Tue, 19 May 2009 04:05:31 -0700
6819065: G1: eliminate high serial card table clearing time
Reviewed-by: iveresov, tonyp
1 /*
2 * Copyright 2001-2007 Sun Microsystems, Inc. All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
25 inline size_t G1RemSet::n_workers() {
26 if (_g1->workers() != NULL) {
27 return _g1->workers()->total_workers();
28 } else {
29 return 1;
30 }
31 }
33 inline void HRInto_G1RemSet::write_ref_nv(HeapRegion* from, oop* p) {
34 par_write_ref(from, p, 0);
35 }
37 inline void HRInto_G1RemSet::write_ref(HeapRegion* from, oop* p) {
38 write_ref_nv(from, p);
39 }
41 inline bool HRInto_G1RemSet::self_forwarded(oop obj) {
42 bool result = (obj->is_forwarded() && (obj->forwardee()== obj));
43 return result;
44 }
46 inline void HRInto_G1RemSet::par_write_ref(HeapRegion* from, oop* p, int tid) {
47 oop obj = *p;
48 #ifdef ASSERT
49 // can't do because of races
50 // assert(obj == NULL || obj->is_oop(), "expected an oop");
52 // Do the safe subset of is_oop
53 if (obj != NULL) {
54 #ifdef CHECK_UNHANDLED_OOPS
55 oopDesc* o = obj.obj();
56 #else
57 oopDesc* o = obj;
58 #endif // CHECK_UNHANDLED_OOPS
59 assert((intptr_t)o % MinObjAlignmentInBytes == 0, "not oop aligned");
60 assert(Universe::heap()->is_in_reserved(obj), "must be in heap");
61 }
62 #endif // ASSERT
63 assert(from == NULL || from->is_in_reserved(p),
64 "p is not in from");
65 HeapRegion* to = _g1->heap_region_containing(obj);
66 // The test below could be optimized by applying a bit op to to and from.
67 if (to != NULL && from != NULL && from != to) {
68 // There is a tricky infinite loop if we keep pushing
69 // self forwarding pointers onto our _new_refs list.
70 // The _par_traversal_in_progress flag is true during the collection pause,
71 // false during the evacuation failure handing.
72 if (_par_traversal_in_progress &&
73 to->in_collection_set() && !self_forwarded(obj)) {
74 _new_refs[tid]->push(p);
75 // Deferred updates to the Cset are either discarded (in the normal case),
76 // or processed (if an evacuation failure occurs) at the end
77 // of the collection.
78 // See HRInto_G1RemSet::cleanup_after_oops_into_collection_set_do().
79 } else {
80 #if G1_REM_SET_LOGGING
81 gclog_or_tty->print_cr("Adding " PTR_FORMAT " (" PTR_FORMAT ") to RS"
82 " for region [" PTR_FORMAT ", " PTR_FORMAT ")",
83 p, obj,
84 to->bottom(), to->end());
85 #endif
86 assert(to->rem_set() != NULL, "Need per-region 'into' remsets.");
87 to->rem_set()->add_reference(p, tid);
88 }
89 }
90 }
92 inline void UpdateRSOopClosure::do_oop(narrowOop* p) {
93 guarantee(false, "NYI");
94 }
96 inline void UpdateRSOopClosure::do_oop(oop* p) {
97 assert(_from != NULL, "from region must be non-NULL");
98 _rs->par_write_ref(_from, p, _worker_i);
99 }