1 /*
   2  * Copyright (c) 2017, 2019, 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/cmsCardTable.hpp"
  27 #include "gc/cms/cmsVMOperations.hpp"
  28 #include "gc/cms/compactibleFreeListSpace.hpp"
  29 #include "gc/cms/concurrentMarkSweepGeneration.hpp"
  30 #include "gc/cms/concurrentMarkSweepThread.hpp"
  31 #include "gc/cms/cmsHeap.hpp"
  32 #include "gc/cms/parNewGeneration.hpp"
  33 #include "gc/shared/genCollectedHeap.hpp"
  34 #include "gc/shared/genMemoryPools.hpp"
  35 #include "gc/shared/genOopClosures.inline.hpp"
  36 #include "gc/shared/strongRootsScope.hpp"
  37 #include "gc/shared/workgroup.hpp"
  38 #include "memory/universe.hpp"
  39 #include "oops/oop.inline.hpp"
  40 #include "runtime/vmThread.hpp"
  41 #include "services/memoryManager.hpp"
  42 #include "utilities/stack.inline.hpp"
  43 
  44 class CompactibleFreeListSpacePool : public CollectedMemoryPool {
  45 private:
  46   CompactibleFreeListSpace* _space;
  47 public:
  48   CompactibleFreeListSpacePool(CompactibleFreeListSpace* space,
  49                                const char* name,
  50                                size_t max_size,
  51                                bool support_usage_threshold) :
  52     CollectedMemoryPool(name, space->capacity(), max_size, support_usage_threshold),
  53     _space(space) {
  54   }
  55 
  56   MemoryUsage get_memory_usage() {
  57     size_t max_heap_size   = (available_for_allocation() ? max_size() : 0);
  58     size_t used      = used_in_bytes();
  59     size_t committed = _space->capacity();
  60 
  61     return MemoryUsage(initial_size(), used, committed, max_heap_size);
  62   }
  63 
  64   size_t used_in_bytes() {
  65     return _space->used_stable();
  66   }
  67 };
  68 
  69 CMSHeap::CMSHeap() :
  70     GenCollectedHeap(Generation::ParNew,
  71                      Generation::ConcurrentMarkSweep,
  72                      "ParNew:CMS"),
  73     _workers(NULL),
  74     _eden_pool(NULL),
  75     _survivor_pool(NULL),
  76     _old_pool(NULL) {
  77 }
  78 
  79 jint CMSHeap::initialize() {
  80   jint status = GenCollectedHeap::initialize();
  81   if (status != JNI_OK) return status;
  82 
  83   _workers = new WorkGang("GC Thread", ParallelGCThreads,
  84                           /* are_GC_task_threads */true,
  85                           /* are_ConcurrentGC_threads */false);
  86   if (_workers == NULL) {
  87     return JNI_ENOMEM;
  88   }
  89   _workers->initialize_workers();
  90 
  91   // If we are running CMS, create the collector responsible
  92   // for collecting the CMS generations.
  93   if (!create_cms_collector()) {
  94     return JNI_ENOMEM;
  95   }
  96 
  97   return JNI_OK;
  98 }
  99 
 100 CardTableRS* CMSHeap::create_rem_set(const MemRegion& reserved_region) {
 101   return new CMSCardTable(reserved_region);
 102 }
 103 
 104 void CMSHeap::initialize_serviceability() {
 105   _young_manager = new GCMemoryManager("ParNew", "end of minor GC");
 106   _old_manager = new GCMemoryManager("ConcurrentMarkSweep", "end of major GC");
 107 
 108   ParNewGeneration* young = young_gen();
 109   _eden_pool = new ContiguousSpacePool(young->eden(),
 110                                        "Par Eden Space",
 111                                        young->max_eden_size(),
 112                                        false);
 113 
 114   _survivor_pool = new SurvivorContiguousSpacePool(young,
 115                                                    "Par Survivor Space",
 116                                                    young->max_survivor_size(),
 117                                                    false);
 118 
 119   ConcurrentMarkSweepGeneration* old = (ConcurrentMarkSweepGeneration*) old_gen();
 120   _old_pool = new CompactibleFreeListSpacePool(old->cmsSpace(),
 121                                                "CMS Old Gen",
 122                                                old->reserved().byte_size(),
 123                                                true);
 124 
 125   _young_manager->add_pool(_eden_pool);
 126   _young_manager->add_pool(_survivor_pool);
 127   young->set_gc_manager(_young_manager);
 128 
 129   _old_manager->add_pool(_eden_pool);
 130   _old_manager->add_pool(_survivor_pool);
 131   _old_manager->add_pool(_old_pool);
 132   old ->set_gc_manager(_old_manager);
 133 
 134 }
 135 
 136 CMSHeap* CMSHeap::heap() {
 137   CollectedHeap* heap = Universe::heap();
 138   assert(heap != NULL, "Uninitialized access to CMSHeap::heap()");
 139   assert(heap->kind() == CollectedHeap::CMS, "Invalid name");
 140   return static_cast<CMSHeap*>(heap);
 141 }
 142 
 143 void CMSHeap::gc_threads_do(ThreadClosure* tc) const {
 144   assert(workers() != NULL, "should have workers here");
 145   workers()->threads_do(tc);
 146   ConcurrentMarkSweepThread::threads_do(tc);
 147 }
 148 
 149 void CMSHeap::print_gc_threads_on(outputStream* st) const {
 150   assert(workers() != NULL, "should have workers here");
 151   workers()->print_worker_threads_on(st);
 152   ConcurrentMarkSweepThread::print_all_on(st);
 153 }
 154 
 155 void CMSHeap::print_on_error(outputStream* st) const {
 156   GenCollectedHeap::print_on_error(st);
 157   st->cr();
 158   CMSCollector::print_on_error(st);
 159 }
 160 
 161 bool CMSHeap::create_cms_collector() {
 162   assert(old_gen()->kind() == Generation::ConcurrentMarkSweep,
 163          "Unexpected generation kinds");
 164   CMSCollector* collector =
 165     new CMSCollector((ConcurrentMarkSweepGeneration*) old_gen(), rem_set());
 166 
 167   if (collector == NULL || !collector->completed_initialization()) {
 168     if (collector) {
 169       delete collector; // Be nice in embedded situation
 170     }
 171     vm_shutdown_during_initialization("Could not create CMS collector");
 172     return false;
 173   }
 174   return true; // success
 175 }
 176 
 177 void CMSHeap::collect(GCCause::Cause cause) {
 178   if (should_do_concurrent_full_gc(cause)) {
 179     // Mostly concurrent full collection.
 180     collect_mostly_concurrent(cause);
 181   } else {
 182     GenCollectedHeap::collect(cause);
 183   }
 184 }
 185 
 186 bool CMSHeap::should_do_concurrent_full_gc(GCCause::Cause cause) {
 187   switch (cause) {
 188     case GCCause::_gc_locker:           return GCLockerInvokesConcurrent;
 189     case GCCause::_java_lang_system_gc:
 190     case GCCause::_dcmd_gc_run:         return ExplicitGCInvokesConcurrent;
 191     default:                            return false;
 192   }
 193 }
 194 
 195 void CMSHeap::collect_mostly_concurrent(GCCause::Cause cause) {
 196   assert(!Heap_lock->owned_by_self(), "Should not own Heap_lock");
 197 
 198   MutexLocker ml(Heap_lock);
 199   // Read the GC counts while holding the Heap_lock
 200   unsigned int full_gc_count_before = total_full_collections();
 201   unsigned int gc_count_before      = total_collections();
 202   {
 203     MutexUnlocker mu(Heap_lock);
 204     VM_GenCollectFullConcurrent op(gc_count_before, full_gc_count_before, cause);
 205     VMThread::execute(&op);
 206   }
 207 }
 208 
 209 void CMSHeap::stop() {
 210   ConcurrentMarkSweepThread::cmst()->stop();
 211 }
 212 
 213 void CMSHeap::safepoint_synchronize_begin() {
 214   ConcurrentMarkSweepThread::synchronize(false);
 215 }
 216 
 217 void CMSHeap::safepoint_synchronize_end() {
 218   ConcurrentMarkSweepThread::desynchronize(false);
 219 }
 220 
 221 void CMSHeap::cms_process_roots(StrongRootsScope* scope,
 222                                 bool young_gen_as_roots,
 223                                 ScanningOption so,
 224                                 bool only_strong_roots,
 225                                 OopsInGenClosure* root_closure,
 226                                 CLDClosure* cld_closure) {
 227   MarkingCodeBlobClosure mark_code_closure(root_closure, !CodeBlobToOopClosure::FixRelocations);
 228   CLDClosure* weak_cld_closure = only_strong_roots ? NULL : cld_closure;
 229 
 230   process_roots(scope, so, root_closure, cld_closure, weak_cld_closure, &mark_code_closure);
 231 
 232   if (young_gen_as_roots &&
 233       _process_strong_tasks->try_claim_task(GCH_PS_younger_gens)) {
 234     root_closure->set_generation(young_gen());
 235     young_gen()->oop_iterate(root_closure);
 236     root_closure->reset_generation();
 237   }
 238 
 239   _process_strong_tasks->all_tasks_completed(scope->n_threads());
 240 }
 241 
 242 void CMSHeap::gc_prologue(bool full) {
 243   always_do_update_barrier = false;
 244   GenCollectedHeap::gc_prologue(full);
 245 };
 246 
 247 void CMSHeap::gc_epilogue(bool full) {
 248   GenCollectedHeap::gc_epilogue(full);
 249   always_do_update_barrier = true;
 250 };
 251 
 252 GrowableArray<GCMemoryManager*> CMSHeap::memory_managers() {
 253   GrowableArray<GCMemoryManager*> memory_managers(2);
 254   memory_managers.append(_young_manager);
 255   memory_managers.append(_old_manager);
 256   return memory_managers;
 257 }
 258 
 259 GrowableArray<MemoryPool*> CMSHeap::memory_pools() {
 260   GrowableArray<MemoryPool*> memory_pools(3);
 261   memory_pools.append(_eden_pool);
 262   memory_pools.append(_survivor_pool);
 263   memory_pools.append(_old_pool);
 264   return memory_pools;
 265 }
--- EOF ---