annotate hotspot/src/share/vm/utilities/hashtable.cpp @ 13195:be27e1b6a4b9

6995781: Native Memory Tracking (Phase 1) 7151532: DCmd for hotspot native memory tracking Summary: Implementation of native memory tracking phase 1, which tracks VM native memory usage, and related DCmd Reviewed-by: acorn, coleenp, fparain
author zgu
date Thu, 28 Jun 2012 17:03:16 -0400
parents c146b608d91f
children 025b0984feea
rev   line source
duke@1 1 /*
coleenp@13087 2 * Copyright (c) 2003, 2012, Oracle and/or its affiliates. All rights reserved.
duke@1 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@1 4 *
duke@1 5 * This code is free software; you can redistribute it and/or modify it
duke@1 6 * under the terms of the GNU General Public License version 2 only, as
duke@1 7 * published by the Free Software Foundation.
duke@1 8 *
duke@1 9 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@1 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@1 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@1 12 * version 2 for more details (a copy is included in the LICENSE file that
duke@1 13 * accompanied this code).
duke@1 14 *
duke@1 15 * You should have received a copy of the GNU General Public License version
duke@1 16 * 2 along with this work; if not, write to the Free Software Foundation,
duke@1 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@1 18 *
trims@5547 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@5547 20 * or visit www.oracle.com if you need additional information or have any
trims@5547 21 * questions.
duke@1 22 *
duke@1 23 */
duke@1 24
stefank@7397 25 #include "precompiled.hpp"
stefank@7397 26 #include "memory/allocation.inline.hpp"
coleenp@13097 27 #include "memory/filemap.hpp"
stefank@7397 28 #include "memory/resourceArea.hpp"
stefank@7397 29 #include "oops/oop.inline.hpp"
stefank@7397 30 #include "runtime/safepoint.hpp"
stefank@7397 31 #include "utilities/dtrace.hpp"
stefank@7397 32 #include "utilities/hashtable.hpp"
stefank@7397 33 #include "utilities/hashtable.inline.hpp"
duke@1 34
coleenp@8076 35
duke@1 36 // This is a generic hashtable, designed to be used for the symbol
duke@1 37 // and string tables.
duke@1 38 //
duke@1 39 // It is implemented as an open hash table with a fixed number of buckets.
duke@1 40 //
duke@1 41 // %note:
duke@1 42 // - HashtableEntrys are allocated in blocks to reduce the space overhead.
duke@1 43
zgu@13195 44 template <MEMFLAGS F> BasicHashtableEntry<F>* BasicHashtable<F>::new_entry(unsigned int hashValue) {
zgu@13195 45 BasicHashtableEntry<F>* entry;
duke@1 46
duke@1 47 if (_free_list) {
duke@1 48 entry = _free_list;
duke@1 49 _free_list = _free_list->next();
duke@1 50 } else {
jrose@1551 51 if (_first_free_entry + _entry_size >= _end_block) {
jrose@1551 52 int block_size = MIN2(512, MAX2((int)_table_size / 2, (int)_number_of_entries));
duke@1 53 int len = _entry_size * block_size;
jrose@1551 54 len = 1 << log2_intptr(len); // round down to power of 2
jrose@1551 55 assert(len >= _entry_size, "");
zgu@13195 56 _first_free_entry = NEW_C_HEAP_ARRAY2(char, len, F, CURRENT_PC);
duke@1 57 _end_block = _first_free_entry + len;
duke@1 58 }
zgu@13195 59 entry = (BasicHashtableEntry<F>*)_first_free_entry;
duke@1 60 _first_free_entry += _entry_size;
duke@1 61 }
duke@1 62
jrose@1551 63 assert(_entry_size % HeapWordSize == 0, "");
duke@1 64 entry->set_hash(hashValue);
duke@1 65 return entry;
duke@1 66 }
duke@1 67
duke@1 68
zgu@13195 69 template <class T, MEMFLAGS F> HashtableEntry<T, F>* Hashtable<T, F>::new_entry(unsigned int hashValue, T obj) {
zgu@13195 70 HashtableEntry<T, F>* entry;
duke@1 71
zgu@13195 72 entry = (HashtableEntry<T, F>*)BasicHashtable<F>::new_entry(hashValue);
coleenp@8076 73 entry->set_literal(obj);
duke@1 74 return entry;
duke@1 75 }
duke@1 76
coleenp@13087 77 // Check to see if the hashtable is unbalanced. The caller set a flag to
coleenp@13087 78 // rehash at the next safepoint. If this bucket is 60 times greater than the
coleenp@13087 79 // expected average bucket length, it's an unbalanced hashtable.
coleenp@13087 80 // This is somewhat an arbitrary heuristic but if one bucket gets to
coleenp@13087 81 // rehash_count which is currently 100, there's probably something wrong.
coleenp@13087 82
zgu@13195 83 template <MEMFLAGS F> bool BasicHashtable<F>::check_rehash_table(int count) {
coleenp@13087 84 assert(table_size() != 0, "underflow");
coleenp@13087 85 if (count > (((double)number_of_entries()/(double)table_size())*rehash_multiple)) {
coleenp@13087 86 // Set a flag for the next safepoint, which should be at some guaranteed
coleenp@13087 87 // safepoint interval.
coleenp@13087 88 return true;
coleenp@13087 89 }
coleenp@13087 90 return false;
coleenp@13087 91 }
coleenp@13087 92
coleenp@13087 93 // Create a new table and using alternate hash code, populate the new table
coleenp@13087 94 // with the existing elements. This can be used to change the hash code
coleenp@13087 95 // and could in the future change the size of the table.
coleenp@13087 96
zgu@13195 97 template <class T, MEMFLAGS F> void Hashtable<T, F>::move_to(Hashtable<T, F>* new_table) {
zgu@13195 98 int saved_entry_count = BasicHashtable<F>::number_of_entries();
coleenp@13087 99
coleenp@13087 100 // Iterate through the table and create a new entry for the new table
coleenp@13087 101 for (int i = 0; i < new_table->table_size(); ++i) {
zgu@13195 102 for (HashtableEntry<T, F>* p = bucket(i); p != NULL; ) {
zgu@13195 103 HashtableEntry<T, F>* next = p->next();
coleenp@13087 104 T string = p->literal();
coleenp@13087 105 // Use alternate hashing algorithm on the symbol in the first table
coleenp@13087 106 unsigned int hashValue = new_hash(string);
coleenp@13087 107 // Get a new index relative to the new table (can also change size)
coleenp@13087 108 int index = new_table->hash_to_index(hashValue);
coleenp@13087 109 p->set_hash(hashValue);
coleenp@13097 110 // Keep the shared bit in the Hashtable entry to indicate that this entry
coleenp@13097 111 // can't be deleted. The shared bit is the LSB in the _next field so
coleenp@13097 112 // walking the hashtable past these entries requires
coleenp@13097 113 // BasicHashtableEntry::make_ptr() call.
coleenp@13097 114 bool keep_shared = p->is_shared();
coleenp@13087 115 unlink_entry(p);
coleenp@13087 116 new_table->add_entry(index, p);
coleenp@13097 117 if (keep_shared) {
coleenp@13097 118 p->set_shared();
coleenp@13097 119 }
coleenp@13087 120 p = next;
coleenp@13087 121 }
coleenp@13087 122 }
coleenp@13087 123 // give the new table the free list as well
coleenp@13087 124 new_table->copy_freelist(this);
coleenp@13087 125 assert(new_table->number_of_entries() == saved_entry_count, "lost entry on dictionary copy?");
coleenp@13087 126
coleenp@13087 127 // Destroy memory used by the buckets in the hashtable. The memory
coleenp@13087 128 // for the elements has been used in a new table and is not
coleenp@13087 129 // destroyed. The memory reuse will benefit resizing the SystemDictionary
coleenp@13087 130 // to avoid a memory allocation spike at safepoint.
zgu@13195 131 BasicHashtable<F>::free_buckets();
coleenp@13087 132 }
coleenp@13087 133
zgu@13195 134 template <MEMFLAGS F> void BasicHashtable<F>::free_buckets() {
coleenp@13097 135 if (NULL != _buckets) {
coleenp@13097 136 // Don't delete the buckets in the shared space. They aren't
coleenp@13097 137 // allocated by os::malloc
coleenp@13097 138 if (!UseSharedSpaces ||
coleenp@13097 139 !FileMapInfo::current_info()->is_in_shared_space(_buckets)) {
zgu@13195 140 FREE_C_HEAP_ARRAY(HashtableBucket, _buckets, F);
coleenp@13097 141 }
coleenp@13097 142 _buckets = NULL;
coleenp@13097 143 }
coleenp@13097 144 }
coleenp@13097 145
coleenp@13097 146
duke@1 147 // Reverse the order of elements in the hash buckets.
duke@1 148
zgu@13195 149 template <MEMFLAGS F> void BasicHashtable<F>::reverse() {
duke@1 150
duke@1 151 for (int i = 0; i < _table_size; ++i) {
zgu@13195 152 BasicHashtableEntry<F>* new_list = NULL;
zgu@13195 153 BasicHashtableEntry<F>* p = bucket(i);
duke@1 154 while (p != NULL) {
zgu@13195 155 BasicHashtableEntry<F>* next = p->next();
duke@1 156 p->set_next(new_list);
duke@1 157 new_list = p;
duke@1 158 p = next;
duke@1 159 }
duke@1 160 *bucket_addr(i) = new_list;
duke@1 161 }
duke@1 162 }
duke@1 163
duke@1 164
duke@1 165 // Copy the table to the shared space.
duke@1 166
zgu@13195 167 template <MEMFLAGS F> void BasicHashtable<F>::copy_table(char** top, char* end) {
duke@1 168
duke@1 169 // Dump the hash table entries.
duke@1 170
duke@1 171 intptr_t *plen = (intptr_t*)(*top);
duke@1 172 *top += sizeof(*plen);
duke@1 173
duke@1 174 int i;
duke@1 175 for (i = 0; i < _table_size; ++i) {
zgu@13195 176 for (BasicHashtableEntry<F>** p = _buckets[i].entry_addr();
duke@1 177 *p != NULL;
duke@1 178 p = (*p)->next_addr()) {
duke@1 179 if (*top + entry_size() > end) {
coleenp@8076 180 report_out_of_shared_space(SharedMiscData);
duke@1 181 }
zgu@13195 182 *p = (BasicHashtableEntry<F>*)memcpy(*top, *p, entry_size());
duke@1 183 *top += entry_size();
duke@1 184 }
duke@1 185 }
duke@1 186 *plen = (char*)(*top) - (char*)plen - sizeof(*plen);
duke@1 187
duke@1 188 // Set the shared bit.
duke@1 189
duke@1 190 for (i = 0; i < _table_size; ++i) {
zgu@13195 191 for (BasicHashtableEntry<F>* p = bucket(i); p != NULL; p = p->next()) {
duke@1 192 p->set_shared();
duke@1 193 }
duke@1 194 }
duke@1 195 }
duke@1 196
duke@1 197
duke@1 198
duke@1 199 // Reverse the order of elements in the hash buckets.
duke@1 200
zgu@13195 201 template <class T, MEMFLAGS F> void Hashtable<T, F>::reverse(void* boundary) {
duke@1 202
zgu@13195 203 for (int i = 0; i < this->table_size(); ++i) {
zgu@13195 204 HashtableEntry<T, F>* high_list = NULL;
zgu@13195 205 HashtableEntry<T, F>* low_list = NULL;
zgu@13195 206 HashtableEntry<T, F>* last_low_entry = NULL;
zgu@13195 207 HashtableEntry<T, F>* p = bucket(i);
duke@1 208 while (p != NULL) {
zgu@13195 209 HashtableEntry<T, F>* next = p->next();
duke@1 210 if ((void*)p->literal() >= boundary) {
duke@1 211 p->set_next(high_list);
duke@1 212 high_list = p;
duke@1 213 } else {
duke@1 214 p->set_next(low_list);
duke@1 215 low_list = p;
duke@1 216 if (last_low_entry == NULL) {
duke@1 217 last_low_entry = p;
duke@1 218 }
duke@1 219 }
duke@1 220 p = next;
duke@1 221 }
duke@1 222 if (low_list != NULL) {
duke@1 223 *bucket_addr(i) = low_list;
duke@1 224 last_low_entry->set_next(high_list);
duke@1 225 } else {
duke@1 226 *bucket_addr(i) = high_list;
duke@1 227 }
duke@1 228 }
duke@1 229 }
duke@1 230
duke@1 231
duke@1 232 // Dump the hash table buckets.
duke@1 233
zgu@13195 234 template <MEMFLAGS F> void BasicHashtable<F>::copy_buckets(char** top, char* end) {
zgu@13195 235 intptr_t len = _table_size * sizeof(HashtableBucket<F>);
duke@1 236 *(intptr_t*)(*top) = len;
duke@1 237 *top += sizeof(intptr_t);
duke@1 238
duke@1 239 *(intptr_t*)(*top) = _number_of_entries;
duke@1 240 *top += sizeof(intptr_t);
duke@1 241
duke@1 242 if (*top + len > end) {
coleenp@8076 243 report_out_of_shared_space(SharedMiscData);
duke@1 244 }
zgu@13195 245 _buckets = (HashtableBucket<F>*)memcpy(*top, _buckets, len);
duke@1 246 *top += len;
duke@1 247 }
duke@1 248
duke@1 249
duke@1 250 #ifndef PRODUCT
duke@1 251
zgu@13195 252 template <class T, MEMFLAGS F> void Hashtable<T, F>::print() {
duke@1 253 ResourceMark rm;
duke@1 254
zgu@13195 255 for (int i = 0; i < BasicHashtable<F>::table_size(); i++) {
zgu@13195 256 HashtableEntry<T, F>* entry = bucket(i);
duke@1 257 while(entry != NULL) {
duke@1 258 tty->print("%d : ", i);
duke@1 259 entry->literal()->print();
duke@1 260 tty->cr();
duke@1 261 entry = entry->next();
duke@1 262 }
duke@1 263 }
duke@1 264 }
duke@1 265
duke@1 266
zgu@13195 267 template <MEMFLAGS F> void BasicHashtable<F>::verify() {
duke@1 268 int count = 0;
duke@1 269 for (int i = 0; i < table_size(); i++) {
zgu@13195 270 for (BasicHashtableEntry<F>* p = bucket(i); p != NULL; p = p->next()) {
duke@1 271 ++count;
duke@1 272 }
duke@1 273 }
duke@1 274 assert(count == number_of_entries(), "number of hashtable entries incorrect");
duke@1 275 }
duke@1 276
duke@1 277
duke@1 278 #endif // PRODUCT
duke@1 279
duke@1 280
duke@1 281 #ifdef ASSERT
duke@1 282
zgu@13195 283 template <MEMFLAGS F> void BasicHashtable<F>::verify_lookup_length(double load) {
duke@1 284 if ((double)_lookup_length / (double)_lookup_count > load * 2.0) {
duke@1 285 warning("Performance bug: SystemDictionary lookup_count=%d "
duke@1 286 "lookup_length=%d average=%lf load=%f",
duke@1 287 _lookup_count, _lookup_length,
duke@1 288 (double) _lookup_length / _lookup_count, load);
duke@1 289 }
duke@1 290 }
duke@1 291
duke@1 292 #endif
coleenp@8076 293 // Explicitly instantiate these types
zgu@13195 294 template class Hashtable<constantPoolOop, mtClass>;
zgu@13195 295 template class Hashtable<Symbol*, mtSymbol>;
zgu@13195 296 template class Hashtable<klassOop, mtClass>;
zgu@13195 297 template class Hashtable<oop, mtClass>;
zgu@13195 298 #ifdef SOLARIS
zgu@13195 299 template class Hashtable<oop, mtSymbol>;
zgu@13195 300 #endif
zgu@13195 301 template class Hashtable<oopDesc*, mtSymbol>;
zgu@13195 302 template class Hashtable<Symbol*, mtClass>;
zgu@13195 303 template class HashtableEntry<Symbol*, mtSymbol>;
zgu@13195 304 template class HashtableEntry<Symbol*, mtClass>;
zgu@13195 305 template class HashtableEntry<oop, mtSymbol>;
zgu@13195 306 template class BasicHashtableEntry<mtSymbol>;
zgu@13195 307 template class BasicHashtableEntry<mtCode>;
zgu@13195 308 template class BasicHashtable<mtClass>;
zgu@13195 309 template class BasicHashtable<mtSymbol>;
zgu@13195 310 template class BasicHashtable<mtCode>;
zgu@13195 311 template class BasicHashtable<mtInternal>;