6684579: SoftReference processing can be made more efficient
Summary: For current soft-ref clearing policies, we can decide at marking time if a soft-reference will definitely not be cleared, postponing the decision of whether it will definitely be cleared to the final reference processing phase. This can be especially beneficial in the case of concurrent collectors where the marking is usually concurrent but reference processing is usually not.
Reviewed-by: jmasa
/*
* Copyright 2001-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*
*/
inline HeapRegion* HeapRegionSeq::addr_to_region(const void* addr) {
assert(_seq_bottom != NULL, "bad _seq_bottom in addr_to_region");
if ((char*) addr >= _seq_bottom) {
size_t diff = (size_t) pointer_delta((HeapWord*) addr,
(HeapWord*) _seq_bottom);
int index = (int) (diff >> HeapRegion::LogOfHRGrainWords);
assert(index >= 0, "invariant / paranoia");
if (index < _regions.length()) {
HeapRegion* hr = _regions.at(index);
assert(hr->is_in_reserved(addr),
"addr_to_region is wrong...");
return hr;
}
}
return NULL;
}