1 /*
2 * Copyright (c) 2017, 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/cms/compactibleFreeListSpace.hpp"
27 #include "gc/cms/concurrentMarkSweepGeneration.hpp"
28 #include "gc/cms/concurrentMarkSweepThread.hpp"
29 #include "gc/cms/cmsHeap.hpp"
30 #include "gc/cms/parNewGeneration.hpp"
31 #include "gc/cms/vmCMSOperations.hpp"
32 #include "gc/shared/genMemoryPools.hpp"
33 #include "gc/shared/genOopClosures.inline.hpp"
34 #include "gc/shared/strongRootsScope.hpp"
35 #include "gc/shared/workgroup.hpp"
36 #include "oops/oop.inline.hpp"
37 #include "runtime/vmThread.hpp"
38 #include "services/memoryManager.hpp"
39 #include "utilities/stack.inline.hpp"
40
41 class CompactibleFreeListSpacePool : public CollectedMemoryPool {
42 private:
43 CompactibleFreeListSpace* _space;
44 public:
45 CompactibleFreeListSpacePool(CompactibleFreeListSpace* space,
46 const char* name,
47 size_t max_size,
48 bool support_usage_threshold) :
49 CollectedMemoryPool(name, space->capacity(), max_size, support_usage_threshold),
50 _space(space) {
51 }
52
53 MemoryUsage get_memory_usage() {
54 size_t max_heap_size = (available_for_allocation() ? max_size() : 0);
55 size_t used = used_in_bytes();
56 size_t committed = _space->capacity();
57
58 return MemoryUsage(initial_size(), used, committed, max_heap_size);
59 }
60
61 size_t used_in_bytes() {
62 return _space->used();
63 }
64 };
65
66 CMSHeap::CMSHeap(GenCollectorPolicy *policy) :
67 GenCollectedHeap(policy), _eden_pool(NULL), _survivor_pool(NULL), _old_pool(NULL) {
68 _workers = new WorkGang("GC Thread", ParallelGCThreads,
69 /* are_GC_task_threads */true,
70 /* are_ConcurrentGC_threads */false);
71 _workers->initialize_workers();
72 }
73
74 jint CMSHeap::initialize() {
75 jint status = GenCollectedHeap::initialize();
76 if (status != JNI_OK) return status;
77
78 // If we are running CMS, create the collector responsible
79 // for collecting the CMS generations.
80 if (!create_cms_collector()) {
81 return JNI_ENOMEM;
82 }
83
84 return JNI_OK;
85 }
86
87 void CMSHeap::initialize_serviceability() {
88 _young_manager = new GCMemoryManager("ParNew", "end of minor GC");
89 _old_manager = new GCMemoryManager("ConcurrentMarkSweep", "end of major GC");
90
91 ParNewGeneration* young = (ParNewGeneration*) young_gen();
92 _eden_pool = new ContiguousSpacePool(young->eden(),
93 "Par Eden Space",
94 young->max_eden_size(),
95 false);
96
97 _survivor_pool = new SurvivorContiguousSpacePool(young,
98 "Par Survivor Space",
99 young->max_survivor_size(),
100 false);
101
102 ConcurrentMarkSweepGeneration* old = (ConcurrentMarkSweepGeneration*) old_gen();
103 _old_pool = new CompactibleFreeListSpacePool(old->cmsSpace(),
104 "CMS Old Gen",
105 old->reserved().byte_size(),
106 true);
107
108 _young_manager->add_pool(_eden_pool);
109 _young_manager->add_pool(_survivor_pool);
110 young->set_gc_manager(_young_manager);
111
112 _old_manager->add_pool(_eden_pool);
113 _old_manager->add_pool(_survivor_pool);
114 _old_manager->add_pool(_old_pool);
115 old ->set_gc_manager(_old_manager);
116
117 }
118
119 void CMSHeap::check_gen_kinds() {
120 assert(young_gen()->kind() == Generation::ParNew,
121 "Wrong youngest generation type");
122 assert(old_gen()->kind() == Generation::ConcurrentMarkSweep,
123 "Wrong generation kind");
124 }
125
126 CMSHeap* CMSHeap::heap() {
127 CollectedHeap* heap = Universe::heap();
128 assert(heap != NULL, "Uninitialized access to CMSHeap::heap()");
129 assert(heap->kind() == CollectedHeap::CMSHeap, "Not a CMSHeap");
130 return (CMSHeap*) heap;
131 }
132
133 void CMSHeap::gc_threads_do(ThreadClosure* tc) const {
134 assert(workers() != NULL, "should have workers here");
135 workers()->threads_do(tc);
136 ConcurrentMarkSweepThread::threads_do(tc);
137 }
138
139 void CMSHeap::print_gc_threads_on(outputStream* st) const {
140 assert(workers() != NULL, "should have workers here");
141 workers()->print_worker_threads_on(st);
142 ConcurrentMarkSweepThread::print_all_on(st);
143 }
144
145 void CMSHeap::print_on_error(outputStream* st) const {
146 GenCollectedHeap::print_on_error(st);
147 st->cr();
148 CMSCollector::print_on_error(st);
149 }
150
151 bool CMSHeap::create_cms_collector() {
152 assert(old_gen()->kind() == Generation::ConcurrentMarkSweep,
153 "Unexpected generation kinds");
154 CMSCollector* collector =
155 new CMSCollector((ConcurrentMarkSweepGeneration*) old_gen(),
156 rem_set(),
157 (ConcurrentMarkSweepPolicy*) gen_policy());
158
159 if (collector == NULL || !collector->completed_initialization()) {
160 if (collector) {
161 delete collector; // Be nice in embedded situation
162 }
163 vm_shutdown_during_initialization("Could not create CMS collector");
164 return false;
165 }
166 return true; // success
167 }
168
169 void CMSHeap::collect(GCCause::Cause cause) {
170 if (should_do_concurrent_full_gc(cause)) {
171 // Mostly concurrent full collection.
172 collect_mostly_concurrent(cause);
173 } else {
174 GenCollectedHeap::collect(cause);
175 }
176 }
177
178 bool CMSHeap::should_do_concurrent_full_gc(GCCause::Cause cause) {
179 switch (cause) {
180 case GCCause::_gc_locker: return GCLockerInvokesConcurrent;
181 case GCCause::_java_lang_system_gc:
182 case GCCause::_dcmd_gc_run: return ExplicitGCInvokesConcurrent;
183 default: return false;
184 }
185 }
186
187 void CMSHeap::collect_mostly_concurrent(GCCause::Cause cause) {
188 assert(!Heap_lock->owned_by_self(), "Should not own Heap_lock");
189
190 MutexLocker ml(Heap_lock);
191 // Read the GC counts while holding the Heap_lock
192 unsigned int full_gc_count_before = total_full_collections();
193 unsigned int gc_count_before = total_collections();
194 {
195 MutexUnlocker mu(Heap_lock);
196 VM_GenCollectFullConcurrent op(gc_count_before, full_gc_count_before, cause);
197 VMThread::execute(&op);
198 }
199 }
200
201 void CMSHeap::stop() {
202 ConcurrentMarkSweepThread::cmst()->stop();
203 }
204
205 void CMSHeap::safepoint_synchronize_begin() {
206 ConcurrentMarkSweepThread::synchronize(false);
207 }
208
209 void CMSHeap::safepoint_synchronize_end() {
210 ConcurrentMarkSweepThread::desynchronize(false);
211 }
212
213 void CMSHeap::cms_process_roots(StrongRootsScope* scope,
214 bool young_gen_as_roots,
215 ScanningOption so,
216 bool only_strong_roots,
217 OopsInGenClosure* root_closure,
218 CLDClosure* cld_closure) {
219 MarkingCodeBlobClosure mark_code_closure(root_closure, !CodeBlobToOopClosure::FixRelocations);
220 OopsInGenClosure* weak_roots = only_strong_roots ? NULL : root_closure;
221 CLDClosure* weak_cld_closure = only_strong_roots ? NULL : cld_closure;
222
223 process_roots(scope, so, root_closure, weak_roots, cld_closure, weak_cld_closure, &mark_code_closure);
224 if (!only_strong_roots) {
225 process_string_table_roots(scope, root_closure);
226 }
227
228 if (young_gen_as_roots &&
229 !_process_strong_tasks->is_task_claimed(GCH_PS_younger_gens)) {
230 root_closure->set_generation(young_gen());
231 young_gen()->oop_iterate(root_closure);
232 root_closure->reset_generation();
233 }
234
235 _process_strong_tasks->all_tasks_completed(scope->n_threads());
236 }
237
238 void CMSHeap::gc_prologue(bool full) {
239 always_do_update_barrier = false;
240 GenCollectedHeap::gc_prologue(full);
241 };
242
243 void CMSHeap::gc_epilogue(bool full) {
244 GenCollectedHeap::gc_epilogue(full);
245 always_do_update_barrier = true;
246 };
247
248 GrowableArray<GCMemoryManager*> CMSHeap::memory_managers() {
249 GrowableArray<GCMemoryManager*> memory_managers(2);
250 memory_managers.append(_young_manager);
251 memory_managers.append(_old_manager);
252 return memory_managers;
253 }
254
255 GrowableArray<MemoryPool*> CMSHeap::memory_pools() {
256 GrowableArray<MemoryPool*> memory_pools(3);
257 memory_pools.append(_eden_pool);
258 memory_pools.append(_survivor_pool);
259 memory_pools.append(_old_pool);
260 return memory_pools;
261 }