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