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src/share/vm/oops/instanceOop.hpp@ba764ed4b6f2 (annotated)

src/share/vm/oops/instanceOop.hpp

Sun, 13 Apr 2008 17:43:42 -0400

author

coleenp

date

Sun, 13 Apr 2008 17:43:42 -0400

changeset 548

ba764ed4b6f2

parent 435

a61af66fc99e

child 600

437d03ea40b1

permissions

-rw-r--r--

6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
Summary: Compressed oops in instances, arrays, and headers. Code contributors are coleenp, phh, never, swamyv
Reviewed-by: jmasa, kamg, acorn, tbell, kvn, rasbold

duke@435	1	/*
duke@435	2	* Copyright 1997-2000 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	// An instanceOop is an instance of a Java Class
duke@435	26	// Evaluating "new HashTable()" will create an instanceOop.
duke@435	27
duke@435	28	class instanceOopDesc : public oopDesc {
duke@435	29	public:
coleenp@548	30	// aligned header size.
duke@435	31	static int header_size() { return sizeof(instanceOopDesc)/HeapWordSize; }
coleenp@548	32
coleenp@548	33	// If compressed, the offset of the fields of the instance may not be aligned.
coleenp@548	34	static int base_offset_in_bytes() {
coleenp@548	35	return UseCompressedOops ?
coleenp@548	36	klass_gap_offset_in_bytes() :
coleenp@548	37	sizeof(instanceOopDesc);
coleenp@548	38	}
coleenp@548	39
coleenp@548	40	static bool contains_field_offset(int offset, int nonstatic_field_size) {
coleenp@548	41	int base_in_bytes = base_offset_in_bytes();
coleenp@548	42	if (UseCompressedOops) {
coleenp@548	43	return (offset >= base_in_bytes &&
coleenp@548	44	// field can be embedded in header, or is after header.
coleenp@548	45	(offset < (int)sizeof(instanceOopDesc) ||
coleenp@548	46	(offset-(int)sizeof(instanceOopDesc))/wordSize < nonstatic_field_size));
coleenp@548	47	} else {
coleenp@548	48	return (offset >= base_in_bytes &&
coleenp@548	49	(offset-base_in_bytes)/wordSize < nonstatic_field_size);
coleenp@548	50	}
coleenp@548	51	}
duke@435	52	};