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(const CMSSettings& settings) :
67 GenCollectedHeap(settings,
68 Generation::ParNew,
69 Generation::ConcurrentMarkSweep),
70 _settings(settings),
71 _eden_pool(NULL),
72 _survivor_pool(NULL),
73 _old_pool(NULL) {
74 _workers = new WorkGang("GC Thread", ParallelGCThreads,
75 /* are_GC_task_threads */true,
76 /* are_ConcurrentGC_threads */false);
77 _workers->initialize_workers();
78 }
79
80 jint CMSHeap::initialize() {
81 jint status = GenCollectedHeap::initialize();
82 if (status != JNI_OK) return status;
83
84 // If we are running CMS, create the collector responsible
85 // for collecting the CMS generations.
86 if (!create_cms_collector()) {
87 return JNI_ENOMEM;
88 }
89
90 return JNI_OK;
91 }
92
93 void CMSHeap::initialize_gc_policy_counters() {
94 initialize_gc_policy_counters_helper("ParNew:CMS");
95 }
96
97 void CMSHeap::initialize_serviceability() {
98 _young_manager = new GCMemoryManager("ParNew", "end of minor GC");
99 _old_manager = new GCMemoryManager("ConcurrentMarkSweep", "end of major GC");
100
101 ParNewGeneration* young = (ParNewGeneration*) young_gen();
102 _eden_pool = new ContiguousSpacePool(young->eden(),
103 "Par Eden Space",
104 young->max_eden_size(),
105 false);
106
107 _survivor_pool = new SurvivorContiguousSpacePool(young,
108 "Par Survivor Space",
109 young->max_survivor_size(),
110 false);
111
112 ConcurrentMarkSweepGeneration* old = (ConcurrentMarkSweepGeneration*) old_gen();
113 _old_pool = new CompactibleFreeListSpacePool(old->cmsSpace(),
114 "CMS Old Gen",
115 old->reserved().byte_size(),
116 true);
117
118 _young_manager->add_pool(_eden_pool);
119 _young_manager->add_pool(_survivor_pool);
120 young->set_gc_manager(_young_manager);
121
122 _old_manager->add_pool(_eden_pool);
123 _old_manager->add_pool(_survivor_pool);
124 _old_manager->add_pool(_old_pool);
125 old ->set_gc_manager(_old_manager);
126
127 }
128
129 void CMSHeap::check_gen_kinds() {
130 assert(young_gen()->kind() == Generation::ParNew,
131 "Wrong youngest generation type");
132 assert(old_gen()->kind() == Generation::ConcurrentMarkSweep,
133 "Wrong generation kind");
134 }
135
136 CMSHeap* CMSHeap::heap() {
137 CollectedHeap* heap = Universe::heap();
138 assert(heap != NULL, "Uninitialized access to CMSHeap::heap()");
139 assert(heap->kind() == CollectedHeap::CMSHeap, "Not a CMSHeap");
140 return (CMSHeap*) heap;
141 }
142
143 void CMSHeap::gc_threads_do(ThreadClosure* tc) const {
144 assert(workers() != NULL, "should have workers here");
145 workers()->threads_do(tc);
146 ConcurrentMarkSweepThread::threads_do(tc);
147 }
148
149 void CMSHeap::print_gc_threads_on(outputStream* st) const {
150 assert(workers() != NULL, "should have workers here");
151 workers()->print_worker_threads_on(st);
152 ConcurrentMarkSweepThread::print_all_on(st);
153 }
154
155 void CMSHeap::print_on_error(outputStream* st) const {
156 GenCollectedHeap::print_on_error(st);
157 st->cr();
158 CMSCollector::print_on_error(st);
159 }
160
161 bool CMSHeap::create_cms_collector() {
162 assert(old_gen()->kind() == Generation::ConcurrentMarkSweep,
163 "Unexpected generation kinds");
164 CMSCollector* collector =
165 new CMSCollector((ConcurrentMarkSweepGeneration*) old_gen(), rem_set());
166
167 if (collector == NULL || !collector->completed_initialization()) {
168 if (collector) {
169 delete collector; // Be nice in embedded situation
170 }
171 vm_shutdown_during_initialization("Could not create CMS collector");
172 return false;
173 }
174 return true; // success
175 }
176
177 void CMSHeap::collect(GCCause::Cause cause) {
178 if (should_do_concurrent_full_gc(cause)) {
179 // Mostly concurrent full collection.
180 collect_mostly_concurrent(cause);
181 } else {
182 GenCollectedHeap::collect(cause);
183 }
184 }
185
186 bool CMSHeap::should_do_concurrent_full_gc(GCCause::Cause cause) {
187 switch (cause) {
188 case GCCause::_gc_locker: return GCLockerInvokesConcurrent;
189 case GCCause::_java_lang_system_gc:
190 case GCCause::_dcmd_gc_run: return ExplicitGCInvokesConcurrent;
191 default: return false;
192 }
193 }
194
195 void CMSHeap::collect_mostly_concurrent(GCCause::Cause cause) {
196 assert(!Heap_lock->owned_by_self(), "Should not own Heap_lock");
197
198 MutexLocker ml(Heap_lock);
199 // Read the GC counts while holding the Heap_lock
200 unsigned int full_gc_count_before = total_full_collections();
201 unsigned int gc_count_before = total_collections();
202 {
203 MutexUnlocker mu(Heap_lock);
204 VM_GenCollectFullConcurrent op(gc_count_before, full_gc_count_before, cause);
205 VMThread::execute(&op);
206 }
207 }
208
209 void CMSHeap::stop() {
210 ConcurrentMarkSweepThread::cmst()->stop();
211 }
212
213 void CMSHeap::safepoint_synchronize_begin() {
214 ConcurrentMarkSweepThread::synchronize(false);
215 }
216
217 void CMSHeap::safepoint_synchronize_end() {
218 ConcurrentMarkSweepThread::desynchronize(false);
219 }
220
221 void CMSHeap::cms_process_roots(StrongRootsScope* scope,
222 bool young_gen_as_roots,
223 ScanningOption so,
224 bool only_strong_roots,
225 OopsInGenClosure* root_closure,
226 CLDClosure* cld_closure) {
227 MarkingCodeBlobClosure mark_code_closure(root_closure, !CodeBlobToOopClosure::FixRelocations);
228 OopsInGenClosure* weak_roots = only_strong_roots ? NULL : root_closure;
229 CLDClosure* weak_cld_closure = only_strong_roots ? NULL : cld_closure;
230
231 process_roots(scope, so, root_closure, weak_roots, cld_closure, weak_cld_closure, &mark_code_closure);
232 if (!only_strong_roots) {
233 process_string_table_roots(scope, root_closure);
234 }
235
236 if (young_gen_as_roots &&
237 !_process_strong_tasks->is_task_claimed(GCH_PS_younger_gens)) {
238 root_closure->set_generation(young_gen());
239 young_gen()->oop_iterate(root_closure);
240 root_closure->reset_generation();
241 }
242
243 _process_strong_tasks->all_tasks_completed(scope->n_threads());
244 }
245
246 void CMSHeap::gc_prologue(bool full) {
247 always_do_update_barrier = false;
248 GenCollectedHeap::gc_prologue(full);
249 };
250
251 void CMSHeap::gc_epilogue(bool full) {
252 GenCollectedHeap::gc_epilogue(full);
253 always_do_update_barrier = true;
254 };
255
256 GrowableArray<GCMemoryManager*> CMSHeap::memory_managers() {
257 GrowableArray<GCMemoryManager*> memory_managers(2);
258 memory_managers.append(_young_manager);
259 memory_managers.append(_old_manager);
260 return memory_managers;
261 }
262
263 GrowableArray<MemoryPool*> CMSHeap::memory_pools() {
264 GrowableArray<MemoryPool*> memory_pools(3);
265 memory_pools.append(_eden_pool);
266 memory_pools.append(_survivor_pool);
267 memory_pools.append(_old_pool);
268 return memory_pools;
269 }