1 /*
2 * Copyright (c) 2001, 2013, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "gc_implementation/g1/concurrentMarkThread.inline.hpp"
27 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
28 #include "gc_implementation/g1/g1CollectorPolicy.hpp"
29 #include "gc_implementation/g1/g1Log.hpp"
30 #include "gc_implementation/g1/vm_operations_g1.hpp"
31 #include "gc_implementation/shared/gcTimer.hpp"
32 #include "gc_implementation/shared/gcTraceTime.hpp"
33 #include "gc_implementation/shared/isGCActiveMark.hpp"
34 #include "gc_implementation/g1/vm_operations_g1.hpp"
35 #include "runtime/interfaceSupport.hpp"
36
37 VM_G1CollectForAllocation::VM_G1CollectForAllocation(
38 unsigned int gc_count_before,
39 size_t word_size)
40 : VM_G1OperationWithAllocRequest(gc_count_before, word_size,
41 GCCause::_allocation_failure) {
42 guarantee(word_size > 0, "an allocation should always be requested");
43 }
44
45 void VM_G1CollectForAllocation::doit() {
46 G1CollectedHeap* g1h = G1CollectedHeap::heap();
47 GCCauseSetter x(g1h, _gc_cause);
48
49 _result = g1h->satisfy_failed_allocation(_word_size, allocation_context(), &_pause_succeeded);
50 assert(_result == NULL || _pause_succeeded,
51 "if we get back a result, the pause should have succeeded");
52 }
53
54 void VM_G1CollectFull::doit() {
55 G1CollectedHeap* g1h = G1CollectedHeap::heap();
56 GCCauseSetter x(g1h, _gc_cause);
57 g1h->do_full_collection(false /* clear_all_soft_refs */);
58 }
59
60 VM_G1IncCollectionPause::VM_G1IncCollectionPause(
61 unsigned int gc_count_before,
62 size_t word_size,
63 bool should_initiate_conc_mark,
64 double target_pause_time_ms,
65 GCCause::Cause gc_cause)
66 : VM_G1OperationWithAllocRequest(gc_count_before, word_size, gc_cause),
67 _should_initiate_conc_mark(should_initiate_conc_mark),
68 _target_pause_time_ms(target_pause_time_ms),
69 _should_retry_gc(false),
70 _old_marking_cycles_completed_before(0) {
71 guarantee(target_pause_time_ms > 0.0,
72 err_msg("target_pause_time_ms = %1.6lf should be positive",
73 target_pause_time_ms));
74 _gc_cause = gc_cause;
75 }
76
77 bool VM_G1IncCollectionPause::doit_prologue() {
78 bool res = VM_GC_Operation::doit_prologue();
79 if (!res) {
80 if (_should_initiate_conc_mark) {
81 // The prologue can fail for a couple of reasons. The first is that another GC
82 // got scheduled and prevented the scheduling of the initial mark GC. The
83 // second is that the GC locker may be active and the heap can't be expanded.
84 // In both cases we want to retry the GC so that the initial mark pause is
85 // actually scheduled. In the second case, however, we should stall until
86 // until the GC locker is no longer active and then retry the initial mark GC.
87 _should_retry_gc = true;
88 }
89 }
90 return res;
91 }
92
93 void VM_G1IncCollectionPause::doit() {
94 G1CollectedHeap* g1h = G1CollectedHeap::heap();
95 assert(!_should_initiate_conc_mark || g1h->should_do_concurrent_full_gc(_gc_cause),
96 "only a GC locker, a System.gc(), stats update, whitebox, or a hum allocation induced GC should start a cycle");
97
98 if (_word_size > 0) {
148
149 _pause_succeeded =
150 g1h->do_collection_pause_at_safepoint(_target_pause_time_ms);
151 if (_pause_succeeded && _word_size > 0) {
152 // An allocation had been requested.
153 _result = g1h->attempt_allocation_at_safepoint(_word_size, allocation_context(),
154 true /* expect_null_cur_alloc_region */);
155 } else {
156 assert(_result == NULL, "invariant");
157 if (!_pause_succeeded) {
158 // Another possible reason reason for the pause to not be successful
159 // is that, again, the GC locker is active (and has become active
160 // since the prologue was executed). In this case we should retry
161 // the pause after waiting for the GC locker to become inactive.
162 _should_retry_gc = true;
163 }
164 }
165 }
166
167 void VM_G1IncCollectionPause::doit_epilogue() {
168 VM_GC_Operation::doit_epilogue();
169
170 // If the pause was initiated by a System.gc() and
171 // +ExplicitGCInvokesConcurrent, we have to wait here for the cycle
172 // that just started (or maybe one that was already in progress) to
173 // finish.
174 if (_gc_cause == GCCause::_java_lang_system_gc &&
175 _should_initiate_conc_mark) {
176 assert(ExplicitGCInvokesConcurrent,
177 "the only way to be here is if ExplicitGCInvokesConcurrent is set");
178
179 G1CollectedHeap* g1h = G1CollectedHeap::heap();
180
181 // In the doit() method we saved g1h->old_marking_cycles_completed()
182 // in the _old_marking_cycles_completed_before field. We have to
183 // wait until we observe that g1h->old_marking_cycles_completed()
184 // has increased by at least one. This can happen if a) we started
185 // a cycle and it completes, b) a cycle already in progress
186 // completes, or c) a Full GC happens.
187
188 // If the condition has already been reached, there's no point in
|
1 /*
2 * Copyright (c) 2001, 2014, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "gc_implementation/g1/concurrentMarkThread.inline.hpp"
27 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
28 #include "gc_implementation/g1/g1CollectorPolicy.hpp"
29 #include "gc_implementation/g1/g1Log.hpp"
30 #include "gc_implementation/g1/vm_operations_g1.hpp"
31 #include "gc_implementation/shared/gcTimer.hpp"
32 #include "gc_implementation/shared/gcTraceTime.hpp"
33 #include "gc_implementation/shared/isGCActiveMark.hpp"
34 #include "gc_implementation/g1/vm_operations_g1.hpp"
35 #include "runtime/interfaceSupport.hpp"
36
37 VM_G1CollectForAllocation::VM_G1CollectForAllocation(uint gc_count_before,
38 size_t word_size)
39 : VM_G1OperationWithAllocRequest(gc_count_before, word_size,
40 GCCause::_allocation_failure) {
41 guarantee(word_size > 0, "an allocation should always be requested");
42 }
43
44 void VM_G1CollectForAllocation::doit() {
45 G1CollectedHeap* g1h = G1CollectedHeap::heap();
46 GCCauseSetter x(g1h, _gc_cause);
47
48 _result = g1h->satisfy_failed_allocation(_word_size, allocation_context(), &_pause_succeeded);
49 assert(_result == NULL || _pause_succeeded,
50 "if we get back a result, the pause should have succeeded");
51 }
52
53 void VM_G1CollectFull::doit() {
54 G1CollectedHeap* g1h = G1CollectedHeap::heap();
55 GCCauseSetter x(g1h, _gc_cause);
56 g1h->do_full_collection(false /* clear_all_soft_refs */);
57 }
58
59 VM_G1IncCollectionPause::VM_G1IncCollectionPause(uint gc_count_before,
60 size_t word_size,
61 bool should_initiate_conc_mark,
62 double target_pause_time_ms,
63 GCCause::Cause gc_cause)
64 : VM_G1OperationWithAllocRequest(gc_count_before, word_size, gc_cause),
65 _should_initiate_conc_mark(should_initiate_conc_mark),
66 _target_pause_time_ms(target_pause_time_ms),
67 _should_retry_gc(false),
68 _old_marking_cycles_completed_before(0) {
69 guarantee(target_pause_time_ms > 0.0,
70 err_msg("target_pause_time_ms = %1.6lf should be positive",
71 target_pause_time_ms));
72 _gc_cause = gc_cause;
73 }
74
75 bool VM_G1IncCollectionPause::doit_prologue() {
76 bool res = VM_G1OperationWithAllocRequest::doit_prologue();
77 if (!res) {
78 if (_should_initiate_conc_mark) {
79 // The prologue can fail for a couple of reasons. The first is that another GC
80 // got scheduled and prevented the scheduling of the initial mark GC. The
81 // second is that the GC locker may be active and the heap can't be expanded.
82 // In both cases we want to retry the GC so that the initial mark pause is
83 // actually scheduled. In the second case, however, we should stall until
84 // until the GC locker is no longer active and then retry the initial mark GC.
85 _should_retry_gc = true;
86 }
87 }
88 return res;
89 }
90
91 void VM_G1IncCollectionPause::doit() {
92 G1CollectedHeap* g1h = G1CollectedHeap::heap();
93 assert(!_should_initiate_conc_mark || g1h->should_do_concurrent_full_gc(_gc_cause),
94 "only a GC locker, a System.gc(), stats update, whitebox, or a hum allocation induced GC should start a cycle");
95
96 if (_word_size > 0) {
146
147 _pause_succeeded =
148 g1h->do_collection_pause_at_safepoint(_target_pause_time_ms);
149 if (_pause_succeeded && _word_size > 0) {
150 // An allocation had been requested.
151 _result = g1h->attempt_allocation_at_safepoint(_word_size, allocation_context(),
152 true /* expect_null_cur_alloc_region */);
153 } else {
154 assert(_result == NULL, "invariant");
155 if (!_pause_succeeded) {
156 // Another possible reason reason for the pause to not be successful
157 // is that, again, the GC locker is active (and has become active
158 // since the prologue was executed). In this case we should retry
159 // the pause after waiting for the GC locker to become inactive.
160 _should_retry_gc = true;
161 }
162 }
163 }
164
165 void VM_G1IncCollectionPause::doit_epilogue() {
166 VM_G1OperationWithAllocRequest::doit_epilogue();
167
168 // If the pause was initiated by a System.gc() and
169 // +ExplicitGCInvokesConcurrent, we have to wait here for the cycle
170 // that just started (or maybe one that was already in progress) to
171 // finish.
172 if (_gc_cause == GCCause::_java_lang_system_gc &&
173 _should_initiate_conc_mark) {
174 assert(ExplicitGCInvokesConcurrent,
175 "the only way to be here is if ExplicitGCInvokesConcurrent is set");
176
177 G1CollectedHeap* g1h = G1CollectedHeap::heap();
178
179 // In the doit() method we saved g1h->old_marking_cycles_completed()
180 // in the _old_marking_cycles_completed_before field. We have to
181 // wait until we observe that g1h->old_marking_cycles_completed()
182 // has increased by at least one. This can happen if a) we started
183 // a cycle and it completes, b) a cycle already in progress
184 // completes, or c) a Full GC happens.
185
186 // If the condition has already been reached, there's no point in
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