Thu, 10 Feb 2011 14:48:07 -0800
7018302: newly added assert related to size of constantPoolOop causes secondary assertions or crashes
Summary: 6912621 used a raw oop in the newly added assert following an allocation attempt that could result in a GC.
Reviewed-by: jmasa
1 /*
2 * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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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 *
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23 */
25 #ifndef SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP
26 #define SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP
28 #include "oops/arrayOop.hpp"
29 #include "oops/cpCacheOop.hpp"
30 #include "oops/symbol.hpp"
31 #include "oops/typeArrayOop.hpp"
32 #include "utilities/constantTag.hpp"
33 #ifdef TARGET_ARCH_x86
34 # include "bytes_x86.hpp"
35 #endif
36 #ifdef TARGET_ARCH_sparc
37 # include "bytes_sparc.hpp"
38 #endif
39 #ifdef TARGET_ARCH_zero
40 # include "bytes_zero.hpp"
41 #endif
43 // A constantPool is an array containing class constants as described in the
44 // class file.
45 //
46 // Most of the constant pool entries are written during class parsing, which
47 // is safe. For klass and string types, the constant pool entry is
48 // modified when the entry is resolved. If a klass or string constant pool
49 // entry is read without a lock, only the resolved state guarantees that
50 // the entry in the constant pool is a klass or String object and
51 // not a Symbol*.
53 class SymbolHashMap;
55 class CPSlot VALUE_OBJ_CLASS_SPEC {
56 intptr_t _ptr;
57 public:
58 CPSlot(intptr_t ptr): _ptr(ptr) {}
59 CPSlot(void* ptr): _ptr((intptr_t)ptr) {}
60 CPSlot(oop ptr): _ptr((intptr_t)ptr) {}
61 CPSlot(Symbol* ptr): _ptr((intptr_t)ptr | 1) {}
63 intptr_t value() { return _ptr; }
64 bool is_oop() { return (_ptr & 1) == 0; }
65 bool is_metadata() { return (_ptr & 1) == 1; }
67 oop get_oop() {
68 assert(is_oop(), "bad call");
69 return oop(_ptr);
70 }
71 Symbol* get_symbol() {
72 assert(is_metadata(), "bad call");
73 return (Symbol*)(_ptr & ~1);
74 }
75 };
77 class constantPoolOopDesc : public oopDesc {
78 friend class VMStructs;
79 friend class BytecodeInterpreter; // Directly extracts an oop in the pool for fast instanceof/checkcast
80 private:
81 typeArrayOop _tags; // the tag array describing the constant pool's contents
82 constantPoolCacheOop _cache; // the cache holding interpreter runtime information
83 klassOop _pool_holder; // the corresponding class
84 typeArrayOop _operands; // for variable-sized (InvokeDynamic) nodes, usually empty
85 int _flags; // a few header bits to describe contents for GC
86 int _length; // number of elements in the array
87 volatile bool _is_conc_safe; // if true, safe for concurrent
88 // GC processing
89 // only set to non-zero if constant pool is merged by RedefineClasses
90 int _orig_length;
92 void set_tags(typeArrayOop tags) { oop_store_without_check((oop*)&_tags, tags); }
93 void tag_at_put(int which, jbyte t) { tags()->byte_at_put(which, t); }
94 void release_tag_at_put(int which, jbyte t) { tags()->release_byte_at_put(which, t); }
96 void set_operands(typeArrayOop operands) { oop_store_without_check((oop*)&_operands, operands); }
98 enum FlagBit {
99 FB_has_invokedynamic = 1,
100 FB_has_pseudo_string = 2
101 };
103 int flags() const { return _flags; }
104 void set_flags(int f) { _flags = f; }
105 bool flag_at(FlagBit fb) const { return (_flags & (1 << (int)fb)) != 0; }
106 void set_flag_at(FlagBit fb);
107 // no clear_flag_at function; they only increase
109 private:
110 intptr_t* base() const { return (intptr_t*) (((char*) this) + sizeof(constantPoolOopDesc)); }
111 oop* tags_addr() { return (oop*)&_tags; }
112 oop* cache_addr() { return (oop*)&_cache; }
113 oop* operands_addr() { return (oop*)&_operands; }
115 CPSlot slot_at(int which) {
116 assert(is_within_bounds(which), "index out of bounds");
117 // There's a transitional value of zero when converting from
118 // Symbol->0->Klass for G1 when resolving classes and strings.
119 // wait for the value to be non-zero (this is temporary)
120 volatile intptr_t adr = (intptr_t)OrderAccess::load_ptr_acquire(obj_at_addr_raw(which));
121 if (adr == 0 && which != 0) {
122 constantTag t = tag_at(which);
123 if (t.is_unresolved_klass() || t.is_klass() ||
124 t.is_unresolved_string() || t.is_string()) {
125 while ((adr = (intptr_t)OrderAccess::load_ptr_acquire(obj_at_addr_raw(which))) == 0);
126 }
127 }
128 return CPSlot(adr);
129 }
131 void slot_at_put(int which, CPSlot s) const {
132 assert(is_within_bounds(which), "index out of bounds");
133 *(intptr_t*)&base()[which] = s.value();
134 }
135 oop* obj_at_addr_raw(int which) const {
136 assert(is_within_bounds(which), "index out of bounds");
137 return (oop*) &base()[which];
138 }
140 void obj_at_put_without_check(int which, oop o) {
141 assert(is_within_bounds(which), "index out of bounds");
142 oop_store_without_check((volatile oop *)obj_at_addr_raw(which), o);
143 }
145 void obj_at_put(int which, oop o) const {
146 assert(is_within_bounds(which), "index out of bounds");
147 oop_store((volatile oop*)obj_at_addr_raw(which), o);
148 }
150 jint* int_at_addr(int which) const {
151 assert(is_within_bounds(which), "index out of bounds");
152 return (jint*) &base()[which];
153 }
155 jlong* long_at_addr(int which) const {
156 assert(is_within_bounds(which), "index out of bounds");
157 return (jlong*) &base()[which];
158 }
160 jfloat* float_at_addr(int which) const {
161 assert(is_within_bounds(which), "index out of bounds");
162 return (jfloat*) &base()[which];
163 }
165 jdouble* double_at_addr(int which) const {
166 assert(is_within_bounds(which), "index out of bounds");
167 return (jdouble*) &base()[which];
168 }
170 public:
171 typeArrayOop tags() const { return _tags; }
172 typeArrayOop operands() const { return _operands; }
174 bool has_pseudo_string() const { return flag_at(FB_has_pseudo_string); }
175 bool has_invokedynamic() const { return flag_at(FB_has_invokedynamic); }
176 void set_pseudo_string() { set_flag_at(FB_has_pseudo_string); }
177 void set_invokedynamic() { set_flag_at(FB_has_invokedynamic); }
179 // Klass holding pool
180 klassOop pool_holder() const { return _pool_holder; }
181 void set_pool_holder(klassOop k) { oop_store_without_check((oop*)&_pool_holder, (oop) k); }
182 oop* pool_holder_addr() { return (oop*)&_pool_holder; }
184 // Interpreter runtime support
185 constantPoolCacheOop cache() const { return _cache; }
186 void set_cache(constantPoolCacheOop cache){ oop_store((oop*)&_cache, cache); }
188 // Assembly code support
189 static int tags_offset_in_bytes() { return offset_of(constantPoolOopDesc, _tags); }
190 static int cache_offset_in_bytes() { return offset_of(constantPoolOopDesc, _cache); }
191 static int operands_offset_in_bytes() { return offset_of(constantPoolOopDesc, _operands); }
192 static int pool_holder_offset_in_bytes() { return offset_of(constantPoolOopDesc, _pool_holder); }
194 // Storing constants
196 void klass_at_put(int which, klassOop k) {
197 // Overwrite the old index with a GC friendly value so
198 // that if G1 looks during the transition during oop_store it won't
199 // assert the symbol is not an oop.
200 *obj_at_addr_raw(which) = NULL;
201 assert(k != NULL, "resolved class shouldn't be null");
202 obj_at_put_without_check(which, k);
203 // The interpreter assumes when the tag is stored, the klass is resolved
204 // and the klassOop is a klass rather than a Symbol*, so we need
205 // hardware store ordering here.
206 release_tag_at_put(which, JVM_CONSTANT_Class);
207 if (UseConcMarkSweepGC) {
208 // In case the earlier card-mark was consumed by a concurrent
209 // marking thread before the tag was updated, redirty the card.
210 obj_at_put_without_check(which, k);
211 }
212 }
214 // For temporary use while constructing constant pool
215 void klass_index_at_put(int which, int name_index) {
216 tag_at_put(which, JVM_CONSTANT_ClassIndex);
217 *int_at_addr(which) = name_index;
218 }
220 // Temporary until actual use
221 void unresolved_klass_at_put(int which, Symbol* s) {
222 release_tag_at_put(which, JVM_CONSTANT_UnresolvedClass);
223 slot_at_put(which, s);
224 }
226 void method_handle_index_at_put(int which, int ref_kind, int ref_index) {
227 tag_at_put(which, JVM_CONSTANT_MethodHandle);
228 *int_at_addr(which) = ((jint) ref_index<<16) | ref_kind;
229 }
231 void method_type_index_at_put(int which, int ref_index) {
232 tag_at_put(which, JVM_CONSTANT_MethodType);
233 *int_at_addr(which) = ref_index;
234 }
236 void invoke_dynamic_at_put(int which, int bootstrap_specifier_index, int name_and_type_index) {
237 tag_at_put(which, JVM_CONSTANT_InvokeDynamic);
238 *int_at_addr(which) = ((jint) name_and_type_index<<16) | bootstrap_specifier_index;
239 }
241 void invoke_dynamic_trans_at_put(int which, int bootstrap_method_index, int name_and_type_index) {
242 tag_at_put(which, JVM_CONSTANT_InvokeDynamicTrans);
243 *int_at_addr(which) = ((jint) name_and_type_index<<16) | bootstrap_method_index;
244 assert(AllowTransitionalJSR292, "");
245 }
247 // Temporary until actual use
248 void unresolved_string_at_put(int which, Symbol* s) {
249 release_tag_at_put(which, JVM_CONSTANT_UnresolvedString);
250 slot_at_put(which, s);
251 }
253 void int_at_put(int which, jint i) {
254 tag_at_put(which, JVM_CONSTANT_Integer);
255 *int_at_addr(which) = i;
256 }
258 void long_at_put(int which, jlong l) {
259 tag_at_put(which, JVM_CONSTANT_Long);
260 // *long_at_addr(which) = l;
261 Bytes::put_native_u8((address)long_at_addr(which), *((u8*) &l));
262 }
264 void float_at_put(int which, jfloat f) {
265 tag_at_put(which, JVM_CONSTANT_Float);
266 *float_at_addr(which) = f;
267 }
269 void double_at_put(int which, jdouble d) {
270 tag_at_put(which, JVM_CONSTANT_Double);
271 // *double_at_addr(which) = d;
272 // u8 temp = *(u8*) &d;
273 Bytes::put_native_u8((address) double_at_addr(which), *((u8*) &d));
274 }
276 Symbol** symbol_at_addr(int which) const {
277 assert(is_within_bounds(which), "index out of bounds");
278 return (Symbol**) &base()[which];
279 }
281 void symbol_at_put(int which, Symbol* s) {
282 assert(s->refcount() != 0, "should have nonzero refcount");
283 tag_at_put(which, JVM_CONSTANT_Utf8);
284 slot_at_put(which, s);
285 }
287 void string_at_put(int which, oop str) {
288 // Overwrite the old index with a GC friendly value so
289 // that if G1 looks during the transition during oop_store it won't
290 // assert the symbol is not an oop.
291 *obj_at_addr_raw(which) = NULL;
292 assert(str != NULL, "resolved string shouldn't be null");
293 obj_at_put(which, str);
294 release_tag_at_put(which, JVM_CONSTANT_String);
295 if (UseConcMarkSweepGC) {
296 // In case the earlier card-mark was consumed by a concurrent
297 // marking thread before the tag was updated, redirty the card.
298 obj_at_put_without_check(which, str);
299 }
300 }
302 void object_at_put(int which, oop str) {
303 obj_at_put(which, str);
304 release_tag_at_put(which, JVM_CONSTANT_Object);
305 if (UseConcMarkSweepGC) {
306 // In case the earlier card-mark was consumed by a concurrent
307 // marking thread before the tag was updated, redirty the card.
308 obj_at_put_without_check(which, str);
309 }
310 }
312 // For temporary use while constructing constant pool
313 void string_index_at_put(int which, int string_index) {
314 tag_at_put(which, JVM_CONSTANT_StringIndex);
315 *int_at_addr(which) = string_index;
316 }
318 void field_at_put(int which, int class_index, int name_and_type_index) {
319 tag_at_put(which, JVM_CONSTANT_Fieldref);
320 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
321 }
323 void method_at_put(int which, int class_index, int name_and_type_index) {
324 tag_at_put(which, JVM_CONSTANT_Methodref);
325 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
326 }
328 void interface_method_at_put(int which, int class_index, int name_and_type_index) {
329 tag_at_put(which, JVM_CONSTANT_InterfaceMethodref);
330 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; // Not so nice
331 }
333 void name_and_type_at_put(int which, int name_index, int signature_index) {
334 tag_at_put(which, JVM_CONSTANT_NameAndType);
335 *int_at_addr(which) = ((jint) signature_index<<16) | name_index; // Not so nice
336 }
338 // Tag query
340 constantTag tag_at(int which) const { return (constantTag)tags()->byte_at_acquire(which); }
342 // Whether the entry is a pointer that must be GC'd.
343 bool is_pointer_entry(int which) {
344 constantTag tag = tag_at(which);
345 return tag.is_klass() ||
346 tag.is_string() ||
347 tag.is_object();
348 }
350 // Whether the entry points to an object for ldc (resolved or not)
351 bool is_object_entry(int which) {
352 constantTag tag = tag_at(which);
353 return is_pointer_entry(which) ||
354 tag.is_unresolved_klass() ||
355 tag.is_unresolved_string() ||
356 tag.is_symbol();
357 }
359 // Fetching constants
361 klassOop klass_at(int which, TRAPS) {
362 constantPoolHandle h_this(THREAD, this);
363 return klass_at_impl(h_this, which, CHECK_NULL);
364 }
366 Symbol* klass_name_at(int which); // Returns the name, w/o resolving.
368 klassOop resolved_klass_at(int which) { // Used by Compiler
369 guarantee(tag_at(which).is_klass(), "Corrupted constant pool");
370 // Must do an acquire here in case another thread resolved the klass
371 // behind our back, lest we later load stale values thru the oop.
372 return klassOop(CPSlot(OrderAccess::load_ptr_acquire(obj_at_addr_raw(which))).get_oop());
373 }
375 // This method should only be used with a cpool lock or during parsing or gc
376 Symbol* unresolved_klass_at(int which) { // Temporary until actual use
377 Symbol* s = CPSlot(OrderAccess::load_ptr_acquire(obj_at_addr_raw(which))).get_symbol();
378 // check that the klass is still unresolved.
379 assert(tag_at(which).is_unresolved_klass(), "Corrupted constant pool");
380 return s;
381 }
383 // RedefineClasses() API support:
384 Symbol* klass_at_noresolve(int which) { return klass_name_at(which); }
386 jint int_at(int which) {
387 assert(tag_at(which).is_int(), "Corrupted constant pool");
388 return *int_at_addr(which);
389 }
391 jlong long_at(int which) {
392 assert(tag_at(which).is_long(), "Corrupted constant pool");
393 // return *long_at_addr(which);
394 u8 tmp = Bytes::get_native_u8((address)&base()[which]);
395 return *((jlong*)&tmp);
396 }
398 jfloat float_at(int which) {
399 assert(tag_at(which).is_float(), "Corrupted constant pool");
400 return *float_at_addr(which);
401 }
403 jdouble double_at(int which) {
404 assert(tag_at(which).is_double(), "Corrupted constant pool");
405 u8 tmp = Bytes::get_native_u8((address)&base()[which]);
406 return *((jdouble*)&tmp);
407 }
409 Symbol* symbol_at(int which) {
410 assert(tag_at(which).is_utf8(), "Corrupted constant pool");
411 return slot_at(which).get_symbol();
412 }
414 oop string_at(int which, TRAPS) {
415 constantPoolHandle h_this(THREAD, this);
416 return string_at_impl(h_this, which, CHECK_NULL);
417 }
419 oop object_at(int which) {
420 assert(tag_at(which).is_object(), "Corrupted constant pool");
421 return slot_at(which).get_oop();
422 }
424 // A "pseudo-string" is an non-string oop that has found is way into
425 // a String entry.
426 // Under AnonymousClasses this can happen if the user patches a live
427 // object into a CONSTANT_String entry of an anonymous class.
428 // Method oops internally created for method handles may also
429 // use pseudo-strings to link themselves to related metaobjects.
431 bool is_pseudo_string_at(int which);
433 oop pseudo_string_at(int which) {
434 assert(tag_at(which).is_string(), "Corrupted constant pool");
435 return slot_at(which).get_oop();
436 }
438 void pseudo_string_at_put(int which, oop x) {
439 assert(AnonymousClasses, "");
440 set_pseudo_string(); // mark header
441 assert(tag_at(which).is_string() || tag_at(which).is_unresolved_string(), "Corrupted constant pool");
442 string_at_put(which, x); // this works just fine
443 }
445 // only called when we are sure a string entry is already resolved (via an
446 // earlier string_at call.
447 oop resolved_string_at(int which) {
448 assert(tag_at(which).is_string(), "Corrupted constant pool");
449 // Must do an acquire here in case another thread resolved the klass
450 // behind our back, lest we later load stale values thru the oop.
451 return CPSlot(OrderAccess::load_ptr_acquire(obj_at_addr_raw(which))).get_oop();
452 }
454 // This method should only be used with a cpool lock or during parsing or gc
455 Symbol* unresolved_string_at(int which) { // Temporary until actual use
456 Symbol* s = CPSlot(OrderAccess::load_ptr_acquire(obj_at_addr_raw(which))).get_symbol();
457 // check that the string is still unresolved.
458 assert(tag_at(which).is_unresolved_string(), "Corrupted constant pool");
459 return s;
460 }
462 // Returns an UTF8 for a CONSTANT_String entry at a given index.
463 // UTF8 char* representation was chosen to avoid conversion of
464 // java_lang_Strings at resolved entries into Symbol*s
465 // or vice versa.
466 // Caller is responsible for checking for pseudo-strings.
467 char* string_at_noresolve(int which);
469 jint name_and_type_at(int which) {
470 assert(tag_at(which).is_name_and_type(), "Corrupted constant pool");
471 return *int_at_addr(which);
472 }
474 int method_handle_ref_kind_at(int which) {
475 assert(tag_at(which).is_method_handle(), "Corrupted constant pool");
476 return extract_low_short_from_int(*int_at_addr(which)); // mask out unwanted ref_index bits
477 }
478 int method_handle_index_at(int which) {
479 assert(tag_at(which).is_method_handle(), "Corrupted constant pool");
480 return extract_high_short_from_int(*int_at_addr(which)); // shift out unwanted ref_kind bits
481 }
482 int method_type_index_at(int which) {
483 assert(tag_at(which).is_method_type(), "Corrupted constant pool");
484 return *int_at_addr(which);
485 }
486 // Derived queries:
487 Symbol* method_handle_name_ref_at(int which) {
488 int member = method_handle_index_at(which);
489 return impl_name_ref_at(member, true);
490 }
491 Symbol* method_handle_signature_ref_at(int which) {
492 int member = method_handle_index_at(which);
493 return impl_signature_ref_at(member, true);
494 }
495 int method_handle_klass_index_at(int which) {
496 int member = method_handle_index_at(which);
497 return impl_klass_ref_index_at(member, true);
498 }
499 Symbol* method_type_signature_at(int which) {
500 int sym = method_type_index_at(which);
501 return symbol_at(sym);
502 }
504 int invoke_dynamic_name_and_type_ref_index_at(int which) {
505 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool");
506 return extract_high_short_from_int(*int_at_addr(which));
507 }
508 int invoke_dynamic_bootstrap_specifier_index(int which) {
509 assert(tag_at(which).value() == JVM_CONSTANT_InvokeDynamic, "Corrupted constant pool");
510 return extract_low_short_from_int(*int_at_addr(which));
511 }
512 int invoke_dynamic_operand_base(int which) {
513 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which);
514 return operand_offset_at(operands(), bootstrap_specifier_index);
515 }
516 // The first part of the operands array consists of an index into the second part.
517 // Extract a 32-bit index value from the first part.
518 static int operand_offset_at(typeArrayOop operands, int bootstrap_specifier_index) {
519 int n = (bootstrap_specifier_index * 2);
520 assert(n >= 0 && n+2 <= operands->length(), "oob");
521 // The first 32-bit index points to the beginning of the second part
522 // of the operands array. Make sure this index is in the first part.
523 DEBUG_ONLY(int second_part = build_int_from_shorts(operands->short_at(0),
524 operands->short_at(1)));
525 assert(second_part == 0 || n+2 <= second_part, "oob (2)");
526 int offset = build_int_from_shorts(operands->short_at(n+0),
527 operands->short_at(n+1));
528 // The offset itself must point into the second part of the array.
529 assert(offset == 0 || offset >= second_part && offset <= operands->length(), "oob (3)");
530 return offset;
531 }
532 static void operand_offset_at_put(typeArrayOop operands, int bootstrap_specifier_index, int offset) {
533 int n = bootstrap_specifier_index * 2;
534 assert(n >= 0 && n+2 <= operands->length(), "oob");
535 operands->short_at_put(n+0, extract_low_short_from_int(offset));
536 operands->short_at_put(n+1, extract_high_short_from_int(offset));
537 }
538 static int operand_array_length(typeArrayOop operands) {
539 if (operands == NULL || operands->length() == 0) return 0;
540 int second_part = operand_offset_at(operands, 0);
541 return (second_part / 2);
542 }
544 #ifdef ASSERT
545 // operand tuples fit together exactly, end to end
546 static int operand_limit_at(typeArrayOop operands, int bootstrap_specifier_index) {
547 int nextidx = bootstrap_specifier_index + 1;
548 if (nextidx == operand_array_length(operands))
549 return operands->length();
550 else
551 return operand_offset_at(operands, nextidx);
552 }
553 int invoke_dynamic_operand_limit(int which) {
554 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which);
555 return operand_limit_at(operands(), bootstrap_specifier_index);
556 }
557 #endif //ASSERT
559 // layout of InvokeDynamic bootstrap method specifier (in second part of operands array):
560 enum {
561 _indy_bsm_offset = 0, // CONSTANT_MethodHandle bsm
562 _indy_argc_offset = 1, // u2 argc
563 _indy_argv_offset = 2 // u2 argv[argc]
564 };
565 int invoke_dynamic_bootstrap_method_ref_index_at(int which) {
566 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool");
567 if (tag_at(which).value() == JVM_CONSTANT_InvokeDynamicTrans)
568 return extract_low_short_from_int(*int_at_addr(which));
569 int op_base = invoke_dynamic_operand_base(which);
570 return operands()->short_at(op_base + _indy_bsm_offset);
571 }
572 int invoke_dynamic_argument_count_at(int which) {
573 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool");
574 if (tag_at(which).value() == JVM_CONSTANT_InvokeDynamicTrans)
575 return 0;
576 int op_base = invoke_dynamic_operand_base(which);
577 int argc = operands()->short_at(op_base + _indy_argc_offset);
578 DEBUG_ONLY(int end_offset = op_base + _indy_argv_offset + argc;
579 int next_offset = invoke_dynamic_operand_limit(which));
580 assert(end_offset == next_offset, "matched ending");
581 return argc;
582 }
583 int invoke_dynamic_argument_index_at(int which, int j) {
584 int op_base = invoke_dynamic_operand_base(which);
585 DEBUG_ONLY(int argc = operands()->short_at(op_base + _indy_argc_offset));
586 assert((uint)j < (uint)argc, "oob");
587 return operands()->short_at(op_base + _indy_argv_offset + j);
588 }
590 // The following methods (name/signature/klass_ref_at, klass_ref_at_noresolve,
591 // name_and_type_ref_index_at) all expect to be passed indices obtained
592 // directly from the bytecode.
593 // If the indices are meant to refer to fields or methods, they are
594 // actually rewritten constant pool cache indices.
595 // The routine remap_instruction_operand_from_cache manages the adjustment
596 // of these values back to constant pool indices.
598 // There are also "uncached" versions which do not adjust the operand index; see below.
600 // FIXME: Consider renaming these with a prefix "cached_" to make the distinction clear.
601 // In a few cases (the verifier) there are uses before a cpcache has been built,
602 // which are handled by a dynamic check in remap_instruction_operand_from_cache.
603 // FIXME: Remove the dynamic check, and adjust all callers to specify the correct mode.
605 // Lookup for entries consisting of (klass_index, name_and_type index)
606 klassOop klass_ref_at(int which, TRAPS);
607 Symbol* klass_ref_at_noresolve(int which);
608 Symbol* name_ref_at(int which) { return impl_name_ref_at(which, false); }
609 Symbol* signature_ref_at(int which) { return impl_signature_ref_at(which, false); }
611 int klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, false); }
612 int name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, false); }
614 // Lookup for entries consisting of (name_index, signature_index)
615 int name_ref_index_at(int which_nt); // == low-order jshort of name_and_type_at(which_nt)
616 int signature_ref_index_at(int which_nt); // == high-order jshort of name_and_type_at(which_nt)
618 BasicType basic_type_for_signature_at(int which);
620 // Resolve string constants (to prevent allocation during compilation)
621 void resolve_string_constants(TRAPS) {
622 constantPoolHandle h_this(THREAD, this);
623 resolve_string_constants_impl(h_this, CHECK);
624 }
626 private:
627 enum { _no_index_sentinel = -1, _possible_index_sentinel = -2 };
628 public:
630 // Resolve late bound constants.
631 oop resolve_constant_at(int index, TRAPS) {
632 constantPoolHandle h_this(THREAD, this);
633 return resolve_constant_at_impl(h_this, index, _no_index_sentinel, THREAD);
634 }
636 oop resolve_cached_constant_at(int cache_index, TRAPS) {
637 constantPoolHandle h_this(THREAD, this);
638 return resolve_constant_at_impl(h_this, _no_index_sentinel, cache_index, THREAD);
639 }
641 oop resolve_possibly_cached_constant_at(int pool_index, TRAPS) {
642 constantPoolHandle h_this(THREAD, this);
643 return resolve_constant_at_impl(h_this, pool_index, _possible_index_sentinel, THREAD);
644 }
646 // Klass name matches name at offset
647 bool klass_name_at_matches(instanceKlassHandle k, int which);
649 // Sizing
650 int length() const { return _length; }
651 void set_length(int length) { _length = length; }
653 // Tells whether index is within bounds.
654 bool is_within_bounds(int index) const {
655 return 0 <= index && index < length();
656 }
658 static int header_size() { return sizeof(constantPoolOopDesc)/HeapWordSize; }
659 static int object_size(int length) { return align_object_size(header_size() + length); }
660 int object_size() { return object_size(length()); }
662 bool is_conc_safe() { return _is_conc_safe; }
663 void set_is_conc_safe(bool v) { _is_conc_safe = v; }
665 friend class constantPoolKlass;
666 friend class ClassFileParser;
667 friend class SystemDictionary;
669 // Used by compiler to prevent classloading.
670 static klassOop klass_at_if_loaded (constantPoolHandle this_oop, int which);
671 static klassOop klass_ref_at_if_loaded (constantPoolHandle this_oop, int which);
672 // Same as above - but does LinkResolving.
673 static klassOop klass_ref_at_if_loaded_check(constantPoolHandle this_oop, int which, TRAPS);
675 // Routines currently used for annotations (only called by jvm.cpp) but which might be used in the
676 // future by other Java code. These take constant pool indices rather than
677 // constant pool cache indices as do the peer methods above.
678 Symbol* uncached_klass_ref_at_noresolve(int which);
679 Symbol* uncached_name_ref_at(int which) { return impl_name_ref_at(which, true); }
680 Symbol* uncached_signature_ref_at(int which) { return impl_signature_ref_at(which, true); }
681 int uncached_klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, true); }
682 int uncached_name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, true); }
684 // Sharing
685 int pre_resolve_shared_klasses(TRAPS);
686 void shared_symbols_iterate(SymbolClosure* closure0);
687 void shared_tags_iterate(OopClosure* closure0);
688 void shared_strings_iterate(OopClosure* closure0);
690 // Debugging
691 const char* printable_name_at(int which) PRODUCT_RETURN0;
693 #ifdef ASSERT
694 enum { CPCACHE_INDEX_TAG = 0x10000 }; // helps keep CP cache indices distinct from CP indices
695 #else
696 enum { CPCACHE_INDEX_TAG = 0 }; // in product mode, this zero value is a no-op
697 #endif //ASSERT
699 private:
701 Symbol* impl_name_ref_at(int which, bool uncached);
702 Symbol* impl_signature_ref_at(int which, bool uncached);
703 int impl_klass_ref_index_at(int which, bool uncached);
704 int impl_name_and_type_ref_index_at(int which, bool uncached);
706 int remap_instruction_operand_from_cache(int operand); // operand must be biased by CPCACHE_INDEX_TAG
708 // Used while constructing constant pool (only by ClassFileParser)
709 jint klass_index_at(int which) {
710 assert(tag_at(which).is_klass_index(), "Corrupted constant pool");
711 return *int_at_addr(which);
712 }
714 jint string_index_at(int which) {
715 assert(tag_at(which).is_string_index(), "Corrupted constant pool");
716 return *int_at_addr(which);
717 }
719 // Performs the LinkResolver checks
720 static void verify_constant_pool_resolve(constantPoolHandle this_oop, KlassHandle klass, TRAPS);
722 // Implementation of methods that needs an exposed 'this' pointer, in order to
723 // handle GC while executing the method
724 static klassOop klass_at_impl(constantPoolHandle this_oop, int which, TRAPS);
725 static oop string_at_impl(constantPoolHandle this_oop, int which, TRAPS);
727 // Resolve string constants (to prevent allocation during compilation)
728 static void resolve_string_constants_impl(constantPoolHandle this_oop, TRAPS);
730 static oop resolve_constant_at_impl(constantPoolHandle this_oop, int index, int cache_index, TRAPS);
732 public:
733 // Merging constantPoolOop support:
734 bool compare_entry_to(int index1, constantPoolHandle cp2, int index2, TRAPS);
735 void copy_cp_to(int start_i, int end_i, constantPoolHandle to_cp, int to_i, TRAPS) {
736 constantPoolHandle h_this(THREAD, this);
737 copy_cp_to_impl(h_this, start_i, end_i, to_cp, to_i, THREAD);
738 }
739 static void copy_cp_to_impl(constantPoolHandle from_cp, int start_i, int end_i, constantPoolHandle to_cp, int to_i, TRAPS);
740 static void copy_entry_to(constantPoolHandle from_cp, int from_i, constantPoolHandle to_cp, int to_i, TRAPS);
741 int find_matching_entry(int pattern_i, constantPoolHandle search_cp, TRAPS);
742 int orig_length() const { return _orig_length; }
743 void set_orig_length(int orig_length) { _orig_length = orig_length; }
745 // Decrease ref counts of symbols that are in the constant pool
746 // when the holder class is unloaded
747 void unreference_symbols();
749 // JVMTI accesss - GetConstantPool, RetransformClasses, ...
750 friend class JvmtiConstantPoolReconstituter;
752 private:
753 jint cpool_entry_size(jint idx);
754 jint hash_entries_to(SymbolHashMap *symmap, SymbolHashMap *classmap);
756 // Copy cpool bytes into byte array.
757 // Returns:
758 // int > 0, count of the raw cpool bytes that have been copied
759 // 0, OutOfMemory error
760 // -1, Internal error
761 int copy_cpool_bytes(int cpool_size,
762 SymbolHashMap* tbl,
763 unsigned char *bytes);
764 };
766 class SymbolHashMapEntry : public CHeapObj {
767 private:
768 unsigned int _hash; // 32-bit hash for item
769 SymbolHashMapEntry* _next; // Next element in the linked list for this bucket
770 Symbol* _symbol; // 1-st part of the mapping: symbol => value
771 u2 _value; // 2-nd part of the mapping: symbol => value
773 public:
774 unsigned int hash() const { return _hash; }
775 void set_hash(unsigned int hash) { _hash = hash; }
777 SymbolHashMapEntry* next() const { return _next; }
778 void set_next(SymbolHashMapEntry* next) { _next = next; }
780 Symbol* symbol() const { return _symbol; }
781 void set_symbol(Symbol* sym) { _symbol = sym; }
783 u2 value() const { return _value; }
784 void set_value(u2 value) { _value = value; }
786 SymbolHashMapEntry(unsigned int hash, Symbol* symbol, u2 value)
787 : _hash(hash), _symbol(symbol), _value(value), _next(NULL) {}
789 }; // End SymbolHashMapEntry class
792 class SymbolHashMapBucket : public CHeapObj {
794 private:
795 SymbolHashMapEntry* _entry;
797 public:
798 SymbolHashMapEntry* entry() const { return _entry; }
799 void set_entry(SymbolHashMapEntry* entry) { _entry = entry; }
800 void clear() { _entry = NULL; }
802 }; // End SymbolHashMapBucket class
805 class SymbolHashMap: public CHeapObj {
807 private:
808 // Default number of entries in the table
809 enum SymbolHashMap_Constants {
810 _Def_HashMap_Size = 256
811 };
813 int _table_size;
814 SymbolHashMapBucket* _buckets;
816 void initialize_table(int table_size) {
817 _table_size = table_size;
818 _buckets = NEW_C_HEAP_ARRAY(SymbolHashMapBucket, table_size);
819 for (int index = 0; index < table_size; index++) {
820 _buckets[index].clear();
821 }
822 }
824 public:
826 int table_size() const { return _table_size; }
828 SymbolHashMap() { initialize_table(_Def_HashMap_Size); }
829 SymbolHashMap(int table_size) { initialize_table(table_size); }
831 // hash P(31) from Kernighan & Ritchie
832 static unsigned int compute_hash(const char* str, int len) {
833 unsigned int hash = 0;
834 while (len-- > 0) {
835 hash = 31*hash + (unsigned) *str;
836 str++;
837 }
838 return hash;
839 }
841 SymbolHashMapEntry* bucket(int i) {
842 return _buckets[i].entry();
843 }
845 void add_entry(Symbol* sym, u2 value);
846 SymbolHashMapEntry* find_entry(Symbol* sym);
848 u2 symbol_to_value(Symbol* sym) {
849 SymbolHashMapEntry *entry = find_entry(sym);
850 return (entry == NULL) ? 0 : entry->value();
851 }
853 ~SymbolHashMap() {
854 SymbolHashMapEntry* next;
855 for (int i = 0; i < _table_size; i++) {
856 for (SymbolHashMapEntry* cur = bucket(i); cur != NULL; cur = next) {
857 next = cur->next();
858 delete(cur);
859 }
860 }
861 delete _buckets;
862 }
863 }; // End SymbolHashMap class
865 #endif // SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP