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src/share/vm/utilities/hashtable.inline.hpp@0fbdb4381b99 (annotated)

src/share/vm/utilities/hashtable.inline.hpp

Mon, 09 Mar 2009 13:28:46 -0700

author

xdono

date

Mon, 09 Mar 2009 13:28:46 -0700

changeset 1014

0fbdb4381b99

parent 435

a61af66fc99e

child 1907

c18cbe5936b8

permissions

-rw-r--r--

6814575: Update copyright year
Summary: Update copyright for files that have been modified in 2009, up to 03/09
Reviewed-by: katleman, tbell, ohair

duke@435	1	/*
duke@435	2	* Copyright 2003 Sun Microsystems, Inc. All Rights Reserved.
duke@435	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435	4	*
duke@435	5	* This code is free software; you can redistribute it and/or modify it
duke@435	6	* under the terms of the GNU General Public License version 2 only, as
duke@435	7	* published by the Free Software Foundation.
duke@435	8	*
duke@435	9	* This code is distributed in the hope that it will be useful, but WITHOUT
duke@435	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435	12	* version 2 for more details (a copy is included in the LICENSE file that
duke@435	13	* accompanied this code).
duke@435	14	*
duke@435	15	* You should have received a copy of the GNU General Public License version
duke@435	16	* 2 along with this work; if not, write to the Free Software Foundation,
duke@435	17	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435	18	*
duke@435	19	* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435	20	* CA 95054 USA or visit www.sun.com if you need additional information or
duke@435	21	* have any questions.
duke@435	22	*
duke@435	23	*/
duke@435	24
duke@435	25	// Inline function definitions for hashtable.hpp.
duke@435	26
duke@435	27
duke@435	28	// --------------------------------------------------------------------------
duke@435	29	// Hash function
duke@435	30
duke@435	31	// We originally used hashpjw, but hash P(31) gives just as good results
duke@435	32	// and is slighly faster. We would like a hash function that looks at every
duke@435	33	// character, since package names have large common prefixes, and also because
duke@435	34	// hash_or_fail does error checking while iterating.
duke@435	35
duke@435	36	// hash P(31) from Kernighan & Ritchie
duke@435	37
duke@435	38	inline unsigned int Hashtable::hash_symbol(const char* s, int len) {
duke@435	39	unsigned int h = 0;
duke@435	40	while (len-- > 0) {
duke@435	41	h = 31*h + (unsigned) *s;
duke@435	42	s++;
duke@435	43	}
duke@435	44	return h;
duke@435	45	}
duke@435	46
duke@435	47
duke@435	48	// --------------------------------------------------------------------------
duke@435	49
duke@435	50	// Initialize a table.
duke@435	51
duke@435	52	inline BasicHashtable::BasicHashtable(int table_size, int entry_size) {
duke@435	53	// Called on startup, no locking needed
duke@435	54	initialize(table_size, entry_size, 0);
duke@435	55	_buckets = NEW_C_HEAP_ARRAY(HashtableBucket, table_size);
duke@435	56	for (int index = 0; index < _table_size; index++) {
duke@435	57	_buckets[index].clear();
duke@435	58	}
duke@435	59	}
duke@435	60
duke@435	61
duke@435	62	inline BasicHashtable::BasicHashtable(int table_size, int entry_size,
duke@435	63	HashtableBucket* buckets,
duke@435	64	int number_of_entries) {
duke@435	65	// Called on startup, no locking needed
duke@435	66	initialize(table_size, entry_size, number_of_entries);
duke@435	67	_buckets = buckets;
duke@435	68	}
duke@435	69
duke@435	70
duke@435	71	inline void BasicHashtable::initialize(int table_size, int entry_size,
duke@435	72	int number_of_entries) {
duke@435	73	// Called on startup, no locking needed
duke@435	74	_table_size = table_size;
duke@435	75	_entry_size = entry_size;
duke@435	76	_free_list = NULL;
duke@435	77	_first_free_entry = NULL;
duke@435	78	_end_block = NULL;
duke@435	79	_number_of_entries = number_of_entries;
duke@435	80	#ifdef ASSERT
duke@435	81	_lookup_count = 0;
duke@435	82	_lookup_length = 0;
duke@435	83	#endif
duke@435	84	}
duke@435	85
duke@435	86
duke@435	87	// The following method is MT-safe and may be used with caution.
duke@435	88	inline BasicHashtableEntry* BasicHashtable::bucket(int i) {
duke@435	89	return _buckets[i].get_entry();
duke@435	90	}
duke@435	91
duke@435	92
duke@435	93	inline void HashtableBucket::set_entry(BasicHashtableEntry* l) {
duke@435	94	// Warning: Preserve store ordering. The SystemDictionary is read
duke@435	95	// without locks. The new SystemDictionaryEntry must be
duke@435	96	// complete before other threads can be allowed to see it
duke@435	97	// via a store to _buckets[index].
duke@435	98	OrderAccess::release_store_ptr(&_entry, l);
duke@435	99	}
duke@435	100
duke@435	101
duke@435	102	inline BasicHashtableEntry* HashtableBucket::get_entry() const {
duke@435	103	// Warning: Preserve load ordering. The SystemDictionary is read
duke@435	104	// without locks. The new SystemDictionaryEntry must be
duke@435	105	// complete before other threads can be allowed to see it
duke@435	106	// via a store to _buckets[index].
duke@435	107	return (BasicHashtableEntry*) OrderAccess::load_ptr_acquire(&_entry);
duke@435	108	}
duke@435	109
duke@435	110
duke@435	111	inline void BasicHashtable::set_entry(int index, BasicHashtableEntry* entry) {
duke@435	112	_buckets[index].set_entry(entry);
duke@435	113	}
duke@435	114
duke@435	115
duke@435	116	inline void BasicHashtable::add_entry(int index, BasicHashtableEntry* entry) {
duke@435	117	entry->set_next(bucket(index));
duke@435	118	_buckets[index].set_entry(entry);
duke@435	119	++_number_of_entries;
duke@435	120	}
duke@435	121
duke@435	122	inline void BasicHashtable::free_entry(BasicHashtableEntry* entry) {
duke@435	123	entry->set_next(_free_list);
duke@435	124	_free_list = entry;
duke@435	125	--_number_of_entries;
duke@435	126	}