1 /*
2 * Copyright (c) 2016, 2018, 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_VM_JFR_UTILITIES_JFRHASHTABLE_HPP
26 #define SHARE_VM_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_ptr_acquire(&_entry);
62 }
63 void set_entry(TableEntry* entry) { OrderAccess::release_store_ptr(&_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 if (NULL != _buckets) {
96 FREE_C_HEAP_ARRAY(Bucket, _buckets, mtTracing);
97 _buckets = NULL;
98 }
99 }
100 TableEntry* bucket(size_t i) { return _buckets[i].get_entry();}
101 TableEntry** bucket_addr(size_t i) { return _buckets[i].entry_addr(); }
102 uintptr_t table_size() const { return _table_size; }
103 size_t number_of_entries() const { return _number_of_entries; }
104 void add_entry(size_t index, TableEntry* entry) {
105 assert(entry != NULL, "invariant");
106 entry->set_next(bucket(index));
107 _buckets[index].set_entry(entry);
108 ++_number_of_entries;
109 }
110 };
111
112 template <typename IdType, typename Entry, typename T>
113 class AscendingId : public CHeapObj<mtTracing> {
114 private:
115 IdType _id;
116 public:
117 AscendingId() : _id(0) {}
118 // callbacks
119 void assign_id(Entry* entry) {
120 assert(entry != NULL, "invariant");
121 assert(entry->id() == 0, "invariant");
122 entry->set_id(++_id);
123 }
124 bool equals(const T& data, uintptr_t hash, const Entry* entry) {
125 assert(entry->hash() == hash, "invariant");
126 return true;
127 }
128 };
129
130 // IdType must be scalar
131 template <typename T, typename IdType>
132 class Entry : public JfrBasicHashtableEntry<T> {
133 public:
134 typedef IdType ID;
135 void init() { _id = 0; }
136 ID id() const { return _id; }
137 void set_id(ID id) { _id = id; }
138 void set_value(const T& value) { this->set_literal(value); }
139 T& value() const { return *const_cast<Entry*>(this)->literal_addr();}
140 const T* value_addr() const { return const_cast<Entry*>(this)->literal_addr(); }
141
142 private:
143 ID _id;
144 };
145
146 template <typename T, typename IdType, template <typename, typename> class Entry,
147 typename Callback = AscendingId<IdType, Entry<T, IdType>, T> ,
148 size_t TABLE_SIZE = 1009>
149 class HashTableHost : public JfrBasicHashtable<T> {
150 public:
151 typedef Entry<T, IdType> HashEntry;
152 HashTableHost() : _callback(new Callback()) {}
153 HashTableHost(Callback* cb) : JfrBasicHashtable<T>(TABLE_SIZE, sizeof(HashEntry)), _callback(cb) {}
154 ~HashTableHost() {
155 this->clear_entries();
156 this->free_buckets();
157 }
158
159 // direct insert assumes non-existing entry
160 HashEntry& put(const T& data, uintptr_t hash);
161
162 // lookup entry, will put if not found
163 HashEntry& lookup_put(const T& data, uintptr_t hash) {
164 HashEntry* entry = lookup_only(data, hash);
165 return entry == NULL ? put(data, hash) : *entry;
166 }
167
168 // read-only lookup
169 HashEntry* lookup_only(const T& query, uintptr_t hash);
170
171 // id retrieval
172 IdType id(const T& data, uintptr_t hash) {
173 assert(data != NULL, "invariant");
174 const HashEntry& entry = lookup_put(data, hash);
175 assert(entry.id() > 0, "invariant");
176 return entry.id();
177 }
178
179 template <typename Functor>
180 void iterate_value(Functor& f);
181
182 template <typename Functor>
183 void iterate_entry(Functor& f);
184
185 size_t cardinality() const { return this->number_of_entries(); }
186 bool has_entries() const { return this->cardinality() > 0; }
187 void clear_entries();
188
189 // removal and deallocation
190 void free_entry(HashEntry* entry) {
191 assert(entry != NULL, "invariant");
192 JfrBasicHashtable<T>::unlink_entry(entry);
193 FREE_C_HEAP_ARRAY(char, entry, mtTracing);
194 }
195
196 private:
197 Callback* _callback;
198 size_t index_for(uintptr_t hash) { return this->hash_to_index(hash); }
199 HashEntry* new_entry(const T& data, uintptr_t hash);
200 void add_entry(size_t index, HashEntry* new_entry) {
201 assert(new_entry != NULL, "invariant");
202 _callback->assign_id(new_entry);
203 assert(new_entry->id() > 0, "invariant");
204 JfrBasicHashtable<T>::add_entry(index, new_entry);
205 }
206 };
207
208 template <typename T, typename IdType, template <typename, typename> class Entry, typename Callback, size_t TABLE_SIZE>
209 Entry<T, IdType>& HashTableHost<T, IdType, Entry, Callback, TABLE_SIZE>::put(const T& data, uintptr_t hash) {
210 assert(lookup_only(data, hash) == NULL, "use lookup_put()");
211 HashEntry* const entry = new_entry(data, hash);
212 add_entry(index_for(hash), entry);
213 return *entry;
214 }
215
216 template <typename T, typename IdType, template <typename, typename> class Entry, typename Callback, size_t TABLE_SIZE>
217 Entry<T, IdType>* HashTableHost<T, IdType, Entry, Callback, TABLE_SIZE>::lookup_only(const T& query, uintptr_t hash) {
218 HashEntry* entry = (HashEntry*)this->bucket(index_for(hash));
219 while (entry != NULL) {
220 if (entry->hash() == hash && _callback->equals(query, hash, entry)) {
221 return entry;
222 }
223 entry = (HashEntry*)entry->next();
224 }
225 return NULL;
226 }
227
228 template <typename T, typename IdType, template <typename, typename> class Entry, typename Callback, size_t TABLE_SIZE>
229 template <typename Functor>
230 void HashTableHost<T, IdType, Entry, Callback, TABLE_SIZE>::iterate_value(Functor& f) {
231 for (size_t i = 0; i < this->table_size(); ++i) {
232 const HashEntry* entry = (const HashEntry*)this->bucket(i);
233 while (entry != NULL) {
234 if (!f(entry->value())) {
235 break;
236 }
237 entry = (HashEntry*)entry->next();
238 }
239 }
240 }
241
242 template <typename T, typename IdType, template <typename, typename> class Entry, typename Callback, size_t TABLE_SIZE>
243 template <typename Functor>
244 void HashTableHost<T, IdType, Entry, Callback, TABLE_SIZE>::iterate_entry(Functor& f) {
245 for (size_t i = 0; i < this->table_size(); ++i) {
246 const HashEntry* entry = (const HashEntry*)this->bucket(i);
247 while (entry != NULL) {
248 if (!f(entry)) {
249 break;
250 }
251 entry = (const HashEntry*)entry->next();
252 }
253 }
254 }
255
256 template <typename T, typename IdType, template <typename, typename> class Entry, typename Callback, size_t TABLE_SIZE>
257 void HashTableHost<T, IdType, Entry, Callback, TABLE_SIZE>::clear_entries() {
258 for (size_t i = 0; i < this->table_size(); ++i) {
259 HashEntry** bucket = (HashEntry**)this->bucket_addr(i);
260 HashEntry* entry = *bucket;
261 while (entry != NULL) {
262 HashEntry* entry_to_remove = entry;
263 entry = (HashEntry*)entry->next();
264 this->free_entry(entry_to_remove);
265 }
266 *bucket = NULL;
267 }
268 assert(this->number_of_entries() == 0, "should have removed all entries");
269 }
270
271 template <typename T, typename IdType, template <typename, typename> class Entry, typename Callback, size_t TABLE_SIZE>
272 Entry<T, IdType>* HashTableHost<T, IdType, Entry, Callback, TABLE_SIZE>::new_entry(const T& data, uintptr_t hash) {
273 assert(sizeof(HashEntry) == this->entry_size(), "invariant");
274 HashEntry* const entry = (HashEntry*) NEW_C_HEAP_ARRAY2(char, this->entry_size(), mtTracing, CURRENT_PC);
275 entry->init();
276 entry->set_hash(hash);
277 entry->set_value(data);
278 entry->set_next(NULL);
279 assert(0 == entry->id(), "invariant");
280 return entry;
281 }
282
283 #endif // SHARE_VM_JFR_UTILITIES_JFRHASHTABLE_HPP