236 int number_of_entries() { return _number_of_entries; }
237
238 template <class T> void verify_table(const char* table_name) PRODUCT_RETURN;
239 };
240
241
242 template <class T, MEMFLAGS F> class Hashtable : public BasicHashtable<F> {
243 friend class VMStructs;
244
245 public:
246 Hashtable(int table_size, int entry_size)
247 : BasicHashtable<F>(table_size, entry_size) { }
248
249 Hashtable(int table_size, int entry_size,
250 HashtableBucket<F>* buckets, int number_of_entries)
251 : BasicHashtable<F>(table_size, entry_size, buckets, number_of_entries) { }
252
253 // Debugging
254 void print() PRODUCT_RETURN;
255
256 protected:
257
258 unsigned int compute_hash(Symbol* name) {
259 return (unsigned int) name->identity_hash();
260 }
261
262 int index_for(Symbol* name) {
263 return this->hash_to_index(compute_hash(name));
264 }
265
266 // Table entry management
267 HashtableEntry<T, F>* new_entry(unsigned int hashValue, T obj);
268
269 // The following method is MT-safe and may be used with caution.
270 HashtableEntry<T, F>* bucket(int i) const {
271 return (HashtableEntry<T, F>*)BasicHashtable<F>::bucket(i);
272 }
273
274 // The following method is not MT-safe and must be done under lock.
275 HashtableEntry<T, F>** bucket_addr(int i) {
276 return (HashtableEntry<T, F>**)BasicHashtable<F>::bucket_addr(i);
277 }
278
279 };
280
281 template <class T, MEMFLAGS F> class RehashableHashtable : public Hashtable<T, F> {
282 friend class VMStructs;
283 protected:
284
285 enum {
286 rehash_count = 100,
287 rehash_multiple = 60
306
307 static int literal_size(Symbol *symbol);
308 static int literal_size(oop oop);
309
310 // The following two are currently not used, but are needed anyway because some
311 // C++ compilers (MacOS and Solaris) force the instantiation of
312 // Hashtable<ConstantPool*, mtClass>::dump_table() even though we never call this function
313 // in the VM code.
314 static int literal_size(ConstantPool *cp) {Unimplemented(); return 0;}
315 static int literal_size(Klass *k) {Unimplemented(); return 0;}
316
317 void dump_table(outputStream* st, const char *table_name);
318
319 private:
320 static juint _seed;
321 };
322
323 template <class T, MEMFLAGS F> juint RehashableHashtable<T, F>::_seed = 0;
324 template <class T, MEMFLAGS F> juint RehashableHashtable<T, F>::seed() { return _seed; };
325 template <class T, MEMFLAGS F> bool RehashableHashtable<T, F>::use_alternate_hashcode() { return _seed != 0; };
326
327 // Versions of hashtable where two handles are used to compute the index.
328
329 template <class T, MEMFLAGS F> class TwoOopHashtable : public Hashtable<T, F> {
330 friend class VMStructs;
331 protected:
332 TwoOopHashtable(int table_size, int entry_size)
333 : Hashtable<T, F>(table_size, entry_size) {}
334
335 TwoOopHashtable(int table_size, int entry_size, HashtableBucket<F>* t,
336 int number_of_entries)
337 : Hashtable<T, F>(table_size, entry_size, t, number_of_entries) {}
338
339 public:
340 unsigned int compute_hash(const Symbol* name, const ClassLoaderData* loader_data) const {
341 unsigned int name_hash = name->identity_hash();
342 // loader is null with CDS
343 assert(loader_data != NULL || UseSharedSpaces || DumpSharedSpaces,
344 "only allowed with shared spaces");
345 unsigned int loader_hash = loader_data == NULL ? 0 : loader_data->identity_hash();
346 return name_hash ^ loader_hash;
347 }
348
349 int index_for(Symbol* name, ClassLoaderData* loader_data) {
350 return this->hash_to_index(compute_hash(name, loader_data));
351 }
352 };
353
354 #endif // SHARE_VM_UTILITIES_HASHTABLE_HPP
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236 int number_of_entries() { return _number_of_entries; }
237
238 template <class T> void verify_table(const char* table_name) PRODUCT_RETURN;
239 };
240
241
242 template <class T, MEMFLAGS F> class Hashtable : public BasicHashtable<F> {
243 friend class VMStructs;
244
245 public:
246 Hashtable(int table_size, int entry_size)
247 : BasicHashtable<F>(table_size, entry_size) { }
248
249 Hashtable(int table_size, int entry_size,
250 HashtableBucket<F>* buckets, int number_of_entries)
251 : BasicHashtable<F>(table_size, entry_size, buckets, number_of_entries) { }
252
253 // Debugging
254 void print() PRODUCT_RETURN;
255
256 unsigned int compute_hash(const Symbol* name) const {
257 return (unsigned int) name->identity_hash();
258 }
259
260 int index_for(const Symbol* name) const {
261 return this->hash_to_index(compute_hash(name));
262 }
263
264 protected:
265
266 // Table entry management
267 HashtableEntry<T, F>* new_entry(unsigned int hashValue, T obj);
268 // Don't create and use freelist
269 HashtableEntry<T, F>* allocate_new_entry(unsigned int hashValue, T obj);
270
271 // The following method is MT-safe and may be used with caution.
272 HashtableEntry<T, F>* bucket(int i) const {
273 return (HashtableEntry<T, F>*)BasicHashtable<F>::bucket(i);
274 }
275
276 // The following method is not MT-safe and must be done under lock.
277 HashtableEntry<T, F>** bucket_addr(int i) {
278 return (HashtableEntry<T, F>**)BasicHashtable<F>::bucket_addr(i);
279 }
280
281 };
282
283 template <class T, MEMFLAGS F> class RehashableHashtable : public Hashtable<T, F> {
284 friend class VMStructs;
285 protected:
286
287 enum {
288 rehash_count = 100,
289 rehash_multiple = 60
308
309 static int literal_size(Symbol *symbol);
310 static int literal_size(oop oop);
311
312 // The following two are currently not used, but are needed anyway because some
313 // C++ compilers (MacOS and Solaris) force the instantiation of
314 // Hashtable<ConstantPool*, mtClass>::dump_table() even though we never call this function
315 // in the VM code.
316 static int literal_size(ConstantPool *cp) {Unimplemented(); return 0;}
317 static int literal_size(Klass *k) {Unimplemented(); return 0;}
318
319 void dump_table(outputStream* st, const char *table_name);
320
321 private:
322 static juint _seed;
323 };
324
325 template <class T, MEMFLAGS F> juint RehashableHashtable<T, F>::_seed = 0;
326 template <class T, MEMFLAGS F> juint RehashableHashtable<T, F>::seed() { return _seed; };
327 template <class T, MEMFLAGS F> bool RehashableHashtable<T, F>::use_alternate_hashcode() { return _seed != 0; };
328
329 #endif // SHARE_VM_UTILITIES_HASHTABLE_HPP
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