duke@435: /*
jrose@1100:  * Copyright 1997-2009 Sun Microsystems, Inc.  All Rights Reserved.
duke@435:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435:  *
duke@435:  * This code is free software; you can redistribute it and/or modify it
duke@435:  * under the terms of the GNU General Public License version 2 only, as
duke@435:  * published by the Free Software Foundation.
duke@435:  *
duke@435:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@435:  * version 2 for more details (a copy is included in the LICENSE file that
duke@435:  * accompanied this code).
duke@435:  *
duke@435:  * You should have received a copy of the GNU General Public License version
duke@435:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@435:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435:  *
duke@435:  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435:  * CA 95054 USA or visit www.sun.com if you need additional information or
duke@435:  * have any questions.
duke@435:  *
duke@435:  */
duke@435: 
duke@435: // The symbol table holds all symbolOops and corresponding interned strings.
duke@435: // symbolOops and literal strings should be canonicalized.
duke@435: //
duke@435: // The interned strings are created lazily.
duke@435: //
duke@435: // It is implemented as an open hash table with a fixed number of buckets.
duke@435: //
duke@435: // %note:
duke@435: //  - symbolTableEntrys are allocated in blocks to reduce the space overhead.
duke@435: 
duke@435: class BoolObjectClosure;
duke@435: 
duke@435: 
duke@435: class SymbolTable : public Hashtable {
duke@435:   friend class VMStructs;
duke@435: 
duke@435: private:
duke@435:   // The symbol table
duke@435:   static SymbolTable* _the_table;
duke@435: 
duke@435:   // Adding elements
duke@435:   symbolOop basic_add(int index, u1* name, int len,
duke@435:                       unsigned int hashValue, TRAPS);
duke@435:   bool basic_add(constantPoolHandle cp, int names_count,
duke@435:                  const char** names, int* lengths, int* cp_indices,
duke@435:                  unsigned int* hashValues, TRAPS);
duke@435: 
duke@435:   // Table size
duke@435:   enum {
duke@435:     symbol_table_size = 20011
duke@435:   };
duke@435: 
duke@435:   symbolOop lookup(int index, const char* name, int len, unsigned int hash);
duke@435: 
duke@435:   SymbolTable()
duke@435:     : Hashtable(symbol_table_size, sizeof (HashtableEntry)) {}
duke@435: 
duke@435:   SymbolTable(HashtableBucket* t, int number_of_entries)
duke@435:     : Hashtable(symbol_table_size, sizeof (HashtableEntry), t,
duke@435:                 number_of_entries) {}
duke@435: 
duke@435: 
duke@435: public:
duke@435:   enum {
duke@435:     symbol_alloc_batch_size = 8
duke@435:   };
duke@435: 
duke@435:   // The symbol table
duke@435:   static SymbolTable* the_table() { return _the_table; }
duke@435: 
duke@435:   static void create_table() {
duke@435:     assert(_the_table == NULL, "One symbol table allowed.");
duke@435:     _the_table = new SymbolTable();
duke@435:   }
duke@435: 
duke@435:   static void create_table(HashtableBucket* t, int length,
duke@435:                            int number_of_entries) {
duke@435:     assert(_the_table == NULL, "One symbol table allowed.");
duke@435:     assert(length == symbol_table_size * sizeof(HashtableBucket),
duke@435:            "bad shared symbol size.");
duke@435:     _the_table = new SymbolTable(t, number_of_entries);
duke@435:   }
duke@435: 
duke@435:   static symbolOop lookup(const char* name, int len, TRAPS);
duke@435:   // lookup only, won't add. Also calculate hash.
duke@435:   static symbolOop lookup_only(const char* name, int len, unsigned int& hash);
duke@435:   // Only copy to C string to be added if lookup failed.
duke@435:   static symbolOop lookup(symbolHandle sym, int begin, int end, TRAPS);
duke@435: 
jrose@1100:   // jchar (utf16) version of lookups
jrose@1100:   static symbolOop lookup_unicode(const jchar* name, int len, TRAPS);
jrose@1100:   static symbolOop lookup_only_unicode(const jchar* name, int len, unsigned int& hash);
jrose@1100: 
duke@435:   static void add(constantPoolHandle cp, int names_count,
duke@435:                   const char** names, int* lengths, int* cp_indices,
duke@435:                   unsigned int* hashValues, TRAPS);
duke@435: 
duke@435:   // GC support
duke@435:   //   Delete pointers to otherwise-unreachable objects.
duke@435:   static void unlink(BoolObjectClosure* cl) {
duke@435:     the_table()->Hashtable::unlink(cl);
duke@435:   }
duke@435: 
duke@435:   // Invoke "f->do_oop" on the locations of all oops in the table.
duke@435:   static void oops_do(OopClosure* f) {
duke@435:     the_table()->Hashtable::oops_do(f);
duke@435:   }
duke@435: 
duke@435:   // Symbol lookup
duke@435:   static symbolOop lookup(int index, const char* name, int len, TRAPS);
duke@435: 
duke@435:   // Needed for preloading classes in signatures when compiling.
duke@435:   // Returns the symbol is already present in symbol table, otherwise
duke@435:   // NULL.  NO ALLOCATION IS GUARANTEED!
jrose@1100:   static symbolOop probe(const char* name, int len) {
jrose@1100:     unsigned int ignore_hash;
jrose@1100:     return lookup_only(name, len, ignore_hash);
jrose@1100:   }
jrose@1100:   static symbolOop probe_unicode(const jchar* name, int len) {
jrose@1100:     unsigned int ignore_hash;
jrose@1100:     return lookup_only_unicode(name, len, ignore_hash);
jrose@1100:   }
duke@435: 
duke@435:   // Histogram
duke@435:   static void print_histogram()     PRODUCT_RETURN;
duke@435: 
duke@435:   // Debugging
duke@435:   static void verify();
duke@435: 
duke@435:   // Sharing
duke@435:   static void copy_buckets(char** top, char*end) {
duke@435:     the_table()->Hashtable::copy_buckets(top, end);
duke@435:   }
duke@435:   static void copy_table(char** top, char*end) {
duke@435:     the_table()->Hashtable::copy_table(top, end);
duke@435:   }
duke@435:   static void reverse(void* boundary = NULL) {
duke@435:     ((Hashtable*)the_table())->reverse(boundary);
duke@435:   }
duke@435: };
duke@435: 
duke@435: 
duke@435: class StringTable : public Hashtable {
duke@435:   friend class VMStructs;
duke@435: 
duke@435: private:
duke@435:   // The string table
duke@435:   static StringTable* _the_table;
duke@435: 
duke@435:   static oop intern(Handle string_or_null, jchar* chars, int length, TRAPS);
duke@435:   oop basic_add(int index, Handle string_or_null, jchar* name, int len,
duke@435:                 unsigned int hashValue, TRAPS);
duke@435: 
duke@435:   // Table size
duke@435:   enum {
duke@435:     string_table_size = 1009
duke@435:   };
duke@435: 
duke@435:   oop lookup(int index, jchar* chars, int length, unsigned int hashValue);
duke@435: 
duke@435:   StringTable() : Hashtable(string_table_size, sizeof (HashtableEntry)) {}
duke@435: 
duke@435:   StringTable(HashtableBucket* t, int number_of_entries)
duke@435:     : Hashtable(string_table_size, sizeof (HashtableEntry), t,
duke@435:                 number_of_entries) {}
duke@435: 
duke@435: public:
duke@435:   // The string table
duke@435:   static StringTable* the_table() { return _the_table; }
duke@435: 
duke@435:   static void create_table() {
duke@435:     assert(_the_table == NULL, "One string table allowed.");
duke@435:     _the_table = new StringTable();
duke@435:   }
duke@435: 
duke@435:   static void create_table(HashtableBucket* t, int length,
duke@435:                            int number_of_entries) {
duke@435:     assert(_the_table == NULL, "One string table allowed.");
duke@435:     assert(length == string_table_size * sizeof(HashtableBucket),
duke@435:            "bad shared string size.");
duke@435:     _the_table = new StringTable(t, number_of_entries);
duke@435:   }
duke@435: 
duke@435: 
duke@435:   static int hash_string(jchar* s, int len);
duke@435: 
duke@435: 
duke@435:   // GC support
duke@435:   //   Delete pointers to otherwise-unreachable objects.
duke@435:   static void unlink(BoolObjectClosure* cl) {
duke@435:     the_table()->Hashtable::unlink(cl);
duke@435:   }
duke@435: 
duke@435:   // Invoke "f->do_oop" on the locations of all oops in the table.
duke@435:   static void oops_do(OopClosure* f) {
duke@435:     the_table()->Hashtable::oops_do(f);
duke@435:   }
duke@435: 
duke@435:   // Probing
duke@435:   static oop lookup(symbolOop symbol);
duke@435: 
duke@435:   // Interning
duke@435:   static oop intern(symbolOop symbol, TRAPS);
duke@435:   static oop intern(oop string, TRAPS);
duke@435:   static oop intern(const char *utf8_string, TRAPS);
duke@435: 
duke@435:   // Debugging
duke@435:   static void verify();
duke@435: 
duke@435:   // Sharing
duke@435:   static void copy_buckets(char** top, char*end) {
duke@435:     the_table()->Hashtable::copy_buckets(top, end);
duke@435:   }
duke@435:   static void copy_table(char** top, char*end) {
duke@435:     the_table()->Hashtable::copy_table(top, end);
duke@435:   }
duke@435:   static void reverse() {
duke@435:     ((BasicHashtable*)the_table())->reverse();
duke@435:   }
duke@435: };