src/share/vm/utilities/hashtable.cpp

Wed, 02 Feb 2011 11:35:26 -0500

author
bobv
date
Wed, 02 Feb 2011 11:35:26 -0500
changeset 2508
b92c45f2bc75
parent 2497
3582bf76420e
child 2708
1d1603768966
permissions
-rw-r--r--

7016023: Enable building ARM and PPC from src/closed repository
Reviewed-by: dholmes, bdelsart

duke@435 1 /*
stefank@2314 2 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
duke@435 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435 4 *
duke@435 5 * This code is free software; you can redistribute it and/or modify it
duke@435 6 * under the terms of the GNU General Public License version 2 only, as
duke@435 7 * published by the Free Software Foundation.
duke@435 8 *
duke@435 9 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435 12 * version 2 for more details (a copy is included in the LICENSE file that
duke@435 13 * accompanied this code).
duke@435 14 *
duke@435 15 * You should have received a copy of the GNU General Public License version
duke@435 16 * 2 along with this work; if not, write to the Free Software Foundation,
duke@435 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435 18 *
trims@1907 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907 20 * or visit www.oracle.com if you need additional information or have any
trims@1907 21 * questions.
duke@435 22 *
duke@435 23 */
duke@435 24
stefank@2314 25 #include "precompiled.hpp"
stefank@2314 26 #include "memory/allocation.inline.hpp"
stefank@2314 27 #include "memory/resourceArea.hpp"
stefank@2314 28 #include "oops/oop.inline.hpp"
stefank@2314 29 #include "runtime/safepoint.hpp"
stefank@2314 30 #include "utilities/dtrace.hpp"
stefank@2314 31 #include "utilities/hashtable.hpp"
stefank@2314 32 #include "utilities/hashtable.inline.hpp"
duke@435 33
coleenp@2497 34
duke@435 35 HS_DTRACE_PROBE_DECL4(hs_private, hashtable__new_entry,
coleenp@2497 36 void*, unsigned int, void*, void*);
duke@435 37
duke@435 38 // This is a generic hashtable, designed to be used for the symbol
duke@435 39 // and string tables.
duke@435 40 //
duke@435 41 // It is implemented as an open hash table with a fixed number of buckets.
duke@435 42 //
duke@435 43 // %note:
duke@435 44 // - HashtableEntrys are allocated in blocks to reduce the space overhead.
duke@435 45
duke@435 46 BasicHashtableEntry* BasicHashtable::new_entry(unsigned int hashValue) {
duke@435 47 BasicHashtableEntry* entry;
duke@435 48
duke@435 49 if (_free_list) {
duke@435 50 entry = _free_list;
duke@435 51 _free_list = _free_list->next();
duke@435 52 } else {
jrose@867 53 if (_first_free_entry + _entry_size >= _end_block) {
jrose@867 54 int block_size = MIN2(512, MAX2((int)_table_size / 2, (int)_number_of_entries));
duke@435 55 int len = _entry_size * block_size;
jrose@867 56 len = 1 << log2_intptr(len); // round down to power of 2
jrose@867 57 assert(len >= _entry_size, "");
duke@435 58 _first_free_entry = NEW_C_HEAP_ARRAY(char, len);
duke@435 59 _end_block = _first_free_entry + len;
duke@435 60 }
duke@435 61 entry = (BasicHashtableEntry*)_first_free_entry;
duke@435 62 _first_free_entry += _entry_size;
duke@435 63 }
duke@435 64
jrose@867 65 assert(_entry_size % HeapWordSize == 0, "");
duke@435 66 entry->set_hash(hashValue);
duke@435 67 return entry;
duke@435 68 }
duke@435 69
duke@435 70
coleenp@2497 71 template <class T> HashtableEntry<T>* Hashtable<T>::new_entry(unsigned int hashValue, T obj) {
coleenp@2497 72 HashtableEntry<T>* entry;
duke@435 73
coleenp@2497 74 entry = (HashtableEntry<T>*)BasicHashtable::new_entry(hashValue);
coleenp@2497 75 entry->set_literal(obj);
duke@435 76 HS_DTRACE_PROBE4(hs_private, hashtable__new_entry,
duke@435 77 this, hashValue, obj, entry);
duke@435 78 return entry;
duke@435 79 }
duke@435 80
duke@435 81
duke@435 82 // Reverse the order of elements in the hash buckets.
duke@435 83
duke@435 84 void BasicHashtable::reverse() {
duke@435 85
duke@435 86 for (int i = 0; i < _table_size; ++i) {
duke@435 87 BasicHashtableEntry* new_list = NULL;
duke@435 88 BasicHashtableEntry* p = bucket(i);
duke@435 89 while (p != NULL) {
duke@435 90 BasicHashtableEntry* next = p->next();
duke@435 91 p->set_next(new_list);
duke@435 92 new_list = p;
duke@435 93 p = next;
duke@435 94 }
duke@435 95 *bucket_addr(i) = new_list;
duke@435 96 }
duke@435 97 }
duke@435 98
duke@435 99
duke@435 100 // Copy the table to the shared space.
duke@435 101
duke@435 102 void BasicHashtable::copy_table(char** top, char* end) {
duke@435 103
duke@435 104 // Dump the hash table entries.
duke@435 105
duke@435 106 intptr_t *plen = (intptr_t*)(*top);
duke@435 107 *top += sizeof(*plen);
duke@435 108
duke@435 109 int i;
duke@435 110 for (i = 0; i < _table_size; ++i) {
duke@435 111 for (BasicHashtableEntry** p = _buckets[i].entry_addr();
duke@435 112 *p != NULL;
duke@435 113 p = (*p)->next_addr()) {
duke@435 114 if (*top + entry_size() > end) {
coleenp@2497 115 report_out_of_shared_space(SharedMiscData);
duke@435 116 }
duke@435 117 *p = (BasicHashtableEntry*)memcpy(*top, *p, entry_size());
duke@435 118 *top += entry_size();
duke@435 119 }
duke@435 120 }
duke@435 121 *plen = (char*)(*top) - (char*)plen - sizeof(*plen);
duke@435 122
duke@435 123 // Set the shared bit.
duke@435 124
duke@435 125 for (i = 0; i < _table_size; ++i) {
duke@435 126 for (BasicHashtableEntry* p = bucket(i); p != NULL; p = p->next()) {
duke@435 127 p->set_shared();
duke@435 128 }
duke@435 129 }
duke@435 130 }
duke@435 131
duke@435 132
duke@435 133
duke@435 134 // Reverse the order of elements in the hash buckets.
duke@435 135
coleenp@2497 136 template <class T> void Hashtable<T>::reverse(void* boundary) {
duke@435 137
duke@435 138 for (int i = 0; i < table_size(); ++i) {
coleenp@2497 139 HashtableEntry<T>* high_list = NULL;
coleenp@2497 140 HashtableEntry<T>* low_list = NULL;
coleenp@2497 141 HashtableEntry<T>* last_low_entry = NULL;
coleenp@2497 142 HashtableEntry<T>* p = bucket(i);
duke@435 143 while (p != NULL) {
coleenp@2497 144 HashtableEntry<T>* next = p->next();
duke@435 145 if ((void*)p->literal() >= boundary) {
duke@435 146 p->set_next(high_list);
duke@435 147 high_list = p;
duke@435 148 } else {
duke@435 149 p->set_next(low_list);
duke@435 150 low_list = p;
duke@435 151 if (last_low_entry == NULL) {
duke@435 152 last_low_entry = p;
duke@435 153 }
duke@435 154 }
duke@435 155 p = next;
duke@435 156 }
duke@435 157 if (low_list != NULL) {
duke@435 158 *bucket_addr(i) = low_list;
duke@435 159 last_low_entry->set_next(high_list);
duke@435 160 } else {
duke@435 161 *bucket_addr(i) = high_list;
duke@435 162 }
duke@435 163 }
duke@435 164 }
duke@435 165
duke@435 166
duke@435 167 // Dump the hash table buckets.
duke@435 168
duke@435 169 void BasicHashtable::copy_buckets(char** top, char* end) {
duke@435 170 intptr_t len = _table_size * sizeof(HashtableBucket);
duke@435 171 *(intptr_t*)(*top) = len;
duke@435 172 *top += sizeof(intptr_t);
duke@435 173
duke@435 174 *(intptr_t*)(*top) = _number_of_entries;
duke@435 175 *top += sizeof(intptr_t);
duke@435 176
duke@435 177 if (*top + len > end) {
coleenp@2497 178 report_out_of_shared_space(SharedMiscData);
duke@435 179 }
duke@435 180 _buckets = (HashtableBucket*)memcpy(*top, _buckets, len);
duke@435 181 *top += len;
duke@435 182 }
duke@435 183
duke@435 184
duke@435 185 #ifndef PRODUCT
duke@435 186
coleenp@2497 187 template <class T> void Hashtable<T>::print() {
duke@435 188 ResourceMark rm;
duke@435 189
duke@435 190 for (int i = 0; i < table_size(); i++) {
coleenp@2497 191 HashtableEntry<T>* entry = bucket(i);
duke@435 192 while(entry != NULL) {
duke@435 193 tty->print("%d : ", i);
duke@435 194 entry->literal()->print();
duke@435 195 tty->cr();
duke@435 196 entry = entry->next();
duke@435 197 }
duke@435 198 }
duke@435 199 }
duke@435 200
duke@435 201
duke@435 202 void BasicHashtable::verify() {
duke@435 203 int count = 0;
duke@435 204 for (int i = 0; i < table_size(); i++) {
duke@435 205 for (BasicHashtableEntry* p = bucket(i); p != NULL; p = p->next()) {
duke@435 206 ++count;
duke@435 207 }
duke@435 208 }
duke@435 209 assert(count == number_of_entries(), "number of hashtable entries incorrect");
duke@435 210 }
duke@435 211
duke@435 212
duke@435 213 #endif // PRODUCT
duke@435 214
duke@435 215
duke@435 216 #ifdef ASSERT
duke@435 217
duke@435 218 void BasicHashtable::verify_lookup_length(double load) {
duke@435 219 if ((double)_lookup_length / (double)_lookup_count > load * 2.0) {
duke@435 220 warning("Performance bug: SystemDictionary lookup_count=%d "
duke@435 221 "lookup_length=%d average=%lf load=%f",
duke@435 222 _lookup_count, _lookup_length,
duke@435 223 (double) _lookup_length / _lookup_count, load);
duke@435 224 }
duke@435 225 }
duke@435 226
duke@435 227 #endif
coleenp@2497 228
coleenp@2497 229 // Explicitly instantiate these types
coleenp@2497 230 template class Hashtable<constantPoolOop>;
coleenp@2497 231 template class Hashtable<Symbol*>;
coleenp@2497 232 template class Hashtable<klassOop>;
coleenp@2497 233 template class Hashtable<oop>;
coleenp@2497 234

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