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