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src/share/vm/gc_implementation/parNew/parOopClosures.inline.hpp@0bfd3fb24150 (annotated)

src/share/vm/gc_implementation/parNew/parOopClosures.inline.hpp

Tue, 13 Apr 2010 13:52:10 -0700

author

jmasa

date

Tue, 13 Apr 2010 13:52:10 -0700

changeset 1822

0bfd3fb24150

parent 548

ba764ed4b6f2

child 1907

c18cbe5936b8

permissions

-rw-r--r--

6858496: Clear all SoftReferences before an out-of-memory due to GC overhead limit.
Summary: Ensure a full GC that clears SoftReferences before throwing an out-of-memory
Reviewed-by: ysr, jcoomes

duke@435	1	/*
duke@435	2	* Copyright (c) 2007 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
coleenp@548	25	template <class T> inline void ParScanWeakRefClosure::do_oop_work(T* p) {
coleenp@548	26	assert (!oopDesc::is_null(*p), "null weak reference?");
coleenp@548	27	oop obj = oopDesc::load_decode_heap_oop_not_null(p);
duke@435	28	// weak references are sometimes scanned twice; must check
duke@435	29	// that to-space doesn't already contain this object
duke@435	30	if ((HeapWord*)obj < _boundary && !_g->to()->is_in_reserved(obj)) {
duke@435	31	// we need to ensure that it is copied (see comment in
duke@435	32	// ParScanClosure::do_oop_work).
duke@435	33	klassOop objK = obj->klass();
duke@435	34	markOop m = obj->mark();
coleenp@548	35	oop new_obj;
duke@435	36	if (m->is_marked()) { // Contains forwarding pointer.
coleenp@548	37	new_obj = ParNewGeneration::real_forwardee(obj);
duke@435	38	} else {
duke@435	39	size_t obj_sz = obj->size_given_klass(objK->klass_part());
coleenp@548	40	new_obj = ((ParNewGeneration*)_g)->copy_to_survivor_space(_par_scan_state,
coleenp@548	41	obj, obj_sz, m);
duke@435	42	}
coleenp@548	43	oopDesc::encode_store_heap_oop_not_null(p, new_obj);
duke@435	44	}
duke@435	45	}
duke@435	46
coleenp@548	47	inline void ParScanWeakRefClosure::do_oop_nv(oop* p) { ParScanWeakRefClosure::do_oop_work(p); }
coleenp@548	48	inline void ParScanWeakRefClosure::do_oop_nv(narrowOop* p) { ParScanWeakRefClosure::do_oop_work(p); }
duke@435	49
coleenp@548	50	template <class T> inline void ParScanClosure::par_do_barrier(T* p) {
duke@435	51	assert(generation()->is_in_reserved(p), "expected ref in generation");
coleenp@548	52	assert(!oopDesc::is_null(*p), "expected non-null object");
coleenp@548	53	oop obj = oopDesc::load_decode_heap_oop_not_null(p);
duke@435	54	// If p points to a younger generation, mark the card.
duke@435	55	if ((HeapWord*)obj < gen_boundary()) {
duke@435	56	rs()->write_ref_field_gc_par(p, obj);
duke@435	57	}
duke@435	58	}
duke@435	59
coleenp@548	60	template <class T>
coleenp@548	61	inline void ParScanClosure::do_oop_work(T* p,
duke@435	62	bool gc_barrier,
duke@435	63	bool root_scan) {
duke@435	64	assert((!Universe::heap()->is_in_reserved(p) ||
duke@435	65	generation()->is_in_reserved(p))
duke@435	66	&& (generation()->level() == 0 || gc_barrier),
duke@435	67	"The gen must be right, and we must be doing the barrier "
duke@435	68	"in older generations.");
coleenp@548	69	T heap_oop = oopDesc::load_heap_oop(p);
coleenp@548	70	if (!oopDesc::is_null(heap_oop)) {
coleenp@548	71	oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
duke@435	72	if ((HeapWord*)obj < _boundary) {
duke@435	73	assert(!_g->to()->is_in_reserved(obj), "Scanning field twice?");
duke@435	74	// OK, we need to ensure that it is copied.
duke@435	75	// We read the klass and mark in this order, so that we can reliably
duke@435	76	// get the size of the object: if the mark we read is not a
duke@435	77	// forwarding pointer, then the klass is valid: the klass is only
duke@435	78	// overwritten with an overflow next pointer after the object is
duke@435	79	// forwarded.
duke@435	80	klassOop objK = obj->klass();
duke@435	81	markOop m = obj->mark();
coleenp@548	82	oop new_obj;
duke@435	83	if (m->is_marked()) { // Contains forwarding pointer.
coleenp@548	84	new_obj = ParNewGeneration::real_forwardee(obj);
coleenp@548	85	oopDesc::encode_store_heap_oop_not_null(p, new_obj);
duke@435	86	} else {
duke@435	87	size_t obj_sz = obj->size_given_klass(objK->klass_part());
coleenp@548	88	new_obj = _g->copy_to_survivor_space(_par_scan_state, obj, obj_sz, m);
coleenp@548	89	oopDesc::encode_store_heap_oop_not_null(p, new_obj);
duke@435	90	if (root_scan) {
duke@435	91	// This may have pushed an object. If we have a root
duke@435	92	// category with a lot of roots, can't let the queue get too
duke@435	93	// full:
duke@435	94	(void)_par_scan_state->trim_queues(10 * ParallelGCThreads);
duke@435	95	}
duke@435	96	}
duke@435	97	if (gc_barrier) {
duke@435	98	// Now call parent closure
duke@435	99	par_do_barrier(p);
duke@435	100	}
duke@435	101	}
duke@435	102	}
duke@435	103	}
coleenp@548	104
coleenp@548	105	inline void ParScanWithBarrierClosure::do_oop_nv(oop* p) { ParScanClosure::do_oop_work(p, true, false); }
coleenp@548	106	inline void ParScanWithBarrierClosure::do_oop_nv(narrowOop* p) { ParScanClosure::do_oop_work(p, true, false); }
coleenp@548	107
coleenp@548	108	inline void ParScanWithoutBarrierClosure::do_oop_nv(oop* p) { ParScanClosure::do_oop_work(p, false, false); }
coleenp@548	109	inline void ParScanWithoutBarrierClosure::do_oop_nv(narrowOop* p) { ParScanClosure::do_oop_work(p, false, false); }