Thu, 18 Mar 2010 12:14:59 -0400
6935821: G1: threads created during marking do not active their SATB queues
Summary: Newly-created threads always had the active field of their SATB queue initialized to false, even if they were created during marking. As a result, updates from threads created during a marking cycle were never enqueued and never processed. The fix includes remaining a method from active() to is_active() for readability and naming consistency.
Reviewed-by: ysr, johnc
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 #include "incls/_precompiled.incl"
26 #include "incls/_g1SATBCardTableModRefBS.cpp.incl"
28 G1SATBCardTableModRefBS::G1SATBCardTableModRefBS(MemRegion whole_heap,
29 int max_covered_regions) :
30 CardTableModRefBSForCTRS(whole_heap, max_covered_regions)
31 {
32 _kind = G1SATBCT;
33 }
36 void G1SATBCardTableModRefBS::enqueue(oop pre_val) {
37 assert(pre_val->is_oop_or_null(true), "Error");
38 if (!JavaThread::satb_mark_queue_set().is_active()) return;
39 Thread* thr = Thread::current();
40 if (thr->is_Java_thread()) {
41 JavaThread* jt = (JavaThread*)thr;
42 jt->satb_mark_queue().enqueue(pre_val);
43 } else {
44 MutexLocker x(Shared_SATB_Q_lock);
45 JavaThread::satb_mark_queue_set().shared_satb_queue()->enqueue(pre_val);
46 }
47 }
49 // When we know the current java thread:
50 template <class T> void
51 G1SATBCardTableModRefBS::write_ref_field_pre_static(T* field,
52 oop new_val,
53 JavaThread* jt) {
54 if (!JavaThread::satb_mark_queue_set().is_active()) return;
55 T heap_oop = oopDesc::load_heap_oop(field);
56 if (!oopDesc::is_null(heap_oop)) {
57 oop pre_val = oopDesc::decode_heap_oop_not_null(heap_oop);
58 assert(pre_val->is_oop(true /* ignore mark word */), "Error");
59 jt->satb_mark_queue().enqueue(pre_val);
60 }
61 }
63 template <class T> void
64 G1SATBCardTableModRefBS::write_ref_array_pre_work(T* dst, int count) {
65 if (!JavaThread::satb_mark_queue_set().is_active()) return;
66 T* elem_ptr = dst;
67 for (int i = 0; i < count; i++, elem_ptr++) {
68 T heap_oop = oopDesc::load_heap_oop(elem_ptr);
69 if (!oopDesc::is_null(heap_oop)) {
70 enqueue(oopDesc::decode_heap_oop_not_null(heap_oop));
71 }
72 }
73 }
75 G1SATBCardTableLoggingModRefBS::
76 G1SATBCardTableLoggingModRefBS(MemRegion whole_heap,
77 int max_covered_regions) :
78 G1SATBCardTableModRefBS(whole_heap, max_covered_regions),
79 _dcqs(JavaThread::dirty_card_queue_set())
80 {
81 _kind = G1SATBCTLogging;
82 }
84 void
85 G1SATBCardTableLoggingModRefBS::write_ref_field_work(void* field,
86 oop new_val) {
87 jbyte* byte = byte_for(field);
88 if (*byte != dirty_card) {
89 *byte = dirty_card;
90 Thread* thr = Thread::current();
91 if (thr->is_Java_thread()) {
92 JavaThread* jt = (JavaThread*)thr;
93 jt->dirty_card_queue().enqueue(byte);
94 } else {
95 MutexLockerEx x(Shared_DirtyCardQ_lock,
96 Mutex::_no_safepoint_check_flag);
97 _dcqs.shared_dirty_card_queue()->enqueue(byte);
98 }
99 }
100 }
102 void
103 G1SATBCardTableLoggingModRefBS::write_ref_field_static(void* field,
104 oop new_val) {
105 uintptr_t field_uint = (uintptr_t)field;
106 uintptr_t new_val_uint = (uintptr_t)new_val;
107 uintptr_t comb = field_uint ^ new_val_uint;
108 comb = comb >> HeapRegion::LogOfHRGrainBytes;
109 if (comb == 0) return;
110 if (new_val == NULL) return;
111 // Otherwise, log it.
112 G1SATBCardTableLoggingModRefBS* g1_bs =
113 (G1SATBCardTableLoggingModRefBS*)Universe::heap()->barrier_set();
114 g1_bs->write_ref_field_work(field, new_val);
115 }
117 void
118 G1SATBCardTableLoggingModRefBS::invalidate(MemRegion mr, bool whole_heap) {
119 jbyte* byte = byte_for(mr.start());
120 jbyte* last_byte = byte_for(mr.last());
121 Thread* thr = Thread::current();
122 if (whole_heap) {
123 while (byte <= last_byte) {
124 *byte = dirty_card;
125 byte++;
126 }
127 } else {
128 // Enqueue if necessary.
129 if (thr->is_Java_thread()) {
130 JavaThread* jt = (JavaThread*)thr;
131 while (byte <= last_byte) {
132 if (*byte != dirty_card) {
133 *byte = dirty_card;
134 jt->dirty_card_queue().enqueue(byte);
135 }
136 byte++;
137 }
138 } else {
139 MutexLockerEx x(Shared_DirtyCardQ_lock,
140 Mutex::_no_safepoint_check_flag);
141 while (byte <= last_byte) {
142 if (*byte != dirty_card) {
143 *byte = dirty_card;
144 _dcqs.shared_dirty_card_queue()->enqueue(byte);
145 }
146 byte++;
147 }
148 }
149 }
150 }