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/*
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* Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*
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*/
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#ifndef SHARE_VM_CLASSFILE_STRINGTABLE_HPP
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#define SHARE_VM_CLASSFILE_STRINGTABLE_HPP
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#include "memory/allocation.inline.hpp"
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#include "utilities/hashtable.hpp"
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class StringTable : public Hashtable<oop, mtSymbol> {
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friend class VMStructs;
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friend class Symbol;
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private:
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// The string table
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static StringTable* _the_table;
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// Set if one bucket is out of balance due to hash algorithm deficiency
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static bool _needs_rehashing;
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// Claimed high water mark for parallel chunked scanning
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static volatile int _parallel_claimed_idx;
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static oop intern(Handle string_or_null, jchar* chars, int length, TRAPS);
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oop basic_add(int index, Handle string_or_null, jchar* name, int len,
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unsigned int hashValue, TRAPS);
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oop lookup(int index, jchar* chars, int length, unsigned int hashValue);
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// Apply the give oop closure to the entries to the buckets
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// in the range [start_idx, end_idx).
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static void buckets_oops_do(OopClosure* f, int start_idx, int end_idx);
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// Unlink or apply the give oop closure to the entries to the buckets
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// in the range [start_idx, end_idx).
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static void buckets_unlink_or_oops_do(BoolObjectClosure* is_alive, OopClosure* f, int start_idx, int end_idx, int* processed, int* removed);
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StringTable() : Hashtable<oop, mtSymbol>((int)StringTableSize,
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sizeof (HashtableEntry<oop, mtSymbol>)) {}
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StringTable(HashtableBucket<mtSymbol>* t, int number_of_entries)
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: Hashtable<oop, mtSymbol>((int)StringTableSize, sizeof (HashtableEntry<oop, mtSymbol>), t,
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number_of_entries) {}
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public:
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// The string table
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static StringTable* the_table() { return _the_table; }
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// Size of one bucket in the string table. Used when checking for rollover.
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static uint bucket_size() { return sizeof(HashtableBucket<mtSymbol>); }
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static void create_table() {
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assert(_the_table == NULL, "One string table allowed.");
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_the_table = new StringTable();
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}
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// GC support
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// Delete pointers to otherwise-unreachable objects.
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static void unlink_or_oops_do(BoolObjectClosure* cl, OopClosure* f) {
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int processed = 0;
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int removed = 0;
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unlink_or_oops_do(cl, f, &processed, &removed);
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}
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static void unlink(BoolObjectClosure* cl) {
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int processed = 0;
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int removed = 0;
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unlink_or_oops_do(cl, NULL, &processed, &removed);
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}
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static void unlink_or_oops_do(BoolObjectClosure* cl, OopClosure* f, int* processed, int* removed);
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static void unlink(BoolObjectClosure* cl, int* processed, int* removed) {
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unlink_or_oops_do(cl, NULL, processed, removed);
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}
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// Serially invoke "f->do_oop" on the locations of all oops in the table.
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static void oops_do(OopClosure* f);
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// Possibly parallel versions of the above
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static void possibly_parallel_unlink_or_oops_do(BoolObjectClosure* cl, OopClosure* f, int* processed, int* removed);
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static void possibly_parallel_unlink(BoolObjectClosure* cl, int* processed, int* removed) {
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possibly_parallel_unlink_or_oops_do(cl, NULL, processed, removed);
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}
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static void possibly_parallel_oops_do(OopClosure* f);
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// Hashing algorithm, used as the hash value used by the
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// StringTable for bucket selection and comparison (stored in the
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// HashtableEntry structures). This is used in the String.intern() method.
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static unsigned int hash_string(const jchar* s, int len);
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// Internal test.
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static void test_alt_hash() PRODUCT_RETURN;
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// Probing
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static oop lookup(Symbol* symbol);
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static oop lookup(jchar* chars, int length);
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// Interning
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static oop intern(Symbol* symbol, TRAPS);
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static oop intern(oop string, TRAPS);
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static oop intern(const char *utf8_string, TRAPS);
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// Debugging
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static void verify();
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static void dump(outputStream* st);
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enum VerifyMesgModes {
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_verify_quietly = 0,
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_verify_with_mesgs = 1
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};
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enum VerifyRetTypes {
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_verify_pass = 0,
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_verify_fail_continue = 1,
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_verify_fail_done = 2
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};
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static VerifyRetTypes compare_entries(int bkt1, int e_cnt1,
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HashtableEntry<oop, mtSymbol>* e_ptr1,
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int bkt2, int e_cnt2,
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HashtableEntry<oop, mtSymbol>* e_ptr2);
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static VerifyRetTypes verify_entry(int bkt, int e_cnt,
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HashtableEntry<oop, mtSymbol>* e_ptr,
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VerifyMesgModes mesg_mode);
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static int verify_and_compare_entries();
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// Sharing
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static void copy_buckets(char** top, char*end) {
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the_table()->Hashtable<oop, mtSymbol>::copy_buckets(top, end);
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}
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static void copy_table(char** top, char*end) {
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the_table()->Hashtable<oop, mtSymbol>::copy_table(top, end);
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}
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static void reverse() {
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the_table()->Hashtable<oop, mtSymbol>::reverse();
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}
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// Rehash the symbol table if it gets out of balance
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static void rehash_table();
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static bool needs_rehashing() { return _needs_rehashing; }
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// Parallel chunked scanning
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static void clear_parallel_claimed_index() { _parallel_claimed_idx = 0; }
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static int parallel_claimed_index() { return _parallel_claimed_idx; }
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};
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#endif // SHARE_VM_CLASSFILE_STRINGTABLE_HPP
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