Mercurial > hg > truffle
view src/share/vm/memory/genOopClosures.inline.hpp @ 453:c96030fff130
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
author | ysr |
---|---|
date | Thu, 20 Nov 2008 16:56:09 -0800 |
parents | 1ee8caae33af |
children | df6caf649ff7 |
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/* * Copyright 2001-2008 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 OopsInGenClosure::OopsInGenClosure(Generation* gen) : OopClosure(gen->ref_processor()), _orig_gen(gen), _rs(NULL) { set_generation(gen); } inline void OopsInGenClosure::set_generation(Generation* gen) { _gen = gen; _gen_boundary = _gen->reserved().start(); // Barrier set for the heap, must be set after heap is initialized if (_rs == NULL) { GenRemSet* rs = SharedHeap::heap()->rem_set(); assert(rs->rs_kind() == GenRemSet::CardTable, "Wrong rem set kind"); _rs = (CardTableRS*)rs; } } template <class T> inline void OopsInGenClosure::do_barrier(T* p) { assert(generation()->is_in_reserved(p), "expected ref in generation"); assert(!oopDesc::is_null(*p), "expected non-null object"); oop obj = oopDesc::load_decode_heap_oop_not_null(p); // If p points to a younger generation, mark the card. if ((HeapWord*)obj < _gen_boundary) { _rs->inline_write_ref_field_gc(p, obj); } } inline void OopsInGenClosure::par_do_barrier(oop* p) { assert(generation()->is_in_reserved(p), "expected ref in generation"); oop obj = *p; assert(obj != NULL, "expected non-null object"); // If p points to a younger generation, mark the card. if ((HeapWord*)obj < gen_boundary()) { rs()->write_ref_field_gc_par(p, obj); } } // NOTE! Any changes made here should also be made // in FastScanClosure::do_oop_work() template <class T> inline void ScanClosure::do_oop_work(T* p) { T heap_oop = oopDesc::load_heap_oop(p); // Should we copy the obj? if (!oopDesc::is_null(heap_oop)) { oop obj = oopDesc::decode_heap_oop_not_null(heap_oop); if ((HeapWord*)obj < _boundary) { assert(!_g->to()->is_in_reserved(obj), "Scanning field twice?"); oop new_obj = obj->is_forwarded() ? obj->forwardee() : _g->copy_to_survivor_space(obj); oopDesc::encode_store_heap_oop_not_null(p, new_obj); } if (_gc_barrier) { // Now call parent closure do_barrier(p); } } } inline void ScanClosure::do_oop_nv(oop* p) { ScanClosure::do_oop_work(p); } inline void ScanClosure::do_oop_nv(narrowOop* p) { ScanClosure::do_oop_work(p); } // NOTE! Any changes made here should also be made // in ScanClosure::do_oop_work() template <class T> inline void FastScanClosure::do_oop_work(T* p) { T heap_oop = oopDesc::load_heap_oop(p); // Should we copy the obj? if (!oopDesc::is_null(heap_oop)) { oop obj = oopDesc::decode_heap_oop_not_null(heap_oop); if ((HeapWord*)obj < _boundary) { assert(!_g->to()->is_in_reserved(obj), "Scanning field twice?"); oop new_obj = obj->is_forwarded() ? obj->forwardee() : _g->copy_to_survivor_space(obj); oopDesc::encode_store_heap_oop_not_null(p, new_obj); if (_gc_barrier) { // Now call parent closure do_barrier(p); } } } } inline void FastScanClosure::do_oop_nv(oop* p) { FastScanClosure::do_oop_work(p); } inline void FastScanClosure::do_oop_nv(narrowOop* p) { FastScanClosure::do_oop_work(p); } // Note similarity to ScanClosure; the difference is that // the barrier set is taken care of outside this closure. template <class T> inline void ScanWeakRefClosure::do_oop_work(T* p) { assert(!oopDesc::is_null(*p), "null weak reference?"); oop obj = oopDesc::load_decode_heap_oop_not_null(p); // weak references are sometimes scanned twice; must check // that to-space doesn't already contain this object if ((HeapWord*)obj < _boundary && !_g->to()->is_in_reserved(obj)) { oop new_obj = obj->is_forwarded() ? obj->forwardee() : _g->copy_to_survivor_space(obj); oopDesc::encode_store_heap_oop_not_null(p, new_obj); } } inline void ScanWeakRefClosure::do_oop_nv(oop* p) { ScanWeakRefClosure::do_oop_work(p); } inline void ScanWeakRefClosure::do_oop_nv(narrowOop* p) { ScanWeakRefClosure::do_oop_work(p); }