Fri, 03 Dec 2010 15:53:57 -0800
7001379: bootstrap method data needs to be moved from constant pool to a classfile attribute
Reviewed-by: twisti
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/cpCacheOop.hpp"
30 #include "oops/typeArrayOop.hpp"
31 #include "utilities/constantTag.hpp"
32 #ifdef TARGET_ARCH_x86
33 # include "bytes_x86.hpp"
34 #endif
35 #ifdef TARGET_ARCH_sparc
36 # include "bytes_sparc.hpp"
37 #endif
38 #ifdef TARGET_ARCH_zero
39 # include "bytes_zero.hpp"
40 #endif
42 // A constantPool is an array containing class constants as described in the
43 // class file.
44 //
45 // Most of the constant pool entries are written during class parsing, which
46 // is safe. For klass and string types, the constant pool entry is
47 // modified when the entry is resolved. If a klass or string constant pool
48 // entry is read without a lock, only the resolved state guarantees that
49 // the entry in the constant pool is a klass or String object and
50 // not a symbolOop.
52 class SymbolHashMap;
54 class constantPoolOopDesc : public oopDesc {
55 friend class VMStructs;
56 friend class BytecodeInterpreter; // Directly extracts an oop in the pool for fast instanceof/checkcast
57 private:
58 typeArrayOop _tags; // the tag array describing the constant pool's contents
59 constantPoolCacheOop _cache; // the cache holding interpreter runtime information
60 klassOop _pool_holder; // the corresponding class
61 typeArrayOop _operands; // for variable-sized (InvokeDynamic) nodes, usually empty
62 int _flags; // a few header bits to describe contents for GC
63 int _length; // number of elements in the array
64 volatile bool _is_conc_safe; // if true, safe for concurrent
65 // GC processing
66 // only set to non-zero if constant pool is merged by RedefineClasses
67 int _orig_length;
69 void set_tags(typeArrayOop tags) { oop_store_without_check((oop*)&_tags, tags); }
70 void tag_at_put(int which, jbyte t) { tags()->byte_at_put(which, t); }
71 void release_tag_at_put(int which, jbyte t) { tags()->release_byte_at_put(which, t); }
73 void set_operands(typeArrayOop operands) { oop_store_without_check((oop*)&_operands, operands); }
75 enum FlagBit {
76 FB_has_invokedynamic = 1,
77 FB_has_pseudo_string = 2
78 };
80 int flags() const { return _flags; }
81 void set_flags(int f) { _flags = f; }
82 bool flag_at(FlagBit fb) const { return (_flags & (1 << (int)fb)) != 0; }
83 void set_flag_at(FlagBit fb);
84 // no clear_flag_at function; they only increase
86 private:
87 intptr_t* base() const { return (intptr_t*) (((char*) this) + sizeof(constantPoolOopDesc)); }
88 oop* tags_addr() { return (oop*)&_tags; }
89 oop* cache_addr() { return (oop*)&_cache; }
90 oop* operands_addr() { return (oop*)&_operands; }
92 oop* obj_at_addr(int which) const {
93 assert(is_within_bounds(which), "index out of bounds");
94 return (oop*) &base()[which];
95 }
97 jint* int_at_addr(int which) const {
98 assert(is_within_bounds(which), "index out of bounds");
99 return (jint*) &base()[which];
100 }
102 jlong* long_at_addr(int which) const {
103 assert(is_within_bounds(which), "index out of bounds");
104 return (jlong*) &base()[which];
105 }
107 jfloat* float_at_addr(int which) const {
108 assert(is_within_bounds(which), "index out of bounds");
109 return (jfloat*) &base()[which];
110 }
112 jdouble* double_at_addr(int which) const {
113 assert(is_within_bounds(which), "index out of bounds");
114 return (jdouble*) &base()[which];
115 }
117 public:
118 typeArrayOop tags() const { return _tags; }
119 typeArrayOop operands() const { return _operands; }
121 bool has_pseudo_string() const { return flag_at(FB_has_pseudo_string); }
122 bool has_invokedynamic() const { return flag_at(FB_has_invokedynamic); }
123 void set_pseudo_string() { set_flag_at(FB_has_pseudo_string); }
124 void set_invokedynamic() { set_flag_at(FB_has_invokedynamic); }
126 // Klass holding pool
127 klassOop pool_holder() const { return _pool_holder; }
128 void set_pool_holder(klassOop k) { oop_store_without_check((oop*)&_pool_holder, (oop) k); }
129 oop* pool_holder_addr() { return (oop*)&_pool_holder; }
131 // Interpreter runtime support
132 constantPoolCacheOop cache() const { return _cache; }
133 void set_cache(constantPoolCacheOop cache){ oop_store((oop*)&_cache, cache); }
135 // Assembly code support
136 static int tags_offset_in_bytes() { return offset_of(constantPoolOopDesc, _tags); }
137 static int cache_offset_in_bytes() { return offset_of(constantPoolOopDesc, _cache); }
138 static int operands_offset_in_bytes() { return offset_of(constantPoolOopDesc, _operands); }
139 static int pool_holder_offset_in_bytes() { return offset_of(constantPoolOopDesc, _pool_holder); }
141 // Storing constants
143 void klass_at_put(int which, klassOop k) {
144 oop_store_without_check((volatile oop *)obj_at_addr(which), oop(k));
145 // The interpreter assumes when the tag is stored, the klass is resolved
146 // and the klassOop is a klass rather than a symbolOop, so we need
147 // hardware store ordering here.
148 release_tag_at_put(which, JVM_CONSTANT_Class);
149 if (UseConcMarkSweepGC) {
150 // In case the earlier card-mark was consumed by a concurrent
151 // marking thread before the tag was updated, redirty the card.
152 oop_store_without_check((volatile oop *)obj_at_addr(which), oop(k));
153 }
154 }
156 // For temporary use while constructing constant pool
157 void klass_index_at_put(int which, int name_index) {
158 tag_at_put(which, JVM_CONSTANT_ClassIndex);
159 *int_at_addr(which) = name_index;
160 }
162 // Temporary until actual use
163 void unresolved_klass_at_put(int which, symbolOop s) {
164 // Overwrite the old index with a GC friendly value so
165 // that if GC looks during the transition it won't try
166 // to treat a small integer as oop.
167 *obj_at_addr(which) = NULL;
168 release_tag_at_put(which, JVM_CONSTANT_UnresolvedClass);
169 oop_store_without_check(obj_at_addr(which), oop(s));
170 }
172 void method_handle_index_at_put(int which, int ref_kind, int ref_index) {
173 tag_at_put(which, JVM_CONSTANT_MethodHandle);
174 *int_at_addr(which) = ((jint) ref_index<<16) | ref_kind;
175 }
177 void method_type_index_at_put(int which, int ref_index) {
178 tag_at_put(which, JVM_CONSTANT_MethodType);
179 *int_at_addr(which) = ref_index;
180 }
182 void invoke_dynamic_at_put(int which, int bootstrap_specifier_index, int name_and_type_index) {
183 tag_at_put(which, JVM_CONSTANT_InvokeDynamic);
184 *int_at_addr(which) = ((jint) name_and_type_index<<16) | bootstrap_specifier_index;
185 }
187 void invoke_dynamic_trans_at_put(int which, int bootstrap_method_index, int name_and_type_index) {
188 tag_at_put(which, JVM_CONSTANT_InvokeDynamicTrans);
189 *int_at_addr(which) = ((jint) name_and_type_index<<16) | bootstrap_method_index;
190 assert(AllowTransitionalJSR292, "");
191 }
193 // Temporary until actual use
194 void unresolved_string_at_put(int which, symbolOop s) {
195 *obj_at_addr(which) = NULL;
196 release_tag_at_put(which, JVM_CONSTANT_UnresolvedString);
197 oop_store_without_check(obj_at_addr(which), oop(s));
198 }
200 void int_at_put(int which, jint i) {
201 tag_at_put(which, JVM_CONSTANT_Integer);
202 *int_at_addr(which) = i;
203 }
205 void long_at_put(int which, jlong l) {
206 tag_at_put(which, JVM_CONSTANT_Long);
207 // *long_at_addr(which) = l;
208 Bytes::put_native_u8((address)long_at_addr(which), *((u8*) &l));
209 }
211 void float_at_put(int which, jfloat f) {
212 tag_at_put(which, JVM_CONSTANT_Float);
213 *float_at_addr(which) = f;
214 }
216 void double_at_put(int which, jdouble d) {
217 tag_at_put(which, JVM_CONSTANT_Double);
218 // *double_at_addr(which) = d;
219 // u8 temp = *(u8*) &d;
220 Bytes::put_native_u8((address) double_at_addr(which), *((u8*) &d));
221 }
223 void symbol_at_put(int which, symbolOop s) {
224 tag_at_put(which, JVM_CONSTANT_Utf8);
225 oop_store_without_check(obj_at_addr(which), oop(s));
226 }
228 void string_at_put(int which, oop str) {
229 oop_store((volatile oop*)obj_at_addr(which), str);
230 release_tag_at_put(which, JVM_CONSTANT_String);
231 if (UseConcMarkSweepGC) {
232 // In case the earlier card-mark was consumed by a concurrent
233 // marking thread before the tag was updated, redirty the card.
234 oop_store_without_check((volatile oop *)obj_at_addr(which), str);
235 }
236 }
238 void object_at_put(int which, oop str) {
239 oop_store((volatile oop*) obj_at_addr(which), str);
240 release_tag_at_put(which, JVM_CONSTANT_Object);
241 if (UseConcMarkSweepGC) {
242 // In case the earlier card-mark was consumed by a concurrent
243 // marking thread before the tag was updated, redirty the card.
244 oop_store_without_check((volatile oop*) obj_at_addr(which), str);
245 }
246 }
248 // For temporary use while constructing constant pool
249 void string_index_at_put(int which, int string_index) {
250 tag_at_put(which, JVM_CONSTANT_StringIndex);
251 *int_at_addr(which) = string_index;
252 }
254 void field_at_put(int which, int class_index, int name_and_type_index) {
255 tag_at_put(which, JVM_CONSTANT_Fieldref);
256 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
257 }
259 void method_at_put(int which, int class_index, int name_and_type_index) {
260 tag_at_put(which, JVM_CONSTANT_Methodref);
261 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
262 }
264 void interface_method_at_put(int which, int class_index, int name_and_type_index) {
265 tag_at_put(which, JVM_CONSTANT_InterfaceMethodref);
266 *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; // Not so nice
267 }
269 void name_and_type_at_put(int which, int name_index, int signature_index) {
270 tag_at_put(which, JVM_CONSTANT_NameAndType);
271 *int_at_addr(which) = ((jint) signature_index<<16) | name_index; // Not so nice
272 }
274 // Tag query
276 constantTag tag_at(int which) const { return (constantTag)tags()->byte_at_acquire(which); }
278 // Whether the entry is a pointer that must be GC'd.
279 bool is_pointer_entry(int which) {
280 constantTag tag = tag_at(which);
281 return tag.is_klass() ||
282 tag.is_unresolved_klass() ||
283 tag.is_symbol() ||
284 tag.is_unresolved_string() ||
285 tag.is_string() ||
286 tag.is_object();
287 }
289 // Fetching constants
291 klassOop klass_at(int which, TRAPS) {
292 constantPoolHandle h_this(THREAD, this);
293 return klass_at_impl(h_this, which, CHECK_NULL);
294 }
296 symbolOop klass_name_at(int which); // Returns the name, w/o resolving.
298 klassOop resolved_klass_at(int which) { // Used by Compiler
299 guarantee(tag_at(which).is_klass(), "Corrupted constant pool");
300 // Must do an acquire here in case another thread resolved the klass
301 // behind our back, lest we later load stale values thru the oop.
302 return klassOop((oop)OrderAccess::load_ptr_acquire(obj_at_addr(which)));
303 }
305 // This method should only be used with a cpool lock or during parsing or gc
306 symbolOop unresolved_klass_at(int which) { // Temporary until actual use
307 symbolOop s = symbolOop((oop)OrderAccess::load_ptr_acquire(obj_at_addr(which)));
308 // check that the klass is still unresolved.
309 assert(tag_at(which).is_unresolved_klass(), "Corrupted constant pool");
310 return s;
311 }
313 // RedefineClasses() API support:
314 symbolOop klass_at_noresolve(int which) { return klass_name_at(which); }
316 jint int_at(int which) {
317 assert(tag_at(which).is_int(), "Corrupted constant pool");
318 return *int_at_addr(which);
319 }
321 jlong long_at(int which) {
322 assert(tag_at(which).is_long(), "Corrupted constant pool");
323 // return *long_at_addr(which);
324 u8 tmp = Bytes::get_native_u8((address)&base()[which]);
325 return *((jlong*)&tmp);
326 }
328 jfloat float_at(int which) {
329 assert(tag_at(which).is_float(), "Corrupted constant pool");
330 return *float_at_addr(which);
331 }
333 jdouble double_at(int which) {
334 assert(tag_at(which).is_double(), "Corrupted constant pool");
335 u8 tmp = Bytes::get_native_u8((address)&base()[which]);
336 return *((jdouble*)&tmp);
337 }
339 symbolOop symbol_at(int which) {
340 assert(tag_at(which).is_utf8(), "Corrupted constant pool");
341 return symbolOop(*obj_at_addr(which));
342 }
344 oop string_at(int which, TRAPS) {
345 constantPoolHandle h_this(THREAD, this);
346 return string_at_impl(h_this, which, CHECK_NULL);
347 }
349 oop object_at(int which) {
350 assert(tag_at(which).is_object(), "Corrupted constant pool");
351 return *obj_at_addr(which);
352 }
354 // A "pseudo-string" is an non-string oop that has found is way into
355 // a String entry.
356 // Under AnonymousClasses this can happen if the user patches a live
357 // object into a CONSTANT_String entry of an anonymous class.
358 // Method oops internally created for method handles may also
359 // use pseudo-strings to link themselves to related metaobjects.
361 bool is_pseudo_string_at(int which);
363 oop pseudo_string_at(int which) {
364 assert(tag_at(which).is_string(), "Corrupted constant pool");
365 return *obj_at_addr(which);
366 }
368 void pseudo_string_at_put(int which, oop x) {
369 assert(AnonymousClasses, "");
370 set_pseudo_string(); // mark header
371 assert(tag_at(which).is_string() || tag_at(which).is_unresolved_string(), "Corrupted constant pool");
372 string_at_put(which, x); // this works just fine
373 }
375 // only called when we are sure a string entry is already resolved (via an
376 // earlier string_at call.
377 oop resolved_string_at(int which) {
378 assert(tag_at(which).is_string(), "Corrupted constant pool");
379 // Must do an acquire here in case another thread resolved the klass
380 // behind our back, lest we later load stale values thru the oop.
381 return (oop)OrderAccess::load_ptr_acquire(obj_at_addr(which));
382 }
384 // This method should only be used with a cpool lock or during parsing or gc
385 symbolOop unresolved_string_at(int which) { // Temporary until actual use
386 symbolOop s = symbolOop((oop)OrderAccess::load_ptr_acquire(obj_at_addr(which)));
387 // check that the string is still unresolved.
388 assert(tag_at(which).is_unresolved_string(), "Corrupted constant pool");
389 return s;
390 }
392 // Returns an UTF8 for a CONSTANT_String entry at a given index.
393 // UTF8 char* representation was chosen to avoid conversion of
394 // java_lang_Strings at resolved entries into symbolOops
395 // or vice versa.
396 // Caller is responsible for checking for pseudo-strings.
397 char* string_at_noresolve(int which);
399 jint name_and_type_at(int which) {
400 assert(tag_at(which).is_name_and_type(), "Corrupted constant pool");
401 return *int_at_addr(which);
402 }
404 int method_handle_ref_kind_at(int which) {
405 assert(tag_at(which).is_method_handle(), "Corrupted constant pool");
406 return extract_low_short_from_int(*int_at_addr(which)); // mask out unwanted ref_index bits
407 }
408 int method_handle_index_at(int which) {
409 assert(tag_at(which).is_method_handle(), "Corrupted constant pool");
410 return extract_high_short_from_int(*int_at_addr(which)); // shift out unwanted ref_kind bits
411 }
412 int method_type_index_at(int which) {
413 assert(tag_at(which).is_method_type(), "Corrupted constant pool");
414 return *int_at_addr(which);
415 }
416 // Derived queries:
417 symbolOop method_handle_name_ref_at(int which) {
418 int member = method_handle_index_at(which);
419 return impl_name_ref_at(member, true);
420 }
421 symbolOop method_handle_signature_ref_at(int which) {
422 int member = method_handle_index_at(which);
423 return impl_signature_ref_at(member, true);
424 }
425 int method_handle_klass_index_at(int which) {
426 int member = method_handle_index_at(which);
427 return impl_klass_ref_index_at(member, true);
428 }
429 symbolOop method_type_signature_at(int which) {
430 int sym = method_type_index_at(which);
431 return symbol_at(sym);
432 }
434 int invoke_dynamic_name_and_type_ref_index_at(int which) {
435 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool");
436 return extract_high_short_from_int(*int_at_addr(which));
437 }
438 int invoke_dynamic_bootstrap_specifier_index(int which) {
439 assert(tag_at(which).value() == JVM_CONSTANT_InvokeDynamic, "Corrupted constant pool");
440 return extract_low_short_from_int(*int_at_addr(which));
441 }
442 int invoke_dynamic_operand_base(int which) {
443 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which);
444 return operand_offset_at(operands(), bootstrap_specifier_index);
445 }
446 // The first part of the operands array consists of an index into the second part.
447 // Extract a 32-bit index value from the first part.
448 static int operand_offset_at(typeArrayOop operands, int bootstrap_specifier_index) {
449 int n = (bootstrap_specifier_index * 2);
450 assert(n >= 0 && n+2 <= operands->length(), "oob");
451 // The first 32-bit index points to the beginning of the second part
452 // of the operands array. Make sure this index is in the first part.
453 DEBUG_ONLY(int second_part = build_int_from_shorts(operands->short_at(0),
454 operands->short_at(1)));
455 assert(second_part == 0 || n+2 <= second_part, "oob (2)");
456 int offset = build_int_from_shorts(operands->short_at(n+0),
457 operands->short_at(n+1));
458 // The offset itself must point into the second part of the array.
459 assert(offset == 0 || offset >= second_part && offset <= operands->length(), "oob (3)");
460 return offset;
461 }
462 static void operand_offset_at_put(typeArrayOop operands, int bootstrap_specifier_index, int offset) {
463 int n = bootstrap_specifier_index * 2;
464 assert(n >= 0 && n+2 <= operands->length(), "oob");
465 operands->short_at_put(n+0, extract_low_short_from_int(offset));
466 operands->short_at_put(n+1, extract_high_short_from_int(offset));
467 }
468 static int operand_array_length(typeArrayOop operands) {
469 if (operands == NULL || operands->length() == 0) return 0;
470 int second_part = operand_offset_at(operands, 0);
471 return (second_part / 2);
472 }
474 #ifdef ASSERT
475 // operand tuples fit together exactly, end to end
476 static int operand_limit_at(typeArrayOop operands, int bootstrap_specifier_index) {
477 int nextidx = bootstrap_specifier_index + 1;
478 if (nextidx == operand_array_length(operands))
479 return operands->length();
480 else
481 return operand_offset_at(operands, nextidx);
482 }
483 int invoke_dynamic_operand_limit(int which) {
484 int bootstrap_specifier_index = invoke_dynamic_bootstrap_specifier_index(which);
485 return operand_limit_at(operands(), bootstrap_specifier_index);
486 }
487 #endif //ASSERT
489 // layout of InvokeDynamic bootstrap method specifier (in second part of operands array):
490 enum {
491 _indy_bsm_offset = 0, // CONSTANT_MethodHandle bsm
492 _indy_argc_offset = 1, // u2 argc
493 _indy_argv_offset = 2 // u2 argv[argc]
494 };
495 int invoke_dynamic_bootstrap_method_ref_index_at(int which) {
496 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool");
497 if (tag_at(which).value() == JVM_CONSTANT_InvokeDynamicTrans)
498 return extract_low_short_from_int(*int_at_addr(which));
499 int op_base = invoke_dynamic_operand_base(which);
500 return operands()->short_at(op_base + _indy_bsm_offset);
501 }
502 int invoke_dynamic_argument_count_at(int which) {
503 assert(tag_at(which).is_invoke_dynamic(), "Corrupted constant pool");
504 if (tag_at(which).value() == JVM_CONSTANT_InvokeDynamicTrans)
505 return 0;
506 int op_base = invoke_dynamic_operand_base(which);
507 int argc = operands()->short_at(op_base + _indy_argc_offset);
508 DEBUG_ONLY(int end_offset = op_base + _indy_argv_offset + argc;
509 int next_offset = invoke_dynamic_operand_limit(which));
510 assert(end_offset == next_offset, "matched ending");
511 return argc;
512 }
513 int invoke_dynamic_argument_index_at(int which, int j) {
514 int op_base = invoke_dynamic_operand_base(which);
515 DEBUG_ONLY(int argc = operands()->short_at(op_base + _indy_argc_offset));
516 assert((uint)j < (uint)argc, "oob");
517 return operands()->short_at(op_base + _indy_argv_offset + j);
518 }
520 // The following methods (name/signature/klass_ref_at, klass_ref_at_noresolve,
521 // name_and_type_ref_index_at) all expect to be passed indices obtained
522 // directly from the bytecode.
523 // If the indices are meant to refer to fields or methods, they are
524 // actually rewritten constant pool cache indices.
525 // The routine remap_instruction_operand_from_cache manages the adjustment
526 // of these values back to constant pool indices.
528 // There are also "uncached" versions which do not adjust the operand index; see below.
530 // FIXME: Consider renaming these with a prefix "cached_" to make the distinction clear.
531 // In a few cases (the verifier) there are uses before a cpcache has been built,
532 // which are handled by a dynamic check in remap_instruction_operand_from_cache.
533 // FIXME: Remove the dynamic check, and adjust all callers to specify the correct mode.
535 // Lookup for entries consisting of (klass_index, name_and_type index)
536 klassOop klass_ref_at(int which, TRAPS);
537 symbolOop klass_ref_at_noresolve(int which);
538 symbolOop name_ref_at(int which) { return impl_name_ref_at(which, false); }
539 symbolOop signature_ref_at(int which) { return impl_signature_ref_at(which, false); }
541 int klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, false); }
542 int name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, false); }
544 // Lookup for entries consisting of (name_index, signature_index)
545 int name_ref_index_at(int which_nt); // == low-order jshort of name_and_type_at(which_nt)
546 int signature_ref_index_at(int which_nt); // == high-order jshort of name_and_type_at(which_nt)
548 BasicType basic_type_for_signature_at(int which);
550 // Resolve string constants (to prevent allocation during compilation)
551 void resolve_string_constants(TRAPS) {
552 constantPoolHandle h_this(THREAD, this);
553 resolve_string_constants_impl(h_this, CHECK);
554 }
556 private:
557 enum { _no_index_sentinel = -1, _possible_index_sentinel = -2 };
558 public:
560 // Resolve late bound constants.
561 oop resolve_constant_at(int index, TRAPS) {
562 constantPoolHandle h_this(THREAD, this);
563 return resolve_constant_at_impl(h_this, index, _no_index_sentinel, THREAD);
564 }
566 oop resolve_cached_constant_at(int cache_index, TRAPS) {
567 constantPoolHandle h_this(THREAD, this);
568 return resolve_constant_at_impl(h_this, _no_index_sentinel, cache_index, THREAD);
569 }
571 oop resolve_possibly_cached_constant_at(int pool_index, TRAPS) {
572 constantPoolHandle h_this(THREAD, this);
573 return resolve_constant_at_impl(h_this, pool_index, _possible_index_sentinel, THREAD);
574 }
576 // Klass name matches name at offset
577 bool klass_name_at_matches(instanceKlassHandle k, int which);
579 // Sizing
580 int length() const { return _length; }
581 void set_length(int length) { _length = length; }
583 // Tells whether index is within bounds.
584 bool is_within_bounds(int index) const {
585 return 0 <= index && index < length();
586 }
588 static int header_size() { return sizeof(constantPoolOopDesc)/HeapWordSize; }
589 static int object_size(int length) { return align_object_size(header_size() + length); }
590 int object_size() { return object_size(length()); }
592 bool is_conc_safe() { return _is_conc_safe; }
593 void set_is_conc_safe(bool v) { _is_conc_safe = v; }
595 friend class constantPoolKlass;
596 friend class ClassFileParser;
597 friend class SystemDictionary;
599 // Used by compiler to prevent classloading.
600 static klassOop klass_at_if_loaded (constantPoolHandle this_oop, int which);
601 static klassOop klass_ref_at_if_loaded (constantPoolHandle this_oop, int which);
602 // Same as above - but does LinkResolving.
603 static klassOop klass_ref_at_if_loaded_check(constantPoolHandle this_oop, int which, TRAPS);
605 // Routines currently used for annotations (only called by jvm.cpp) but which might be used in the
606 // future by other Java code. These take constant pool indices rather than
607 // constant pool cache indices as do the peer methods above.
608 symbolOop uncached_klass_ref_at_noresolve(int which);
609 symbolOop uncached_name_ref_at(int which) { return impl_name_ref_at(which, true); }
610 symbolOop uncached_signature_ref_at(int which) { return impl_signature_ref_at(which, true); }
611 int uncached_klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, true); }
612 int uncached_name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, true); }
614 // Sharing
615 int pre_resolve_shared_klasses(TRAPS);
616 void shared_symbols_iterate(OopClosure* closure0);
617 void shared_tags_iterate(OopClosure* closure0);
618 void shared_strings_iterate(OopClosure* closure0);
620 // Debugging
621 const char* printable_name_at(int which) PRODUCT_RETURN0;
623 #ifdef ASSERT
624 enum { CPCACHE_INDEX_TAG = 0x10000 }; // helps keep CP cache indices distinct from CP indices
625 #else
626 enum { CPCACHE_INDEX_TAG = 0 }; // in product mode, this zero value is a no-op
627 #endif //ASSERT
629 private:
631 symbolOop impl_name_ref_at(int which, bool uncached);
632 symbolOop impl_signature_ref_at(int which, bool uncached);
633 int impl_klass_ref_index_at(int which, bool uncached);
634 int impl_name_and_type_ref_index_at(int which, bool uncached);
636 int remap_instruction_operand_from_cache(int operand); // operand must be biased by CPCACHE_INDEX_TAG
638 // Used while constructing constant pool (only by ClassFileParser)
639 jint klass_index_at(int which) {
640 assert(tag_at(which).is_klass_index(), "Corrupted constant pool");
641 return *int_at_addr(which);
642 }
644 jint string_index_at(int which) {
645 assert(tag_at(which).is_string_index(), "Corrupted constant pool");
646 return *int_at_addr(which);
647 }
649 // Performs the LinkResolver checks
650 static void verify_constant_pool_resolve(constantPoolHandle this_oop, KlassHandle klass, TRAPS);
652 // Implementation of methods that needs an exposed 'this' pointer, in order to
653 // handle GC while executing the method
654 static klassOop klass_at_impl(constantPoolHandle this_oop, int which, TRAPS);
655 static oop string_at_impl(constantPoolHandle this_oop, int which, TRAPS);
657 // Resolve string constants (to prevent allocation during compilation)
658 static void resolve_string_constants_impl(constantPoolHandle this_oop, TRAPS);
660 static oop resolve_constant_at_impl(constantPoolHandle this_oop, int index, int cache_index, TRAPS);
662 public:
663 // Merging constantPoolOop support:
664 bool compare_entry_to(int index1, constantPoolHandle cp2, int index2, TRAPS);
665 void copy_cp_to(int start_i, int end_i, constantPoolHandle to_cp, int to_i, TRAPS) {
666 constantPoolHandle h_this(THREAD, this);
667 copy_cp_to_impl(h_this, start_i, end_i, to_cp, to_i, THREAD);
668 }
669 static void copy_cp_to_impl(constantPoolHandle from_cp, int start_i, int end_i, constantPoolHandle to_cp, int to_i, TRAPS);
670 static void copy_entry_to(constantPoolHandle from_cp, int from_i, constantPoolHandle to_cp, int to_i, TRAPS);
671 int find_matching_entry(int pattern_i, constantPoolHandle search_cp, TRAPS);
672 int orig_length() const { return _orig_length; }
673 void set_orig_length(int orig_length) { _orig_length = orig_length; }
676 // JVMTI accesss - GetConstantPool, RetransformClasses, ...
677 friend class JvmtiConstantPoolReconstituter;
679 private:
680 jint cpool_entry_size(jint idx);
681 jint hash_entries_to(SymbolHashMap *symmap, SymbolHashMap *classmap);
683 // Copy cpool bytes into byte array.
684 // Returns:
685 // int > 0, count of the raw cpool bytes that have been copied
686 // 0, OutOfMemory error
687 // -1, Internal error
688 int copy_cpool_bytes(int cpool_size,
689 SymbolHashMap* tbl,
690 unsigned char *bytes);
691 };
693 class SymbolHashMapEntry : public CHeapObj {
694 private:
695 unsigned int _hash; // 32-bit hash for item
696 SymbolHashMapEntry* _next; // Next element in the linked list for this bucket
697 symbolOop _symbol; // 1-st part of the mapping: symbol => value
698 u2 _value; // 2-nd part of the mapping: symbol => value
700 public:
701 unsigned int hash() const { return _hash; }
702 void set_hash(unsigned int hash) { _hash = hash; }
704 SymbolHashMapEntry* next() const { return _next; }
705 void set_next(SymbolHashMapEntry* next) { _next = next; }
707 symbolOop symbol() const { return _symbol; }
708 void set_symbol(symbolOop sym) { _symbol = sym; }
710 u2 value() const { return _value; }
711 void set_value(u2 value) { _value = value; }
713 SymbolHashMapEntry(unsigned int hash, symbolOop symbol, u2 value)
714 : _hash(hash), _symbol(symbol), _value(value), _next(NULL) {}
716 }; // End SymbolHashMapEntry class
719 class SymbolHashMapBucket : public CHeapObj {
721 private:
722 SymbolHashMapEntry* _entry;
724 public:
725 SymbolHashMapEntry* entry() const { return _entry; }
726 void set_entry(SymbolHashMapEntry* entry) { _entry = entry; }
727 void clear() { _entry = NULL; }
729 }; // End SymbolHashMapBucket class
732 class SymbolHashMap: public CHeapObj {
734 private:
735 // Default number of entries in the table
736 enum SymbolHashMap_Constants {
737 _Def_HashMap_Size = 256
738 };
740 int _table_size;
741 SymbolHashMapBucket* _buckets;
743 void initialize_table(int table_size) {
744 _table_size = table_size;
745 _buckets = NEW_C_HEAP_ARRAY(SymbolHashMapBucket, table_size);
746 for (int index = 0; index < table_size; index++) {
747 _buckets[index].clear();
748 }
749 }
751 public:
753 int table_size() const { return _table_size; }
755 SymbolHashMap() { initialize_table(_Def_HashMap_Size); }
756 SymbolHashMap(int table_size) { initialize_table(table_size); }
758 // hash P(31) from Kernighan & Ritchie
759 static unsigned int compute_hash(const char* str, int len) {
760 unsigned int hash = 0;
761 while (len-- > 0) {
762 hash = 31*hash + (unsigned) *str;
763 str++;
764 }
765 return hash;
766 }
768 SymbolHashMapEntry* bucket(int i) {
769 return _buckets[i].entry();
770 }
772 void add_entry(symbolOop sym, u2 value);
773 SymbolHashMapEntry* find_entry(symbolOop sym);
775 u2 symbol_to_value(symbolOop sym) {
776 SymbolHashMapEntry *entry = find_entry(sym);
777 return (entry == NULL) ? 0 : entry->value();
778 }
780 ~SymbolHashMap() {
781 SymbolHashMapEntry* next;
782 for (int i = 0; i < _table_size; i++) {
783 for (SymbolHashMapEntry* cur = bucket(i); cur != NULL; cur = next) {
784 next = cur->next();
785 delete(cur);
786 }
787 }
788 delete _buckets;
789 }
790 }; // End SymbolHashMap class
792 #endif // SHARE_VM_OOPS_CONSTANTPOOLOOP_HPP