Wed, 23 Jan 2013 10:34:29 -0500
8006040: NPG: on_stack processing wastes space in ConstantPool
Summary: Added on_stack bit to flags. Also MetadataMarkOnStack is used for more than JVMTI so had to be moved.
Reviewed-by: dholmes, stefank
1 /*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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25 #ifndef SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP
26 #define SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP
28 #include "oops/arrayOop.hpp"
29 #include "oops/cpCache.hpp"
30 #include "oops/objArrayOop.hpp"
31 #include "oops/symbol.hpp"
32 #include "oops/typeArrayOop.hpp"
33 #include "runtime/handles.hpp"
34 #include "utilities/constantTag.hpp"
35 #ifdef TARGET_ARCH_x86
36 # include "bytes_x86.hpp"
37 #endif
38 #ifdef TARGET_ARCH_sparc
39 # include "bytes_sparc.hpp"
40 #endif
41 #ifdef TARGET_ARCH_zero
42 # include "bytes_zero.hpp"
43 #endif
44 #ifdef TARGET_ARCH_arm
45 # include "bytes_arm.hpp"
46 #endif
47 #ifdef TARGET_ARCH_ppc
48 # include "bytes_ppc.hpp"
49 #endif
51 // A constantPool is an array containing class constants as described in the
52 // class file.
53 //
54 // Most of the constant pool entries are written during class parsing, which
55 // is safe. For klass types, the constant pool entry is
56 // modified when the entry is resolved. If a klass constant pool
57 // entry is read without a lock, only the resolved state guarantees that
58 // the entry in the constant pool is a klass object and not a Symbol*.
60 class SymbolHashMap;
62 class CPSlot VALUE_OBJ_CLASS_SPEC {
63 intptr_t _ptr;
64 public:
65 CPSlot(intptr_t ptr): _ptr(ptr) {}
66 CPSlot(Klass* ptr): _ptr((intptr_t)ptr) {}
67 CPSlot(Symbol* ptr): _ptr((intptr_t)ptr | 1) {}
69 intptr_t value() { return _ptr; }
70 bool is_resolved() { return (_ptr & 1) == 0; }
71 bool is_unresolved() { return (_ptr & 1) == 1; }
73 Symbol* get_symbol() {
74 assert(is_unresolved(), "bad call");
75 return (Symbol*)(_ptr & ~1);
76 }
77 Klass* get_klass() {
78 assert(is_resolved(), "bad call");
79 return (Klass*)_ptr;
80 }
81 };
83 class ConstantPool : public Metadata {
84 friend class VMStructs;
85 friend class BytecodeInterpreter; // Directly extracts an oop in the pool for fast instanceof/checkcast
86 friend class Universe; // For null constructor
87 private:
88 Array<u1>* _tags; // the tag array describing the constant pool's contents
89 ConstantPoolCache* _cache; // the cache holding interpreter runtime information
90 InstanceKlass* _pool_holder; // the corresponding class
91 Array<u2>* _operands; // for variable-sized (InvokeDynamic) nodes, usually empty
93 // Array of resolved objects from the constant pool and map from resolved
94 // object index to original constant pool index
95 jobject _resolved_references;
96 Array<u2>* _reference_map;
98 enum {
99 _has_invokedynamic = 1, // Flags
100 _has_pseudo_string = 2,
101 _has_preresolution = 4,
102 _on_stack = 8
103 };
105 int _flags; // old fashioned bit twiddling
106 int _length; // number of elements in the array
108 union {
109 // set for CDS to restore resolved references
110 int _resolved_reference_length;
111 // keeps version number for redefined classes (used in backtrace)
112 int _version;
113 } _saved;
115 Monitor* _lock;
117 void set_tags(Array<u1>* tags) { _tags = tags; }
118 void tag_at_put(int which, jbyte t) { tags()->at_put(which, t); }
119 void release_tag_at_put(int which, jbyte t) { tags()->release_at_put(which, t); }
121 void set_operands(Array<u2>* operands) { _operands = operands; }
123 int flags() const { return _flags; }
124 void set_flags(int f) { _flags = f; }
126 private:
127 intptr_t* base() const { return (intptr_t*) (((char*) this) + sizeof(ConstantPool)); }
129 CPSlot slot_at(int which) {
130 assert(is_within_bounds(which), "index out of bounds");
131 // Uses volatile because the klass slot changes without a lock.
132 volatile intptr_t adr = (intptr_t)OrderAccess::load_ptr_acquire(obj_at_addr_raw(which));
133 assert(adr != 0 || which == 0, "cp entry for klass should not be zero");
134 return CPSlot(adr);
135 }
137 void slot_at_put(int which, CPSlot s) const {
138 assert(is_within_bounds(which), "index out of bounds");
139 assert(s.value() != 0, "Caught something");
140 *(intptr_t*)&base()[which] = s.value();
141 }
142 intptr_t* obj_at_addr_raw(int which) const {
143 assert(is_within_bounds(which), "index out of bounds");
144 return (intptr_t*) &base()[which];
145 }
147 jint* int_at_addr(int which) const {
148 assert(is_within_bounds(which), "index out of bounds");
149 return (jint*) &base()[which];
150 }
152 jlong* long_at_addr(int which) const {
153 assert(is_within_bounds(which), "index out of bounds");
154 return (jlong*) &base()[which];
155 }
157 jfloat* float_at_addr(int which) const {
158 assert(is_within_bounds(which), "index out of bounds");
159 return (jfloat*) &base()[which];
160 }
162 jdouble* double_at_addr(int which) const {
163 assert(is_within_bounds(which), "index out of bounds");
164 return (jdouble*) &base()[which];
165 }
167 ConstantPool(Array<u1>* tags);
168 ConstantPool() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); }
169 public:
170 static ConstantPool* allocate(ClassLoaderData* loader_data, int length, TRAPS);
172 bool is_constantPool() const volatile { return true; }
174 Array<u1>* tags() const { return _tags; }
175 Array<u2>* operands() const { return _operands; }
177 bool has_invokedynamic() const { return (_flags & _has_invokedynamic) != 0; }
178 void set_has_invokedynamic() { _flags |= _has_invokedynamic; }
180 bool has_pseudo_string() const { return (_flags & _has_pseudo_string) != 0; }
181 void set_has_pseudo_string() { _flags |= _has_pseudo_string; }
183 bool has_preresolution() const { return (_flags & _has_preresolution) != 0; }
184 void set_has_preresolution() { _flags |= _has_preresolution; }
186 // Redefine classes support. If a method refering to this constant pool
187 // is on the executing stack, or as a handle in vm code, this constant pool
188 // can't be removed from the set of previous versions saved in the instance
189 // class.
190 bool on_stack() const { return (_flags &_on_stack) != 0; }
191 void set_on_stack(const bool value);
193 // Klass holding pool
194 InstanceKlass* pool_holder() const { return _pool_holder; }
195 void set_pool_holder(InstanceKlass* k) { _pool_holder = k; }
196 InstanceKlass** pool_holder_addr() { return &_pool_holder; }
198 // Interpreter runtime support
199 ConstantPoolCache* cache() const { return _cache; }
200 void set_cache(ConstantPoolCache* cache){ _cache = cache; }
202 // Create object cache in the constant pool
203 void initialize_resolved_references(ClassLoaderData* loader_data,
204 intStack reference_map,
205 int constant_pool_map_length,
206 TRAPS);
208 // resolved strings, methodHandles and callsite objects from the constant pool
209 objArrayOop resolved_references() const;
210 // mapping resolved object array indexes to cp indexes and back.
211 int object_to_cp_index(int index) { return _reference_map->at(index); }
212 int cp_to_object_index(int index);
214 // Invokedynamic indexes.
215 // They must look completely different from normal indexes.
216 // The main reason is that byte swapping is sometimes done on normal indexes.
217 // Finally, it is helpful for debugging to tell the two apart.
218 static bool is_invokedynamic_index(int i) { return (i < 0); }
219 static int decode_invokedynamic_index(int i) { assert(is_invokedynamic_index(i), ""); return ~i; }
220 static int encode_invokedynamic_index(int i) { assert(!is_invokedynamic_index(i), ""); return ~i; }
223 // The invokedynamic points at a CP cache entry. This entry points back
224 // at the original CP entry (CONSTANT_InvokeDynamic) and also (via f2) at an entry
225 // in the resolved_references array (which provides the appendix argument).
226 int invokedynamic_cp_cache_index(int index) const {
227 assert (is_invokedynamic_index(index), "should be a invokedynamic index");
228 int cache_index = decode_invokedynamic_index(index);
229 return cache_index;
230 }
231 ConstantPoolCacheEntry* invokedynamic_cp_cache_entry_at(int index) const {
232 // decode index that invokedynamic points to.
233 int cp_cache_index = invokedynamic_cp_cache_index(index);
234 return cache()->entry_at(cp_cache_index);
235 }
237 // Assembly code support
238 static int tags_offset_in_bytes() { return offset_of(ConstantPool, _tags); }
239 static int cache_offset_in_bytes() { return offset_of(ConstantPool, _cache); }
240 static int pool_holder_offset_in_bytes() { return offset_of(ConstantPool, _pool_holder); }
241 static int resolved_references_offset_in_bytes() { return offset_of(ConstantPool, _resolved_references); }
242 static int reference_map_offset_in_bytes() { return offset_of(ConstantPool, _reference_map); }
244 // Storing constants
246 void klass_at_put(int which, Klass* k) {
247 assert(k != NULL, "resolved class shouldn't be null");
248 assert(is_within_bounds(which), "index out of bounds");
249 OrderAccess::release_store_ptr((Klass* volatile *)obj_at_addr_raw(which), k);
250 // The interpreter assumes when the tag is stored, the klass is resolved
251 // and the Klass* is a klass rather than a Symbol*, so we need
252 // hardware store ordering here.
253 release_tag_at_put(which, JVM_CONSTANT_Class);
254 }
256 // For temporary use while constructing constant pool
257 void klass_index_at_put(int which, int name_index) {
258 tag_at_put(which, JVM_CONSTANT_ClassIndex);
259 *int_at_addr(which) = name_index;
260 }
262 // Temporary until actual use
263 void unresolved_klass_at_put(int which, Symbol* s) {
264 release_tag_at_put(which, JVM_CONSTANT_UnresolvedClass);
265 slot_at_put(which, s);
266 }
268 void method_handle_index_at_put(int which, int ref_kind, int ref_index) {
269 tag_at_put(which, JVM_CONSTANT_MethodHandle);
270 *int_at_addr(which) = ((jint) ref_index<<16) | ref_kind;
271 }
273 void method_type_index_at_put(int which, int ref_index) {
274 tag_at_put(which, JVM_CONSTANT_MethodType);
275 *int_at_addr(which) = ref_index;
276 }
278 void invoke_dynamic_at_put(int which, int bootstrap_specifier_index, int name_and_type_index) {
279 tag_at_put(which, JVM_CONSTANT_InvokeDynamic);
280 *int_at_addr(which) = ((jint) name_and_type_index<<16) | bootstrap_specifier_index;
281 }
283 void unresolved_string_at_put(int which, Symbol* s) {
284 release_tag_at_put(which, JVM_CONSTANT_String);
285 *symbol_at_addr(which) = s;
286 }
288 void int_at_put(int which, jint i) {
289 tag_at_put(which, JVM_CONSTANT_Integer);
290 *int_at_addr(which) = i;
291 }
293 void long_at_put(int which, jlong l) {
294 tag_at_put(which, JVM_CONSTANT_Long);
295 // *long_at_addr(which) = l;
296 Bytes::put_native_u8((address)long_at_addr(which), *((u8*) &l));
297 }
299 void float_at_put(int which, jfloat f) {
300 tag_at_put(which, JVM_CONSTANT_Float);
301 *float_at_addr(which) = f;
302 }
304 void double_at_put(int which, jdouble d) {
305 tag_at_put(which, JVM_CONSTANT_Double);
306 // *double_at_addr(which) = d;
307 // u8 temp = *(u8*) &d;
308 Bytes::put_native_u8((address) double_at_addr(which), *((u8*) &d));
309 }
311 Symbol** symbol_at_addr(int which) const {
312 assert(is_within_bounds(which), "index out of bounds");
313 return (Symbol**) &base()[which];
314 }
316 void symbol_at_put(int which, Symbol* s) {
317 assert(s->refcount() != 0, "should have nonzero refcount");
318 tag_at_put(which, JVM_CONSTANT_Utf8);
319 *symbol_at_addr(which) = s;
320 }
322 void string_at_put(int which, int obj_index, oop str) {
323 resolved_references()->obj_at_put(obj_index, str);
324 }
326 void set_object_tag_at(int which) {
327 release_tag_at_put(which, JVM_CONSTANT_Object);
328 }
330 void object_at_put(int which, oop obj) {
331 resolved_references()->obj_at_put(cp_to_object_index(which), obj);
332 }
334 // For temporary use while constructing constant pool
335 void string_index_at_put(int which, int string_index) {
336 tag_at_put(which, JVM_CONSTANT_StringIndex);
337 *int_at_addr(which) = string_index;
338 }
340 void field_at_put(int which, int class_index, int name_and_type_index) {
341 tag_at_put(which, JVM_CONSTANT_Fieldref);
342 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
343 }
345 void method_at_put(int which, int class_index, int name_and_type_index) {
346 tag_at_put(which, JVM_CONSTANT_Methodref);
347 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
348 }
350 void interface_method_at_put(int which, int class_index, int name_and_type_index) {
351 tag_at_put(which, JVM_CONSTANT_InterfaceMethodref);
352 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; // Not so nice
353 }
355 void name_and_type_at_put(int which, int name_index, int signature_index) {
356 tag_at_put(which, JVM_CONSTANT_NameAndType);
357 *int_at_addr(which) = ((jint) signature_index<<16) | name_index; // Not so nice
358 }
360 // Tag query
362 constantTag tag_at(int which) const { return (constantTag)tags()->at_acquire(which); }
364 // Fetching constants
366 Klass* klass_at(int which, TRAPS) {
367 constantPoolHandle h_this(THREAD, this);
368 return klass_at_impl(h_this, which, CHECK_NULL);
369 }
371 Symbol* klass_name_at(int which); // Returns the name, w/o resolving.
373 Klass* resolved_klass_at(int which) { // Used by Compiler
374 guarantee(tag_at(which).is_klass(), "Corrupted constant pool");
375 // Must do an acquire here in case another thread resolved the klass
376 // behind our back, lest we later load stale values thru the oop.
377 return CPSlot((Klass*)OrderAccess::load_ptr_acquire(obj_at_addr_raw(which))).get_klass();
378 }
380 // This method should only be used with a cpool lock or during parsing or gc
381 Symbol* unresolved_klass_at(int which) { // Temporary until actual use
382 Symbol* s = CPSlot((Symbol*)OrderAccess::load_ptr_acquire(obj_at_addr_raw(which))).get_symbol();
383 // check that the klass is still unresolved.
384 assert(tag_at(which).is_unresolved_klass(), "Corrupted constant pool");
385 return s;
386 }
388 // RedefineClasses() API support:
389 Symbol* klass_at_noresolve(int which) { return klass_name_at(which); }
391 jint int_at(int which) {
392 assert(tag_at(which).is_int(), "Corrupted constant pool");
393 return *int_at_addr(which);
394 }
396 jlong long_at(int which) {
397 assert(tag_at(which).is_long(), "Corrupted constant pool");
398 // return *long_at_addr(which);
399 u8 tmp = Bytes::get_native_u8((address)&base()[which]);
400 return *((jlong*)&tmp);
401 }
403 jfloat float_at(int which) {
404 assert(tag_at(which).is_float(), "Corrupted constant pool");
405 return *float_at_addr(which);
406 }
408 jdouble double_at(int which) {
409 assert(tag_at(which).is_double(), "Corrupted constant pool");
410 u8 tmp = Bytes::get_native_u8((address)&base()[which]);
411 return *((jdouble*)&tmp);
412 }
414 Symbol* symbol_at(int which) {
415 assert(tag_at(which).is_utf8(), "Corrupted constant pool");
416 return *symbol_at_addr(which);
417 }
419 oop string_at(int which, int obj_index, TRAPS) {
420 constantPoolHandle h_this(THREAD, this);
421 return string_at_impl(h_this, which, obj_index, THREAD);
422 }
423 oop string_at(int which, TRAPS) {
424 int obj_index = cp_to_object_index(which);
425 return string_at(which, obj_index, THREAD);
426 }
428 // Version that can be used before string oop array is created.
429 oop uncached_string_at(int which, TRAPS);
431 oop object_at(int which) {
432 assert(tag_at(which).is_object(), "Corrupted constant pool");
433 int obj_index = cp_to_object_index(which);
434 return resolved_references()->obj_at(obj_index);
435 }
437 // A "pseudo-string" is an non-string oop that has found is way into
438 // a String entry.
439 // Under EnableInvokeDynamic this can happen if the user patches a live
440 // object into a CONSTANT_String entry of an anonymous class.
441 // Method oops internally created for method handles may also
442 // use pseudo-strings to link themselves to related metaobjects.
444 bool is_pseudo_string_at(int which) {
445 // A pseudo string is a string that doesn't have a symbol in the cpSlot
446 return unresolved_string_at(which) == NULL;
447 }
449 oop pseudo_string_at(int which, int obj_index) {
450 assert(tag_at(which).is_string(), "Corrupted constant pool");
451 assert(unresolved_string_at(which) == NULL, "shouldn't have symbol");
452 oop s = resolved_references()->obj_at(obj_index);
453 return s;
454 }
456 void pseudo_string_at_put(int which, int obj_index, oop x) {
457 assert(EnableInvokeDynamic, "");
458 set_has_pseudo_string(); // mark header
459 assert(tag_at(which).is_string(), "Corrupted constant pool");
460 string_at_put(which, obj_index, x); // this works just fine
461 }
463 // only called when we are sure a string entry is already resolved (via an
464 // earlier string_at call.
465 oop resolved_string_at(int which) {
466 assert(tag_at(which).is_string(), "Corrupted constant pool");
467 // Must do an acquire here in case another thread resolved the klass
468 // behind our back, lest we later load stale values thru the oop.
469 // we might want a volatile_obj_at in ObjArrayKlass.
470 int obj_index = cp_to_object_index(which);
471 return resolved_references()->obj_at(obj_index);
472 }
474 Symbol* unresolved_string_at(int which) {
475 assert(tag_at(which).is_string(), "Corrupted constant pool");
476 Symbol* s = *symbol_at_addr(which);
477 return s;
478 }
480 // Returns an UTF8 for a CONSTANT_String entry at a given index.
481 // UTF8 char* representation was chosen to avoid conversion of
482 // java_lang_Strings at resolved entries into Symbol*s
483 // or vice versa.
484 // Caller is responsible for checking for pseudo-strings.
485 char* string_at_noresolve(int which);
487 jint name_and_type_at(int which) {
488 assert(tag_at(which).is_name_and_type(), "Corrupted constant pool");
489 return *int_at_addr(which);
490 }
492 int method_handle_ref_kind_at(int which) {
493 assert(tag_at(which).is_method_handle(), "Corrupted constant pool");
494 return extract_low_short_from_int(*int_at_addr(which)); // mask out unwanted ref_index bits
495 }
496 int method_handle_index_at(int which) {
497 assert(tag_at(which).is_method_handle(), "Corrupted constant pool");
498 return extract_high_short_from_int(*int_at_addr(which)); // shift out unwanted ref_kind bits
499 }
500 int method_type_index_at(int which) {
501 assert(tag_at(which).is_method_type(), "Corrupted constant pool");
502 return *int_at_addr(which);
503 }
504 // Derived queries:
505 Symbol* method_handle_name_ref_at(int which) {
506 int member = method_handle_index_at(which);
507 return impl_name_ref_at(member, true);
508 }
509 Symbol* method_handle_signature_ref_at(int which) {
510 int member = method_handle_index_at(which);
511 return impl_signature_ref_at(member, true);
512 }
513 int method_handle_klass_index_at(int which) {
514 int member = method_handle_index_at(which);
515 return impl_klass_ref_index_at(member, true);
516 }
517 Symbol* method_type_signature_at(int which) {
518 int sym = method_type_index_at(which);
519 return symbol_at(sym);
520 }
522 int invoke_dynamic_name_and_type_ref_index_at(int which) {
523 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool");
524 return extract_high_short_from_int(*int_at_addr(which));
525 }
526 int invoke_dynamic_bootstrap_specifier_index(int which) {
527 assert(tag_at(which).value() == JVM_CONSTANT_InvokeDynamic, "Corrupted constant pool");
528 return extract_low_short_from_int(*int_at_addr(which));
529 }
530 int invoke_dynamic_operand_base(int which) {
531 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which);
532 return operand_offset_at(operands(), bootstrap_specifier_index);
533 }
534 // The first part of the operands array consists of an index into the second part.
535 // Extract a 32-bit index value from the first part.
536 static int operand_offset_at(Array<u2>* operands, int bootstrap_specifier_index) {
537 int n = (bootstrap_specifier_index * 2);
538 assert(n >= 0 && n+2 <= operands->length(), "oob");
539 // The first 32-bit index points to the beginning of the second part
540 // of the operands array. Make sure this index is in the first part.
541 DEBUG_ONLY(int second_part = build_int_from_shorts(operands->at(0),
542 operands->at(1)));
543 assert(second_part == 0 || n+2 <= second_part, "oob (2)");
544 int offset = build_int_from_shorts(operands->at(n+0),
545 operands->at(n+1));
546 // The offset itself must point into the second part of the array.
547 assert(offset == 0 || offset >= second_part && offset <= operands->length(), "oob (3)");
548 return offset;
549 }
550 static void operand_offset_at_put(Array<u2>* operands, int bootstrap_specifier_index, int offset) {
551 int n = bootstrap_specifier_index * 2;
552 assert(n >= 0 && n+2 <= operands->length(), "oob");
553 operands->at_put(n+0, extract_low_short_from_int(offset));
554 operands->at_put(n+1, extract_high_short_from_int(offset));
555 }
556 static int operand_array_length(Array<u2>* operands) {
557 if (operands == NULL || operands->length() == 0) return 0;
558 int second_part = operand_offset_at(operands, 0);
559 return (second_part / 2);
560 }
562 #ifdef ASSERT
563 // operand tuples fit together exactly, end to end
564 static int operand_limit_at(Array<u2>* operands, int bootstrap_specifier_index) {
565 int nextidx = bootstrap_specifier_index + 1;
566 if (nextidx == operand_array_length(operands))
567 return operands->length();
568 else
569 return operand_offset_at(operands, nextidx);
570 }
571 int invoke_dynamic_operand_limit(int which) {
572 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which);
573 return operand_limit_at(operands(), bootstrap_specifier_index);
574 }
575 #endif //ASSERT
577 // layout of InvokeDynamic bootstrap method specifier (in second part of operands array):
578 enum {
579 _indy_bsm_offset = 0, // CONSTANT_MethodHandle bsm
580 _indy_argc_offset = 1, // u2 argc
581 _indy_argv_offset = 2 // u2 argv[argc]
582 };
583 int invoke_dynamic_bootstrap_method_ref_index_at(int which) {
584 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool");
585 int op_base = invoke_dynamic_operand_base(which);
586 return operands()->at(op_base + _indy_bsm_offset);
587 }
588 int invoke_dynamic_argument_count_at(int which) {
589 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool");
590 int op_base = invoke_dynamic_operand_base(which);
591 int argc = operands()->at(op_base + _indy_argc_offset);
592 DEBUG_ONLY(int end_offset = op_base + _indy_argv_offset + argc;
593 int next_offset = invoke_dynamic_operand_limit(which));
594 assert(end_offset == next_offset, "matched ending");
595 return argc;
596 }
597 int invoke_dynamic_argument_index_at(int which, int j) {
598 int op_base = invoke_dynamic_operand_base(which);
599 DEBUG_ONLY(int argc = operands()->at(op_base + _indy_argc_offset));
600 assert((uint)j < (uint)argc, "oob");
601 return operands()->at(op_base + _indy_argv_offset + j);
602 }
604 // The following methods (name/signature/klass_ref_at, klass_ref_at_noresolve,
605 // name_and_type_ref_index_at) all expect to be passed indices obtained
606 // directly from the bytecode.
607 // If the indices are meant to refer to fields or methods, they are
608 // actually rewritten constant pool cache indices.
609 // The routine remap_instruction_operand_from_cache manages the adjustment
610 // of these values back to constant pool indices.
612 // There are also "uncached" versions which do not adjust the operand index; see below.
614 // FIXME: Consider renaming these with a prefix "cached_" to make the distinction clear.
615 // In a few cases (the verifier) there are uses before a cpcache has been built,
616 // which are handled by a dynamic check in remap_instruction_operand_from_cache.
617 // FIXME: Remove the dynamic check, and adjust all callers to specify the correct mode.
619 // Lookup for entries consisting of (klass_index, name_and_type index)
620 Klass* klass_ref_at(int which, TRAPS);
621 Symbol* klass_ref_at_noresolve(int which);
622 Symbol* name_ref_at(int which) { return impl_name_ref_at(which, false); }
623 Symbol* signature_ref_at(int which) { return impl_signature_ref_at(which, false); }
625 int klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, false); }
626 int name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, false); }
628 // Lookup for entries consisting of (name_index, signature_index)
629 int name_ref_index_at(int which_nt); // == low-order jshort of name_and_type_at(which_nt)
630 int signature_ref_index_at(int which_nt); // == high-order jshort of name_and_type_at(which_nt)
632 BasicType basic_type_for_signature_at(int which);
634 // Resolve string constants (to prevent allocation during compilation)
635 void resolve_string_constants(TRAPS) {
636 constantPoolHandle h_this(THREAD, this);
637 resolve_string_constants_impl(h_this, CHECK);
638 }
640 // CDS support
641 void remove_unshareable_info();
642 void restore_unshareable_info(TRAPS);
643 bool resolve_class_constants(TRAPS);
644 // The ConstantPool vtable is restored by this call when the ConstantPool is
645 // in the shared archive. See patch_klass_vtables() in metaspaceShared.cpp for
646 // all the gory details. SA, dtrace and pstack helpers distinguish metadata
647 // by their vtable.
648 void restore_vtable() { guarantee(is_constantPool(), "vtable restored by this call"); }
650 private:
651 enum { _no_index_sentinel = -1, _possible_index_sentinel = -2 };
652 public:
654 // Resolve late bound constants.
655 oop resolve_constant_at(int index, TRAPS) {
656 constantPoolHandle h_this(THREAD, this);
657 return resolve_constant_at_impl(h_this, index, _no_index_sentinel, THREAD);
658 }
660 oop resolve_cached_constant_at(int cache_index, TRAPS) {
661 constantPoolHandle h_this(THREAD, this);
662 return resolve_constant_at_impl(h_this, _no_index_sentinel, cache_index, THREAD);
663 }
665 oop resolve_possibly_cached_constant_at(int pool_index, TRAPS) {
666 constantPoolHandle h_this(THREAD, this);
667 return resolve_constant_at_impl(h_this, pool_index, _possible_index_sentinel, THREAD);
668 }
670 oop resolve_bootstrap_specifier_at(int index, TRAPS) {
671 constantPoolHandle h_this(THREAD, this);
672 return resolve_bootstrap_specifier_at_impl(h_this, index, THREAD);
673 }
675 // Klass name matches name at offset
676 bool klass_name_at_matches(instanceKlassHandle k, int which);
678 // Sizing
679 int length() const { return _length; }
680 void set_length(int length) { _length = length; }
682 // Tells whether index is within bounds.
683 bool is_within_bounds(int index) const {
684 return 0 <= index && index < length();
685 }
687 static int header_size() { return sizeof(ConstantPool)/HeapWordSize; }
688 static int size(int length) { return align_object_size(header_size() + length); }
689 int size() const { return size(length()); }
691 friend class ClassFileParser;
692 friend class SystemDictionary;
694 // Used by compiler to prevent classloading.
695 static Method* method_at_if_loaded (constantPoolHandle this_oop, int which);
696 static bool has_appendix_at_if_loaded (constantPoolHandle this_oop, int which);
697 static oop appendix_at_if_loaded (constantPoolHandle this_oop, int which);
698 static bool has_method_type_at_if_loaded (constantPoolHandle this_oop, int which);
699 static oop method_type_at_if_loaded (constantPoolHandle this_oop, int which);
700 static Klass* klass_at_if_loaded (constantPoolHandle this_oop, int which);
701 static Klass* klass_ref_at_if_loaded (constantPoolHandle this_oop, int which);
702 // Same as above - but does LinkResolving.
703 static Klass* klass_ref_at_if_loaded_check(constantPoolHandle this_oop, int which, TRAPS);
705 // Routines currently used for annotations (only called by jvm.cpp) but which might be used in the
706 // future by other Java code. These take constant pool indices rather than
707 // constant pool cache indices as do the peer methods above.
708 Symbol* uncached_klass_ref_at_noresolve(int which);
709 Symbol* uncached_name_ref_at(int which) { return impl_name_ref_at(which, true); }
710 Symbol* uncached_signature_ref_at(int which) { return impl_signature_ref_at(which, true); }
711 int uncached_klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, true); }
712 int uncached_name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, true); }
714 // Sharing
715 int pre_resolve_shared_klasses(TRAPS);
717 // Debugging
718 const char* printable_name_at(int which) PRODUCT_RETURN0;
720 #ifdef ASSERT
721 enum { CPCACHE_INDEX_TAG = 0x10000 }; // helps keep CP cache indices distinct from CP indices
722 #else
723 enum { CPCACHE_INDEX_TAG = 0 }; // in product mode, this zero value is a no-op
724 #endif //ASSERT
726 static int decode_cpcache_index(int raw_index, bool invokedynamic_ok = false) {
727 if (invokedynamic_ok && is_invokedynamic_index(raw_index))
728 return decode_invokedynamic_index(raw_index);
729 else
730 return raw_index - CPCACHE_INDEX_TAG;
731 }
733 private:
735 void set_resolved_references(jobject s) { _resolved_references = s; }
736 Array<u2>* reference_map() const { return _reference_map; }
737 void set_reference_map(Array<u2>* o) { _reference_map = o; }
739 // patch JSR 292 resolved references after the class is linked.
740 void patch_resolved_references(GrowableArray<Handle>* cp_patches);
742 Symbol* impl_name_ref_at(int which, bool uncached);
743 Symbol* impl_signature_ref_at(int which, bool uncached);
744 int impl_klass_ref_index_at(int which, bool uncached);
745 int impl_name_and_type_ref_index_at(int which, bool uncached);
747 int remap_instruction_operand_from_cache(int operand); // operand must be biased by CPCACHE_INDEX_TAG
749 // Used while constructing constant pool (only by ClassFileParser)
750 jint klass_index_at(int which) {
751 assert(tag_at(which).is_klass_index(), "Corrupted constant pool");
752 return *int_at_addr(which);
753 }
755 jint string_index_at(int which) {
756 assert(tag_at(which).is_string_index(), "Corrupted constant pool");
757 return *int_at_addr(which);
758 }
760 // Performs the LinkResolver checks
761 static void verify_constant_pool_resolve(constantPoolHandle this_oop, KlassHandle klass, TRAPS);
763 // Implementation of methods that needs an exposed 'this' pointer, in order to
764 // handle GC while executing the method
765 static Klass* klass_at_impl(constantPoolHandle this_oop, int which, TRAPS);
766 static oop string_at_impl(constantPoolHandle this_oop, int which, int obj_index, TRAPS);
768 // Resolve string constants (to prevent allocation during compilation)
769 static void resolve_string_constants_impl(constantPoolHandle this_oop, TRAPS);
771 static oop resolve_constant_at_impl(constantPoolHandle this_oop, int index, int cache_index, TRAPS);
772 static void save_and_throw_exception(constantPoolHandle this_oop, int which, int tag_value, TRAPS);
773 static oop resolve_bootstrap_specifier_at_impl(constantPoolHandle this_oop, int index, TRAPS);
775 public:
776 // Merging ConstantPool* support:
777 bool compare_entry_to(int index1, constantPoolHandle cp2, int index2, TRAPS);
778 void copy_cp_to(int start_i, int end_i, constantPoolHandle to_cp, int to_i, TRAPS) {
779 constantPoolHandle h_this(THREAD, this);
780 copy_cp_to_impl(h_this, start_i, end_i, to_cp, to_i, THREAD);
781 }
782 static void copy_cp_to_impl(constantPoolHandle from_cp, int start_i, int end_i, constantPoolHandle to_cp, int to_i, TRAPS);
783 static void copy_entry_to(constantPoolHandle from_cp, int from_i, constantPoolHandle to_cp, int to_i, TRAPS);
784 int find_matching_entry(int pattern_i, constantPoolHandle search_cp, TRAPS);
785 int version() const { return _saved._version; }
786 void set_version(int version) { _saved._version = version; }
787 void increment_and_save_version(int version) {
788 _saved._version = version >= 0 ? (version + 1) : version; // keep overflow
789 }
791 void set_resolved_reference_length(int length) { _saved._resolved_reference_length = length; }
792 int resolved_reference_length() const { return _saved._resolved_reference_length; }
793 void set_lock(Monitor* lock) { _lock = lock; }
794 Monitor* lock() { return _lock; }
796 // Decrease ref counts of symbols that are in the constant pool
797 // when the holder class is unloaded
798 void unreference_symbols();
800 // Deallocate constant pool for RedefineClasses
801 void deallocate_contents(ClassLoaderData* loader_data);
802 void release_C_heap_structures();
804 // JVMTI accesss - GetConstantPool, RetransformClasses, ...
805 friend class JvmtiConstantPoolReconstituter;
807 private:
808 jint cpool_entry_size(jint idx);
809 jint hash_entries_to(SymbolHashMap *symmap, SymbolHashMap *classmap);
811 // Copy cpool bytes into byte array.
812 // Returns:
813 // int > 0, count of the raw cpool bytes that have been copied
814 // 0, OutOfMemory error
815 // -1, Internal error
816 int copy_cpool_bytes(int cpool_size,
817 SymbolHashMap* tbl,
818 unsigned char *bytes);
820 public:
821 // Verify
822 void verify_on(outputStream* st);
824 // Printing
825 void print_on(outputStream* st) const;
826 void print_value_on(outputStream* st) const;
827 void print_entry_on(int index, outputStream* st);
829 const char* internal_name() const { return "{constant pool}"; }
831 #ifndef PRODUCT
832 // Compile the world support
833 static void preload_and_initialize_all_classes(ConstantPool* constant_pool, TRAPS);
834 #endif
835 };
837 class SymbolHashMapEntry : public CHeapObj<mtSymbol> {
838 private:
839 unsigned int _hash; // 32-bit hash for item
840 SymbolHashMapEntry* _next; // Next element in the linked list for this bucket
841 Symbol* _symbol; // 1-st part of the mapping: symbol => value
842 u2 _value; // 2-nd part of the mapping: symbol => value
844 public:
845 unsigned int hash() const { return _hash; }
846 void set_hash(unsigned int hash) { _hash = hash; }
848 SymbolHashMapEntry* next() const { return _next; }
849 void set_next(SymbolHashMapEntry* next) { _next = next; }
851 Symbol* symbol() const { return _symbol; }
852 void set_symbol(Symbol* sym) { _symbol = sym; }
854 u2 value() const { return _value; }
855 void set_value(u2 value) { _value = value; }
857 SymbolHashMapEntry(unsigned int hash, Symbol* symbol, u2 value)
858 : _hash(hash), _symbol(symbol), _value(value), _next(NULL) {}
860 }; // End SymbolHashMapEntry class
863 class SymbolHashMapBucket : public CHeapObj<mtSymbol> {
865 private:
866 SymbolHashMapEntry* _entry;
868 public:
869 SymbolHashMapEntry* entry() const { return _entry; }
870 void set_entry(SymbolHashMapEntry* entry) { _entry = entry; }
871 void clear() { _entry = NULL; }
873 }; // End SymbolHashMapBucket class
876 class SymbolHashMap: public CHeapObj<mtSymbol> {
878 private:
879 // Default number of entries in the table
880 enum SymbolHashMap_Constants {
881 _Def_HashMap_Size = 256
882 };
884 int _table_size;
885 SymbolHashMapBucket* _buckets;
887 void initialize_table(int table_size) {
888 _table_size = table_size;
889 _buckets = NEW_C_HEAP_ARRAY(SymbolHashMapBucket, table_size, mtSymbol);
890 for (int index = 0; index < table_size; index++) {
891 _buckets[index].clear();
892 }
893 }
895 public:
897 int table_size() const { return _table_size; }
899 SymbolHashMap() { initialize_table(_Def_HashMap_Size); }
900 SymbolHashMap(int table_size) { initialize_table(table_size); }
902 // hash P(31) from Kernighan & Ritchie
903 static unsigned int compute_hash(const char* str, int len) {
904 unsigned int hash = 0;
905 while (len-- > 0) {
906 hash = 31*hash + (unsigned) *str;
907 str++;
908 }
909 return hash;
910 }
912 SymbolHashMapEntry* bucket(int i) {
913 return _buckets[i].entry();
914 }
916 void add_entry(Symbol* sym, u2 value);
917 SymbolHashMapEntry* find_entry(Symbol* sym);
919 u2 symbol_to_value(Symbol* sym) {
920 SymbolHashMapEntry *entry = find_entry(sym);
921 return (entry == NULL) ? 0 : entry->value();
922 }
924 ~SymbolHashMap() {
925 SymbolHashMapEntry* next;
926 for (int i = 0; i < _table_size; i++) {
927 for (SymbolHashMapEntry* cur = bucket(i); cur != NULL; cur = next) {
928 next = cur->next();
929 delete(cur);
930 }
931 }
932 delete _buckets;
933 }
934 }; // End SymbolHashMap class
936 #endif // SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP