1 /*
2 * Copyright (c) 2015, 2019, 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/classLoaderDataGraph.hpp"
27 #include "classfile/stringTable.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "code/codeCache.hpp"
30 #include "gc/shenandoah/shenandoahRootProcessor.inline.hpp"
31 #include "gc/shenandoah/shenandoahHeap.hpp"
32 #include "gc/shenandoah/shenandoahPhaseTimings.hpp"
33 #include "gc/shenandoah/shenandoahStringDedup.hpp"
34 #include "gc/shenandoah/shenandoahTimingTracker.hpp"
35 #include "gc/shenandoah/shenandoahVMOperations.hpp"
36 #include "jfr/jfr.hpp"
37 #include "memory/iterator.hpp"
38 #include "memory/resourceArea.hpp"
39 #include "memory/universe.hpp"
40 #include "runtime/thread.hpp"
41 #include "services/management.hpp"
42
43 ShenandoahSerialRoot::ShenandoahSerialRoot(ShenandoahSerialRoot::OopsDo oops_do, ShenandoahPhaseTimings::GCParPhases phase) :
44 _claimed(false), _oops_do(oops_do), _phase(phase) {
45 }
46
47 void ShenandoahSerialRoot::oops_do(OopClosure* cl, uint worker_id) {
48 if (!_claimed && Atomic::cmpxchg(true, &_claimed, false) == false) {
49 ShenandoahWorkerTimings* worker_times = ShenandoahHeap::heap()->phase_timings()->worker_times();
50 ShenandoahWorkerTimingsTracker timer(worker_times, _phase, worker_id);
51 _oops_do(cl);
52 }
53 }
54
55 ShenandoahSerialRoots::ShenandoahSerialRoots() :
56 _universe_root(&Universe::oops_do, ShenandoahPhaseTimings::UniverseRoots),
57 _object_synchronizer_root(&ObjectSynchronizer::oops_do, ShenandoahPhaseTimings::ObjectSynchronizerRoots),
58 _management_root(&Management::oops_do, ShenandoahPhaseTimings::ManagementRoots),
59 _system_dictionary_root(&SystemDictionary::oops_do, ShenandoahPhaseTimings::SystemDictionaryRoots),
60 _jvmti_root(&JvmtiExport::oops_do, ShenandoahPhaseTimings::JVMTIRoots) {
61 }
62
63 void ShenandoahSerialRoots::oops_do(OopClosure* cl, uint worker_id) {
64 _universe_root.oops_do(cl, worker_id);
65 _object_synchronizer_root.oops_do(cl, worker_id);
66 _management_root.oops_do(cl, worker_id);
67 _system_dictionary_root.oops_do(cl, worker_id);
68 _jvmti_root.oops_do(cl, worker_id);
69 }
70
71 ShenandoahWeakSerialRoot::ShenandoahWeakSerialRoot(ShenandoahWeakSerialRoot::WeakOopsDo weak_oops_do, ShenandoahPhaseTimings::GCParPhases phase) :
72 _weak_oops_do(weak_oops_do), _phase(phase) {
73 }
74
75 void ShenandoahWeakSerialRoot::weak_oops_do(BoolObjectClosure* is_alive, OopClosure* keep_alive, uint worker_id) {
76 if (_claimed.try_set()) {
77 ShenandoahWorkerTimings* worker_times = ShenandoahHeap::heap()->phase_timings()->worker_times();
78 ShenandoahWorkerTimingsTracker timer(worker_times, _phase, worker_id);
79 _weak_oops_do(is_alive, keep_alive);
80 }
81 }
82
83 #if INCLUDE_JVMTI
84 ShenandoahJVMTIWeakRoot::ShenandoahJVMTIWeakRoot() :
85 ShenandoahWeakSerialRoot(&JvmtiExport::weak_oops_do, ShenandoahPhaseTimings::JVMTIWeakRoots) {
86 }
87 #endif // INCLUDE_JVMTI
88
89 #if INCLUDE_JFR
90 ShenandoahJFRWeakRoot::ShenandoahJFRWeakRoot() :
91 ShenandoahWeakSerialRoot(&Jfr::weak_oops_do, ShenandoahPhaseTimings::JFRWeakRoots) {
92 }
93 #endif // INCLUDE_JFR
94
95 void ShenandoahSerialWeakRoots::weak_oops_do(BoolObjectClosure* is_alive, OopClosure* keep_alive, uint worker_id) {
96 JVMTI_ONLY(_jvmti_weak_roots.weak_oops_do(is_alive, keep_alive, worker_id);)
97 JFR_ONLY(_jfr_weak_roots.weak_oops_do(is_alive, keep_alive, worker_id);)
98 }
99
100 void ShenandoahSerialWeakRoots::weak_oops_do(OopClosure* cl, uint worker_id) {
101 AlwaysTrueClosure always_true;
102 weak_oops_do(&always_true, cl, worker_id);
103 }
104
105 ShenandoahThreadRoots::ShenandoahThreadRoots(bool is_par) : _is_par(is_par) {
106 Threads::change_thread_claim_token();
107 }
108
109 void ShenandoahThreadRoots::oops_do(OopClosure* oops_cl, CodeBlobClosure* code_cl, uint worker_id) {
110 ShenandoahWorkerTimings* worker_times = ShenandoahHeap::heap()->phase_timings()->worker_times();
111 ShenandoahWorkerTimingsTracker timer(worker_times, ShenandoahPhaseTimings::ThreadRoots, worker_id);
112 ResourceMark rm;
113 Threads::possibly_parallel_oops_do(_is_par, oops_cl, code_cl);
114 }
115
116 void ShenandoahThreadRoots::threads_do(ThreadClosure* tc, uint worker_id) {
117 ShenandoahWorkerTimings* worker_times = ShenandoahHeap::heap()->phase_timings()->worker_times();
118 ShenandoahWorkerTimingsTracker timer(worker_times, ShenandoahPhaseTimings::ThreadRoots, worker_id);
119 ResourceMark rm;
120 Threads::possibly_parallel_threads_do(_is_par, tc);
121 }
122
123 ShenandoahThreadRoots::~ShenandoahThreadRoots() {
124 Threads::assert_all_threads_claimed();
125 }
126
127 ShenandoahStringDedupRoots::ShenandoahStringDedupRoots() {
128 if (ShenandoahStringDedup::is_enabled()) {
129 StringDedup::gc_prologue(false);
130 }
131 }
132
133 ShenandoahStringDedupRoots::~ShenandoahStringDedupRoots() {
134 if (ShenandoahStringDedup::is_enabled()) {
135 StringDedup::gc_epilogue();
136 }
137 }
138
139 void ShenandoahStringDedupRoots::oops_do(BoolObjectClosure* is_alive, OopClosure* keep_alive, uint worker_id) {
140 if (ShenandoahStringDedup::is_enabled()) {
141 ShenandoahStringDedup::parallel_oops_do(is_alive, keep_alive, worker_id);
142 }
143 }
144
145 ShenandoahRootProcessor::ShenandoahRootProcessor(ShenandoahPhaseTimings::Phase phase) :
146 _heap(ShenandoahHeap::heap()),
147 _phase(phase) {
148 assert(SafepointSynchronize::is_at_safepoint(), "Must at safepoint");
149 _heap->phase_timings()->record_workers_start(_phase);
150 }
151
152 ShenandoahRootProcessor::~ShenandoahRootProcessor() {
153 assert(SafepointSynchronize::is_at_safepoint(), "Must at safepoint");
154 _heap->phase_timings()->record_workers_end(_phase);
155 }
156
157 ShenandoahRootEvacuator::ShenandoahRootEvacuator(uint n_workers, ShenandoahPhaseTimings::Phase phase, bool include_concurrent_roots) :
158 ShenandoahRootProcessor(phase),
159 _thread_roots(n_workers > 1),
160 _include_concurrent_roots(include_concurrent_roots) {
161 }
162
163 void ShenandoahRootEvacuator::roots_do(uint worker_id, OopClosure* oops) {
164 MarkingCodeBlobClosure blobsCl(oops, CodeBlobToOopClosure::FixRelocations);
165 CLDToOopClosure clds(oops, ClassLoaderData::_claim_strong);
166 AlwaysTrueClosure always_true;
167
168 _serial_roots.oops_do(oops, worker_id);
169 _serial_weak_roots.weak_oops_do(oops, worker_id);
170 if (_include_concurrent_roots) {
171 _jni_roots.oops_do<OopClosure>(oops, worker_id);
172 _weak_roots.oops_do<OopClosure>(oops, worker_id);
173 }
174
175 _thread_roots.oops_do(oops, NULL, worker_id);
176 _cld_roots.cld_do(&clds, worker_id);
177 _code_roots.code_blobs_do(&blobsCl, worker_id);
178
179 _dedup_roots.oops_do(&always_true, oops, worker_id);
180 }
181
182 ShenandoahRootUpdater::ShenandoahRootUpdater(uint n_workers, ShenandoahPhaseTimings::Phase phase, bool update_code_cache) :
183 ShenandoahRootProcessor(phase),
184 _thread_roots(n_workers > 1),
185 _update_code_cache(update_code_cache) {
186 }
187
188 ShenandoahRootAdjuster::ShenandoahRootAdjuster(uint n_workers, ShenandoahPhaseTimings::Phase phase) :
189 ShenandoahRootProcessor(phase),
190 _thread_roots(n_workers > 1) {
191 assert(ShenandoahHeap::heap()->is_full_gc_in_progress(), "Full GC only");
192 }
193
194 void ShenandoahRootAdjuster::roots_do(uint worker_id, OopClosure* oops) {
195 CodeBlobToOopClosure adjust_code_closure(oops, CodeBlobToOopClosure::FixRelocations);
196 CLDToOopClosure adjust_cld_closure(oops, ClassLoaderData::_claim_strong);
197 AlwaysTrueClosure always_true;
198
199 _serial_roots.oops_do(oops, worker_id);
200 _jni_roots.oops_do(oops, worker_id);
201
202 _thread_roots.oops_do(oops, NULL, worker_id);
203 _cld_roots.cld_do(&adjust_cld_closure, worker_id);
204 _code_roots.code_blobs_do(&adjust_code_closure, worker_id);
205
206 _serial_weak_roots.weak_oops_do(oops, worker_id);
207 _weak_roots.oops_do<OopClosure>(oops, worker_id);
208 _dedup_roots.oops_do(&always_true, oops, worker_id);
209 }
210
211 ShenandoahHeapIterationRootScanner::ShenandoahHeapIterationRootScanner() :
212 ShenandoahRootProcessor(ShenandoahPhaseTimings::_num_phases),
213 _thread_roots(false /*is par*/) {
214 }
215
216 void ShenandoahHeapIterationRootScanner::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, ClassLoaderData::_claim_none);
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.cld_do(&clds, 0);
227 _thread_roots.threads_do(&tc_cl, 0);
228 _code_roots.code_blobs_do(&code, 0);
229 }
230
231 void ShenandoahHeapIterationRootScanner::strong_roots_do(OopClosure* oops) {
232 assert(Thread::current()->is_VM_thread(), "Only by VM thread");
233 // Must use _claim_none to avoid interfering with concurrent CLDG iteration
234 CLDToOopClosure clds(oops, ClassLoaderData::_claim_none);
235 MarkingCodeBlobClosure code(oops, !CodeBlobToOopClosure::FixRelocations);
236 ShenandoahParallelOopsDoThreadClosure tc_cl(oops, &code, NULL);
237 ResourceMark rm;
238
239 _serial_roots.oops_do(oops, 0);
240 _jni_roots.oops_do(oops, 0);
241 _cld_roots.always_strong_cld_do(&clds, 0);
242 _thread_roots.threads_do(&tc_cl, 0);
243 }