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/genOopClosures.inline.hpp" 33 #include "gc/shared/strongRootsScope.hpp" 34 #include "gc/shared/workgroup.hpp" 35 #include "oops/oop.inline.hpp" 36 #include "runtime/vmThread.hpp" 37 #include "services/memoryManager.hpp" 38 #include "services/memoryPool.hpp" 39 #include "utilities/stack.inline.hpp" 40 41 CMSHeap::CMSHeap(GenCollectorPolicy *policy) : GenCollectedHeap(policy) { 42 _workers = new WorkGang("GC Thread", ParallelGCThreads, 43 /* are_GC_task_threads */true, 44 /* are_ConcurrentGC_threads */false); 45 _workers->initialize_workers(); 46 } 47 48 jint CMSHeap::initialize() { 49 jint status = GenCollectedHeap::initialize(); 50 if (status != JNI_OK) return status; 51 52 // If we are running CMS, create the collector responsible 53 // for collecting the CMS generations. 54 assert(collector_policy()->is_concurrent_mark_sweep_policy(), "must be CMS policy"); 55 if (!create_cms_collector()) { 56 return JNI_ENOMEM; 57 } 58 59 return JNI_OK; 60 } 61 62 void CMSHeap::check_gen_kinds() { 63 assert(young_gen()->kind() == Generation::ParNew, 64 "Wrong youngest generation type"); 65 assert(old_gen()->kind() == Generation::ConcurrentMarkSweep, 66 "Wrong generation kind"); 67 } 68 69 CMSHeap* CMSHeap::heap() { 70 CollectedHeap* heap = Universe::heap(); 71 assert(heap != NULL, "Uninitialized access to CMSHeap::heap()"); 72 assert(heap->kind() == CollectedHeap::CMSHeap, "Not a CMSHeap"); 73 return (CMSHeap*) heap; 74 } 75 76 void CMSHeap::gc_threads_do(ThreadClosure* tc) const { 77 assert(workers() != NULL, "should have workers here"); 78 workers()->threads_do(tc); 79 ConcurrentMarkSweepThread::threads_do(tc); 80 } 81 82 void CMSHeap::print_gc_threads_on(outputStream* st) const { 83 assert(workers() != NULL, "should have workers here"); 84 workers()->print_worker_threads_on(st); 85 ConcurrentMarkSweepThread::print_all_on(st); 86 } 87 88 void CMSHeap::print_on_error(outputStream* st) const { 89 GenCollectedHeap::print_on_error(st); 90 st->cr(); 91 CMSCollector::print_on_error(st); 92 } 93 94 bool CMSHeap::create_cms_collector() { 95 assert(old_gen()->kind() == Generation::ConcurrentMarkSweep, 96 "Unexpected generation kinds"); 97 assert(gen_policy()->is_concurrent_mark_sweep_policy(), "Unexpected policy type"); 98 CMSCollector* collector = 99 new CMSCollector((ConcurrentMarkSweepGeneration*) old_gen(), 100 rem_set(), 101 gen_policy()->as_concurrent_mark_sweep_policy()); 102 103 if (collector == NULL || !collector->completed_initialization()) { 104 if (collector) { 105 delete collector; // Be nice in embedded situation 106 } 107 vm_shutdown_during_initialization("Could not create CMS collector"); 108 return false; 109 } 110 return true; // success 111 } 112 113 void CMSHeap::collect(GCCause::Cause cause) { 114 if (should_do_concurrent_full_gc(cause)) { 115 // Mostly concurrent full collection. 116 collect_mostly_concurrent(cause); 117 } else { 118 GenCollectedHeap::collect(cause); 119 } 120 } 121 122 bool CMSHeap::should_do_concurrent_full_gc(GCCause::Cause cause) { 123 switch (cause) { 124 case GCCause::_gc_locker: return GCLockerInvokesConcurrent; 125 case GCCause::_java_lang_system_gc: 126 case GCCause::_dcmd_gc_run: return ExplicitGCInvokesConcurrent; 127 default: return false; 128 } 129 } 130 131 void CMSHeap::collect_mostly_concurrent(GCCause::Cause cause) { 132 assert(!Heap_lock->owned_by_self(), "Should not own Heap_lock"); 133 134 MutexLocker ml(Heap_lock); 135 // Read the GC counts while holding the Heap_lock 136 unsigned int full_gc_count_before = total_full_collections(); 137 unsigned int gc_count_before = total_collections(); 138 { 139 MutexUnlocker mu(Heap_lock); 140 VM_GenCollectFullConcurrent op(gc_count_before, full_gc_count_before, cause); 141 VMThread::execute(&op); 142 } 143 } 144 145 void CMSHeap::stop() { 146 ConcurrentMarkSweepThread::cmst()->stop(); 147 } 148 149 void CMSHeap::safepoint_synchronize_begin() { 150 ConcurrentMarkSweepThread::synchronize(false); 151 } 152 153 void CMSHeap::safepoint_synchronize_end() { 154 ConcurrentMarkSweepThread::desynchronize(false); 155 } 156 157 void CMSHeap::cms_process_roots(StrongRootsScope* scope, 158 bool young_gen_as_roots, 159 ScanningOption so, 160 bool only_strong_roots, 161 OopsInGenClosure* root_closure, 162 CLDClosure* cld_closure) { 163 MarkingCodeBlobClosure mark_code_closure(root_closure, !CodeBlobToOopClosure::FixRelocations); 164 OopsInGenClosure* weak_roots = only_strong_roots ? NULL : root_closure; 165 CLDClosure* weak_cld_closure = only_strong_roots ? NULL : cld_closure; 166 167 process_roots(scope, so, root_closure, weak_roots, cld_closure, weak_cld_closure, &mark_code_closure); 168 if (!only_strong_roots) { 169 process_string_table_roots(scope, root_closure); 170 } 171 172 if (young_gen_as_roots && 173 !_process_strong_tasks->is_task_claimed(GCH_PS_younger_gens)) { 174 root_closure->set_generation(young_gen()); 175 young_gen()->oop_iterate(root_closure); 176 root_closure->reset_generation(); 177 } 178 179 _process_strong_tasks->all_tasks_completed(scope->n_threads()); 180 } 181 182 void CMSHeap::gc_prologue(bool full) { 183 always_do_update_barrier = false; 184 GenCollectedHeap::gc_prologue(full); 185 }; 186 187 void CMSHeap::gc_epilogue(bool full) { 188 GenCollectedHeap::gc_epilogue(full); 189 always_do_update_barrier = true; 190 }; 191 192 class ParNewMemoryManager : public GCMemoryManager { 193 private: 194 public: 195 ParNewMemoryManager() : GCMemoryManager() {} 196 197 const char* name() { return "ParNew"; } 198 virtual const char* gc_end_message() { return "end of major GC"; } 199 }; 200 201 class CMSMemoryManager : public GCMemoryManager { 202 private: 203 public: 204 CMSMemoryManager() : GCMemoryManager() {} 205 206 const char* name() { return "ConcurrentMarkSweep";} 207 virtual const char* gc_end_message() { return "end of minor GC"; } 208 }; 209 210 class CompactibleFreeListSpacePool : public CollectedMemoryPool { 211 private: 212 CompactibleFreeListSpace* _space; 213 public: 214 CompactibleFreeListSpacePool(CompactibleFreeListSpace* space, 215 const char* name, 216 PoolType type, 217 size_t max_size, 218 bool support_usage_threshold) : 219 CollectedMemoryPool(name, type, space->capacity(), max_size, 220 support_usage_threshold), _space(space) { 221 } 222 223 MemoryUsage get_memory_usage() { 224 size_t maxSize = (available_for_allocation() ? max_size() : 0); 225 size_t used = used_in_bytes(); 226 size_t committed = _space->capacity(); 227 228 return MemoryUsage(initial_size(), used, committed, maxSize); 229 } 230 231 size_t used_in_bytes() { 232 return _space->used(); 233 } 234 }; 235 236 void CMSHeap::init_memory_managers() { 237 _minor_mgr = new ParNewMemoryManager(); 238 _major_mgr = new CMSMemoryManager(); 239 } 240 241 GrowableArray<MemoryManager*> CMSHeap::memory_managers() { 242 GrowableArray<MemoryManager*> cms_memory_managers; 243 cms_memory_managers.append(_minor_mgr); 244 cms_memory_managers.append(_major_mgr); 245 return cms_memory_managers; 246 } 247 248 GrowableArray<MemoryPool*> CMSHeap::memory_pools() { 249 GrowableArray<MemoryPool*> cms_memory_pools; 250 251 ParNewGeneration* young = (ParNewGeneration*) young_gen(); 252 ContiguousSpacePool* eden = new ContiguousSpacePool(young->eden(), "Par Eden Space", MemoryPool::Heap, young->max_eden_size(), false); 253 SurvivorContiguousSpacePool* survivor = new SurvivorContiguousSpacePool(young, "Par Survivor Space", MemoryPool::Heap, young->max_survivor_size(), false); 254 255 ConcurrentMarkSweepGeneration* cms = (ConcurrentMarkSweepGeneration*) old_gen(); 256 CompactibleFreeListSpacePool* old = new CompactibleFreeListSpacePool(cms->cmsSpace(), "CMS Old Gen", MemoryPool::Heap, cms->reserved().byte_size(), true); 257 258 cms_memory_pools.append(eden); 259 cms_memory_pools.append(survivor); 260 cms_memory_pools.append(old); 261 262 _minor_mgr->add_pool(eden); 263 _major_mgr->add_pool(eden); 264 _minor_mgr->add_pool(survivor); 265 _major_mgr->add_pool(survivor); 266 _major_mgr->add_pool(old); 267 268 return cms_memory_pools; 269 }