1 /*
2 * Copyright (c) 2015, 2018, Red Hat, Inc. All rights reserved.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation.
7 *
8 * This code is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
11 * version 2 for more details (a copy is included in the LICENSE file that
12 * accompanied this code).
13 *
14 * You should have received a copy of the GNU General Public License version
15 * 2 along with this work; if not, write to the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
17 *
18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
19 * or visit www.oracle.com if you need additional information or have any
20 * questions.
21 *
22 */
23
24 #include "precompiled.hpp"
25
26 #include "classfile/classLoaderData.hpp"
27 #include "classfile/stringTable.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "code/codeCache.hpp"
30 #include "gc/shenandoah/shenandoahClosures.inline.hpp"
31 #include "gc/shenandoah/shenandoahRootProcessor.inline.hpp"
32 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
33 #include "gc/shenandoah/shenandoahHeuristics.hpp"
34 #include "gc/shenandoah/shenandoahPhaseTimings.hpp"
35 #include "gc/shenandoah/shenandoahStringDedup.hpp"
36 #include "gc/shenandoah/shenandoahTimingTracker.hpp"
37 #include "gc/shenandoah/shenandoahVMOperations.hpp"
38 #include "gc/shared/weakProcessor.hpp"
39 #include "memory/allocation.inline.hpp"
40 #include "memory/iterator.hpp"
41 #include "memory/resourceArea.hpp"
42 #include "runtime/thread.hpp"
43 #include "services/management.hpp"
44
45 ShenandoahSerialRoot::ShenandoahSerialRoot(ShenandoahSerialRoot::OopsDo oops_do, ShenandoahPhaseTimings::GCParPhases phase) :
46 _claimed(false), _oops_do(oops_do), _phase(phase) {
47 }
48
49 void ShenandoahSerialRoot::oops_do(OopClosure* cl, uint worker_id) {
50 if (!_claimed && Atomic::cmpxchg(true, &_claimed, false) == false) {
51 ShenandoahWorkerTimings* worker_times = ShenandoahHeap::heap()->phase_timings()->worker_times();
52 ShenandoahWorkerTimingsTracker timer(worker_times, _phase, worker_id);
53 _oops_do(cl);
54 }
55 }
56
57 ShenandoahSerialRoots::ShenandoahSerialRoots() :
58 _universe_root(&ShenandoahSerialRoots::universe_oops_do, ShenandoahPhaseTimings::UniverseRoots),
59 _object_synchronizer_root(&ObjectSynchronizer::oops_do, ShenandoahPhaseTimings::ObjectSynchronizerRoots),
60 _management_root(&Management::oops_do, ShenandoahPhaseTimings::ManagementRoots),
61 _system_dictionary_root(&SystemDictionary::oops_do, ShenandoahPhaseTimings::SystemDictionaryRoots),
62 _jvmti_root(&JvmtiExport::oops_do, ShenandoahPhaseTimings::JVMTIRoots) {
63 }
64
65 void ShenandoahSerialRoots::oops_do(OopClosure* cl, uint worker_id) {
66 _universe_root.oops_do(cl, worker_id);
67 _object_synchronizer_root.oops_do(cl, worker_id);
68 _management_root.oops_do(cl, worker_id);
69 _system_dictionary_root.oops_do(cl, worker_id);
70 _jvmti_root.oops_do(cl, worker_id);
71 }
72
73 ShenandoahJNIHandleRoots::ShenandoahJNIHandleRoots() :
74 ShenandoahSerialRoot(&JNIHandles::oops_do, ShenandoahPhaseTimings::JNIRoots) {
75 }
76
77 ShenandoahThreadRoots::ShenandoahThreadRoots(bool is_par) : _is_par(is_par) {
78 Threads::change_thread_claim_parity();
79 }
80
81 void ShenandoahThreadRoots::oops_do(OopClosure* oops_cl, CodeBlobClosure* code_cl, uint worker_id) {
82 ShenandoahWorkerTimings* worker_times = ShenandoahHeap::heap()->phase_timings()->worker_times();
83 ShenandoahWorkerTimingsTracker timer(worker_times, ShenandoahPhaseTimings::ThreadRoots, worker_id);
84 ResourceMark rm;
85 Threads::possibly_parallel_oops_do(_is_par, oops_cl, code_cl);
86 }
87
88 void ShenandoahThreadRoots::threads_do(ThreadClosure* tc, uint worker_id) {
89 ShenandoahWorkerTimings* worker_times = ShenandoahHeap::heap()->phase_timings()->worker_times();
90 ShenandoahWorkerTimingsTracker timer(worker_times, ShenandoahPhaseTimings::ThreadRoots, worker_id);
91 ResourceMark rm;
92 Threads::possibly_parallel_threads_do(_is_par, tc);
93 }
94
95 ShenandoahThreadRoots::~ShenandoahThreadRoots() {
96 Threads::assert_all_threads_claimed();
97 }
98
99 ShenandoahWeakRoots::ShenandoahWeakRoots(uint n_workers) :
100 _par_state_string(StringTable::weak_storage()),
101 _claimed(false) {
102 }
103
104 ShenandoahWeakRoots::~ShenandoahWeakRoots() {
105 }
106
107 ShenandoahStringDedupRoots::ShenandoahStringDedupRoots() {
108 if (ShenandoahStringDedup::is_enabled()) {
109 StringDedup::gc_prologue(false);
110 }
111 }
112
113 ShenandoahStringDedupRoots::~ShenandoahStringDedupRoots() {
114 if (ShenandoahStringDedup::is_enabled()) {
115 StringDedup::gc_epilogue();
116 }
117 }
118
119 void ShenandoahStringDedupRoots::oops_do(BoolObjectClosure* is_alive, OopClosure* keep_alive, uint worker_id) {
120 if (ShenandoahStringDedup::is_enabled()) {
121 ShenandoahStringDedup::parallel_oops_do(is_alive, keep_alive, worker_id);
122 }
123 }
124
125 ShenandoahRootProcessor::ShenandoahRootProcessor(ShenandoahPhaseTimings::Phase phase) :
126 _heap(ShenandoahHeap::heap()),
127 _phase(phase) {
128 assert(SafepointSynchronize::is_at_safepoint(), "Must at safepoint");
129 _heap->phase_timings()->record_workers_start(_phase);
130 }
131
132 ShenandoahRootProcessor::~ShenandoahRootProcessor() {
133 assert(SafepointSynchronize::is_at_safepoint(), "Must at safepoint");
134 _heap->phase_timings()->record_workers_end(_phase);
135 }
136
137 ShenandoahRootEvacuator::ShenandoahRootEvacuator(uint n_workers, ShenandoahPhaseTimings::Phase phase) :
138 ShenandoahRootProcessor(phase),
139 _thread_roots(n_workers > 1),
140 _weak_roots(n_workers) {
141 }
142
143 void ShenandoahRootEvacuator::roots_do(uint worker_id, OopClosure* oops) {
144 MarkingCodeBlobClosure blobsCl(oops, CodeBlobToOopClosure::FixRelocations);
145 CLDToOopClosure clds(oops);
146 CLDToOopClosure* weak_clds = ShenandoahHeap::heap()->unload_classes() ? NULL : &clds;
147
148 AlwaysTrueClosure always_true;
149
150 _serial_roots.oops_do(oops, worker_id);
151 _jni_roots.oops_do(oops, worker_id);
152
153 _thread_roots.oops_do(oops, NULL, worker_id);
154 _cld_roots.cld_do(&clds, worker_id);
155 _code_roots.code_blobs_do(&blobsCl, worker_id);
156
157 _weak_roots.oops_do<AlwaysTrueClosure, OopClosure>(&always_true, oops, worker_id);
158 _dedup_roots.oops_do(&always_true, oops, worker_id);
159 }
160
161 ShenandoahRootUpdater::ShenandoahRootUpdater(uint n_workers, ShenandoahPhaseTimings::Phase phase, bool update_code_cache) :
162 ShenandoahRootProcessor(phase),
163 _thread_roots(n_workers > 1),
164 _weak_roots(n_workers),
165 _update_code_cache(update_code_cache) {
166 }
167
168 ShenandoahRootAdjuster::ShenandoahRootAdjuster(uint n_workers, ShenandoahPhaseTimings::Phase phase) :
169 ShenandoahRootProcessor(phase),
170 _thread_roots(n_workers > 1),
171 _weak_roots(n_workers) {
172 assert(ShenandoahHeap::heap()->is_full_gc_in_progress(), "Full GC only");
173 }
174
175 void ShenandoahRootAdjuster::roots_do(uint worker_id, OopClosure* oops) {
176 CodeBlobToOopClosure adjust_code_closure(oops, CodeBlobToOopClosure::FixRelocations);
177 CLDToOopClosure adjust_cld_closure(oops);
178 AlwaysTrueClosure always_true;
179
180 _serial_roots.oops_do(oops, worker_id);
181 _jni_roots.oops_do(oops, worker_id);
182
183 _thread_roots.oops_do(oops, NULL, worker_id);
184 _cld_roots.cld_do(&adjust_cld_closure, worker_id);
185 _code_roots.code_blobs_do(&adjust_code_closure, worker_id);
186
187 _weak_roots.oops_do<AlwaysTrueClosure, OopClosure>(&always_true, oops, worker_id);
188 _dedup_roots.oops_do(&always_true, oops, worker_id);
189 }
190
191 ShenandoahHeapIterationRootScanner::ShenandoahHeapIterationRootScanner() :
192 ShenandoahRootProcessor(ShenandoahPhaseTimings::_num_phases),
193 _thread_roots(false /*is par*/),
194 _weak_roots(1) {
195 }
196
197 void ShenandoahHeapIterationRootScanner::roots_do(OopClosure* oops) {
198 assert(Thread::current()->is_VM_thread(), "Only by VM thread");
199 // Must use _claim_none to avoid interfering with concurrent CLDG iteration
200 CLDToOopClosure clds(oops, false);
201 MarkingCodeBlobClosure code(oops, !CodeBlobToOopClosure::FixRelocations);
202 ShenandoahParallelOopsDoThreadClosure tc_cl(oops, &code, NULL);
203 AlwaysTrueClosure always_true;
204 ResourceMark rm;
205
206 _serial_roots.oops_do(oops, 0);
207 _jni_roots.oops_do(oops, 0);
208 _cld_roots.cld_do(&clds, 0);
209 _thread_roots.threads_do(&tc_cl, 0);
210 _code_roots.code_blobs_do(&code, 0);
211
212 _weak_roots.oops_do<AlwaysTrueClosure, OopClosure>(&always_true, oops, 0);
213 _dedup_roots.oops_do(&always_true, oops, 0);
214 }
215
216 void ShenandoahHeapIterationRootScanner::strong_roots_do(OopClosure* oops) {
217 assert(Thread::current()->is_VM_thread(), "Only by VM thread");
218 // Must use _claim_none to avoid interfering with concurrent CLDG iteration
219 CLDToOopClosure clds(oops, false);
220 MarkingCodeBlobClosure code(oops, !CodeBlobToOopClosure::FixRelocations);
221 ShenandoahParallelOopsDoThreadClosure tc_cl(oops, &code, NULL);
222 ResourceMark rm;
223
224 _serial_roots.oops_do(oops, 0);
225 _jni_roots.oops_do(oops, 0);
226 _cld_roots.always_strong_cld_do(&clds, 0);
227 _thread_roots.threads_do(&tc_cl, 0);
228 }