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src/share/vm/gc_implementation/parallelScavenge/asPSYoungGen.hpp@1fdb98a17101 (annotated)

src/share/vm/gc_implementation/parallelScavenge/asPSYoungGen.hpp

Sat, 19 Jul 2008 17:38:22 -0400

author

coleenp

date

Sat, 19 Jul 2008 17:38:22 -0400

changeset 672

1fdb98a17101

parent 435

a61af66fc99e

child 1907

c18cbe5936b8

permissions

-rw-r--r--

6716785: implicit null checks not triggering with CompressedOops
Summary: allocate alignment-sized page(s) below java heap so that memory accesses at heap_base+1page give signal and cause an implicit null check
Reviewed-by: kvn, jmasa, phh, jcoomes

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	class ASPSYoungGen : public PSYoungGen {
duke@435	26	friend class VMStructs;
duke@435	27	private:
duke@435	28	size_t _gen_size_limit;
duke@435	29	protected:
duke@435	30	virtual size_t available_to_live();
duke@435	31
duke@435	32	public:
duke@435	33	ASPSYoungGen(size_t initial_byte_size,
duke@435	34	size_t minimum_byte_size,
duke@435	35	size_t byte_size_limit);
duke@435	36
duke@435	37	ASPSYoungGen(PSVirtualSpace* vs,
duke@435	38	size_t initial_byte_size,
duke@435	39	size_t minimum_byte_size,
duke@435	40	size_t byte_size_limit);
duke@435	41
duke@435	42	void initialize(ReservedSpace rs, size_t alignment);
duke@435	43	void initialize_virtual_space(ReservedSpace rs, size_t alignment);
duke@435	44
duke@435	45	size_t gen_size_limit() { return _gen_size_limit; }
duke@435	46	void set_gen_size_limit(size_t v) { _gen_size_limit = v; }
duke@435	47
duke@435	48	bool resize_generation(size_t eden_size, size_t survivor_size);
duke@435	49	void resize_spaces(size_t eden_size, size_t survivor_size);
duke@435	50
duke@435	51	// Adjust eden to be consistent with the virtual space.
duke@435	52	void reset_after_change();
duke@435	53
duke@435	54	// Adaptive size policy support
duke@435	55	// Return number of bytes that the generation can expand/contract.
duke@435	56	size_t available_for_expansion();
duke@435	57	size_t available_for_contraction();
duke@435	58
duke@435	59	// Accessors
duke@435	60	void set_reserved(MemRegion v) { _reserved = v; }
duke@435	61
duke@435	62	// Printing support
duke@435	63	virtual const char* short_name() const { return "ASPSYoungGen"; }
duke@435	64	};