Mercurial > hg > graal-compiler
view src/share/vm/utilities/hashtable.hpp @ 17699:54436d3b2a91 hs25.20-b05
Merge
author | amurillo |
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date | Fri, 28 Feb 2014 08:43:42 -0800 |
parents | 55fb97c4c58d |
children | cd6b3f1a94ff |
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/* * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #ifndef SHARE_VM_UTILITIES_HASHTABLE_HPP #define SHARE_VM_UTILITIES_HASHTABLE_HPP #include "classfile/classLoaderData.hpp" #include "memory/allocation.hpp" #include "oops/oop.hpp" #include "oops/symbol.hpp" #include "runtime/handles.hpp" // This is a generic hashtable, designed to be used for the symbol // and string tables. // // It is implemented as an open hash table with a fixed number of buckets. // // %note: // - TableEntrys are allocated in blocks to reduce the space overhead. template <MEMFLAGS F> class BasicHashtableEntry : public CHeapObj<F> { friend class VMStructs; private: unsigned int _hash; // 32-bit hash for item // Link to next element in the linked list for this bucket. EXCEPT // bit 0 set indicates that this entry is shared and must not be // unlinked from the table. Bit 0 is set during the dumping of the // archive. Since shared entries are immutable, _next fields in the // shared entries will not change. New entries will always be // unshared and since pointers are align, bit 0 will always remain 0 // with no extra effort. BasicHashtableEntry<F>* _next; // Windows IA64 compiler requires subclasses to be able to access these protected: // Entry objects should not be created, they should be taken from the // free list with BasicHashtable.new_entry(). BasicHashtableEntry() { ShouldNotReachHere(); } // Entry objects should not be destroyed. They should be placed on // the free list instead with BasicHashtable.free_entry(). ~BasicHashtableEntry() { ShouldNotReachHere(); } public: unsigned int hash() const { return _hash; } void set_hash(unsigned int hash) { _hash = hash; } unsigned int* hash_addr() { return &_hash; } static BasicHashtableEntry<F>* make_ptr(BasicHashtableEntry<F>* p) { return (BasicHashtableEntry*)((intptr_t)p & -2); } BasicHashtableEntry<F>* next() const { return make_ptr(_next); } void set_next(BasicHashtableEntry<F>* next) { _next = next; } BasicHashtableEntry<F>** next_addr() { return &_next; } bool is_shared() const { return ((intptr_t)_next & 1) != 0; } void set_shared() { _next = (BasicHashtableEntry<F>*)((intptr_t)_next | 1); } }; template <class T, MEMFLAGS F> class HashtableEntry : public BasicHashtableEntry<F> { friend class VMStructs; private: T _literal; // ref to item in table. public: // Literal T literal() const { return _literal; } T* literal_addr() { return &_literal; } void set_literal(T s) { _literal = s; } HashtableEntry* next() const { return (HashtableEntry*)BasicHashtableEntry<F>::next(); } HashtableEntry** next_addr() { return (HashtableEntry**)BasicHashtableEntry<F>::next_addr(); } }; template <MEMFLAGS F> class HashtableBucket : public CHeapObj<F> { friend class VMStructs; private: // Instance variable BasicHashtableEntry<F>* _entry; public: // Accessing void clear() { _entry = NULL; } // The following methods use order access methods to avoid race // conditions in multiprocessor systems. BasicHashtableEntry<F>* get_entry() const; void set_entry(BasicHashtableEntry<F>* l); // The following method is not MT-safe and must be done under lock. BasicHashtableEntry<F>** entry_addr() { return &_entry; } }; template <MEMFLAGS F> class BasicHashtable : public CHeapObj<F> { friend class VMStructs; public: BasicHashtable(int table_size, int entry_size); BasicHashtable(int table_size, int entry_size, HashtableBucket<F>* buckets, int number_of_entries); // Sharing support. void copy_buckets(char** top, char* end); void copy_table(char** top, char* end); // Bucket handling int hash_to_index(unsigned int full_hash) { int h = full_hash % _table_size; assert(h >= 0 && h < _table_size, "Illegal hash value"); return h; } // Reverse the order of elements in each of the buckets. void reverse(); private: // Instance variables int _table_size; HashtableBucket<F>* _buckets; BasicHashtableEntry<F>* _free_list; char* _first_free_entry; char* _end_block; int _entry_size; int _number_of_entries; protected: #ifdef ASSERT int _lookup_count; int _lookup_length; void verify_lookup_length(double load); #endif enum { rehash_count = 100, rehash_multiple = 60 }; void initialize(int table_size, int entry_size, int number_of_entries); // Accessor int entry_size() const { return _entry_size; } // The following method is MT-safe and may be used with caution. BasicHashtableEntry<F>* bucket(int i); // The following method is not MT-safe and must be done under lock. BasicHashtableEntry<F>** bucket_addr(int i) { return _buckets[i].entry_addr(); } // Table entry management BasicHashtableEntry<F>* new_entry(unsigned int hashValue); // Check that the table is unbalanced bool check_rehash_table(int count); // Used when moving the entry to another table // Clean up links, but do not add to free_list void unlink_entry(BasicHashtableEntry<F>* entry) { entry->set_next(NULL); --_number_of_entries; } // Move over freelist and free block for allocation void copy_freelist(BasicHashtable* src) { _free_list = src->_free_list; src->_free_list = NULL; _first_free_entry = src->_first_free_entry; src->_first_free_entry = NULL; _end_block = src->_end_block; src->_end_block = NULL; } // Free the buckets in this hashtable void free_buckets(); public: int table_size() { return _table_size; } void set_entry(int index, BasicHashtableEntry<F>* entry); void add_entry(int index, BasicHashtableEntry<F>* entry); void free_entry(BasicHashtableEntry<F>* entry); int number_of_entries() { return _number_of_entries; } void verify() PRODUCT_RETURN; }; template <class T, MEMFLAGS F> class Hashtable : public BasicHashtable<F> { friend class VMStructs; public: Hashtable(int table_size, int entry_size) : BasicHashtable<F>(table_size, entry_size) { } Hashtable(int table_size, int entry_size, HashtableBucket<F>* buckets, int number_of_entries) : BasicHashtable<F>(table_size, entry_size, buckets, number_of_entries) { } // Debugging void print() PRODUCT_RETURN; // Reverse the order of elements in each of the buckets. Hashtable // entries which refer to objects at a lower address than 'boundary' // are separated from those which refer to objects at higher // addresses, and appear first in the list. void reverse(void* boundary = NULL); protected: unsigned int compute_hash(Symbol* name) { return (unsigned int) name->identity_hash(); } int index_for(Symbol* name) { return this->hash_to_index(compute_hash(name)); } // Table entry management HashtableEntry<T, F>* new_entry(unsigned int hashValue, T obj); // The following method is MT-safe and may be used with caution. HashtableEntry<T, F>* bucket(int i) { return (HashtableEntry<T, F>*)BasicHashtable<F>::bucket(i); } // The following method is not MT-safe and must be done under lock. HashtableEntry<T, F>** bucket_addr(int i) { return (HashtableEntry<T, F>**)BasicHashtable<F>::bucket_addr(i); } // Function to move these elements into the new table. void move_to(Hashtable<T, F>* new_table); static bool use_alternate_hashcode() { return _seed != 0; } static jint seed() { return _seed; } static int literal_size(Symbol *symbol); static int literal_size(oop oop); // The following two are currently not used, but are needed anyway because some // C++ compilers (MacOS and Solaris) force the instantiation of // Hashtable<ConstantPool*, mtClass>::dump_table() even though we never call this function // in the VM code. static int literal_size(ConstantPool *cp) {Unimplemented(); return 0;} static int literal_size(Klass *k) {Unimplemented(); return 0;} public: void dump_table(outputStream* st, const char *table_name); private: static jint _seed; }; // Verions of hashtable where two handles are used to compute the index. template <class T, MEMFLAGS F> class TwoOopHashtable : public Hashtable<T, F> { friend class VMStructs; protected: TwoOopHashtable(int table_size, int entry_size) : Hashtable<T, F>(table_size, entry_size) {} TwoOopHashtable(int table_size, int entry_size, HashtableBucket<F>* t, int number_of_entries) : Hashtable<T, F>(table_size, entry_size, t, number_of_entries) {} public: unsigned int compute_hash(Symbol* name, ClassLoaderData* loader_data) { unsigned int name_hash = name->identity_hash(); // loader is null with CDS assert(loader_data != NULL || UseSharedSpaces || DumpSharedSpaces, "only allowed with shared spaces"); unsigned int loader_hash = loader_data == NULL ? 0 : loader_data->identity_hash(); return name_hash ^ loader_hash; } int index_for(Symbol* name, ClassLoaderData* loader_data) { return this->hash_to_index(compute_hash(name, loader_data)); } }; #endif // SHARE_VM_UTILITIES_HASHTABLE_HPP