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