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 "jfr/utilities/jfrAllocation.hpp"
29 #include "runtime/atomic.hpp"
30 #include "utilities/debug.hpp"
31 #include "utilities/macros.hpp"
32
33 template <typename T>
34 class JfrBasicHashtableEntry : public JfrCHeapObj {
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 JfrBasicHashtableEntry(uintptr_t hash, const T& data) : _next(NULL), _literal(data), _hash(hash) {}
43 uintptr_t hash() const { return _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*)Atomic::load_acquire(&_entry);
62 }
63 void set_entry(TableEntry* entry) { Atomic::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 }
97 TableEntry* bucket(size_t i) { return _buckets[i].get_entry();}
98 TableEntry** bucket_addr(size_t i) { return _buckets[i].entry_addr(); }
99 uintptr_t table_size() const { return _table_size; }
100 size_t number_of_entries() const { return _number_of_entries; }
101 void add_entry(size_t index, TableEntry* entry) {
102 assert(entry != NULL, "invariant");
103 entry->set_next(bucket(index));
104 _buckets[index].set_entry(entry);
105 ++_number_of_entries;
106 }
107 };
108
109 template <typename IdType, typename Entry, typename T>
110 class AscendingId : public JfrCHeapObj {
111 private:
112 IdType _id;
113 public:
114 AscendingId() : _id(0) {}
115 // callbacks
116 void on_link(Entry* entry) {
117 assert(entry != NULL, "invariant");
118 assert(entry->id() == 0, "invariant");
119 entry->set_id(++_id);
120 }
121 bool on_equals(uintptr_t hash, const Entry* entry) {
122 assert(entry->hash() == hash, "invariant");
123 return true;
124 }
125 };
126
127 // IdType must be scalar
128 template <typename T, typename IdType>
129 class JfrHashtableEntry : public JfrBasicHashtableEntry<T> {
130 public:
131 JfrHashtableEntry(uintptr_t hash, const T& data) : JfrBasicHashtableEntry<T>(hash, data), _id(0) {}
132 typedef IdType ID;
133 ID id() const { return _id; }
134 void set_id(ID id) const { _id = id; }
135 T& value() const { return *const_cast<JfrHashtableEntry*>(this)->literal_addr();}
136 const T* value_addr() const { return const_cast<JfrHashtableEntry*>(this)->literal_addr(); }
137 private:
138 mutable ID _id;
139 };
140
141 template <typename T, typename IdType, template <typename, typename> class Entry,
142 typename Callback = AscendingId<IdType, Entry<T, IdType>, T> ,
143 size_t TABLE_SIZE = 1009>
144 class HashTableHost : public JfrBasicHashtable<T> {
145 public:
146 typedef Entry<T, IdType> HashEntry;
147 HashTableHost(size_t size = 0) : JfrBasicHashtable<T>(size == 0 ? TABLE_SIZE : size, sizeof(HashEntry)), _callback(new Callback()) {}
148 HashTableHost(Callback* cb, size_t size = 0) : JfrBasicHashtable<T>(size == 0 ? TABLE_SIZE : size, sizeof(HashEntry)), _callback(cb) {}
149 ~HashTableHost() {
150 this->clear_entries();
151 this->free_buckets();
152 }
153
154 // direct insert assumes non-existing entry
155 HashEntry& put(uintptr_t hash, const T& data);
156
157 // lookup entry, will put if not found
158 HashEntry& lookup_put(uintptr_t hash, const T& data) {
159 HashEntry* entry = lookup_only(hash);
160 return entry == NULL ? put(hash, data) : *entry;
161 }
162
163 HashEntry* lookup_only(uintptr_t hash);
164
165 // id retrieval
166 IdType id(uintptr_t hash, const T& data) {
167 assert(data != NULL, "invariant");
168 const HashEntry& entry = lookup_put(hash, data);
169 assert(entry.id() > 0, "invariant");
170 return entry.id();
171 }
172
173 template <typename Functor>
174 void iterate_value(Functor& f);
175
176 template <typename Functor>
177 void iterate_entry(Functor& f);
178
179 size_t cardinality() const { return this->number_of_entries(); }
180 bool has_entries() const { return this->cardinality() > 0; }
181 void clear_entries();
182
183 // removal and deallocation
184 void free_entry(HashEntry* entry) {
185 assert(entry != NULL, "invariant");
186 JfrBasicHashtable<T>::unlink_entry(entry);
187 _callback->on_unlink(entry);
188 delete entry;
189 }
190
191 private:
192 Callback* _callback;
193 size_t index_for(uintptr_t hash) { return this->hash_to_index(hash); }
194 HashEntry* new_entry(uintptr_t hash, const T& data);
195 void add_entry(size_t index, HashEntry* new_entry) {
196 assert(new_entry != NULL, "invariant");
197 _callback->on_link(new_entry);
198 assert(new_entry->id() > 0, "invariant");
199 JfrBasicHashtable<T>::add_entry(index, new_entry);
200 }
201 };
202
203 template <typename T, typename IdType, template <typename, typename> class Entry, typename Callback, size_t TABLE_SIZE>
204 Entry<T, IdType>& HashTableHost<T, IdType, Entry, Callback, TABLE_SIZE>::put(uintptr_t hash, const T& data) {
205 assert(lookup_only(hash) == NULL, "use lookup_put()");
206 HashEntry* const entry = new_entry(hash, data);
207 add_entry(index_for(hash), entry);
208 return *entry;
209 }
210
211 template <typename T, typename IdType, template <typename, typename> class Entry, typename Callback, size_t TABLE_SIZE>
212 Entry<T, IdType>* HashTableHost<T, IdType, Entry, Callback, TABLE_SIZE>::lookup_only(uintptr_t hash) {
213 HashEntry* entry = (HashEntry*)this->bucket(index_for(hash));
214 while (entry != NULL) {
215 if (entry->hash() == hash && _callback->on_equals(hash, entry)) {
216 return entry;
217 }
218 entry = (HashEntry*)entry->next();
219 }
220 return NULL;
221 }
222
223 template <typename T, typename IdType, template <typename, typename> class Entry, typename Callback, size_t TABLE_SIZE>
224 template <typename Functor>
225 void HashTableHost<T, IdType, Entry, Callback, TABLE_SIZE>::iterate_value(Functor& f) {
226 for (size_t i = 0; i < this->table_size(); ++i) {
227 const HashEntry* entry = (const HashEntry*)this->bucket(i);
228 while (entry != NULL) {
229 if (!f(entry->value())) {
230 break;
231 }
232 entry = (HashEntry*)entry->next();
233 }
234 }
235 }
236
237 template <typename T, typename IdType, template <typename, typename> class Entry, typename Callback, size_t TABLE_SIZE>
238 template <typename Functor>
239 void HashTableHost<T, IdType, Entry, Callback, TABLE_SIZE>::iterate_entry(Functor& f) {
240 for (size_t i = 0; i < this->table_size(); ++i) {
241 const HashEntry* entry = (const HashEntry*)this->bucket(i);
242 while (entry != NULL) {
243 if (!f(entry)) {
244 break;
245 }
246 entry = (const HashEntry*)entry->next();
247 }
248 }
249 }
250
251 template <typename T, typename IdType, template <typename, typename> class Entry, typename Callback, size_t TABLE_SIZE>
252 void HashTableHost<T, IdType, Entry, Callback, TABLE_SIZE>::clear_entries() {
253 for (size_t i = 0; i < this->table_size(); ++i) {
254 HashEntry** bucket = (HashEntry**)this->bucket_addr(i);
255 HashEntry* entry = *bucket;
256 while (entry != NULL) {
257 HashEntry* entry_to_remove = entry;
258 entry = (HashEntry*)entry->next();
259 this->free_entry(entry_to_remove);
260 }
261 *bucket = NULL;
262 }
263 assert(this->number_of_entries() == 0, "should have removed all entries");
264 }
265
266 template <typename T, typename IdType, template <typename, typename> class Entry, typename Callback, size_t TABLE_SIZE>
267 Entry<T, IdType>* HashTableHost<T, IdType, Entry, Callback, TABLE_SIZE>::new_entry(uintptr_t hash, const T& data) {
268 assert(sizeof(HashEntry) == this->entry_size(), "invariant");
269 HashEntry* const entry = new HashEntry(hash, data);
270 assert(entry != NULL, "invariant");
271 assert(0 == entry->id(), "invariant");
272 return entry;
273 }
274
275 #endif // SHARE_JFR_UTILITIES_JFRHASHTABLE_HPP