--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/oops/constantPoolOop.hpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,528 @@
+/*
+ * Copyright 1997-2007 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+// A constantPool is an array containing class constants as described in the
+// class file.
+//
+// Most of the constant pool entries are written during class parsing, which
+// is safe.  For klass and string types, the constant pool entry is
+// modified when the entry is resolved.  If a klass or string constant pool
+// entry is read without a lock, only the resolved state guarantees that
+// the entry in the constant pool is a klass or String object and
+// not a symbolOop.
+
+class SymbolHashMap;
+
+class constantPoolOopDesc : public arrayOopDesc {
+  friend class VMStructs;
+  friend class BytecodeInterpreter;  // Directly extracts an oop in the pool for fast instanceof/checkcast
+ private:
+  typeArrayOop         _tags; // the tag array describing the constant pool's contents
+  constantPoolCacheOop _cache;         // the cache holding interpreter runtime information
+  klassOop             _pool_holder;   // the corresponding class
+  // only set to non-zero if constant pool is merged by RedefineClasses
+  int                  _orig_length;
+
+  void set_tags(typeArrayOop tags)             { oop_store_without_check((oop*)&_tags, tags); }
+  void tag_at_put(int which, jbyte t)          { tags()->byte_at_put(which, t); }
+  void release_tag_at_put(int which, jbyte t)  { tags()->release_byte_at_put(which, t); }
+
+ private:
+  intptr_t* base() const { return (intptr_t*) (((char*) this) + sizeof(constantPoolOopDesc)); }
+  oop* tags_addr()       { return (oop*)&_tags; }
+  oop* cache_addr()      { return (oop*)&_cache; }
+
+  oop* obj_at_addr(int which) const {
+    assert(is_within_bounds(which), "index out of bounds");
+    return (oop*) &base()[which];
+  }
+
+  jint* int_at_addr(int which) const {
+    assert(is_within_bounds(which), "index out of bounds");
+    return (jint*) &base()[which];
+  }
+
+  jlong* long_at_addr(int which) const {
+    assert(is_within_bounds(which), "index out of bounds");
+    return (jlong*) &base()[which];
+  }
+
+  jfloat* float_at_addr(int which) const {
+    assert(is_within_bounds(which), "index out of bounds");
+    return (jfloat*) &base()[which];
+  }
+
+  jdouble* double_at_addr(int which) const {
+    assert(is_within_bounds(which), "index out of bounds");
+    return (jdouble*) &base()[which];
+  }
+
+ public:
+  typeArrayOop tags() const                 { return _tags; }
+
+  // Klass holding pool
+  klassOop pool_holder() const              { return _pool_holder; }
+  void set_pool_holder(klassOop k)          { oop_store_without_check((oop*)&_pool_holder, (oop) k); }
+  oop* pool_holder_addr()                   { return (oop*)&_pool_holder; }
+
+  // Interpreter runtime support
+  constantPoolCacheOop cache() const        { return _cache; }
+  void set_cache(constantPoolCacheOop cache){ oop_store((oop*)&_cache, cache); }
+
+  // Assembly code support
+  static int tags_offset_in_bytes()         { return offset_of(constantPoolOopDesc, _tags); }
+  static int cache_offset_in_bytes()        { return offset_of(constantPoolOopDesc, _cache); }
+  static int pool_holder_offset_in_bytes()  { return offset_of(constantPoolOopDesc, _pool_holder); }
+
+  // Storing constants
+
+  void klass_at_put(int which, klassOop k) {
+    oop_store_without_check((volatile oop *)obj_at_addr(which), oop(k));
+    // The interpreter assumes when the tag is stored, the klass is resolved
+    // and the klassOop is a klass rather than a symbolOop, so we need
+    // hardware store ordering here.
+    release_tag_at_put(which, JVM_CONSTANT_Class);
+    if (UseConcMarkSweepGC) {
+      // In case the earlier card-mark was consumed by a concurrent
+      // marking thread before the tag was updated, redirty the card.
+      oop_store_without_check((volatile oop *)obj_at_addr(which), oop(k));
+    }
+  }
+
+  // For temporary use while constructing constant pool
+  void klass_index_at_put(int which, int name_index) {
+    tag_at_put(which, JVM_CONSTANT_ClassIndex);
+    *int_at_addr(which) = name_index;
+  }
+
+  // Temporary until actual use
+  void unresolved_klass_at_put(int which, symbolOop s) {
+    // Overwrite the old index with a GC friendly value so
+    // that if GC looks during the transition it won't try
+    // to treat a small integer as oop.
+    *obj_at_addr(which) = NULL;
+    release_tag_at_put(which, JVM_CONSTANT_UnresolvedClass);
+    oop_store_without_check(obj_at_addr(which), oop(s));
+  }
+
+  // Temporary until actual use
+  void unresolved_string_at_put(int which, symbolOop s) {
+    *obj_at_addr(which) = NULL;
+    release_tag_at_put(which, JVM_CONSTANT_UnresolvedString);
+    oop_store_without_check(obj_at_addr(which), oop(s));
+  }
+
+  void int_at_put(int which, jint i) {
+    tag_at_put(which, JVM_CONSTANT_Integer);
+    *int_at_addr(which) = i;
+  }
+
+  void long_at_put(int which, jlong l) {
+    tag_at_put(which, JVM_CONSTANT_Long);
+    // *long_at_addr(which) = l;
+    Bytes::put_native_u8((address)long_at_addr(which), *((u8*) &l));
+  }
+
+  void float_at_put(int which, jfloat f) {
+    tag_at_put(which, JVM_CONSTANT_Float);
+    *float_at_addr(which) = f;
+  }
+
+  void double_at_put(int which, jdouble d) {
+    tag_at_put(which, JVM_CONSTANT_Double);
+    // *double_at_addr(which) = d;
+    // u8 temp = *(u8*) &d;
+    Bytes::put_native_u8((address) double_at_addr(which), *((u8*) &d));
+  }
+
+  void symbol_at_put(int which, symbolOop s) {
+    tag_at_put(which, JVM_CONSTANT_Utf8);
+    oop_store_without_check(obj_at_addr(which), oop(s));
+  }
+
+  void string_at_put(int which, oop str) {
+    oop_store((volatile oop*)obj_at_addr(which), str);
+    release_tag_at_put(which, JVM_CONSTANT_String);
+    if (UseConcMarkSweepGC) {
+      // In case the earlier card-mark was consumed by a concurrent
+      // marking thread before the tag was updated, redirty the card.
+      oop_store_without_check((volatile oop *)obj_at_addr(which), str);
+    }
+  }
+
+  // For temporary use while constructing constant pool
+  void string_index_at_put(int which, int string_index) {
+    tag_at_put(which, JVM_CONSTANT_StringIndex);
+    *int_at_addr(which) = string_index;
+  }
+
+  void field_at_put(int which, int class_index, int name_and_type_index) {
+    tag_at_put(which, JVM_CONSTANT_Fieldref);
+    *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
+  }
+
+  void method_at_put(int which, int class_index, int name_and_type_index) {
+    tag_at_put(which, JVM_CONSTANT_Methodref);
+    *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
+  }
+
+  void interface_method_at_put(int which, int class_index, int name_and_type_index) {
+    tag_at_put(which, JVM_CONSTANT_InterfaceMethodref);
+    *int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;  // Not so nice
+  }
+
+  void name_and_type_at_put(int which, int name_index, int signature_index) {
+    tag_at_put(which, JVM_CONSTANT_NameAndType);
+    *int_at_addr(which) = ((jint) signature_index<<16) | name_index;  // Not so nice
+  }
+
+  // Tag query
+
+  constantTag tag_at(int which) const { return (constantTag)tags()->byte_at_acquire(which); }
+
+  // Whether the entry is a pointer that must be GC'd.
+  bool is_pointer_entry(int which) {
+    constantTag tag = tag_at(which);
+    return tag.is_klass() ||
+      tag.is_unresolved_klass() ||
+      tag.is_symbol() ||
+      tag.is_unresolved_string() ||
+      tag.is_string();
+  }
+
+  // Fetching constants
+
+  klassOop klass_at(int which, TRAPS) {
+    constantPoolHandle h_this(THREAD, this);
+    return klass_at_impl(h_this, which, CHECK_NULL);
+  }
+
+  symbolOop klass_name_at(int which);  // Returns the name, w/o resolving.
+
+  klassOop resolved_klass_at(int which) {  // Used by Compiler
+    guarantee(tag_at(which).is_klass(), "Corrupted constant pool");
+    // Must do an acquire here in case another thread resolved the klass
+    // behind our back, lest we later load stale values thru the oop.
+    return klassOop((oop)OrderAccess::load_ptr_acquire(obj_at_addr(which)));
+  }
+
+  // This method should only be used with a cpool lock or during parsing or gc
+  symbolOop unresolved_klass_at(int which) {     // Temporary until actual use
+    symbolOop s = symbolOop((oop)OrderAccess::load_ptr_acquire(obj_at_addr(which)));
+    // check that the klass is still unresolved.
+    assert(tag_at(which).is_unresolved_klass(), "Corrupted constant pool");
+    return s;
+  }
+
+  // RedefineClasses() API support:
+  symbolOop klass_at_noresolve(int which) { return klass_name_at(which); }
+
+  jint int_at(int which) {
+    assert(tag_at(which).is_int(), "Corrupted constant pool");
+    return *int_at_addr(which);
+  }
+
+  jlong long_at(int which) {
+    assert(tag_at(which).is_long(), "Corrupted constant pool");
+    // return *long_at_addr(which);
+    u8 tmp = Bytes::get_native_u8((address)&base()[which]);
+    return *((jlong*)&tmp);
+  }
+
+  jfloat float_at(int which) {
+    assert(tag_at(which).is_float(), "Corrupted constant pool");
+    return *float_at_addr(which);
+  }
+
+  jdouble double_at(int which) {
+    assert(tag_at(which).is_double(), "Corrupted constant pool");
+    u8 tmp = Bytes::get_native_u8((address)&base()[which]);
+    return *((jdouble*)&tmp);
+  }
+
+  symbolOop symbol_at(int which) {
+    assert(tag_at(which).is_utf8(), "Corrupted constant pool");
+    return symbolOop(*obj_at_addr(which));
+  }
+
+  oop string_at(int which, TRAPS) {
+    constantPoolHandle h_this(THREAD, this);
+    return string_at_impl(h_this, which, CHECK_NULL);
+  }
+
+  // only called when we are sure a string entry is already resolved (via an
+  // earlier string_at call.
+  oop resolved_string_at(int which) {
+    assert(tag_at(which).is_string(), "Corrupted constant pool");
+    // Must do an acquire here in case another thread resolved the klass
+    // behind our back, lest we later load stale values thru the oop.
+    return (oop)OrderAccess::load_ptr_acquire(obj_at_addr(which));
+  }
+
+  // This method should only be used with a cpool lock or during parsing or gc
+  symbolOop unresolved_string_at(int which) {    // Temporary until actual use
+    symbolOop s = symbolOop((oop)OrderAccess::load_ptr_acquire(obj_at_addr(which)));
+    // check that the string is still unresolved.
+    assert(tag_at(which).is_unresolved_string(), "Corrupted constant pool");
+    return s;
+  }
+
+  // Returns an UTF8 for a CONSTANT_String entry at a given index.
+  // UTF8 char* representation was chosen to avoid conversion of
+  // java_lang_Strings at resolved entries into symbolOops
+  // or vice versa.
+  char* string_at_noresolve(int which);
+
+  jint name_and_type_at(int which) {
+    assert(tag_at(which).is_name_and_type(), "Corrupted constant pool");
+    return *int_at_addr(which);
+  }
+
+  // The following methods (klass_ref_at, klass_ref_at_noresolve, name_ref_at,
+  // signature_ref_at, klass_ref_index_at, name_and_type_ref_index_at,
+  // name_ref_index_at, signature_ref_index_at) all expect constant pool indices
+  // from the bytecodes to be passed in, which are actually potentially byte-swapped
+  // contstant pool cache indices. See field_or_method_at.
+
+  // Lookup for entries consisting of (klass_index, name_and_type index)
+  klassOop klass_ref_at(int which, TRAPS);
+  symbolOop klass_ref_at_noresolve(int which);
+  symbolOop name_ref_at(int which);
+  symbolOop signature_ref_at(int which);    // the type descriptor
+
+  int klass_ref_index_at(int which);
+  int name_and_type_ref_index_at(int which);
+
+  // Lookup for entries consisting of (name_index, signature_index)
+  int name_ref_index_at(int which);
+  int signature_ref_index_at(int which);
+
+  BasicType basic_type_for_signature_at(int which);
+
+  // Resolve string constants (to prevent allocation during compilation)
+  void resolve_string_constants(TRAPS) {
+    constantPoolHandle h_this(THREAD, this);
+    resolve_string_constants_impl(h_this, CHECK);
+  }
+
+  // Klass name matches name at offset
+  bool klass_name_at_matches(instanceKlassHandle k, int which);
+
+  // Sizing
+  static int header_size()             { return sizeof(constantPoolOopDesc)/HeapWordSize; }
+  static int object_size(int length)   { return align_object_size(header_size() + length); }
+  int object_size()                    { return object_size(length()); }
+
+  friend class constantPoolKlass;
+  friend class ClassFileParser;
+  friend class SystemDictionary;
+
+  // Used by compiler to prevent classloading.
+  static klassOop klass_at_if_loaded          (constantPoolHandle this_oop, int which);
+  static klassOop klass_ref_at_if_loaded      (constantPoolHandle this_oop, int which);
+  // Same as above - but does LinkResolving.
+  static klassOop klass_ref_at_if_loaded_check(constantPoolHandle this_oop, int which, TRAPS);
+
+  // Routines currently used for annotations (only called by jvm.cpp) but which might be used in the
+  // future by other Java code. These take constant pool indices rather than possibly-byte-swapped
+  // constant pool cache indices as do the peer methods above.
+  symbolOop uncached_name_ref_at(int which);
+  symbolOop uncached_signature_ref_at(int which);
+  int       uncached_klass_ref_index_at(int which);
+  int       uncached_name_and_type_ref_index_at(int which);
+
+  // Sharing
+  int pre_resolve_shared_klasses(TRAPS);
+  void shared_symbols_iterate(OopClosure* closure0);
+  void shared_tags_iterate(OopClosure* closure0);
+  void shared_strings_iterate(OopClosure* closure0);
+
+  // Debugging
+  const char* printable_name_at(int which) PRODUCT_RETURN0;
+
+ private:
+
+  // Takes either a constant pool cache index in possibly byte-swapped
+  // byte order (which comes from the bytecodes after rewriting) or,
+  // if "uncached" is true, a vanilla constant pool index
+  jint field_or_method_at(int which, bool uncached) {
+    int i = -1;
+    if (uncached || cache() == NULL) {
+      i = which;
+    } else {
+      // change byte-ordering and go via cache
+      i = cache()->entry_at(Bytes::swap_u2(which))->constant_pool_index();
+    }
+    assert(tag_at(i).is_field_or_method(), "Corrupted constant pool");
+    return *int_at_addr(i);
+  }
+
+  // Used while constructing constant pool (only by ClassFileParser)
+  jint klass_index_at(int which) {
+    assert(tag_at(which).is_klass_index(), "Corrupted constant pool");
+    return *int_at_addr(which);
+  }
+
+  jint string_index_at(int which) {
+    assert(tag_at(which).is_string_index(), "Corrupted constant pool");
+    return *int_at_addr(which);
+  }
+
+  // Performs the LinkResolver checks
+  static void verify_constant_pool_resolve(constantPoolHandle this_oop, KlassHandle klass, TRAPS);
+
+  // Implementation of methods that needs an exposed 'this' pointer, in order to
+  // handle GC while executing the method
+  static klassOop klass_at_impl(constantPoolHandle this_oop, int which, TRAPS);
+  static oop string_at_impl(constantPoolHandle this_oop, int which, TRAPS);
+
+  // Resolve string constants (to prevent allocation during compilation)
+  static void resolve_string_constants_impl(constantPoolHandle this_oop, TRAPS);
+
+ public:
+  // Merging constantPoolOop support:
+  bool compare_entry_to(int index1, constantPoolHandle cp2, int index2, TRAPS);
+  void copy_cp_to(int start_i, int end_i, constantPoolHandle to_cp, int to_i,
+    TRAPS);
+  void copy_entry_to(int from_i, constantPoolHandle to_cp, int to_i, TRAPS);
+  int  find_matching_entry(int pattern_i, constantPoolHandle search_cp, TRAPS);
+  int  orig_length() const                { return _orig_length; }
+  void set_orig_length(int orig_length)   { _orig_length = orig_length; }
+
+
+  // JVMTI accesss - GetConstantPool, RetransformClasses, ...
+  friend class JvmtiConstantPoolReconstituter;
+
+ private:
+  jint cpool_entry_size(jint idx);
+  jint hash_entries_to(SymbolHashMap *symmap, SymbolHashMap *classmap);
+
+  // Copy cpool bytes into byte array.
+  // Returns:
+  //  int > 0, count of the raw cpool bytes that have been copied
+  //        0, OutOfMemory error
+  //       -1, Internal error
+  int  copy_cpool_bytes(int cpool_size,
+                        SymbolHashMap* tbl,
+                        unsigned char *bytes);
+};
+
+class SymbolHashMapEntry : public CHeapObj {
+ private:
+  unsigned int        _hash;   // 32-bit hash for item
+  SymbolHashMapEntry* _next;   // Next element in the linked list for this bucket
+  symbolOop           _symbol; // 1-st part of the mapping: symbol => value
+  u2                  _value;  // 2-nd part of the mapping: symbol => value
+
+ public:
+  unsigned   int hash() const             { return _hash;   }
+  void       set_hash(unsigned int hash)  { _hash = hash;   }
+
+  SymbolHashMapEntry* next() const        { return _next;   }
+  void set_next(SymbolHashMapEntry* next) { _next = next;   }
+
+  symbolOop  symbol() const               { return _symbol; }
+  void       set_symbol(symbolOop sym)    { _symbol = sym;  }
+
+  u2         value() const                {  return _value; }
+  void       set_value(u2 value)          { _value = value; }
+
+  SymbolHashMapEntry(unsigned int hash, symbolOop symbol, u2 value)
+    : _hash(hash), _symbol(symbol), _value(value), _next(NULL) {}
+
+}; // End SymbolHashMapEntry class
+
+
+class SymbolHashMapBucket : public CHeapObj {
+
+private:
+  SymbolHashMapEntry*    _entry;
+
+public:
+  SymbolHashMapEntry* entry() const         {  return _entry; }
+  void set_entry(SymbolHashMapEntry* entry) { _entry = entry; }
+  void clear()                              { _entry = NULL;  }
+
+}; // End SymbolHashMapBucket class
+
+
+class SymbolHashMap: public CHeapObj {
+
+ private:
+  // Default number of entries in the table
+  enum SymbolHashMap_Constants {
+    _Def_HashMap_Size = 256
+  };
+
+  int                   _table_size;
+  SymbolHashMapBucket*  _buckets;
+
+  void initialize_table(int table_size) {
+    _table_size = table_size;
+    _buckets = NEW_C_HEAP_ARRAY(SymbolHashMapBucket, table_size);
+    for (int index = 0; index < table_size; index++) {
+      _buckets[index].clear();
+    }
+  }
+
+ public:
+
+  int table_size() const        { return _table_size; }
+
+  SymbolHashMap()               { initialize_table(_Def_HashMap_Size); }
+  SymbolHashMap(int table_size) { initialize_table(table_size); }
+
+  // hash P(31) from Kernighan & Ritchie
+  static unsigned int compute_hash(const char* str, int len) {
+    unsigned int hash = 0;
+    while (len-- > 0) {
+      hash = 31*hash + (unsigned) *str;
+      str++;
+    }
+    return hash;
+  }
+
+  SymbolHashMapEntry* bucket(int i) {
+    return _buckets[i].entry();
+  }
+
+  void add_entry(symbolOop sym, u2 value);
+  SymbolHashMapEntry* find_entry(symbolOop sym);
+
+  u2 symbol_to_value(symbolOop sym) {
+    SymbolHashMapEntry *entry = find_entry(sym);
+    return (entry == NULL) ? 0 : entry->value();
+  }
+
+  ~SymbolHashMap() {
+    SymbolHashMapEntry* next;
+    for (int i = 0; i < _table_size; i++) {
+      for (SymbolHashMapEntry* cur = bucket(i); cur != NULL; cur = next) {
+        next = cur->next();
+        delete(cur);
+      }
+    }
+    delete _buckets;
+  }
+}; // End SymbolHashMap class