1 /*
2 * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_JFR_UTILITIES_JFRHASHTABLE_HPP
26 #define SHARE_JFR_UTILITIES_JFRHASHTABLE_HPP
27
28 #include "memory/allocation.inline.hpp"
29 #include "runtime/orderAccess.hpp"
30 #include "utilities/debug.hpp"
31 #include "utilities/macros.hpp"
32
33 template <typename T>
34 class JfrBasicHashtableEntry {
35 private:
36 typedef JfrBasicHashtableEntry<T> Entry;
37 Entry* _next;
38 T _literal; // ref to item in table.
39 uintptr_t _hash;
40
41 public:
42 uintptr_t hash() const { return _hash; }
43 void set_hash(uintptr_t hash) { _hash = hash; }
44 T literal() const { return _literal; }
45 T* literal_addr() { return &_literal; }
46 void set_literal(T s) { _literal = s; }
47 void set_next(Entry* next) { _next = next; }
48 Entry* next() const { return _next; }
49 Entry** next_addr() { return &_next; }
50 };
51
52 template <typename T>
53 class JfrHashtableBucket : public CHeapObj<mtTracing> {
54 template <typename>
55 friend class JfrBasicHashtable;
56 private:
57 typedef JfrBasicHashtableEntry<T> TableEntry;
58 TableEntry* _entry;
59
60 TableEntry* get_entry() const {
61 return (TableEntry*)OrderAccess::load_acquire(&_entry);
62 }
63 void set_entry(TableEntry* entry) { OrderAccess::release_store(&_entry, entry);}
64 TableEntry** entry_addr() { return &_entry; }
65 };
66
67 template <typename T>
68 class JfrBasicHashtable : public CHeapObj<mtTracing> {
69 private:
70 typedef JfrHashtableBucket<T> Bucket;
71 typedef JfrBasicHashtableEntry<T> TableEntry;
72 Bucket* _buckets;
73 uintptr_t _table_size;
74 const size_t _entry_size;
75 size_t _number_of_entries;
76
77 protected:
78 JfrBasicHashtable(uintptr_t table_size, size_t entry_size) :
79 _buckets(NULL), _table_size(table_size), _entry_size(entry_size), _number_of_entries(0) {
80 _buckets = NEW_C_HEAP_ARRAY2(Bucket, table_size, mtTracing, CURRENT_PC);
81 memset((void*)_buckets, 0, table_size * sizeof(Bucket));
82 }
83
84 size_t hash_to_index(uintptr_t full_hash) const {
85 const uintptr_t h = full_hash % _table_size;
86 assert(h >= 0 && h < _table_size, "Illegal hash value");
87 return (size_t)h;
88 }
89 size_t entry_size() const { return _entry_size; }
90 void unlink_entry(TableEntry* entry) {
91 entry->set_next(NULL);
92 --_number_of_entries;
93 }
94 void free_buckets() {
95 FREE_C_HEAP_ARRAY(Bucket, _buckets);
96 _buckets = NULL;
97 }
98 TableEntry* bucket(size_t i) { return _buckets[i].get_entry();}
99 TableEntry** bucket_addr(size_t i) { return _buckets[i].entry_addr(); }
100 uintptr_t table_size() const { return _table_size; }
101 size_t number_of_entries() const { return _number_of_entries; }
102 void add_entry(size_t index, TableEntry* entry) {
103 assert(entry != NULL, "invariant");
104 entry->set_next(bucket(index));
105 _buckets[index].set_entry(entry);
106 ++_number_of_entries;
107 }
108 };
109
110 template <typename IdType, typename Entry, typename T>
111 class AscendingId : public CHeapObj<mtTracing> {
112 private:
113 IdType _id;
114 public:
115 AscendingId() : _id(0) {}
116 // callbacks
117 void assign_id(Entry* entry) {
118 assert(entry != NULL, "invariant");
119 assert(entry->id() == 0, "invariant");
120 entry->set_id(++_id);
121 }
122 bool equals(const T& data, uintptr_t hash, const Entry* entry) {
123 assert(entry->hash() == hash, "invariant");
124 return true;
125 }
126 };
127
128 // IdType must be scalar
129 template <typename T, typename IdType>
130 class Entry : public JfrBasicHashtableEntry<T> {
131 public:
132 typedef IdType ID;
133 void init() { _id = 0; }
134 ID id() const { return _id; }
135 void set_id(ID id) { _id = id; }
136 void set_value(const T& value) { this->set_literal(value); }
137 T& value() const { return *const_cast<Entry*>(this)->literal_addr();}
138 const T* value_addr() const { return const_cast<Entry*>(this)->literal_addr(); }
139
140 private:
141 ID _id;
142 };
143
144 template <typename T, typename IdType, template <typename, typename> class Entry,
145 typename Callback = AscendingId<IdType, Entry<T, IdType>, T> ,
146 size_t TABLE_SIZE = 1009>
147 class HashTableHost : public JfrBasicHashtable<T> {
148 public:
149 typedef Entry<T, IdType> HashEntry;
150 HashTableHost() : _callback(new Callback()) {}
151 HashTableHost(Callback* cb) : JfrBasicHashtable<T>(TABLE_SIZE, sizeof(HashEntry)), _callback(cb) {}
152 ~HashTableHost() {
153 this->clear_entries();
154 this->free_buckets();
155 }
156
157 // direct insert assumes non-existing entry
158 HashEntry& put(const T& data, uintptr_t hash);
159
160 // lookup entry, will put if not found
161 HashEntry& lookup_put(const T& data, uintptr_t hash) {
162 HashEntry* entry = lookup_only(data, hash);
163 return entry == NULL ? put(data, hash) : *entry;
164 }
165
166 // read-only lookup
167 HashEntry* lookup_only(const T& query, uintptr_t hash);
168
169 // id retrieval
170 IdType id(const T& data, uintptr_t hash) {
171 assert(data != NULL, "invariant");
172 const HashEntry& entry = lookup_put(data, hash);
173 assert(entry.id() > 0, "invariant");
174 return entry.id();
175 }
176
177 template <typename Functor>
178 void iterate_value(Functor& f);
179
180 template <typename Functor>
181 void iterate_entry(Functor& f);
182
183 size_t cardinality() const { return this->number_of_entries(); }
184 bool has_entries() const { return this->cardinality() > 0; }
185 void clear_entries();
186
187 // removal and deallocation
188 void free_entry(HashEntry* entry) {
189 assert(entry != NULL, "invariant");
190 JfrBasicHashtable<T>::unlink_entry(entry);
191 FREE_C_HEAP_ARRAY(char, entry);
192 }
193
194 private:
195 Callback* _callback;
196 size_t index_for(uintptr_t hash) { return this->hash_to_index(hash); }
197 HashEntry* new_entry(const T& data, uintptr_t hash);
198 void add_entry(size_t index, HashEntry* new_entry) {
199 assert(new_entry != NULL, "invariant");
200 _callback->assign_id(new_entry);
201 assert(new_entry->id() > 0, "invariant");
202 JfrBasicHashtable<T>::add_entry(index, new_entry);
203 }
204 };
205
206 template <typename T, typename IdType, template <typename, typename> class Entry, typename Callback, size_t TABLE_SIZE>
207 Entry<T, IdType>& HashTableHost<T, IdType, Entry, Callback, TABLE_SIZE>::put(const T& data, uintptr_t hash) {
208 assert(lookup_only(data, hash) == NULL, "use lookup_put()");
209 HashEntry* const entry = new_entry(data, hash);
210 add_entry(index_for(hash), entry);
211 return *entry;
212 }
213
214 template <typename T, typename IdType, template <typename, typename> class Entry, typename Callback, size_t TABLE_SIZE>
215 Entry<T, IdType>* HashTableHost<T, IdType, Entry, Callback, TABLE_SIZE>::lookup_only(const T& query, uintptr_t hash) {
216 HashEntry* entry = (HashEntry*)this->bucket(index_for(hash));
217 while (entry != NULL) {
218 if (entry->hash() == hash && _callback->equals(query, hash, entry)) {
219 return entry;
220 }
221 entry = (HashEntry*)entry->next();
222 }
223 return NULL;
224 }
225
226 template <typename T, typename IdType, template <typename, typename> class Entry, typename Callback, size_t TABLE_SIZE>
227 template <typename Functor>
228 void HashTableHost<T, IdType, Entry, Callback, TABLE_SIZE>::iterate_value(Functor& f) {
229 for (size_t i = 0; i < this->table_size(); ++i) {
230 const HashEntry* entry = (const HashEntry*)this->bucket(i);
231 while (entry != NULL) {
232 if (!f(entry->value())) {
233 break;
234 }
235 entry = (HashEntry*)entry->next();
236 }
237 }
238 }
239
240 template <typename T, typename IdType, template <typename, typename> class Entry, typename Callback, size_t TABLE_SIZE>
241 template <typename Functor>
242 void HashTableHost<T, IdType, Entry, Callback, TABLE_SIZE>::iterate_entry(Functor& f) {
243 for (size_t i = 0; i < this->table_size(); ++i) {
244 const HashEntry* entry = (const HashEntry*)this->bucket(i);
245 while (entry != NULL) {
246 if (!f(entry)) {
247 break;
248 }
249 entry = (const HashEntry*)entry->next();
250 }
251 }
252 }
253
254 template <typename T, typename IdType, template <typename, typename> class Entry, typename Callback, size_t TABLE_SIZE>
255 void HashTableHost<T, IdType, Entry, Callback, TABLE_SIZE>::clear_entries() {
256 for (size_t i = 0; i < this->table_size(); ++i) {
257 HashEntry** bucket = (HashEntry**)this->bucket_addr(i);
258 HashEntry* entry = *bucket;
259 while (entry != NULL) {
260 HashEntry* entry_to_remove = entry;
261 entry = (HashEntry*)entry->next();
262 this->free_entry(entry_to_remove);
263 }
264 *bucket = NULL;
265 }
266 assert(this->number_of_entries() == 0, "should have removed all entries");
267 }
268
269 template <typename T, typename IdType, template <typename, typename> class Entry, typename Callback, size_t TABLE_SIZE>
270 Entry<T, IdType>* HashTableHost<T, IdType, Entry, Callback, TABLE_SIZE>::new_entry(const T& data, uintptr_t hash) {
271 assert(sizeof(HashEntry) == this->entry_size(), "invariant");
272 HashEntry* const entry = (HashEntry*) NEW_C_HEAP_ARRAY2(char, this->entry_size(), mtTracing, CURRENT_PC);
273 entry->init();
274 entry->set_hash(hash);
275 entry->set_value(data);
276 entry->set_next(NULL);
277 assert(0 == entry->id(), "invariant");
278 return entry;
279 }
280
281 #endif // SHARE_JFR_UTILITIES_JFRHASHTABLE_HPP