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