_offset() { return byte_offset_of(ConstantPoolCacheEntry, _flags); }
370
371#if INCLUDE_JVMTI
372 // RedefineClasses() API support:
373 // If this ConstantPoolCacheEntry refers to old_method then update it
374 // to refer to new_method.
375 // trace_name_printed is set to true if the current call has
376 // printed the klass name so that other routines in the adjust_*
377 // group don't print the klass name.
378 void adjust_method_entry(Method* old_method, Method* new_method,
379 bool* trace_name_printed);
380 bool check_no_old_or_obsolete_entries();
381 Method* get_interesting_method_entry();
382#endif // INCLUDE_JVMTI
383
384 // Debugging & Printing
385 void print (outputStream* st, int index) const;
386 void verify(outputStream* st) const;
387
388 static void verify_tos_state_shift() {
389 // When shifting flags as a 32-bit int, make sure we don't need an extra mask for tos_state:
390 assert((((u4)-1 >> tos_state_shift) & ~tos_state_mask) == 0, "no need for tos_state mask");
391 }
392
393 void verify_just_initialized(bool f2_used);
394 void reinitialize(bool f2_used);
395};
396
397
398// A constant pool cache is a runtime data structure set aside to a constant pool. The cache
399// holds interpreter runtime information for all field access and invoke bytecodes. The cache
400// is created and initialized before a class is actively used (i.e., initialized), the indivi-
401// dual cache entries are filled at resolution (i.e., "link") time (see also: rewriter.*).
402
403class ConstantPoolCache: public MetaspaceObj {
404 friend class VMStructs;
405 friend class MetadataFactory;
406 private:
407 // If you add a new field that points to any metaspace object, you
408 // must add this field to ConstantPoolCache::metaspace_pointers_do().
409 int _length;
410 ConstantPool* _constant_pool; // the corresponding constant pool
411
412 // The following fields need to be modified at runtime, so they cannot be
413 // stored in the ConstantPool, which is read-only.
414 // Array of resolved objects from the constant pool and map from resolved
415 // object index to original constant pool index
416 OopHandle _resolved_references;
417 Array<u2>* _reference_map;
418 // The narrowOop pointer to the archived resolved_references. Set at CDS dump
419 // time when caching java heap object is supported.
420 CDS_JAVA_HEAP_ONLY(narrowOop _archived_references;)
421
422 // Sizing
423 debug_only(friend class ClassVerifier;)
424
425 // Constructor
426 ConstantPoolCache(int length,
427 const intStack& inverse_index_map,
428 const intStack& invokedynamic_inverse_index_map,
429 const intStack& invokedynamic_references_map);
430
431 // Initialization
432 void initialize(const intArray& inverse_index_map,
433 const intArray& invokedynamic_inverse_index_map,
434 const intArray& invokedynamic_references_map);
435 public:
436 static ConstantPoolCache* allocate(ClassLoaderData* loader_data,
437 const intStack& cp_cache_map,
438 const intStack& invokedynamic_cp_cache_map,
439 const intStack& invokedynamic_references_map, TRAPS);
440
441 int length() const { return _length; }
442 void metaspace_pointers_do(MetaspaceClosure* it);
443 MetaspaceObj::Type type() const { return ConstantPoolCacheType; }
444
445 oop archived_references() NOT_CDS_JAVA_HEAP_RETURN_(NULL);
446 void set_archived_references(oop o) NOT_CDS_JAVA_HEAP_RETURN;
447
448 inline oop resolved_references();
449 void set_resolved_references(OopHandle s) { _resolved_references = s; }
450 Array<u2>* reference_map() const { return _reference_map; }
451 void set_reference_map(Array<u2>* o) { _reference_map = o; }
452
453 // Assembly code support
454 static int resolved_references_offset_in_bytes() { return offset_of(ConstantPoolCache, _resolved_references); }
455
456 // CDS support
457 void remove_unshareable_info();
458 void verify_just_initialized();
459 private:
460 void walk_entries_for_initialization(bool check_only);
461 void set_length(int length) { _length = length; }
462
463 static int header_size() { return sizeof(ConstantPoolCache) / wordSize; }
464 static int size(int length) { return align_metadata_size(header_size() + length * in_words(ConstantPoolCacheEntry::size())); }
465 public:
466 int size() const { return size(length()); }
467 private:
468
469 // Helpers
470 ConstantPool** constant_pool_addr() { return &_constant_pool; }
471 ConstantPoolCacheEntry* base() const { return (ConstantPoolCacheEntry*)((address)this + in_bytes(base_offset())); }
472
473 friend class constantPoolCacheKlass;
474 friend class ConstantPoolCacheEntry;
475
476 public:
477 // Accessors
478 void set_constant_pool(ConstantPool* pool) { _constant_pool = pool; }
479 ConstantPool* constant_pool() const { return _constant_pool; }
480 // Fetches the entry at the given index.
481 // In either case the index must not be encoded or byte-swapped in any way.
482 ConstantPoolCacheEntry* entry_at(int i) const {
483 assert(0 <= i && i < length(), "index out of bounds");
484 return base() + i;
485 }
486
487 // Code generation
488 static ByteSize base_offset() { return in_ByteSize(sizeof(ConstantPoolCache)); }
489 static ByteSize entry_offset(int raw_index) {
490 int index = raw_index;
491 return (base_offset() + ConstantPoolCacheEntry::size_in_bytes() * index);
492 }
493
494#if INCLUDE_JVMTI
495 // RedefineClasses() API support:
496 // If any entry of this ConstantPoolCache points to any of
497 // old_methods, replace it with the corresponding new_method.
498 // trace_name_printed is set to true if the current call has
499 // printed the klass name so that other routines in the adjust_*
500 // group don't print the klass name.
501 void adjust_method_entries(bool* trace_name_printed);
502 bool check_no_old_or_obsolete_entries();
503 void dump_cache();
504#endif // INCLUDE_JVMTI
505
506 // RedefineClasses support
507 DEBUG_ONLY(bool on_stack() { return false; })
508 void deallocate_contents(ClassLoaderData* data);
509 bool is_klass() const { return false; }
510
511 // Printing
512 void print_on(outputStream* st) const;
513 void print_value_on(outputStream* st) const;
514
515 const char* internal_name() const { return "{constant pool cache}"; }
516
517 // Verify
518 void verify_on(outputStream* st);
519};
520
521#endif // SHARE_OOPS_CPCACHE_HPP
522